android/android-9.0.0_r35 : android/inputmethodservice/Keyboard.java

Keyboard
https://source.android.com/
/*
 * Copyright (C) 2008-2009 Google Inc.
 * 
 * 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.inputmethodservice;

import org.xmlpull.v1.XmlPullParserException;

import android.annotation.XmlRes;
import android.content.Context;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.content.res.XmlResourceParser;
import android.graphics.drawable.Drawable;
import android.text.TextUtils;
import android.util.Log;
import android.util.TypedValue;
import android.util.Xml;
import android.util.DisplayMetrics;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;


Loads an XML description of a keyboard and stores the attributes of the keys. A keyboard
consists of rows of keys.
The layout file for a keyboard contains XML that looks like the following snippet:
<Keyboard
        android:keyWidth="%10p"
        android:keyHeight="50px"
        android:horizontalGap="2px"
        android:verticalGap="2px" >
    <Row android:keyWidth="32px" >
        <Key android:keyLabel="A" />
        ...
    </Row>
    ...
</Keyboard>

@attr ref android.R.styleable#Keyboard_keyWidth
@attr ref android.R.styleable#Keyboard_keyHeight
@attr ref android.R.styleable#Keyboard_horizontalGap
@attr ref android.R.styleable#Keyboard_verticalGap/**
 * Loads an XML description of a keyboard and stores the attributes of the keys. A keyboard
 * consists of rows of keys.
 * <p>The layout file for a keyboard contains XML that looks like the following snippet:</p>
 * <pre>
 * &lt;Keyboard
 *         android:keyWidth="%10p"
 *         android:keyHeight="50px"
 *         android:horizontalGap="2px"
 *         android:verticalGap="2px" &gt;
 *     &lt;Row android:keyWidth="32px" &gt;
 *         &lt;Key android:keyLabel="A" /&gt;
 *         ...
 *     &lt;/Row&gt;
 *     ...
 * &lt;/Keyboard&gt;
 * </pre>
 * @attr ref android.R.styleable#Keyboard_keyWidth
 * @attr ref android.R.styleable#Keyboard_keyHeight
 * @attr ref android.R.styleable#Keyboard_horizontalGap
 * @attr ref android.R.styleable#Keyboard_verticalGap
 */
public class Keyboard {

    static final String TAG = "Keyboard";
    
    // Keyboard XML Tags
    private static final String TAG_KEYBOARD = "Keyboard";
    private static final String TAG_ROW = "Row";
    private static final String TAG_KEY = "Key";

    public static final int EDGE_LEFT = 0x01;
    public static final int EDGE_RIGHT = 0x02;
    public static final int EDGE_TOP = 0x04;
    public static final int EDGE_BOTTOM = 0x08;

    public static final int KEYCODE_SHIFT = -1;
    public static final int KEYCODE_MODE_CHANGE = -2;
    public static final int KEYCODE_CANCEL = -3;
    public static final int KEYCODE_DONE = -4;
    public static final int KEYCODE_DELETE = -5;
    public static final int KEYCODE_ALT = -6;
    
    Keyboard label /** Keyboard label **/
    private CharSequence mLabel;

    Horizontal gap default for all rows /** Horizontal gap default for all rows */
    private int mDefaultHorizontalGap;
    
    Default key width /** Default key width */
    private int mDefaultWidth;

    Default key height /** Default key height */
    private int mDefaultHeight;

    Default gap between rows /** Default gap between rows */
    private int mDefaultVerticalGap;

    Is the keyboard in the shifted state /** Is the keyboard in the shifted state */
    private boolean mShifted;
    
    Key instance for the shift key, if present /** Key instance for the shift key, if present */
    private Key[] mShiftKeys = { null, null };

    Key index for the shift key, if present /** Key index for the shift key, if present */
    private int[] mShiftKeyIndices = {-1, -1};

    Current key width, while loading the keyboard /** Current key width, while loading the keyboard */
    private int mKeyWidth;
    
    Current key height, while loading the keyboard /** Current key height, while loading the keyboard */
    private int mKeyHeight;
    
    Total height of the keyboard, including the padding and keys /** Total height of the keyboard, including the padding and keys */
    private int mTotalHeight;
    
    Total width of the keyboard, including left side gaps and keys, but not any gaps on the
right side.
/** 
     * Total width of the keyboard, including left side gaps and keys, but not any gaps on the
     * right side.
     */
    private int mTotalWidth;
    
    List of keys in this keyboard /** List of keys in this keyboard */
    private List<Key> mKeys;
    
    List of modifier keys such as Shift & Alt, if any /** List of modifier keys such as Shift & Alt, if any */
    private List<Key> mModifierKeys;
    
    Width of the screen available to fit the keyboard /** Width of the screen available to fit the keyboard */
    private int mDisplayWidth;

    Height of the screen /** Height of the screen */
    private int mDisplayHeight;

    Keyboard mode, or zero, if none.  /** Keyboard mode, or zero, if none.  */
    private int mKeyboardMode;

    // Variables for pre-computing nearest keys.
    
