https://source.android.com/ 
/*
 * Copyright (C) 2006 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.graphics.drawable;

import com.android.internal.R;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;

import android.annotation.AttrRes;
import android.annotation.ColorInt;
import android.annotation.IntRange;
import android.annotation.NonNull;
import android.annotation.Nullable;
import android.annotation.TestApi;
import android.content.pm.ActivityInfo.Config;
import android.content.res.ColorStateList;
import android.content.res.Resources;
import android.content.res.Resources.Theme;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.ColorFilter;
import android.graphics.ImageDecoder;
import android.graphics.Insets;
import android.graphics.NinePatch;
import android.graphics.Outline;
import android.graphics.PixelFormat;
import android.graphics.PorterDuff;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffColorFilter;
import android.graphics.Rect;
import android.graphics.Region;
import android.graphics.Xfermode;
import android.os.Trace;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.util.Log;
import android.util.StateSet;
import android.util.TypedValue;
import android.util.Xml;
import android.view.View;

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.ref.WeakReference;
import java.util.Arrays;


A Drawable is a general abstraction for "something that can be drawn." Most often you will deal with Drawable as the type of resource retrieved for drawing things to the screen; the Drawable class provides a generic API for dealing with an underlying visual resource that may take a variety of forms. Unlike a View, a Drawable does not have any facility to receive events or otherwise interact with the user. 
In addition to simple drawing, Drawable provides a number of generic
mechanisms for its client to interact with what is being drawn:

    
    
  •  The setBounds method must be called to tell the Drawable where it is drawn and how large it should be. All Drawables should respect the requested size, often simply by scaling their imagery. A client can find the preferred size for some Drawables with the getIntrinsicHeight and getIntrinsicWidth methods. 
  •  The getPadding method can return from some Drawables information about how to frame content that is placed inside of them. For example, a Drawable that is intended to be the frame for a button widget would need to return padding that correctly places the label inside of itself. 
  •  The setState method allows the client to tell the Drawable in which state it is to be drawn, such as "focused", "selected", etc. Some drawables may modify their imagery based on the selected state. 
  •  The setLevel method allows the client to supply a single continuous controller that can modify the Drawable is displayed, such as a battery level or progress level. Some drawables may modify their imagery based on the current level. 
  •  A Drawable can perform animations by calling back to its client through the Callback interface. All clients should support this interface (via setCallback) so that animations will work. A simple way to do this is through the system facilities such as View.setBackground(Drawable) and ImageView. 

Though usually not visible to the application, Drawables may take a variety
of forms:

    
    
  •  Bitmap: the simplest Drawable, a PNG or JPEG image.
    
  •  Nine Patch: an extension to the PNG format allows it to
    specify information about how to stretch it and place things inside of
    it.
    
  • Vector: a drawable defined in an XML file as a set of points,
    lines, and curves along with its associated color information. This type
    of drawable can be scaled without loss of display quality.
    
  •  Shape: contains simple drawing commands instead of a raw
    bitmap, allowing it to resize better in some cases.
    
  •  Layers: a compound drawable, which draws multiple underlying
    drawables on top of each other.
    
  •  States: a compound drawable that selects one of a set of
    drawables based on its state.
    
  •  Levels: a compound drawable that selects one of a set of
    drawables based on its level.
    
  •  Scale: a compound drawable with a single child drawable,
    whose overall size is modified based on the current level.




Custom drawables


 All versions of Android allow the Drawable class to be extended and used at run time in place of framework-provided drawable classes. Starting in API 24, custom drawables classes may also be used in XML. 

Note: Custom drawable classes are only accessible from
within your application package. Other applications will not be able to load
them.

 At a minimum, custom drawable classes must implement the abstract methods on Drawable and should override the draw(Canvas) method to draw content. 

Custom drawables classes may be used in XML in multiple ways:

    
    
  • 
        Using the fully-qualified class name as the XML element name. For
        this method, the custom drawable class must be a public top-level
        class.

    <com.myapp.MyCustomDrawable xmlns:android="http://schemas.android.com/apk/res/android"
    android:color="#ffff0000" />

    
    
    • 
    
  • 
        Using drawable as the XML element name and specifying the
        fully-qualified class name from the class attribute. This
        method may be used for both public top-level classes and public
        static inner classes.

    <drawable xmlns:android="http://schemas.android.com/apk/res/android"
    class="com.myapp.MyTopLevelClass$InnerCustomDrawable"
    android:color="#ffff0000" />

    
    
    • 





Developer Guides


For more information about how to use drawables, read the
Canvas and Drawables developer
guide. For information and examples of creating drawable resources (XML or bitmap files that
can be loaded in code), read the
Drawable Resources
document.


/**
 * A Drawable is a general abstraction for "something that can be drawn."  Most
 * often you will deal with Drawable as the type of resource retrieved for
 * drawing things to the screen; the Drawable class provides a generic API for
 * dealing with an underlying visual resource that may take a variety of forms.
 * Unlike a {@link android.view.View}, a Drawable does not have any facility to
 * receive events or otherwise interact with the user.
 *
 * <p>In addition to simple drawing, Drawable provides a number of generic
 * mechanisms for its client to interact with what is being drawn:
 *
 * <ul>
 *     <li> The {@link #setBounds} method <var>must</var> be called to tell the
 *     Drawable where it is drawn and how large it should be.  All Drawables
 *     should respect the requested size, often simply by scaling their
 *     imagery.  A client can find the preferred size for some Drawables with
 *     the {@link #getIntrinsicHeight} and {@link #getIntrinsicWidth} methods.
 *
 *     <li> The {@link #getPadding} method can return from some Drawables
 *     information about how to frame content that is placed inside of them.
 *     For example, a Drawable that is intended to be the frame for a button
 *     widget would need to return padding that correctly places the label
 *     inside of itself.
 *
 *     <li> The {@link #setState} method allows the client to tell the Drawable
 *     in which state it is to be drawn, such as "focused", "selected", etc.
 *     Some drawables may modify their imagery based on the selected state.
 *
 *     <li> The {@link #setLevel} method allows the client to supply a single
 *     continuous controller that can modify the Drawable is displayed, such as
 *     a battery level or progress level.  Some drawables may modify their
 *     imagery based on the current level.
 *
 *     <li> A Drawable can perform animations by calling back to its client
 *     through the {@link Callback} interface.  All clients should support this
 *     interface (via {@link #setCallback}) so that animations will work.  A
 *     simple way to do this is through the system facilities such as
 *     {@link android.view.View#setBackground(Drawable)} and
 *     {@link android.widget.ImageView}.
 * </ul>
 *
 * Though usually not visible to the application, Drawables may take a variety
 * of forms:
 *
 * <ul>
 *     <li> <b>Bitmap</b>: the simplest Drawable, a PNG or JPEG image.
 *     <li> <b>Nine Patch</b>: an extension to the PNG format allows it to
 *     specify information about how to stretch it and place things inside of
 *     it.
 *     <li><b>Vector</b>: a drawable defined in an XML file as a set of points,
 *     lines, and curves along with its associated color information. This type
 *     of drawable can be scaled without loss of display quality.
 *     <li> <b>Shape</b>: contains simple drawing commands instead of a raw
 *     bitmap, allowing it to resize better in some cases.
 *     <li> <b>Layers</b>: a compound drawable, which draws multiple underlying
 *     drawables on top of each other.
 *     <li> <b>States</b>: a compound drawable that selects one of a set of
 *     drawables based on its state.
 *     <li> <b>Levels</b>: a compound drawable that selects one of a set of
 *     drawables based on its level.
 *     <li> <b>Scale</b>: a compound drawable with a single child drawable,
 *     whose overall size is modified based on the current level.
 * </ul>
 *
 * <a name="Custom"></a>
 * <h3>Custom drawables</h3>
 *
 * <p>
 * All versions of Android allow the Drawable class to be extended and used at
 * run time in place of framework-provided drawable classes. Starting in
 * {@link android.os.Build.VERSION_CODES#N API 24}, custom drawables classes
 * may also be used in XML.
 * <p>
 * <strong>Note:</strong> Custom drawable classes are only accessible from
 * within your application package. Other applications will not be able to load
 * them.
 * <p>
 * At a minimum, custom drawable classes must implement the abstract methods on
 * Drawable and should override the {@link Drawable#draw(Canvas)} method to
 * draw content.
 * <p>
 * Custom drawables classes may be used in XML in multiple ways:
 * <ul>
 *     <li>
 *         Using the fully-qualified class name as the XML element name. For
 *         this method, the custom drawable class must be a public top-level
 *         class.
 * <pre>
 * &lt;com.myapp.MyCustomDrawable xmlns:android="http://schemas.android.com/apk/res/android"
 *     android:color="#ffff0000" /&gt;
 * </pre>
 *     </li>
 *     <li>
 *         Using <em>drawable</em> as the XML element name and specifying the
 *         fully-qualified class name from the <em>class</em> attribute. This
 *         method may be used for both public top-level classes and public
 *         static inner classes.
 * <pre>
 * &lt;drawable xmlns:android="http://schemas.android.com/apk/res/android"
 *     class="com.myapp.MyTopLevelClass$InnerCustomDrawable"
 *     android:color="#ffff0000" /&gt;
 * </pre>
 *     </li>
 * </ul>
 *
 * <div class="special reference">
 * <h3>Developer Guides</h3>
 * <p>For more information about how to use drawables, read the
 * <a href="{@docRoot}guide/topics/graphics/2d-graphics.html">Canvas and Drawables</a> developer
 * guide. For information and examples of creating drawable resources (XML or bitmap files that
 * can be loaded in code), read the
 * <a href="{@docRoot}guide/topics/resources/drawable-resource.html">Drawable Resources</a>
 * document.</p></div>
 */
public abstract class Drawable {
    private static final Rect ZERO_BOUNDS_RECT = new Rect();

    static final PorterDuff.Mode DEFAULT_TINT_MODE = PorterDuff.Mode.SRC_IN;

    private int[] mStateSet = StateSet.WILD_CARD;
    private int mLevel = 0;
    private @Config int mChangingConfigurations = 0;
    private Rect mBounds = ZERO_BOUNDS_RECT;  // lazily becomes a new Rect()
    private WeakReference<Callback> mCallback = null;
    private boolean mVisible = true;

    private int mLayoutDirection;

    
The source density to use when looking up resources using Resources.getDrawableForDensity(int, int, Theme). A value of 0 means there is no override and the system density will be used. NOTE(adamlesinski): This is transient state used to get around the public API that does not account for source density overrides. Custom drawables implemented by developers do not need to be aware of the source density override, as it is only used by Launcher to load higher resolution icons from external Resources packages, which do not execute custom code. This is all to support the Resources.getDrawableForDensity(int, int, Theme) API. 
@hide
/**
     * The source density to use when looking up resources using
     * {@link Resources#getDrawableForDensity(int, int, Theme)}. A value of 0 means there is no
     * override and the system density will be used.
     *
     * NOTE(adamlesinski): This is transient state used to get around the public API that does not
     * account for source density overrides. Custom drawables implemented by developers do not need
     * to be aware of the source density override, as it is only used by Launcher to load higher
     * resolution icons from external Resources packages, which do not execute custom code.
     * This is all to support the {@link Resources#getDrawableForDensity(int, int, Theme)} API.
     *
     * @hide
     */
    protected int mSrcDensityOverride = 0;

    
Draw in its bounds (set via setBounds) respecting optional effects such
as alpha (set via setAlpha) and color filter (set via setColorFilter).

Params:
  • canvas – The canvas to draw into
/**
     * Draw in its bounds (set via setBounds) respecting optional effects such
     * as alpha (set via setAlpha) and color filter (set via setColorFilter).
     *
     * @param canvas The canvas to draw into
     */
    public abstract void draw(@NonNull Canvas canvas);

    
Specify a bounding rectangle for the Drawable. This is where the drawable
will draw when its draw() method is called.

/**
     * Specify a bounding rectangle for the Drawable. This is where the drawable
     * will draw when its draw() method is called.
     */
    public void setBounds(int left, int top, int right, int bottom) {
        Rect oldBounds = mBounds;

        if (oldBounds == ZERO_BOUNDS_RECT) {
            oldBounds = mBounds = new Rect();
        }

        if (oldBounds.left != left || oldBounds.top != top ||
                oldBounds.right != right || oldBounds.bottom != bottom) {
            if (!oldBounds.isEmpty()) {
                // first invalidate the previous bounds
                invalidateSelf();
            }
            mBounds.set(left, top, right, bottom);
            onBoundsChange(mBounds);
        }
    }

    
Specify a bounding rectangle for the Drawable. This is where the drawable
will draw when its draw() method is called.

/**
     * Specify a bounding rectangle for the Drawable. This is where the drawable
     * will draw when its draw() method is called.
     */
    public void setBounds(@NonNull Rect bounds) {
        setBounds(bounds.left, bounds.top, bounds.right, bounds.bottom);
    }

    
Return a copy of the drawable's bounds in the specified Rect (allocated
by the caller). The bounds specify where this will draw when its draw()
method is called.

Params:
  • bounds – Rect to receive the drawable's bounds (allocated by the
              caller).
/**
     * Return a copy of the drawable's bounds in the specified Rect (allocated
     * by the caller). The bounds specify where this will draw when its draw()
     * method is called.
     *
     * @param bounds Rect to receive the drawable's bounds (allocated by the
     *               caller).
     */
    public final void copyBounds(@NonNull Rect bounds) {
        bounds.set(mBounds);
    }

    
Return a copy of the drawable's bounds in a new Rect. This returns the
same values as getBounds(), but the returned object is guaranteed to not
be changed later by the drawable (i.e. it retains no reference to this
rect). If the caller already has a Rect allocated, call copyBounds(rect).

Returns:A copy of the drawable's bounds
/**
     * Return a copy of the drawable's bounds in a new Rect. This returns the
     * same values as getBounds(), but the returned object is guaranteed to not
     * be changed later by the drawable (i.e. it retains no reference to this
     * rect). If the caller already has a Rect allocated, call copyBounds(rect).
     *
     * @return A copy of the drawable's bounds
     */
    @NonNull
    public final Rect copyBounds() {
        return new Rect(mBounds);
    }

    
Return the drawable's bounds Rect. Note: for efficiency, the returned
object may be the same object stored in the drawable (though this is not
guaranteed), so if a persistent copy of the bounds is needed, call
copyBounds(rect) instead.
You should also not change the object returned by this method as it may
be the same object stored in the drawable.

See Also:
Returns:The bounds of the drawable (which may change later, so caller
        beware). DO NOT ALTER the returned object as it may change the
        stored bounds of this drawable.
/**
     * Return the drawable's bounds Rect. Note: for efficiency, the returned
     * object may be the same object stored in the drawable (though this is not
     * guaranteed), so if a persistent copy of the bounds is needed, call
     * copyBounds(rect) instead.
     * You should also not change the object returned by this method as it may
     * be the same object stored in the drawable.
     *
     * @return The bounds of the drawable (which may change later, so caller
     *         beware). DO NOT ALTER the returned object as it may change the
     *         stored bounds of this drawable.
     *
     * @see #copyBounds()
     * @see #copyBounds(android.graphics.Rect)
     */
    @NonNull
    public final Rect getBounds() {
        if (mBounds == ZERO_BOUNDS_RECT) {
            mBounds = new Rect();
        }

        return mBounds;
    }

    
Return the drawable's dirty bounds Rect. Note: for efficiency, the
returned object may be the same object stored in the drawable (though
this is not guaranteed).


By default, this returns the full drawable bounds. Custom drawables may
override this method to perform more precise invalidation.

Returns:The dirty bounds of this drawable
/**
     * Return the drawable's dirty bounds Rect. Note: for efficiency, the
     * returned object may be the same object stored in the drawable (though
     * this is not guaranteed).
     * <p>
     * By default, this returns the full drawable bounds. Custom drawables may
     * override this method to perform more precise invalidation.
     *
     * @return The dirty bounds of this drawable
     */
    @NonNull
    public Rect getDirtyBounds() {
        return getBounds();
    }

    
Set a mask of the configuration parameters for which this drawable
may change, requiring that it be re-created.

Params:
  • configs – A mask of the changing configuration parameters, as defined by ActivityInfo.
See Also:
/**
     * Set a mask of the configuration parameters for which this drawable
     * may change, requiring that it be re-created.
     *
     * @param configs A mask of the changing configuration parameters, as
     * defined by {@link android.content.pm.ActivityInfo}.
     *
     * @see android.content.pm.ActivityInfo
     */
    public void setChangingConfigurations(@Config int configs) {
        mChangingConfigurations = configs;
    }

    
Return a mask of the configuration parameters for which this drawable may change, requiring that it be re-created. The default implementation returns whatever was provided through setChangingConfigurations(int) or 0 by default. Subclasses may extend this to or in the changing configurations of any other drawables they hold. 
See Also:
Returns:Returns a mask of the changing configuration parameters, as defined by ActivityInfo.
/**
     * Return a mask of the configuration parameters for which this drawable
     * may change, requiring that it be re-created.  The default implementation
     * returns whatever was provided through
     * {@link #setChangingConfigurations(int)} or 0 by default.  Subclasses
     * may extend this to or in the changing configurations of any other
     * drawables they hold.
     *
     * @return Returns a mask of the changing configuration parameters, as
     * defined by {@link android.content.pm.ActivityInfo}.
     *
     * @see android.content.pm.ActivityInfo
     */
    public @Config int getChangingConfigurations() {
        return mChangingConfigurations;
    }

    
Set to true to have the drawable dither its colors when drawn to a
device with fewer than 8-bits per color component.

See Also:
  • android.graphics.Paint#setDither(boolean);
Deprecated:This property is ignored.
/**
     * Set to true to have the drawable dither its colors when drawn to a
     * device with fewer than 8-bits per color component.
     *
     * @see android.graphics.Paint#setDither(boolean);
     * @deprecated This property is ignored.
     */
    @Deprecated
    public void setDither(boolean dither) {}

    
Set to true to have the drawable filter its bitmaps with bilinear
sampling when they are scaled or rotated.

This can improve appearance when bitmaps are rotated. If the drawable
does not use bitmaps, this call is ignored.


See Also:
  • isFilterBitmap()
  • android.graphics.Paint#setFilterBitmap(boolean);
/**
     * Set to true to have the drawable filter its bitmaps with bilinear
     * sampling when they are scaled or rotated.
     *
     * <p>This can improve appearance when bitmaps are rotated. If the drawable
     * does not use bitmaps, this call is ignored.</p>
     *
     * @see #isFilterBitmap()
     * @see android.graphics.Paint#setFilterBitmap(boolean);
     */
    public void setFilterBitmap(boolean filter) {}

    
See Also:
Returns:whether this drawable filters its bitmaps
/**
     * @return whether this drawable filters its bitmaps
     * @see #setFilterBitmap(boolean)
     */
    public boolean isFilterBitmap() {
        return false;
    }

    
Implement this interface if you want to create an animated drawable that extends Drawable. Upon retrieving a drawable, use Drawable.setCallback(Callback) to supply your implementation of the interface to the drawable; it uses this interface to schedule and execute animation changes. 
/**
     * Implement this interface if you want to create an animated drawable that
     * extends {@link android.graphics.drawable.Drawable Drawable}.
     * Upon retrieving a drawable, use
     * {@link Drawable#setCallback(android.graphics.drawable.Drawable.Callback)}
     * to supply your implementation of the interface to the drawable; it uses
     * this interface to schedule and execute animation changes.
     */
    public interface Callback {
        
Called when the drawable needs to be redrawn.  A view at this point
should invalidate itself (or at least the part of itself where the
drawable appears).