    private static final int GRID_WIDTH = 10;
    private static final int GRID_HEIGHT = 5;
    private static final int GRID_SIZE = GRID_WIDTH * GRID_HEIGHT;
    private int mCellWidth;
    private int mCellHeight;
    private int[][] mGridNeighbors;
    private int mProximityThreshold;
    Number of key widths from current touch point to search for nearest keys. /** Number of key widths from current touch point to search for nearest keys. */
    private static float SEARCH_DISTANCE = 1.8f;

    private ArrayList<Row> rows = new ArrayList<Row>();

    Container for keys in the keyboard. All keys in a row are at the same Y-coordinate. Some of the key size defaults can be overridden per row from what the Keyboard defines. 
@attr ref android.R.styleable#Keyboard_keyWidth
@attr ref android.R.styleable#Keyboard_keyHeight
@attr ref android.R.styleable#Keyboard_horizontalGap
@attr ref android.R.styleable#Keyboard_verticalGap
@attr ref android.R.styleable#Keyboard_Row_rowEdgeFlags
@attr ref android.R.styleable#Keyboard_Row_keyboardMode/**
     * Container for keys in the keyboard. All keys in a row are at the same Y-coordinate. 
     * Some of the key size defaults can be overridden per row from what the {@link Keyboard}
     * defines. 
     * @attr ref android.R.styleable#Keyboard_keyWidth
     * @attr ref android.R.styleable#Keyboard_keyHeight
     * @attr ref android.R.styleable#Keyboard_horizontalGap
     * @attr ref android.R.styleable#Keyboard_verticalGap
     * @attr ref android.R.styleable#Keyboard_Row_rowEdgeFlags
     * @attr ref android.R.styleable#Keyboard_Row_keyboardMode
     */
    public static class Row {
        Default width of a key in this row. /** Default width of a key in this row. */
        public int defaultWidth;
        Default height of a key in this row. /** Default height of a key in this row. */
        public int defaultHeight;
        Default horizontal gap between keys in this row. /** Default horizontal gap between keys in this row. */
        public int defaultHorizontalGap;
        Vertical gap following this row. /** Vertical gap following this row. */
        public int verticalGap;

        ArrayList<Key> mKeys = new ArrayList<Key>();

        Edge flags for this row of keys. Possible values that can be assigned are EDGE_TOP and EDGE_BOTTOM /**
         * Edge flags for this row of keys. Possible values that can be assigned are
         * {@link Keyboard#EDGE_TOP EDGE_TOP} and {@link Keyboard#EDGE_BOTTOM EDGE_BOTTOM}  
         */
        public int rowEdgeFlags;
        
        The keyboard mode for this row /** The keyboard mode for this row */
        public int mode;
        
        private Keyboard parent;

        public Row(Keyboard parent) {
            this.parent = parent;
        }
        
        public Row(Resources res, Keyboard parent, XmlResourceParser parser) {
            this.parent = parent;
            TypedArray a = res.obtainAttributes(Xml.asAttributeSet(parser), 
                    com.android.internal.R.styleable.Keyboard);
            defaultWidth = getDimensionOrFraction(a, 
                    com.android.internal.R.styleable.Keyboard_keyWidth, 
                    parent.mDisplayWidth, parent.mDefaultWidth);
            defaultHeight = getDimensionOrFraction(a, 
                    com.android.internal.R.styleable.Keyboard_keyHeight, 
                    parent.mDisplayHeight, parent.mDefaultHeight);
            defaultHorizontalGap = getDimensionOrFraction(a,
                    com.android.internal.R.styleable.Keyboard_horizontalGap, 
                    parent.mDisplayWidth, parent.mDefaultHorizontalGap);
            verticalGap = getDimensionOrFraction(a, 
                    com.android.internal.R.styleable.Keyboard_verticalGap, 
                    parent.mDisplayHeight, parent.mDefaultVerticalGap);
            a.recycle();
            a = res.obtainAttributes(Xml.asAttributeSet(parser),
                    com.android.internal.R.styleable.Keyboard_Row);
            rowEdgeFlags = a.getInt(com.android.internal.R.styleable.Keyboard_Row_rowEdgeFlags, 0);
            mode = a.getResourceId(com.android.internal.R.styleable.Keyboard_Row_keyboardMode,
                    0);
        }
    }