Params:
  • who – The drawable that is requesting the update.
/**
         * Called when the drawable needs to be redrawn.  A view at this point
         * should invalidate itself (or at least the part of itself where the
         * drawable appears).
         *
         * @param who The drawable that is requesting the update.
         */
        void invalidateDrawable(@NonNull Drawable who);

        
A Drawable can call this to schedule the next frame of its animation. An implementation can generally simply call Handler.postAtTime(Runnable, Object, long) with the parameters (what, who, when) to perform the
scheduling.

Params:
  • who – The drawable being scheduled.
  • what – The action to execute.
  • when – The time (in milliseconds) to run. The timebase is SystemClock.uptimeMillis
/**
         * A Drawable can call this to schedule the next frame of its
         * animation.  An implementation can generally simply call
         * {@link android.os.Handler#postAtTime(Runnable, Object, long)} with
         * the parameters <var>(what, who, when)</var> to perform the
         * scheduling.
         *
         * @param who The drawable being scheduled.
         * @param what The action to execute.
         * @param when The time (in milliseconds) to run.  The timebase is
         *             {@link android.os.SystemClock#uptimeMillis}
         */
        void scheduleDrawable(@NonNull Drawable who, @NonNull Runnable what, long when);

        
A Drawable can call this to unschedule an action previously scheduled with scheduleDrawable. An implementation can generally simply call Handler.removeCallbacks(Runnable, Object) with the parameters (what, who) to unschedule the drawable.

Params:
  • who – The drawable being unscheduled.
  • what – The action being unscheduled.
/**
         * A Drawable can call this to unschedule an action previously
         * scheduled with {@link #scheduleDrawable}.  An implementation can
         * generally simply call
         * {@link android.os.Handler#removeCallbacks(Runnable, Object)} with
         * the parameters <var>(what, who)</var> to unschedule the drawable.
         *
         * @param who The drawable being unscheduled.
         * @param what The action being unscheduled.
         */
        void unscheduleDrawable(@NonNull Drawable who, @NonNull Runnable what);
    }

    
Bind a Callback object to this Drawable. Required for clients that want to support animated drawables. 
Params:
  • cb – The client's Callback implementation.
See Also:
/**
     * Bind a {@link Callback} object to this Drawable.  Required for clients
     * that want to support animated drawables.
     *
     * @param cb The client's Callback implementation.
     *
     * @see #getCallback()
     */
    public final void setCallback(@Nullable Callback cb) {
        mCallback = cb != null ? new WeakReference<>(cb) : null;
    }

    
Return the current Callback implementation attached to this Drawable. 
See Also:
Returns:A Callback instance or null if no callback was set.
/**
     * Return the current {@link Callback} implementation attached to this
     * Drawable.
     *
     * @return A {@link Callback} instance or null if no callback was set.
     *
     * @see #setCallback(android.graphics.drawable.Drawable.Callback)
     */
    @Nullable
    public Callback getCallback() {
        return mCallback != null ? mCallback.get() : null;
    }

    
Use the current Callback implementation to have this Drawable redrawn. Does nothing if there is no Callback attached to the Drawable. 
See Also:
/**
     * Use the current {@link Callback} implementation to have this Drawable
     * redrawn.  Does nothing if there is no Callback attached to the
     * Drawable.
     *
     * @see Callback#invalidateDrawable
     * @see #getCallback()
     * @see #setCallback(android.graphics.drawable.Drawable.Callback)
     */
    public void invalidateSelf() {
        final Callback callback = getCallback();
        if (callback != null) {
            callback.invalidateDrawable(this);
        }
    }

    
Use the current Callback implementation to have this Drawable scheduled. Does nothing if there is no Callback attached to the Drawable. 
Params:
  • what – The action being scheduled.
  • when – The time (in milliseconds) to run.
See Also:
/**
     * Use the current {@link Callback} implementation to have this Drawable
     * scheduled.  Does nothing if there is no Callback attached to the
     * Drawable.
     *
     * @param what The action being scheduled.
     * @param when The time (in milliseconds) to run.
     *
     * @see Callback#scheduleDrawable
     */
    public void scheduleSelf(@NonNull Runnable what, long when) {
        final Callback callback = getCallback();
        if (callback != null) {
            callback.scheduleDrawable(this, what, when);
        }
    }

    
Use the current Callback implementation to have this Drawable unscheduled. Does nothing if there is no Callback attached to the Drawable. 
Params:
  • what – The runnable that you no longer want called.
See Also:
/**
     * Use the current {@link Callback} implementation to have this Drawable
     * unscheduled.  Does nothing if there is no Callback attached to the
     * Drawable.
     *
     * @param what The runnable that you no longer want called.
     *
     * @see Callback#unscheduleDrawable
     */
    public void unscheduleSelf(@NonNull Runnable what) {
        final Callback callback = getCallback();
        if (callback != null) {
            callback.unscheduleDrawable(this, what);
        }
    }

    
Returns the resolved layout direction for this Drawable.

See Also:
Returns:One of View.LAYOUT_DIRECTION_LTR, View.LAYOUT_DIRECTION_RTL
/**
     * Returns the resolved layout direction for this Drawable.
     *
     * @return One of {@link android.view.View#LAYOUT_DIRECTION_LTR},
     *         {@link android.view.View#LAYOUT_DIRECTION_RTL}
     * @see #setLayoutDirection(int)
     */
    public @View.ResolvedLayoutDir int getLayoutDirection() {
        return mLayoutDirection;
    }

    
Set the layout direction for this drawable. Should be a resolved
layout direction, as the Drawable has no capacity to do the resolution on
its own.

Params:
See Also:
Returns:true if the layout direction change has caused the appearance of the drawable to change such that it needs to be re-drawn, false otherwise
/**
     * Set the layout direction for this drawable. Should be a resolved
     * layout direction, as the Drawable has no capacity to do the resolution on
     * its own.
     *
     * @param layoutDirection the resolved layout direction for the drawable,
     *                        either {@link android.view.View#LAYOUT_DIRECTION_LTR}
     *                        or {@link android.view.View#LAYOUT_DIRECTION_RTL}
     * @return {@code true} if the layout direction change has caused the
     *         appearance of the drawable to change such that it needs to be
     *         re-drawn, {@code false} otherwise
     * @see #getLayoutDirection()
     */
    public final boolean setLayoutDirection(@View.ResolvedLayoutDir int layoutDirection) {
        if (mLayoutDirection != layoutDirection) {
            mLayoutDirection = layoutDirection;
            return onLayoutDirectionChanged(layoutDirection);
        }
        return false;
    }

    
Called when the drawable's resolved layout direction changes.

Params:
  • layoutDirection – the new resolved layout direction
See Also:
Returns:true if the layout direction change has caused the appearance of the drawable to change such that it needs to be re-drawn, false otherwise
/**
     * Called when the drawable's resolved layout direction changes.
     *
     * @param layoutDirection the new resolved layout direction
     * @return {@code true} if the layout direction change has caused the
     *         appearance of the drawable to change such that it needs to be
     *         re-drawn, {@code false} otherwise
     * @see #setLayoutDirection(int)
     */
    public boolean onLayoutDirectionChanged(@View.ResolvedLayoutDir int layoutDirection) {
        return false;
    }

    
Specify an alpha value for the drawable. 0 means fully transparent, and
255 means fully opaque.

/**
     * Specify an alpha value for the drawable. 0 means fully transparent, and
     * 255 means fully opaque.
     */
    public abstract void setAlpha(@IntRange(from=0,to=255) int alpha);

    
Gets the current alpha value for the drawable. 0 means fully transparent,
255 means fully opaque. This method is implemented by
Drawable subclasses and the value returned is specific to how that class treats alpha.
The default return value is 255 if the class does not override this method to return a value
specific to its use of alpha.

/**
     * Gets the current alpha value for the drawable. 0 means fully transparent,
     * 255 means fully opaque. This method is implemented by
     * Drawable subclasses and the value returned is specific to how that class treats alpha.
     * The default return value is 255 if the class does not override this method to return a value
     * specific to its use of alpha.
     */
    @IntRange(from=0,to=255)
    public int getAlpha() {
        return 0xFF;
    }

    
@hide
Internal-only method for setting xfermode on certain supported drawables.
Should not be made public since the layers and drawing area with which
Drawables draw is private implementation detail, and not something apps
should rely upon.
/**
     * @hide
     *
     * Internal-only method for setting xfermode on certain supported drawables.
     *
     * Should not be made public since the layers and drawing area with which
     * Drawables draw is private implementation detail, and not something apps
     * should rely upon.
     */
    public void setXfermode(@Nullable Xfermode mode) {
        // Base implementation drops it on the floor for compatibility. Whee!
    }

    
Specify an optional color filter for the drawable.


If a Drawable has a ColorFilter, each output pixel of the Drawable's
drawing contents will be modified by the color filter before it is
blended onto the render target of a Canvas.



 Pass null to remove any existing color filter. 


Note: Setting a non-null color filter disables tint. 


Params:
  • colorFilter – The color filter to apply, or null to remove the existing color filter
/**
     * Specify an optional color filter for the drawable.
     * <p>
     * If a Drawable has a ColorFilter, each output pixel of the Drawable's
     * drawing contents will be modified by the color filter before it is
     * blended onto the render target of a Canvas.
     * </p>
     * <p>
     * Pass {@code null} to remove any existing color filter.
     * </p>
     * <p class="note"><strong>Note:</strong> Setting a non-{@code null} color
     * filter disables {@link #setTintList(ColorStateList) tint}.
     * </p>
     *
     * @param colorFilter The color filter to apply, or {@code null} to remove the
     *            existing color filter
     */
    public abstract void setColorFilter(@Nullable ColorFilter colorFilter);

    
Specify a color and Porter-Duff mode to be the color filter for this
drawable.

 Convenience for setColorFilter(ColorFilter) which constructs a PorterDuffColorFilter. 


Note: Setting a color filter disables tint. 


/**
     * Specify a color and Porter-Duff mode to be the color filter for this
     * drawable.
     * <p>
     * Convenience for {@link #setColorFilter(ColorFilter)} which constructs a
     * {@link PorterDuffColorFilter}.
     * </p>
     * <p class="note"><strong>Note:</strong> Setting a color filter disables
     * {@link #setTintList(ColorStateList) tint}.
     * </p>
     */
    public void setColorFilter(@ColorInt int color, @NonNull PorterDuff.Mode mode) {
        if (getColorFilter() instanceof PorterDuffColorFilter) {
            PorterDuffColorFilter existing = (PorterDuffColorFilter) getColorFilter();
            if (existing.getColor() == color && existing.getMode() == mode) {
                return;
            }
        }
        setColorFilter(new PorterDuffColorFilter(color, mode));
    }

    
Specifies tint color for this drawable.

 A Drawable's drawing content will be blended together with its tint before it is drawn to the screen. This functions similarly to setColorFilter(int, Mode). 


 To clear the tint, pass null to setTintList(ColorStateList). 


Note: Setting a color filter via setColorFilter(ColorFilter) or setColorFilter(int, Mode) overrides tint. 


Params:
  • tintColor – Color to use for tinting this drawable
See Also:
/**
     * Specifies tint color for this drawable.
     * <p>
     * A Drawable's drawing content will be blended together with its tint
     * before it is drawn to the screen. This functions similarly to
     * {@link #setColorFilter(int, PorterDuff.Mode)}.
     * </p>
     * <p>
     * To clear the tint, pass {@code null} to
     * {@link #setTintList(ColorStateList)}.
     * </p>
     * <p class="note"><strong>Note:</strong> Setting a color filter via
     * {@link #setColorFilter(ColorFilter)} or
     * {@link #setColorFilter(int, PorterDuff.Mode)} overrides tint.
     * </p>
     *
     * @param tintColor Color to use for tinting this drawable
     * @see #setTintList(ColorStateList)
     * @see #setTintMode(PorterDuff.Mode)
     */
    public void setTint(@ColorInt int tintColor) {
        setTintList(ColorStateList.valueOf(tintColor));
    }

    
Specifies tint color for this drawable as a color state list.

 A Drawable's drawing content will be blended together with its tint before it is drawn to the screen. This functions similarly to setColorFilter(int, Mode). 


Note: Setting a color filter via setColorFilter(ColorFilter) or setColorFilter(int, Mode) overrides tint. 


Params:
  • tint – Color state list to use for tinting this drawable, or null to clear the tint
See Also:
/**
     * Specifies tint color for this drawable as a color state list.
     * <p>
     * A Drawable's drawing content will be blended together with its tint
     * before it is drawn to the screen. This functions similarly to
     * {@link #setColorFilter(int, PorterDuff.Mode)}.
     * </p>
     * <p class="note"><strong>Note:</strong> Setting a color filter via
     * {@link #setColorFilter(ColorFilter)} or
     * {@link #setColorFilter(int, PorterDuff.Mode)} overrides tint.
     * </p>
     *
     * @param tint Color state list to use for tinting this drawable, or
     *            {@code null} to clear the tint
     * @see #setTint(int)
     * @see #setTintMode(PorterDuff.Mode)
     */
    public void setTintList(@Nullable ColorStateList tint) {}

    
Specifies a tint blending mode for this drawable.

 Defines how this drawable's tint color should be blended into the drawable before it is drawn to screen. Default tint mode is Mode.SRC_IN. 


Note: Setting a color filter via setColorFilter(ColorFilter) or setColorFilter(int, Mode) overrides tint. 


Params:
  • tintMode – A Porter-Duff blending mode
See Also:
/**
     * Specifies a tint blending mode for this drawable.
     * <p>
     * Defines how this drawable's tint color should be blended into the drawable
     * before it is drawn to screen. Default tint mode is {@link PorterDuff.Mode#SRC_IN}.
     * </p>
     * <p class="note"><strong>Note:</strong> Setting a color filter via
     * {@link #setColorFilter(ColorFilter)} or
     * {@link #setColorFilter(int, PorterDuff.Mode)} overrides tint.
     * </p>
     *
     * @param tintMode A Porter-Duff blending mode
     * @see #setTint(int)
     * @see #setTintList(ColorStateList)
     */
    public void setTintMode(@NonNull PorterDuff.Mode tintMode) {}

    
Returns the current color filter, or null if none set. 
Returns:the current color filter, or null if none set
/**
     * Returns the current color filter, or {@code null} if none set.
     *
     * @return the current color filter, or {@code null} if none set
     */
    public @Nullable ColorFilter getColorFilter() {
        return null;
    }

    
Removes the color filter for this drawable.

/**
     * Removes the color filter for this drawable.
     */
    public void clearColorFilter() {
        setColorFilter(null);
    }

    
Specifies the hotspot's location within the drawable.

Params:
  • x – The X coordinate of the center of the hotspot
  • y – The Y coordinate of the center of the hotspot
/**
     * Specifies the hotspot's location within the drawable.
     *
     * @param x The X coordinate of the center of the hotspot
     * @param y The Y coordinate of the center of the hotspot
     */
    public void setHotspot(float x, float y) {}

    
Sets the bounds to which the hotspot is constrained, if they should be
different from the drawable bounds.

Params:
  • left – position in pixels of the left bound
  • top – position in pixels of the top bound
  • right – position in pixels of the right bound
  • bottom – position in pixels of the bottom bound
See Also:
/**
     * Sets the bounds to which the hotspot is constrained, if they should be
     * different from the drawable bounds.
     *
     * @param left position in pixels of the left bound
     * @param top position in pixels of the top bound
     * @param right position in pixels of the right bound
     * @param bottom position in pixels of the bottom bound
     * @see #getHotspotBounds(android.graphics.Rect)
     */
    public void setHotspotBounds(int left, int top, int right, int bottom) {}

    
Populates outRect with the hotspot bounds. 
Params:
  • outRect – the rect to populate with the hotspot bounds
See Also:
/**
     * Populates {@code outRect} with the hotspot bounds.
     *
     * @param outRect the rect to populate with the hotspot bounds
     * @see #setHotspotBounds(int, int, int, int)
     */
    public void getHotspotBounds(@NonNull Rect outRect) {
        outRect.set(getBounds());
    }

    
Whether this drawable requests projection.

@hidemagic!
/**
     * Whether this drawable requests projection.
     *
     * @hide magic!
     */
    public boolean isProjected() {
        return false;
    }

    
Indicates whether this drawable will change its appearance based on
state. Clients can use this to determine whether it is necessary to
calculate their state and call setState.

See Also:
Returns:True if this drawable changes its appearance based on state,
        false otherwise.
/**
     * Indicates whether this drawable will change its appearance based on
     * state. Clients can use this to determine whether it is necessary to
     * calculate their state and call setState.
     *
     * @return True if this drawable changes its appearance based on state,
     *         false otherwise.
     * @see #setState(int[])
     */
    public boolean isStateful() {
        return false;
    }

    
Indicates whether this drawable has at least one state spec explicitly specifying state_focused.state_focused. 
Note: A View uses a Drawable instance as its background and it changes its appearance based on a state. On keyboard devices, it should specify its state_focused.state_focused to make sure the user knows which view is holding the focus.


Returns:true if state_focused.state_focused is specified for this drawable.
@hide
/**
     * Indicates whether this drawable has at least one state spec explicitly
     * specifying {@link android.R.attr#state_focused}.
     *
     * <p>Note: A View uses a {@link Drawable} instance as its background and it
     * changes its appearance based on a state. On keyboard devices, it should
     * specify its {@link android.R.attr#state_focused} to make sure the user
     * knows which view is holding the focus.</p>
     *
     * @return {@code true} if {@link android.R.attr#state_focused} is specified
     * for this drawable.
     *
     * @hide
     */
    @TestApi
    public boolean hasFocusStateSpecified() {
        return false;
    }

    
Specify a set of states for the drawable. These are use-case specific, so see the relevant documentation. As an example, the background for widgets like Button understand the following states: [state_focused.state_focused, state_pressed.state_pressed]. 
If the new state you are supplying causes the appearance of the Drawable to change, then it is responsible for calling invalidateSelf in order to have itself redrawn, and
true will be returned from this function.

Note: The Drawable holds a reference on to stateSet
until a new state array is given to it, so you must not modify this
array during that time.


Params:
  • stateSet – The new set of states to be displayed.
Returns:Returns true if this change in state has caused the appearance
of the Drawable to change (hence requiring an invalidate), otherwise
returns false.
/**
     * Specify a set of states for the drawable. These are use-case specific,
     * so see the relevant documentation. As an example, the background for
     * widgets like Button understand the following states:
     * [{@link android.R.attr#state_focused},
     *  {@link android.R.attr#state_pressed}].
     *
     * <p>If the new state you are supplying causes the appearance of the
     * Drawable to change, then it is responsible for calling
     * {@link #invalidateSelf} in order to have itself redrawn, <em>and</em>
     * true will be returned from this function.
     *
     * <p>Note: The Drawable holds a reference on to <var>stateSet</var>
     * until a new state array is given to it, so you must not modify this
     * array during that time.</p>
     *
     * @param stateSet The new set of states to be displayed.
     *
     * @return Returns true if this change in state has caused the appearance
     * of the Drawable to change (hence requiring an invalidate), otherwise
     * returns false.
     */
    public boolean setState(@NonNull final int[] stateSet) {
        if (!Arrays.equals(mStateSet, stateSet)) {
            mStateSet = stateSet;
            return onStateChange(stateSet);
        }
        return false;
    }

    
Describes the current state, as a union of primitve states, such as state_focused.state_focused, state_selected.state_selected, etc. Some drawables may modify their imagery based on the selected state. 
Returns:An array of resource Ids describing the current state.
/**
     * Describes the current state, as a union of primitve states, such as
     * {@link android.R.attr#state_focused},
     * {@link android.R.attr#state_selected}, etc.
     * Some drawables may modify their imagery based on the selected state.
     * @return An array of resource Ids describing the current state.
     */
    public @NonNull int[] getState() {
        return mStateSet;
    }

    
If this Drawable does transition animations between states, ask that
it immediately jump to the current state and skip any active animations.