    Class for describing the position and characteristics of a single key in the keyboard.
@attr ref android.R.styleable#Keyboard_keyWidth
@attr ref android.R.styleable#Keyboard_keyHeight
@attr ref android.R.styleable#Keyboard_horizontalGap
@attr ref android.R.styleable#Keyboard_Key_codes
@attr ref android.R.styleable#Keyboard_Key_keyIcon
@attr ref android.R.styleable#Keyboard_Key_keyLabel
@attr ref android.R.styleable#Keyboard_Key_iconPreview
@attr ref android.R.styleable#Keyboard_Key_isSticky
@attr ref android.R.styleable#Keyboard_Key_isRepeatable
@attr ref android.R.styleable#Keyboard_Key_isModifier
@attr ref android.R.styleable#Keyboard_Key_popupKeyboard
@attr ref android.R.styleable#Keyboard_Key_popupCharacters
@attr ref android.R.styleable#Keyboard_Key_keyOutputText
@attr ref android.R.styleable#Keyboard_Key_keyEdgeFlags/**
     * Class for describing the position and characteristics of a single key in the keyboard.
     * 
     * @attr ref android.R.styleable#Keyboard_keyWidth
     * @attr ref android.R.styleable#Keyboard_keyHeight
     * @attr ref android.R.styleable#Keyboard_horizontalGap
     * @attr ref android.R.styleable#Keyboard_Key_codes
     * @attr ref android.R.styleable#Keyboard_Key_keyIcon
     * @attr ref android.R.styleable#Keyboard_Key_keyLabel
     * @attr ref android.R.styleable#Keyboard_Key_iconPreview
     * @attr ref android.R.styleable#Keyboard_Key_isSticky
     * @attr ref android.R.styleable#Keyboard_Key_isRepeatable
     * @attr ref android.R.styleable#Keyboard_Key_isModifier
     * @attr ref android.R.styleable#Keyboard_Key_popupKeyboard
     * @attr ref android.R.styleable#Keyboard_Key_popupCharacters
     * @attr ref android.R.styleable#Keyboard_Key_keyOutputText
     * @attr ref android.R.styleable#Keyboard_Key_keyEdgeFlags
     */
    public static class Key {
        All the key codes (unicode or custom code) that this key could generate, zero'th 
being the most important.
/** 
         * All the key codes (unicode or custom code) that this key could generate, zero'th 
         * being the most important.
         */
        public int[] codes;
        
        Label to display /** Label to display */
        public CharSequence label;
        
        Icon to display instead of a label. Icon takes precedence over a label /** Icon to display instead of a label. Icon takes precedence over a label */
        public Drawable icon;
        Preview version of the icon, for the preview popup /** Preview version of the icon, for the preview popup */
        public Drawable iconPreview;
        Width of the key, not including the gap /** Width of the key, not including the gap */
        public int width;
        Height of the key, not including the gap /** Height of the key, not including the gap */
        public int height;
        The horizontal gap before this key /** The horizontal gap before this key */
        public int gap;
        Whether this key is sticky, i.e., a toggle key /** Whether this key is sticky, i.e., a toggle key */
        public boolean sticky;
        X coordinate of the key in the keyboard layout /** X coordinate of the key in the keyboard layout */
        public int x;
        Y coordinate of the key in the keyboard layout /** Y coordinate of the key in the keyboard layout */
        public int y;
        The current pressed state of this key /** The current pressed state of this key */
        public boolean pressed;
        If this is a sticky key, is it on? /** If this is a sticky key, is it on? */
        public boolean on;
        Text to output when pressed. This can be multiple characters, like ".com" /** Text to output when pressed. This can be multiple characters, like ".com" */
        public CharSequence text;
        Popup characters /** Popup characters */
        public CharSequence popupCharacters;

        Flags that specify the anchoring to edges of the keyboard for detecting touch events that are just out of the boundary of the key. This is a bit mask of Keyboard.EDGE_LEFT, Keyboard.EDGE_RIGHT, Keyboard.EDGE_TOP and Keyboard.EDGE_BOTTOM. /** 
         * Flags that specify the anchoring to edges of the keyboard for detecting touch events
         * that are just out of the boundary of the key. This is a bit mask of 
         * {@link Keyboard#EDGE_LEFT}, {@link Keyboard#EDGE_RIGHT}, {@link Keyboard#EDGE_TOP} and
         * {@link Keyboard#EDGE_BOTTOM}.
         */
        public int edgeFlags;
        Whether this is a modifier key, such as Shift or Alt /** Whether this is a modifier key, such as Shift or Alt */
        public boolean modifier;
        The keyboard that this key belongs to /** The keyboard that this key belongs to */
        private Keyboard keyboard;
        If this key pops up a mini keyboard, this is the resource id for the XML layout for that
keyboard.
/** 
         * If this key pops up a mini keyboard, this is the resource id for the XML layout for that
         * keyboard.
         */
        public int popupResId;
        Whether this key repeats itself when held down /** Whether this key repeats itself when held down */
        public boolean repeatable;

        
        private final static int[] KEY_STATE_NORMAL_ON = { 
            android.R.attr.state_checkable, 
            android.R.attr.state_checked
        };
        
        private final static int[] KEY_STATE_PRESSED_ON = { 
            android.R.attr.state_pressed, 
            android.R.attr.state_checkable, 
            android.R.attr.state_checked 
        };
        
        private final static int[] KEY_STATE_NORMAL_OFF = { 
            android.R.attr.state_checkable 
        };
        
        private final static int[] KEY_STATE_PRESSED_OFF = { 
            android.R.attr.state_pressed, 
            android.R.attr.state_checkable 
        };
        
        private final static int[] KEY_STATE_NORMAL = {
        };
        
        private final static int[] KEY_STATE_PRESSED = {
            android.R.attr.state_pressed
        };