/**
     * If this Drawable does transition animations between states, ask that
     * it immediately jump to the current state and skip any active animations.
     */
    public void jumpToCurrentState() {
    }

    
Returns:The current drawable that will be used by this drawable. For simple drawables, this is just the drawable itself. For drawables that change state like StateListDrawable and LevelListDrawable this will be the child drawable currently in use.
/**
     * @return The current drawable that will be used by this drawable. For simple drawables, this
     *         is just the drawable itself. For drawables that change state like
     *         {@link StateListDrawable} and {@link LevelListDrawable} this will be the child drawable
     *         currently in use.
     */
    public @NonNull Drawable getCurrent() {
        return this;
    }

    
Specify the level for the drawable.  This allows a drawable to vary its
imagery based on a continuous controller, for example to show progress
or volume level.

If the new level you are supplying causes the appearance of the Drawable to change, then it is responsible for calling invalidateSelf in order to have itself redrawn, and
true will be returned from this function.

Params:
  • level – The new level, from 0 (minimum) to 10000 (maximum).
Returns:Returns true if this change in level has caused the appearance
of the Drawable to change (hence requiring an invalidate), otherwise
returns false.
/**
     * Specify the level for the drawable.  This allows a drawable to vary its
     * imagery based on a continuous controller, for example to show progress
     * or volume level.
     *
     * <p>If the new level you are supplying causes the appearance of the
     * Drawable to change, then it is responsible for calling
     * {@link #invalidateSelf} in order to have itself redrawn, <em>and</em>
     * true will be returned from this function.
     *
     * @param level The new level, from 0 (minimum) to 10000 (maximum).
     *
     * @return Returns true if this change in level has caused the appearance
     * of the Drawable to change (hence requiring an invalidate), otherwise
     * returns false.
     */
    public final boolean setLevel(@IntRange(from=0,to=10000) int level) {
        if (mLevel != level) {
            mLevel = level;
            return onLevelChange(level);
        }
        return false;
    }

    
Retrieve the current level.

Returns:int Current level, from 0 (minimum) to 10000 (maximum).
/**
     * Retrieve the current level.
     *
     * @return int Current level, from 0 (minimum) to 10000 (maximum).
     */
    public final @IntRange(from=0,to=10000) int getLevel() {
        return mLevel;
    }

    
Set whether this Drawable is visible.  This generally does not impact
the Drawable's behavior, but is a hint that can be used by some
Drawables, for example, to decide whether run animations.

Params:
  • visible – Set to true if visible, false if not.
  • restart – You can supply true here to force the drawable to behave
               as if it has just become visible, even if it had last
               been set visible.  Used for example to force animations
               to restart.
Returns:boolean Returns true if the new visibility is different than
        its previous state.
/**
     * Set whether this Drawable is visible.  This generally does not impact
     * the Drawable's behavior, but is a hint that can be used by some
     * Drawables, for example, to decide whether run animations.
     *
     * @param visible Set to true if visible, false if not.
     * @param restart You can supply true here to force the drawable to behave
     *                as if it has just become visible, even if it had last
     *                been set visible.  Used for example to force animations
     *                to restart.
     *
     * @return boolean Returns true if the new visibility is different than
     *         its previous state.
     */
    public boolean setVisible(boolean visible, boolean restart) {
        boolean changed = mVisible != visible;
        if (changed) {
            mVisible = visible;
            invalidateSelf();
        }
        return changed;
    }

    public final boolean isVisible() {
        return mVisible;
    }

    
Set whether this Drawable is automatically mirrored when its layout direction is RTL (right-to left). See LayoutDirection. 
Params:
  • mirrored – Set to true if the Drawable should be mirrored, false if not.
/**
     * Set whether this Drawable is automatically mirrored when its layout direction is RTL
     * (right-to left). See {@link android.util.LayoutDirection}.
     *
     * @param mirrored Set to true if the Drawable should be mirrored, false if not.
     */
    public void setAutoMirrored(boolean mirrored) {
    }

    
Tells if this Drawable will be automatically mirrored when its layout direction is RTL right-to-left. See LayoutDirection. 
Returns:boolean Returns true if this Drawable will be automatically mirrored.
/**
     * Tells if this Drawable will be automatically mirrored  when its layout direction is RTL
     * right-to-left. See {@link android.util.LayoutDirection}.
     *
     * @return boolean Returns true if this Drawable will be automatically mirrored.
     */
    public boolean isAutoMirrored() {
        return false;
    }

    
Applies the specified theme to this Drawable and its children.

Params:
  • t – the theme to apply
/**
     * Applies the specified theme to this Drawable and its children.
     *
     * @param t the theme to apply
     */
    public void applyTheme(@NonNull @SuppressWarnings("unused") Theme t) {
    }

    public boolean canApplyTheme() {
        return false;
    }

    
Return the opacity/transparency of this Drawable. The returned value is one of the abstract format constants in PixelFormat: PixelFormat.UNKNOWN, PixelFormat.TRANSLUCENT, PixelFormat.TRANSPARENT, or PixelFormat.OPAQUE. 
An OPAQUE drawable is one that draws all all content within its bounds, completely
covering anything behind the drawable. A TRANSPARENT drawable is one that draws nothing
within its bounds, allowing everything behind it to show through. A TRANSLUCENT drawable
is a drawable in any other state, where the drawable will draw some, but not all,
of the content within its bounds and at least some content behind the drawable will
be visible. If the visibility of the drawable's contents cannot be determined, the
safest/best return value is TRANSLUCENT.

Generally a Drawable should be as conservative as possible with the value it returns. For example, if it contains multiple child drawables and only shows one of them at a time, if only one of the children is TRANSLUCENT and the others are OPAQUE then TRANSLUCENT should be returned. You can use the method resolveOpacity to perform a standard reduction of two opacities to the appropriate single output. 
Note that the returned value does not necessarily take into account a custom alpha or color filter that has been applied by the client through the setAlpha or setColorFilter methods. Some subclasses, such as BitmapDrawable, ColorDrawable, and GradientDrawable, do account for the value of setAlpha, but the general behavior is dependent upon the implementation of the subclass. 
See Also:
Returns:int The opacity class of the Drawable.
/**
     * Return the opacity/transparency of this Drawable.  The returned value is
     * one of the abstract format constants in
     * {@link android.graphics.PixelFormat}:
     * {@link android.graphics.PixelFormat#UNKNOWN},
     * {@link android.graphics.PixelFormat#TRANSLUCENT},
     * {@link android.graphics.PixelFormat#TRANSPARENT}, or
     * {@link android.graphics.PixelFormat#OPAQUE}.
     *
     * <p>An OPAQUE drawable is one that draws all all content within its bounds, completely
     * covering anything behind the drawable. A TRANSPARENT drawable is one that draws nothing
     * within its bounds, allowing everything behind it to show through. A TRANSLUCENT drawable
     * is a drawable in any other state, where the drawable will draw some, but not all,
     * of the content within its bounds and at least some content behind the drawable will
     * be visible. If the visibility of the drawable's contents cannot be determined, the
     * safest/best return value is TRANSLUCENT.
     *
     * <p>Generally a Drawable should be as conservative as possible with the
     * value it returns.  For example, if it contains multiple child drawables
     * and only shows one of them at a time, if only one of the children is
     * TRANSLUCENT and the others are OPAQUE then TRANSLUCENT should be
     * returned.  You can use the method {@link #resolveOpacity} to perform a
     * standard reduction of two opacities to the appropriate single output.
     *
     * <p>Note that the returned value does not necessarily take into account a
     * custom alpha or color filter that has been applied by the client through
     * the {@link #setAlpha} or {@link #setColorFilter} methods. Some subclasses,
     * such as {@link BitmapDrawable}, {@link ColorDrawable}, and {@link GradientDrawable},
     * do account for the value of {@link #setAlpha}, but the general behavior is dependent
     * upon the implementation of the subclass.
     *
     * @return int The opacity class of the Drawable.
     *
     * @see android.graphics.PixelFormat
     */
    public abstract @PixelFormat.Opacity int getOpacity();

    
Return the appropriate opacity value for two source opacities.  If
either is UNKNOWN, that is returned; else, if either is TRANSLUCENT,
that is returned; else, if either is TRANSPARENT, that is returned;
else, OPAQUE is returned.

This is to help in implementing getOpacity. 
Params:
  • op1 – One opacity value.
  • op2 – Another opacity value.
See Also:
Returns:int The combined opacity value.
/**
     * Return the appropriate opacity value for two source opacities.  If
     * either is UNKNOWN, that is returned; else, if either is TRANSLUCENT,
     * that is returned; else, if either is TRANSPARENT, that is returned;
     * else, OPAQUE is returned.
     *
     * <p>This is to help in implementing {@link #getOpacity}.
     *
     * @param op1 One opacity value.
     * @param op2 Another opacity value.
     *
     * @return int The combined opacity value.
     *
     * @see #getOpacity
     */
    public static @PixelFormat.Opacity int resolveOpacity(@PixelFormat.Opacity int op1,
            @PixelFormat.Opacity int op2) {
        if (op1 == op2) {
            return op1;
        }
        if (op1 == PixelFormat.UNKNOWN || op2 == PixelFormat.UNKNOWN) {
            return PixelFormat.UNKNOWN;
        }
        if (op1 == PixelFormat.TRANSLUCENT || op2 == PixelFormat.TRANSLUCENT) {
            return PixelFormat.TRANSLUCENT;
        }
        if (op1 == PixelFormat.TRANSPARENT || op2 == PixelFormat.TRANSPARENT) {
            return PixelFormat.TRANSPARENT;
        }
        return PixelFormat.OPAQUE;
    }

    
Returns a Region representing the part of the Drawable that is completely
transparent.  This can be used to perform drawing operations, identifying
which parts of the target will not change when rendering the Drawable.
The default implementation returns null, indicating no transparent
region; subclasses can optionally override this to return an actual
Region if they want to supply this optimization information, but it is
not required that they do so.