        Create an empty key with no attributes. /** Create an empty key with no attributes. */
        public Key(Row parent) {
            keyboard = parent.parent;
            height = parent.defaultHeight;
            width = parent.defaultWidth;
            gap = parent.defaultHorizontalGap;
            edgeFlags = parent.rowEdgeFlags;
        }
        
        Create a key with the given top-left coordinate and extract its attributes from
the XML parser.
Params: res – resources associated with the caller's context
parent – the row that this key belongs to. The row must already be attached to a Keyboard.
x – the x coordinate of the top-left
y – the y coordinate of the top-left
parser – the XML parser containing the attributes for this key/** Create a key with the given top-left coordinate and extract its attributes from
         * the XML parser.
         * @param res resources associated with the caller's context
         * @param parent the row that this key belongs to. The row must already be attached to
         * a {@link Keyboard}.
         * @param x the x coordinate of the top-left
         * @param y the y coordinate of the top-left
         * @param parser the XML parser containing the attributes for this key
         */
        public Key(Resources res, Row parent, int x, int y, XmlResourceParser parser) {
            this(parent);

            this.x = x;
            this.y = y;
            
            TypedArray a = res.obtainAttributes(Xml.asAttributeSet(parser), 
                    com.android.internal.R.styleable.Keyboard);

            width = getDimensionOrFraction(a, 
                    com.android.internal.R.styleable.Keyboard_keyWidth,
                    keyboard.mDisplayWidth, parent.defaultWidth);
            height = getDimensionOrFraction(a, 
                    com.android.internal.R.styleable.Keyboard_keyHeight,
                    keyboard.mDisplayHeight, parent.defaultHeight);
            gap = getDimensionOrFraction(a, 
                    com.android.internal.R.styleable.Keyboard_horizontalGap,
                    keyboard.mDisplayWidth, parent.defaultHorizontalGap);
            a.recycle();
            a = res.obtainAttributes(Xml.asAttributeSet(parser),
                    com.android.internal.R.styleable.Keyboard_Key);
            this.x += gap;
            TypedValue codesValue = new TypedValue();
            a.getValue(com.android.internal.R.styleable.Keyboard_Key_codes, 
                    codesValue);
            if (codesValue.type == TypedValue.TYPE_INT_DEC 
                    || codesValue.type == TypedValue.TYPE_INT_HEX) {
                codes = new int[] { codesValue.data };
            } else if (codesValue.type == TypedValue.TYPE_STRING) {
                codes = parseCSV(codesValue.string.toString());
            }
            
            iconPreview = a.getDrawable(com.android.internal.R.styleable.Keyboard_Key_iconPreview);
            if (iconPreview != null) {
                iconPreview.setBounds(0, 0, iconPreview.getIntrinsicWidth(), 
                        iconPreview.getIntrinsicHeight());
            }
            popupCharacters = a.getText(
                    com.android.internal.R.styleable.Keyboard_Key_popupCharacters);
            popupResId = a.getResourceId(
                    com.android.internal.R.styleable.Keyboard_Key_popupKeyboard, 0);
            repeatable = a.getBoolean(
                    com.android.internal.R.styleable.Keyboard_Key_isRepeatable, false);
            modifier = a.getBoolean(
                    com.android.internal.R.styleable.Keyboard_Key_isModifier, false);
            sticky = a.getBoolean(
                    com.android.internal.R.styleable.Keyboard_Key_isSticky, false);
            edgeFlags = a.getInt(com.android.internal.R.styleable.Keyboard_Key_keyEdgeFlags, 0);
            edgeFlags |= parent.rowEdgeFlags;

            icon = a.getDrawable(
                    com.android.internal.R.styleable.Keyboard_Key_keyIcon);
            if (icon != null) {
                icon.setBounds(0, 0, icon.getIntrinsicWidth(), icon.getIntrinsicHeight());
            }
            label = a.getText(com.android.internal.R.styleable.Keyboard_Key_keyLabel);
            text = a.getText(com.android.internal.R.styleable.Keyboard_Key_keyOutputText);
            
            if (codes == null && !TextUtils.isEmpty(label)) {
                codes = new int[] { label.charAt(0) };
            }
            a.recycle();
        }
        
        Informs the key that it has been pressed, in case it needs to change its appearance or
state.
See Also: onReleased(boolean)/**
         * Informs the key that it has been pressed, in case it needs to change its appearance or
         * state.
         * @see #onReleased(boolean)
         */
        public void onPressed() {
            pressed = !pressed;
        }

        Changes the pressed state of the key.
Toggled state of the key will be flipped when all the following conditions are
fulfilled:

    This is a sticky key, that is, sticky is true. 
The parameter inside is true. 
VERSION.SDK_INT is greater than VERSION_CODES.LOLLIPOP_MR1. 
Params: inside – whether the finger was released inside the key. Works only on Android M and
later. See the method document for details.
See Also: onPressed()/**
         * Changes the pressed state of the key.
         *
         * <p>Toggled state of the key will be flipped when all the following conditions are
         * fulfilled:</p>
         *
         * <ul>
         *     <li>This is a sticky key, that is, {@link #sticky} is {@code true}.
         *     <li>The parameter {@code inside} is {@code true}.
         *     <li>{@link android.os.Build.VERSION#SDK_INT} is greater than
         *         {@link android.os.Build.VERSION_CODES#LOLLIPOP_MR1}.
         * </ul>
         *
         * @param inside whether the finger was released inside the key. Works only on Android M and
         * later. See the method document for details.
         * @see #onPressed()
         */
        public void onReleased(boolean inside) {
            pressed = !pressed;
            if (sticky && inside) {
                on = !on;
            }
        }

        int[] parseCSV(String value) {
            int count = 0;
            int lastIndex = 0;
            if (value.length() > 0) {
                count++;
                while ((lastIndex = value.indexOf(",", lastIndex + 1)) > 0) {
                    count++;
                }
            }
            int[] values = new int[count];
            count = 0;
            StringTokenizer st = new StringTokenizer(value, ",");
            while (st.hasMoreTokens()) {
                try {
                    values[count++] = Integer.parseInt(st.nextToken());
                } catch (NumberFormatException nfe) {
                    Log.e(TAG, "Error parsing keycodes " + value);
                }
            }
            return values;
        }

        Detects if a point falls inside this key.
Params: x – the x-coordinate of the point
y – the y-coordinate of the point
Returns: whether or not the point falls inside the key. If the key is attached to an edge,
it will assume that all points between the key and the edge are considered to be inside
the key./**
         * Detects if a point falls inside this key.
         * @param x the x-coordinate of the point 
         * @param y the y-coordinate of the point
         * @return whether or not the point falls inside the key. If the key is attached to an edge,
         * it will assume that all points between the key and the edge are considered to be inside
         * the key.
         */
        public boolean isInside(int x, int y) {
            boolean leftEdge = (edgeFlags & EDGE_LEFT) > 0;
            boolean rightEdge = (edgeFlags & EDGE_RIGHT) > 0;
            boolean topEdge = (edgeFlags & EDGE_TOP) > 0;
            boolean bottomEdge = (edgeFlags & EDGE_BOTTOM) > 0;
            if ((x >= this.x || (leftEdge && x <= this.x + this.width)) 
                    && (x < this.x + this.width || (rightEdge && x >= this.x)) 
                    && (y >= this.y || (topEdge && y <= this.y + this.height))
                    && (y < this.y + this.height || (bottomEdge && y >= this.y))) {
                return true;
            } else {
                return false;
            }
        }

        Returns the square of the distance between the center of the key and the given point.
Params: x – the x-coordinate of the point
y – the y-coordinate of the point
Returns: the square of the distance of the point from the center of the key/**
         * Returns the square of the distance between the center of the key and the given point.
         * @param x the x-coordinate of the point
         * @param y the y-coordinate of the point
         * @return the square of the distance of the point from the center of the key
         */
        public int squaredDistanceFrom(int x, int y) {
            int xDist = this.x + width / 2 - x;
            int yDist = this.y + height / 2 - y;
            return xDist * xDist + yDist * yDist;
        }
        
        Returns the drawable state for the key, based on the current state and type of the key.
See Also: Drawable.setState(int[])
Returns: the drawable state of the key./**
         * Returns the drawable state for the key, based on the current state and type of the key.
         * @return the drawable state of the key.
         * @see android.graphics.drawable.StateListDrawable#setState(int[])
         */
        public int[] getCurrentDrawableState() {
            int[] states = KEY_STATE_NORMAL;

            if (on) {
                if (pressed) {
                    states = KEY_STATE_PRESSED_ON;
                } else {
                    states = KEY_STATE_NORMAL_ON;
                }
            } else {
                if (sticky) {
                    if (pressed) {
                        states = KEY_STATE_PRESSED_OFF;
                    } else {
                        states = KEY_STATE_NORMAL_OFF;
                    }
                } else {
                    if (pressed) {
                        states = KEY_STATE_PRESSED;
                    }
                }
            }
            return states;
        }
    }

    Creates a keyboard from the given xml key layout file.
Params: context – the application or service context
xmlLayoutResId – the resource file that contains the keyboard layout and keys./**
     * Creates a keyboard from the given xml key layout file.
     * @param context the application or service context
     * @param xmlLayoutResId the resource file that contains the keyboard layout and keys.
     */
    public Keyboard(Context context, int xmlLayoutResId) {
        this(context, xmlLayoutResId, 0);
    }

    Creates a keyboard from the given xml key layout file. Weeds out rows
that have a keyboard mode defined but don't match the specified mode.
Params: context – the application or service context
xmlLayoutResId – the resource file that contains the keyboard layout and keys.
modeId – keyboard mode identifier
width – sets width of keyboard
height – sets height of keyboard/**
     * Creates a keyboard from the given xml key layout file. Weeds out rows
     * that have a keyboard mode defined but don't match the specified mode.
     * @param context the application or service context
     * @param xmlLayoutResId the resource file that contains the keyboard layout and keys.
     * @param modeId keyboard mode identifier
     * @param width sets width of keyboard
     * @param height sets height of keyboard
     */
    public Keyboard(Context context, @XmlRes int xmlLayoutResId, int modeId, int width,
            int height) {
        mDisplayWidth = width;
        mDisplayHeight = height;

        mDefaultHorizontalGap = 0;
        mDefaultWidth = mDisplayWidth / 10;
        mDefaultVerticalGap = 0;
        mDefaultHeight = mDefaultWidth;
        mKeys = new ArrayList<Key>();
        mModifierKeys = new ArrayList<Key>();
        mKeyboardMode = modeId;
        loadKeyboard(context, context.getResources().getXml(xmlLayoutResId));
    }