Returns:Returns null if the Drawables has no transparent region to
report, else a Region holding the parts of the Drawable's bounds that
are transparent.
/**
     * Returns a Region representing the part of the Drawable that is completely
     * transparent.  This can be used to perform drawing operations, identifying
     * which parts of the target will not change when rendering the Drawable.
     * The default implementation returns null, indicating no transparent
     * region; subclasses can optionally override this to return an actual
     * Region if they want to supply this optimization information, but it is
     * not required that they do so.
     *
     * @return Returns null if the Drawables has no transparent region to
     * report, else a Region holding the parts of the Drawable's bounds that
     * are transparent.
     */
    public @Nullable Region getTransparentRegion() {
        return null;
    }

    
Override this in your subclass to change appearance if you recognize the
specified state.

Returns:Returns true if the state change has caused the appearance of
the Drawable to change (that is, it needs to be drawn), else false
if it looks the same and there is no need to redraw it since its
last state.
/**
     * Override this in your subclass to change appearance if you recognize the
     * specified state.
     *
     * @return Returns true if the state change has caused the appearance of
     * the Drawable to change (that is, it needs to be drawn), else false
     * if it looks the same and there is no need to redraw it since its
     * last state.
     */
    protected boolean onStateChange(int[] state) {
        return false;
    }

    
Override this in your subclass to change appearance if you vary based
 on level.

Returns:Returns true if the level change has caused the appearance of
the Drawable to change (that is, it needs to be drawn), else false
if it looks the same and there is no need to redraw it since its
last level.
/** Override this in your subclass to change appearance if you vary based
     *  on level.
     * @return Returns true if the level change has caused the appearance of
     * the Drawable to change (that is, it needs to be drawn), else false
     * if it looks the same and there is no need to redraw it since its
     * last level.
     */
    protected boolean onLevelChange(int level) {
        return false;
    }

    
Override this in your subclass to change appearance if you vary based on
the bounds.

/**
     * Override this in your subclass to change appearance if you vary based on
     * the bounds.
     */
    protected void onBoundsChange(Rect bounds) {
        // Stub method.
    }

    
Returns the drawable's intrinsic width.


Intrinsic width is the width at which the drawable would like to be laid
out, including any inherent padding. If the drawable has no intrinsic
width, such as a solid color, this method returns -1.

Returns:the intrinsic width, or -1 if no intrinsic width
/**
     * Returns the drawable's intrinsic width.
     * <p>
     * Intrinsic width is the width at which the drawable would like to be laid
     * out, including any inherent padding. If the drawable has no intrinsic
     * width, such as a solid color, this method returns -1.
     *
     * @return the intrinsic width, or -1 if no intrinsic width
     */
    public int getIntrinsicWidth() {
        return -1;
    }

    
Returns the drawable's intrinsic height.


Intrinsic height is the height at which the drawable would like to be
laid out, including any inherent padding. If the drawable has no
intrinsic height, such as a solid color, this method returns -1.

Returns:the intrinsic height, or -1 if no intrinsic height
/**
     * Returns the drawable's intrinsic height.
     * <p>
     * Intrinsic height is the height at which the drawable would like to be
     * laid out, including any inherent padding. If the drawable has no
     * intrinsic height, such as a solid color, this method returns -1.
     *
     * @return the intrinsic height, or -1 if no intrinsic height
     */
    public int getIntrinsicHeight() {
        return -1;
    }

    
Returns the minimum width suggested by this Drawable. If a View uses this
Drawable as a background, it is suggested that the View use at least this
value for its width. (There will be some scenarios where this will not be
possible.) This value should INCLUDE any padding.

Returns:The minimum width suggested by this Drawable. If this Drawable
        doesn't have a suggested minimum width, 0 is returned.
/**
     * Returns the minimum width suggested by this Drawable. If a View uses this
     * Drawable as a background, it is suggested that the View use at least this
     * value for its width. (There will be some scenarios where this will not be
     * possible.) This value should INCLUDE any padding.
     *
     * @return The minimum width suggested by this Drawable. If this Drawable
     *         doesn't have a suggested minimum width, 0 is returned.
     */
    public int getMinimumWidth() {
        final int intrinsicWidth = getIntrinsicWidth();
        return intrinsicWidth > 0 ? intrinsicWidth : 0;
    }

    
Returns the minimum height suggested by this Drawable. If a View uses this
Drawable as a background, it is suggested that the View use at least this
value for its height. (There will be some scenarios where this will not be
possible.) This value should INCLUDE any padding.

Returns:The minimum height suggested by this Drawable. If this Drawable
        doesn't have a suggested minimum height, 0 is returned.
/**
     * Returns the minimum height suggested by this Drawable. If a View uses this
     * Drawable as a background, it is suggested that the View use at least this
     * value for its height. (There will be some scenarios where this will not be
     * possible.) This value should INCLUDE any padding.
     *
     * @return The minimum height suggested by this Drawable. If this Drawable
     *         doesn't have a suggested minimum height, 0 is returned.
     */
    public int getMinimumHeight() {
        final int intrinsicHeight = getIntrinsicHeight();
        return intrinsicHeight > 0 ? intrinsicHeight : 0;
    }

    
Return in padding the insets suggested by this Drawable for placing
content inside the drawable's bounds. Positive values move toward the
center of the Drawable (set Rect.inset).

Returns:true if this drawable actually has a padding, else false. When false is returned,
the padding is always set to 0.
/**
     * Return in padding the insets suggested by this Drawable for placing
     * content inside the drawable's bounds. Positive values move toward the
     * center of the Drawable (set Rect.inset).
     *
     * @return true if this drawable actually has a padding, else false. When false is returned,
     * the padding is always set to 0.
     */
    public boolean getPadding(@NonNull Rect padding) {
        padding.set(0, 0, 0, 0);
        return false;
    }

    
Return in insets the layout insets suggested by this Drawable for use with alignment
operations during layout.

@hide
/**
     * Return in insets the layout insets suggested by this Drawable for use with alignment
     * operations during layout.
     *
     * @hide
     */
    public @NonNull Insets getOpticalInsets() {
        return Insets.NONE;
    }

    
Called to get the drawable to populate the Outline that defines its drawing area.

 This method is called by the default ViewOutlineProvider to define the outline of the View. 

The default behavior defines the outline to be the bounding rectangle of 0 alpha.
Subclasses that wish to convey a different shape or alpha value must override this method.

See Also:
/**
     * Called to get the drawable to populate the Outline that defines its drawing area.
     * <p>
     * This method is called by the default {@link android.view.ViewOutlineProvider} to define
     * the outline of the View.
     * <p>
     * The default behavior defines the outline to be the bounding rectangle of 0 alpha.
     * Subclasses that wish to convey a different shape or alpha value must override this method.
     *
     * @see android.view.View#setOutlineProvider(android.view.ViewOutlineProvider)
     */
    public void getOutline(@NonNull Outline outline) {
        outline.setRect(getBounds());
        outline.setAlpha(0);
    }

    
Make this drawable mutable. This operation cannot be reversed. A mutable
drawable is guaranteed to not share its state with any other drawable.
This is especially useful when you need to modify properties of drawables
loaded from resources. By default, all drawables instances loaded from
the same resource share a common state; if you modify the state of one
instance, all the other instances will receive the same modification.
Calling this method on a mutable Drawable will have no effect.

See Also:
Returns:This drawable.
/**
     * Make this drawable mutable. This operation cannot be reversed. A mutable
     * drawable is guaranteed to not share its state with any other drawable.
     * This is especially useful when you need to modify properties of drawables
     * loaded from resources. By default, all drawables instances loaded from
     * the same resource share a common state; if you modify the state of one
     * instance, all the other instances will receive the same modification.
     *
     * Calling this method on a mutable Drawable will have no effect.
     *
     * @return This drawable.
     * @see ConstantState
     * @see #getConstantState()
     */
    public @NonNull Drawable mutate() {
        return this;
    }

    
Clears the mutated state, allowing this drawable to be cached and
mutated again.


This is hidden because only framework drawables can be cached, so
custom drawables don't need to support constant state, mutate(), or
clearMutated().

@hide
/**
     * Clears the mutated state, allowing this drawable to be cached and
     * mutated again.
     * <p>
     * This is hidden because only framework drawables can be cached, so
     * custom drawables don't need to support constant state, mutate(), or
     * clearMutated().
     *
     * @hide
     */
    public void clearMutated() {
        // Default implementation is no-op.
    }

    
Create a drawable from an inputstream

/**
     * Create a drawable from an inputstream
     */
    public static Drawable createFromStream(InputStream is, String srcName) {
        Trace.traceBegin(Trace.TRACE_TAG_RESOURCES, srcName != null ? srcName : "Unknown drawable");
        try {
            return createFromResourceStream(null, null, is, srcName);
        } finally {
            Trace.traceEnd(Trace.TRACE_TAG_RESOURCES);
        }
    }

    
Create a drawable from an inputstream, using the given resources and
value to determine density information.

/**
     * Create a drawable from an inputstream, using the given resources and
     * value to determine density information.
     */
    public static Drawable createFromResourceStream(Resources res, TypedValue value,
            InputStream is, String srcName) {
        Trace.traceBegin(Trace.TRACE_TAG_RESOURCES, srcName != null ? srcName : "Unknown drawable");
        try {
            return createFromResourceStream(res, value, is, srcName, null);
        } finally {
            Trace.traceEnd(Trace.TRACE_TAG_RESOURCES);
        }
    }

    
Create a drawable from an inputstream, using the given resources and
value to determine density information.