    Creates a keyboard from the given xml key layout file. Weeds out rows
that have a keyboard mode defined but don't match the specified mode. 
Params: context – the application or service context
xmlLayoutResId – the resource file that contains the keyboard layout and keys.
modeId – keyboard mode identifier/**
     * Creates a keyboard from the given xml key layout file. Weeds out rows
     * that have a keyboard mode defined but don't match the specified mode. 
     * @param context the application or service context
     * @param xmlLayoutResId the resource file that contains the keyboard layout and keys.
     * @param modeId keyboard mode identifier
     */
    public Keyboard(Context context, @XmlRes int xmlLayoutResId, int modeId) {
        DisplayMetrics dm = context.getResources().getDisplayMetrics();
        mDisplayWidth = dm.widthPixels;
        mDisplayHeight = dm.heightPixels;
        //Log.v(TAG, "keyboard's display metrics:" + dm);

        mDefaultHorizontalGap = 0;
        mDefaultWidth = mDisplayWidth / 10;
        mDefaultVerticalGap = 0;
        mDefaultHeight = mDefaultWidth;
        mKeys = new ArrayList<Key>();
        mModifierKeys = new ArrayList<Key>();
        mKeyboardMode = modeId;
        loadKeyboard(context, context.getResources().getXml(xmlLayoutResId));
    }

    Creates a blank keyboard from the given resource file and populates it with the specified
characters in left-to-right, top-to-bottom fashion, using the specified number of columns.

If the specified number of columns is -1, then the keyboard will fit as many keys as
possible in each row.
Params: context – the application or service context
layoutTemplateResId – the layout template file, containing no keys.
characters – the list of characters to display on the keyboard. One key will be created
for each character.
columns – the number of columns of keys to display. If this number is greater than the 
number of keys that can fit in a row, it will be ignored. If this number is -1, the 
keyboard will fit as many keys as possible in each row./**
     * <p>Creates a blank keyboard from the given resource file and populates it with the specified
     * characters in left-to-right, top-to-bottom fashion, using the specified number of columns.
     * </p>
     * <p>If the specified number of columns is -1, then the keyboard will fit as many keys as
     * possible in each row.</p>
     * @param context the application or service context
     * @param layoutTemplateResId the layout template file, containing no keys.
     * @param characters the list of characters to display on the keyboard. One key will be created
     * for each character.
     * @param columns the number of columns of keys to display. If this number is greater than the 
     * number of keys that can fit in a row, it will be ignored. If this number is -1, the 
     * keyboard will fit as many keys as possible in each row.
     */
    public Keyboard(Context context, int layoutTemplateResId, 
            CharSequence characters, int columns, int horizontalPadding) {
        this(context, layoutTemplateResId);
        int x = 0;
        int y = 0;
        int column = 0;
        mTotalWidth = 0;
        
        Row row = new Row(this);
        row.defaultHeight = mDefaultHeight;
        row.defaultWidth = mDefaultWidth;
        row.defaultHorizontalGap = mDefaultHorizontalGap;
        row.verticalGap = mDefaultVerticalGap;
        row.rowEdgeFlags = EDGE_TOP | EDGE_BOTTOM;
        final int maxColumns = columns == -1 ? Integer.MAX_VALUE : columns;
        for (int i = 0; i < characters.length(); i++) {
            char c = characters.charAt(i);
            if (column >= maxColumns 
                    || x + mDefaultWidth + horizontalPadding > mDisplayWidth) {
                x = 0;
                y += mDefaultVerticalGap + mDefaultHeight;
                column = 0;
            }
            final Key key = new Key(row);
            key.x = x;
            key.y = y;
            key.label = String.valueOf(c);
            key.codes = new int[] { c };
            column++;
            x += key.width + key.gap;
            mKeys.add(key);
            row.mKeys.add(key);
            if (x > mTotalWidth) {
                mTotalWidth = x;
            }
        }
        mTotalHeight = y + mDefaultHeight;
        rows.add(row);
    }

    final void resize(int newWidth, int newHeight) {
        int numRows = rows.size();
        for (int rowIndex = 0; rowIndex < numRows; ++rowIndex) {
            Row row = rows.get(rowIndex);
            int numKeys = row.mKeys.size();
            int totalGap = 0;
            int totalWidth = 0;
            for (int keyIndex = 0; keyIndex < numKeys; ++keyIndex) {
                Key key = row.mKeys.get(keyIndex);
                if (keyIndex > 0) {
                    totalGap += key.gap;
                }
                totalWidth += key.width;
            }
            if (totalGap + totalWidth > newWidth) {
                int x = 0;
                float scaleFactor = (float)(newWidth - totalGap) / totalWidth;
                for (int keyIndex = 0; keyIndex < numKeys; ++keyIndex) {
                    Key key = row.mKeys.get(keyIndex);
                    key.width *= scaleFactor;
                    key.x = x;
                    x += key.width + key.gap;
                }
            }
        }
        mTotalWidth = newWidth;
        // TODO: This does not adjust the vertical placement according to the new size.
        // The main problem in the previous code was horizontal placement/size, but we should
        // also recalculate the vertical sizes/positions when we get this resize call.
    }
    
    public List<Key> getKeys() {
        return mKeys;
    }
    
    public List<Key> getModifierKeys() {
        return mModifierKeys;
    }
    
    protected int getHorizontalGap() {
        return mDefaultHorizontalGap;
    }
    
    protected void setHorizontalGap(int gap) {
        mDefaultHorizontalGap = gap;
    }

    protected int getVerticalGap() {
        return mDefaultVerticalGap;
    }

    protected void setVerticalGap(int gap) {
        mDefaultVerticalGap = gap;
    }

    protected int getKeyHeight() {
        return mDefaultHeight;
    }

    protected void setKeyHeight(int height) {
        mDefaultHeight = height;
    }

    protected int getKeyWidth() {
        return mDefaultWidth;
    }
    
    protected void setKeyWidth(int width) {
        mDefaultWidth = width;
    }

    Returns the total height of the keyboard
Returns: the total height of the keyboard/**
     * Returns the total height of the keyboard
     * @return the total height of the keyboard
     */
    public int getHeight() {
        return mTotalHeight;
    }
    
    public int getMinWidth() {
        return mTotalWidth;
    }

    public boolean setShifted(boolean shiftState) {
        for (Key shiftKey : mShiftKeys) {
            if (shiftKey != null) {
                shiftKey.on = shiftState;
            }
        }
        if (mShifted != shiftState) {
            mShifted = shiftState;
            return true;
        }
        return false;
    }

    public boolean isShifted() {
        return mShifted;
    }

    @hide /**
     * @hide
     */
    public int[] getShiftKeyIndices() {
        return mShiftKeyIndices;
    }

    public int getShiftKeyIndex() {
        return mShiftKeyIndices[0];
    }
    
    private void computeNearestNeighbors() {
        // Round-up so we don't have any pixels outside the grid
        mCellWidth = (getMinWidth() + GRID_WIDTH - 1) / GRID_WIDTH;
        mCellHeight = (getHeight() + GRID_HEIGHT - 1) / GRID_HEIGHT;
        mGridNeighbors = new int[GRID_SIZE][];
        int[] indices = new int[mKeys.size()];
        final int gridWidth = GRID_WIDTH * mCellWidth;
        final int gridHeight = GRID_HEIGHT * mCellHeight;
        for (int x = 0; x < gridWidth; x += mCellWidth) {
            for (int y = 0; y < gridHeight; y += mCellHeight) {
                int count = 0;
                for (int i = 0; i < mKeys.size(); i++) {
                    final Key key = mKeys.get(i);
                    if (key.squaredDistanceFrom(x, y) < mProximityThreshold ||
                            key.squaredDistanceFrom(x + mCellWidth - 1, y) < mProximityThreshold ||
                            key.squaredDistanceFrom(x + mCellWidth - 1, y + mCellHeight - 1) 
                                < mProximityThreshold ||
                            key.squaredDistanceFrom(x, y + mCellHeight - 1) < mProximityThreshold) {
                        indices[count++] = i;
                    }
                }
                int [] cell = new int[count];
                System.arraycopy(indices, 0, cell, 0, count);
                mGridNeighbors[(y / mCellHeight) * GRID_WIDTH + (x / mCellWidth)] = cell;
            }
        }
    }
    
    Returns the indices of the keys that are closest to the given point.
Params: x – the x-coordinate of the point
y – the y-coordinate of the point
Returns: the array of integer indices for the nearest keys to the given point. If the given
point is out of range, then an array of size zero is returned./**
     * Returns the indices of the keys that are closest to the given point.
     * @param x the x-coordinate of the point
     * @param y the y-coordinate of the point
     * @return the array of integer indices for the nearest keys to the given point. If the given
     * point is out of range, then an array of size zero is returned.
     */
    public int[] getNearestKeys(int x, int y) {
        if (mGridNeighbors == null) computeNearestNeighbors();
        if (x >= 0 && x < getMinWidth() && y >= 0 && y < getHeight()) {
            int index = (y / mCellHeight) * GRID_WIDTH + (x / mCellWidth);
            if (index < GRID_SIZE) {
                return mGridNeighbors[index];
            }
        }
        return new int[0];
    }

    protected Row createRowFromXml(Resources res, XmlResourceParser parser) {
        return new Row(res, this, parser);
    }
    
    protected Key createKeyFromXml(Resources res, Row parent, int x, int y, 
            XmlResourceParser parser) {
        return new Key(res, parent, x, y, parser);
    }