Deprecated:Prefer the version without an Options object.
/**
     * Create a drawable from an inputstream, using the given resources and
     * value to determine density information.
     *
     * @deprecated Prefer the version without an Options object.
     */
    @Nullable
    public static Drawable createFromResourceStream(@Nullable Resources res,
            @Nullable TypedValue value, @Nullable InputStream is, @Nullable String srcName,
            @Nullable BitmapFactory.Options opts) {
        if (is == null) {
            return null;
        }

        if (opts == null) {
            return getBitmapDrawable(res, value, is);
        }

        /*  ugh. The decodeStream contract is that we have already allocated
            the pad rect, but if the bitmap does not had a ninepatch chunk,
            then the pad will be ignored. If we could change this to lazily
            alloc/assign the rect, we could avoid the GC churn of making new
            Rects only to drop them on the floor.
        */
        Rect pad = new Rect();

        // Special stuff for compatibility mode: if the target density is not
        // the same as the display density, but the resource -is- the same as
        // the display density, then don't scale it down to the target density.
        // This allows us to load the system's density-correct resources into
        // an application in compatibility mode, without scaling those down
        // to the compatibility density only to have them scaled back up when
        // drawn to the screen.
        opts.inScreenDensity = Drawable.resolveDensity(res, 0);
        Bitmap  bm = BitmapFactory.decodeResourceStream(res, value, is, pad, opts);
        if (bm != null) {
            byte[] np = bm.getNinePatchChunk();
            if (np == null || !NinePatch.isNinePatchChunk(np)) {
                np = null;
                pad = null;
            }

            final Rect opticalInsets = new Rect();
            bm.getOpticalInsets(opticalInsets);
            return drawableFromBitmap(res, bm, np, pad, opticalInsets, srcName);
        }
        return null;
    }

    private static Drawable getBitmapDrawable(Resources res, TypedValue value, InputStream is) {
        try {
            ImageDecoder.Source source = null;
            if (value != null) {
                int density = Bitmap.DENSITY_NONE;
                if (value.density == TypedValue.DENSITY_DEFAULT) {
                    density = DisplayMetrics.DENSITY_DEFAULT;
                } else if (value.density != TypedValue.DENSITY_NONE) {
                    density = value.density;
                }
                source = ImageDecoder.createSource(res, is, density);
            } else {
                source = ImageDecoder.createSource(res, is);
            }

            return ImageDecoder.decodeDrawable(source, (decoder, info, src) -> {
                decoder.setAllocator(ImageDecoder.ALLOCATOR_SOFTWARE);
            });
        } catch (IOException e) {
            /*  do nothing.
                If the exception happened on decode, the drawable will be null.
            */
            Log.e("Drawable", "Unable to decode stream: " + e);
        }
        return null;
    }

    
Create a drawable from an XML document. For more information on how to
create resources in XML, see
Drawable Resources.

/**
     * Create a drawable from an XML document. For more information on how to
     * create resources in XML, see
     * <a href="{@docRoot}guide/topics/resources/drawable-resource.html">Drawable Resources</a>.
     */
    @NonNull
    public static Drawable createFromXml(@NonNull Resources r, @NonNull XmlPullParser parser)
            throws XmlPullParserException, IOException {
        return createFromXml(r, parser, null);
    }

    
Create a drawable from an XML document using an optional Theme. For more information on how to create resources in XML, see Drawable Resources.

/**
     * Create a drawable from an XML document using an optional {@link Theme}.
     * For more information on how to create resources in XML, see
     * <a href="{@docRoot}guide/topics/resources/drawable-resource.html">Drawable Resources</a>.
     */
    @NonNull
    public static Drawable createFromXml(@NonNull Resources r, @NonNull XmlPullParser parser,
            @Nullable Theme theme) throws XmlPullParserException, IOException {
        return createFromXmlForDensity(r, parser, 0, theme);
    }

    
Version of createFromXml(Resources, XmlPullParser, Theme) that accepts a density override. 
@hide
/**
     * Version of {@link #createFromXml(Resources, XmlPullParser, Theme)} that accepts a density
     * override.
     * @hide
     */
    @NonNull
    public static Drawable createFromXmlForDensity(@NonNull Resources r,
            @NonNull XmlPullParser parser, int density, @Nullable Theme theme)
            throws XmlPullParserException, IOException {
        AttributeSet attrs = Xml.asAttributeSet(parser);

        int type;
        //noinspection StatementWithEmptyBody
        while ((type=parser.next()) != XmlPullParser.START_TAG
                && type != XmlPullParser.END_DOCUMENT) {
            // Empty loop.
        }

        if (type != XmlPullParser.START_TAG) {
            throw new XmlPullParserException("No start tag found");
        }

        Drawable drawable = createFromXmlInnerForDensity(r, parser, attrs, density, theme);

        if (drawable == null) {
            throw new RuntimeException("Unknown initial tag: " + parser.getName());
        }

        return drawable;
    }

    
Create from inside an XML document.  Called on a parser positioned at
a tag in an XML document, tries to create a Drawable from that tag.
Returns null if the tag is not a valid drawable.

/**
     * Create from inside an XML document.  Called on a parser positioned at
     * a tag in an XML document, tries to create a Drawable from that tag.
     * Returns null if the tag is not a valid drawable.
     */
    @NonNull
    public static Drawable createFromXmlInner(@NonNull Resources r, @NonNull XmlPullParser parser,
            @NonNull AttributeSet attrs) throws XmlPullParserException, IOException {
        return createFromXmlInner(r, parser, attrs, null);
    }

    
Create a drawable from inside an XML document using an optional Theme. Called on a parser positioned at a tag in an XML document, tries to create a Drawable from that tag. Returns null if the tag is not a valid drawable. 
/**
     * Create a drawable from inside an XML document using an optional
     * {@link Theme}. Called on a parser positioned at a tag in an XML
     * document, tries to create a Drawable from that tag. Returns {@code null}
     * if the tag is not a valid drawable.
     */
    @NonNull
    public static Drawable createFromXmlInner(@NonNull Resources r, @NonNull XmlPullParser parser,
            @NonNull AttributeSet attrs, @Nullable Theme theme)
            throws XmlPullParserException, IOException {
        return createFromXmlInnerForDensity(r, parser, attrs, 0, theme);
    }

    
Version of createFromXmlInner(Resources, XmlPullParser, AttributeSet, Theme) that accepts an override density. 
/**
     * Version of {@link #createFromXmlInner(Resources, XmlPullParser, AttributeSet, Theme)} that
     * accepts an override density.
     */
    @NonNull
    static Drawable createFromXmlInnerForDensity(@NonNull Resources r,
            @NonNull XmlPullParser parser, @NonNull AttributeSet attrs, int density,
            @Nullable Theme theme) throws XmlPullParserException, IOException {
        return r.getDrawableInflater().inflateFromXmlForDensity(parser.getName(), parser, attrs,
                density, theme);
    }

    
Create a drawable from file path name.

/**
     * Create a drawable from file path name.
     */
    @Nullable
    public static Drawable createFromPath(String pathName) {
        if (pathName == null) {
            return null;
        }

        Trace.traceBegin(Trace.TRACE_TAG_RESOURCES, pathName);
        try (FileInputStream stream = new FileInputStream(pathName)) {
            return getBitmapDrawable(null, null, stream);
        } catch(IOException e) {
            // Do nothing; we will just return null if the FileInputStream had an error
        } finally {
            Trace.traceEnd(Trace.TRACE_TAG_RESOURCES);
        }

        return null;
    }

    
Inflate this Drawable from an XML resource. Does not apply a theme.

See Also:
  • inflate(Resources, XmlPullParser, AttributeSet, Theme)
/**
     * Inflate this Drawable from an XML resource. Does not apply a theme.
     *
     * @see #inflate(Resources, XmlPullParser, AttributeSet, Theme)
     */
    public void inflate(@NonNull Resources r, @NonNull XmlPullParser parser,
            @NonNull AttributeSet attrs) throws XmlPullParserException, IOException {
        inflate(r, parser, attrs, null);
    }

    
Inflate this Drawable from an XML resource optionally styled by a theme.
This can't be called more than once for each Drawable. Note that framework may have called
this once to create the Drawable instance from XML resource.

Params:
  • r – Resources used to resolve attribute values
  • parser – XML parser from which to inflate this Drawable
  • attrs – Base set of attribute values
  • theme – Theme to apply, may be null
Throws:
/**
     * Inflate this Drawable from an XML resource optionally styled by a theme.
     * This can't be called more than once for each Drawable. Note that framework may have called
     * this once to create the Drawable instance from XML resource.
     *
     * @param r Resources used to resolve attribute values
     * @param parser XML parser from which to inflate this Drawable
     * @param attrs Base set of attribute values
     * @param theme Theme to apply, may be null
     * @throws XmlPullParserException
     * @throws IOException
     */
    public void inflate(@NonNull Resources r, @NonNull XmlPullParser parser,
            @NonNull AttributeSet attrs, @Nullable Theme theme)
            throws XmlPullParserException, IOException {
        final TypedArray a = obtainAttributes(r, theme, attrs, R.styleable.Drawable);
        mVisible = a.getBoolean(R.styleable.Drawable_visible, mVisible);
        a.recycle();
    }

    
Inflate a Drawable from an XML resource.