    private void loadKeyboard(Context context, XmlResourceParser parser) {
        boolean inKey = false;
        boolean inRow = false;
        boolean leftMostKey = false;
        int row = 0;
        int x = 0;
        int y = 0;
        Key key = null;
        Row currentRow = null;
        Resources res = context.getResources();
        boolean skipRow = false;

        try {
            int event;
            while ((event = parser.next()) != XmlResourceParser.END_DOCUMENT) {
                if (event == XmlResourceParser.START_TAG) {
                    String tag = parser.getName();
                    if (TAG_ROW.equals(tag)) {
                        inRow = true;
                        x = 0;
                        currentRow = createRowFromXml(res, parser);
                        rows.add(currentRow);
                        skipRow = currentRow.mode != 0 && currentRow.mode != mKeyboardMode;
                        if (skipRow) {
                            skipToEndOfRow(parser);
                            inRow = false;
                        }
                   } else if (TAG_KEY.equals(tag)) {
                        inKey = true;
                        key = createKeyFromXml(res, currentRow, x, y, parser);
                        mKeys.add(key);
                        if (key.codes[0] == KEYCODE_SHIFT) {
                            // Find available shift key slot and put this shift key in it
                            for (int i = 0; i < mShiftKeys.length; i++) {
                                if (mShiftKeys[i] == null) {
                                    mShiftKeys[i] = key;
                                    mShiftKeyIndices[i] = mKeys.size()-1;
                                    break;
                                }
                            }
                            mModifierKeys.add(key);
                        } else if (key.codes[0] == KEYCODE_ALT) {
                            mModifierKeys.add(key);
                        }
                        currentRow.mKeys.add(key);
                    } else if (TAG_KEYBOARD.equals(tag)) {
                        parseKeyboardAttributes(res, parser);
                    }
                } else if (event == XmlResourceParser.END_TAG) {
                    if (inKey) {
                        inKey = false;
                        x += key.gap + key.width;
                        if (x > mTotalWidth) {
                            mTotalWidth = x;
                        }
                    } else if (inRow) {
                        inRow = false;
                        y += currentRow.verticalGap;
                        y += currentRow.defaultHeight;
                        row++;
                    } else {
                        // TODO: error or extend?
                    }
                }
            }
        } catch (Exception e) {
            Log.e(TAG, "Parse error:" + e);
            e.printStackTrace();
        }
        mTotalHeight = y - mDefaultVerticalGap;
    }

    private void skipToEndOfRow(XmlResourceParser parser) 
            throws XmlPullParserException, IOException {
        int event;
        while ((event = parser.next()) != XmlResourceParser.END_DOCUMENT) {
            if (event == XmlResourceParser.END_TAG 
                    && parser.getName().equals(TAG_ROW)) {
                break;
            }
        }
    }
    
    private void parseKeyboardAttributes(Resources res, XmlResourceParser parser) {
        TypedArray a = res.obtainAttributes(Xml.asAttributeSet(parser), 
                com.android.internal.R.styleable.Keyboard);

        mDefaultWidth = getDimensionOrFraction(a,
                com.android.internal.R.styleable.Keyboard_keyWidth,
                mDisplayWidth, mDisplayWidth / 10);
        mDefaultHeight = getDimensionOrFraction(a,
                com.android.internal.R.styleable.Keyboard_keyHeight,
                mDisplayHeight, 50);
        mDefaultHorizontalGap = getDimensionOrFraction(a,
                com.android.internal.R.styleable.Keyboard_horizontalGap,
                mDisplayWidth, 0);
        mDefaultVerticalGap = getDimensionOrFraction(a,
                com.android.internal.R.styleable.Keyboard_verticalGap,
                mDisplayHeight, 0);
        mProximityThreshold = (int) (mDefaultWidth * SEARCH_DISTANCE);
        mProximityThreshold = mProximityThreshold * mProximityThreshold; // Square it for comparison
        a.recycle();
    }
    
    static int getDimensionOrFraction(TypedArray a, int index, int base, int defValue) {
        TypedValue value = a.peekValue(index);
        if (value == null) return defValue;
        if (value.type == TypedValue.TYPE_DIMENSION) {
            return a.getDimensionPixelOffset(index, defValue);
        } else if (value.type == TypedValue.TYPE_FRACTION) {
            // Round it to avoid values like 47.9999 from getting truncated
            return Math.round(a.getFraction(index, base, base, defValue));
        }
        return defValue;
    }
}
@attr	ref android.R.styleable#Keyboard_keyWidth
@attr	ref android.R.styleable#Keyboard_keyHeight
@attr	ref android.R.styleable#Keyboard_horizontalGap
@attr	ref android.R.styleable#Keyboard_verticalGap
Params:	inside – whether the finger was released inside the key. Works only on Android M and later. See the method document for details.
See Also:	onPressed()
Params:	x – the x-coordinate of the point y – the y-coordinate of the point
Returns:	whether or not the point falls inside the key. If the key is attached to an edge, it will assume that all points between the key and the edge are considered to be inside the key.
See Also:	Drawable.setState(int[])
Returns:	the drawable state of the key.
/

android/ android-9.0.0_r35/ android/inputmethodservice/Keyboard.java