Throws:
/**
     * Inflate a Drawable from an XML resource.
     *
     * @throws XmlPullParserException
     * @throws IOException
     */
    void inflateWithAttributes(@NonNull @SuppressWarnings("unused") Resources r,
            @NonNull @SuppressWarnings("unused") XmlPullParser parser, @NonNull TypedArray attrs,
            @AttrRes int visibleAttr) throws XmlPullParserException, IOException {
        mVisible = attrs.getBoolean(visibleAttr, mVisible);
    }

    
Sets the source override density for this Drawable. If non-zero, this density is to be used for any calls to Resources.getDrawableForDensity(int, int, Theme) or Resources.getValueForDensity(int, int, TypedValue, boolean). 
@hide
/**
     * Sets the source override density for this Drawable. If non-zero, this density is to be used
     * for any calls to {@link Resources#getDrawableForDensity(int, int, Theme)} or
     * {@link Resources#getValueForDensity(int, int, TypedValue, boolean)}.
     * @hide
     */
    final void setSrcDensityOverride(int density) {
        mSrcDensityOverride = density;
    }

    
This abstract class is used by Drawables to store shared constant state and data between Drawables. BitmapDrawables created from the same resource will for instance share a unique bitmap stored in their ConstantState. 
 newDrawable(Resources) can be used as a factory to create new Drawable instances from this ConstantState. 
 Use Drawable.getConstantState() to retrieve the ConstantState of a Drawable. Calling Drawable.mutate() on a Drawable should typically create a new ConstantState for that Drawable. 
/**
     * This abstract class is used by {@link Drawable}s to store shared constant state and data
     * between Drawables. {@link BitmapDrawable}s created from the same resource will for instance
     * share a unique bitmap stored in their ConstantState.
     *
     * <p>
     * {@link #newDrawable(Resources)} can be used as a factory to create new Drawable instances
     * from this ConstantState.
     * </p>
     *
     * Use {@link Drawable#getConstantState()} to retrieve the ConstantState of a Drawable. Calling
     * {@link Drawable#mutate()} on a Drawable should typically create a new ConstantState for that
     * Drawable.
     */
    public static abstract class ConstantState {
        
Creates a new Drawable instance from its constant state.


Note: Using this method means density-dependent properties, such as pixel dimensions or bitmap images, will not be updated to match the density of the target display. To ensure correct scaling, use newDrawable(Resources) instead to provide an appropriate Resources object. 
See Also:
Returns:a new drawable object based on this constant state
/**
         * Creates a new Drawable instance from its constant state.
         * <p>
         * <strong>Note:</strong> Using this method means density-dependent
         * properties, such as pixel dimensions or bitmap images, will not be
         * updated to match the density of the target display. To ensure
         * correct scaling, use {@link #newDrawable(Resources)} instead to
         * provide an appropriate Resources object.
         *
         * @return a new drawable object based on this constant state
         * @see #newDrawable(Resources)
         */
        public abstract @NonNull Drawable newDrawable();

        
Creates a new Drawable instance from its constant state using the
specified resources. This method should be implemented for drawables
that have density-dependent properties.

 The default implementation for this method calls through to newDrawable(). 
Params:
  • res – the resources of the context in which the drawable will
           be displayed
Returns:a new drawable object based on this constant state
/**
         * Creates a new Drawable instance from its constant state using the
         * specified resources. This method should be implemented for drawables
         * that have density-dependent properties.
         * <p>
         * The default implementation for this method calls through to
         * {@link #newDrawable()}.
         *
         * @param res the resources of the context in which the drawable will
         *            be displayed
         * @return a new drawable object based on this constant state
         */
        public @NonNull Drawable newDrawable(@Nullable Resources res) {
            return newDrawable();
        }

        
Creates a new Drawable instance from its constant state using the
specified resources and theme. This method should be implemented for
drawables that have theme-dependent properties.

 The default implementation for this method calls through to newDrawable(Resources). 
Params:
  • res – the resources of the context in which the drawable will
           be displayed
  • theme – the theme of the context in which the drawable will be
             displayed
Returns:a new drawable object based on this constant state
/**
         * Creates a new Drawable instance from its constant state using the
         * specified resources and theme. This method should be implemented for
         * drawables that have theme-dependent properties.
         * <p>
         * The default implementation for this method calls through to
         * {@link #newDrawable(Resources)}.
         *
         * @param res the resources of the context in which the drawable will
         *            be displayed
         * @param theme the theme of the context in which the drawable will be
         *              displayed
         * @return a new drawable object based on this constant state
         */
        public @NonNull Drawable newDrawable(@Nullable Resources res,
                @Nullable @SuppressWarnings("unused") Theme theme) {
            return newDrawable(res);
        }

        
Return a bit mask of configuration changes that will impact
this drawable (and thus require completely reloading it).

/**
         * Return a bit mask of configuration changes that will impact
         * this drawable (and thus require completely reloading it).
         */
        public abstract @Config int getChangingConfigurations();

        
Return whether this constant state can have a theme applied.

/**
         * Return whether this constant state can have a theme applied.
         */
        public boolean canApplyTheme() {
            return false;
        }
    }

    
Return a ConstantState instance that holds the shared state of this Drawable. 
See Also:
Returns:The ConstantState associated to that Drawable.
/**
     * Return a {@link ConstantState} instance that holds the shared state of this Drawable.
     *
     * @return The ConstantState associated to that Drawable.
     * @see ConstantState
     * @see Drawable#mutate()
     */
    public @Nullable ConstantState getConstantState() {
        return null;
    }

    private static Drawable drawableFromBitmap(Resources res, Bitmap bm, byte[] np,
            Rect pad, Rect layoutBounds, String srcName) {

        if (np != null) {
            return new NinePatchDrawable(res, bm, np, pad, layoutBounds, srcName);
        }

        return new BitmapDrawable(res, bm);
    }

    
Ensures the tint filter is consistent with the current tint color and
mode.

/**
     * Ensures the tint filter is consistent with the current tint color and
     * mode.
     */
    @Nullable PorterDuffColorFilter updateTintFilter(@Nullable PorterDuffColorFilter tintFilter,
            @Nullable ColorStateList tint, @Nullable PorterDuff.Mode tintMode) {
        if (tint == null || tintMode == null) {
            return null;
        }

        final int color = tint.getColorForState(getState(), Color.TRANSPARENT);
        if (tintFilter == null) {
            return new PorterDuffColorFilter(color, tintMode);
        }

        tintFilter.setColor(color);
        tintFilter.setMode(tintMode);
        return tintFilter;
    }

    
Obtains styled attributes from the theme, if available, or unstyled
resources if the theme is null.

@hide
/**
     * Obtains styled attributes from the theme, if available, or unstyled
     * resources if the theme is null.
     * @hide
     */
    protected static @NonNull TypedArray obtainAttributes(@NonNull Resources res,
            @Nullable Theme theme, @NonNull AttributeSet set, @NonNull int[] attrs) {
        if (theme == null) {
            return res.obtainAttributes(set, attrs);
        }
        return theme.obtainStyledAttributes(set, attrs, 0, 0);
    }

    
Scales a floating-point pixel value from the source density to the
target density.

Params:
  • pixels – the pixel value for use in source density
  • sourceDensity – the source density
  • targetDensity – the target density
Returns:the scaled pixel value for use in target density
/**
     * Scales a floating-point pixel value from the source density to the
     * target density.
     *
     * @param pixels the pixel value for use in source density
     * @param sourceDensity the source density
     * @param targetDensity the target density
     * @return the scaled pixel value for use in target density
     */
    static float scaleFromDensity(float pixels, int sourceDensity, int targetDensity) {
        return pixels * targetDensity / sourceDensity;
    }

    
Scales a pixel value from the source density to the target density,
optionally handling the resulting pixel value as a size rather than an
offset.


A size conversion involves rounding the base value and ensuring that
a non-zero base value is at least one pixel in size.


An offset conversion involves simply truncating the base value to an
integer.

Params:
  • pixels – the pixel value for use in source density
  • sourceDensity – the source density
  • targetDensity – the target density
  • isSize – true to handle the resulting scaled value as a size, or false to handle it as an offset
Returns:the scaled pixel value for use in target density
/**
     * Scales a pixel value from the source density to the target density,
     * optionally handling the resulting pixel value as a size rather than an
     * offset.
     * <p>
     * A size conversion involves rounding the base value and ensuring that
     * a non-zero base value is at least one pixel in size.
     * <p>
     * An offset conversion involves simply truncating the base value to an
     * integer.
     *
     * @param pixels the pixel value for use in source density
     * @param sourceDensity the source density
     * @param targetDensity the target density
     * @param isSize {@code true} to handle the resulting scaled value as a
     *               size, or {@code false} to handle it as an offset
     * @return the scaled pixel value for use in target density
     */
    static int scaleFromDensity(
            int pixels, int sourceDensity, int targetDensity, boolean isSize) {
        if (pixels == 0 || sourceDensity == targetDensity) {
            return pixels;
        }

        final float result = pixels * targetDensity / (float) sourceDensity;
        if (!isSize) {
            return (int) result;
        }

        final int rounded = Math.round(result);
        if (rounded != 0) {
            return rounded;
        } else if (pixels > 0) {
            return 1;
        } else {
            return -1;
        }
    }

    static int resolveDensity(@Nullable Resources r, int parentDensity) {
        final int densityDpi = r == null ? parentDensity : r.getDisplayMetrics().densityDpi;
        return densityDpi == 0 ? DisplayMetrics.DENSITY_DEFAULT : densityDpi;
    }

    
Re-throws an exception as a RuntimeException with an empty stack trace to avoid cluttering the log. The original exception's stack trace will still be included. 
Params:
  • cause – the exception to re-throw
Throws:
/**
     * Re-throws an exception as a {@link RuntimeException} with an empty stack
     * trace to avoid cluttering the log. The original exception's stack trace
     * will still be included.
     *
     * @param cause the exception to re-throw
     * @throws RuntimeException
     */
    static void rethrowAsRuntimeException(@NonNull Exception cause) throws RuntimeException {
        final RuntimeException e = new RuntimeException(cause);
        e.setStackTrace(new StackTraceElement[0]);
        throw e;
    }

    
Parses a Mode from a tintMode attribute's enum value. 
@hide
/**
     * Parses a {@link android.graphics.PorterDuff.Mode} from a tintMode
     * attribute's enum value.
     *
     * @hide
     */
    public static PorterDuff.Mode parseTintMode(int value, Mode defaultMode) {
        switch (value) {
            case 3: return Mode.SRC_OVER;
            case 5: return Mode.SRC_IN;
            case 9: return Mode.SRC_ATOP;
            case 14: return Mode.MULTIPLY;
            case 15: return Mode.SCREEN;
            case 16: return Mode.ADD;
            default: return defaultMode;
        }
    }
}