/*
 * 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.widget;

import android.content.Context;
import android.content.res.TypedArray;
import android.database.DataSetObserver;
import android.graphics.Rect;
import android.os.Parcel;
import android.os.Parcelable;
import android.util.AttributeSet;
import android.util.Log;
import android.util.SparseArray;
import android.view.View;
import android.view.ViewGroup;
import android.view.autofill.AutofillValue;

import com.android.internal.R;

An abstract base class for spinner widgets. SDK users will probably not
need to use this class.
@attr
ref android.R.styleable#AbsSpinner_entries/**
 * An abstract base class for spinner widgets. SDK users will probably not
 * need to use this class.
 *
 * @attr ref android.R.styleable#AbsSpinner_entries
 */
public abstract class AbsSpinner extends AdapterView<SpinnerAdapter> {
    private static final String LOG_TAG = AbsSpinner.class.getSimpleName();

    SpinnerAdapter mAdapter;

    int mHeightMeasureSpec;
    int mWidthMeasureSpec;

    int mSelectionLeftPadding = 0;
    int mSelectionTopPadding = 0;
    int mSelectionRightPadding = 0;
    int mSelectionBottomPadding = 0;
    final Rect mSpinnerPadding = new Rect();

    final RecycleBin mRecycler = new RecycleBin();
    private DataSetObserver mDataSetObserver;

    
Temporary frame to hold a child View's frame rectangle /** Temporary frame to hold a child View's frame rectangle */
    private Rect mTouchFrame;

    public AbsSpinner(Context context) {
        super(context);
        initAbsSpinner();
    }

    public AbsSpinner(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public AbsSpinner(Context context, AttributeSet attrs, int defStyleAttr) {
        this(context, attrs, defStyleAttr, 0);
    }

    public AbsSpinner(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);

        // Spinner is important by default, unless app developer overrode attribute.
        if (getImportantForAutofill() == IMPORTANT_FOR_AUTOFILL_AUTO) {
            setImportantForAutofill(IMPORTANT_FOR_AUTOFILL_YES);
        }

        initAbsSpinner();

        final TypedArray a = context.obtainStyledAttributes(
                attrs, R.styleable.AbsSpinner, defStyleAttr, defStyleRes);

        final CharSequence[] entries = a.getTextArray(R.styleable.AbsSpinner_entries);
        if (entries != null) {
            final ArrayAdapter<CharSequence> adapter = new ArrayAdapter<CharSequence>(
                    context, R.layout.simple_spinner_item, entries);
            adapter.setDropDownViewResource(R.layout.simple_spinner_dropdown_item);
            setAdapter(adapter);
        }

        a.recycle();
    }

    
Common code for different constructor flavors
/**
     * Common code for different constructor flavors
     */
    private void initAbsSpinner() {
        setFocusable(true);
        setWillNotDraw(false);
    }

    
The Adapter is used to provide the data which backs this Spinner.
It also provides methods to transform spinner items based on their position
relative to the selected item.
Params:
adapter – The SpinnerAdapter to use for this Spinner/**
     * The Adapter is used to provide the data which backs this Spinner.
     * It also provides methods to transform spinner items based on their position
     * relative to the selected item.
     * @param adapter The SpinnerAdapter to use for this Spinner
     */
    @Override
    public void setAdapter(SpinnerAdapter adapter) {
        if (null != mAdapter) {
            mAdapter.unregisterDataSetObserver(mDataSetObserver);
            resetList();
        }

        mAdapter = adapter;

        mOldSelectedPosition = INVALID_POSITION;
        mOldSelectedRowId = INVALID_ROW_ID;

        if (mAdapter != null) {
            mOldItemCount = mItemCount;
            mItemCount = mAdapter.getCount();
            checkFocus();

            mDataSetObserver = new AdapterDataSetObserver();
            mAdapter.registerDataSetObserver(mDataSetObserver);

            int position = mItemCount > 0 ? 0 : INVALID_POSITION;

            setSelectedPositionInt(position);
            setNextSelectedPositionInt(position);

            if (mItemCount == 0) {
                // Nothing selected
                checkSelectionChanged();
            }

        } else {
            checkFocus();
            resetList();
            // Nothing selected
            checkSelectionChanged();
        }

        requestLayout();
    }

    
Clear out all children from the list
/**
     * Clear out all children from the list
     */
    void resetList() {
        mDataChanged = false;
        mNeedSync = false;

        removeAllViewsInLayout();
        mOldSelectedPosition = INVALID_POSITION;
        mOldSelectedRowId = INVALID_ROW_ID;

        setSelectedPositionInt(INVALID_POSITION);
        setNextSelectedPositionInt(INVALID_POSITION);
        invalidate();
    }

    
See Also:

Figure out the dimensions of this Spinner. The width comes from
the widthMeasureSpec as Spinnners can't have their width set to
UNSPECIFIED. The height is based on the height of the selected item
plus padding./**
     * @see android.view.View#measure(int, int)
     *
     * Figure out the dimensions of this Spinner. The width comes from
     * the widthMeasureSpec as Spinnners can't have their width set to
     * UNSPECIFIED. The height is based on the height of the selected item
     * plus padding.
     */
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int widthMode = MeasureSpec.getMode(widthMeasureSpec);
        int widthSize;
        int heightSize;

        mSpinnerPadding.left = mPaddingLeft > mSelectionLeftPadding ? mPaddingLeft
                : mSelectionLeftPadding;
        mSpinnerPadding.top = mPaddingTop > mSelectionTopPadding ? mPaddingTop
                : mSelectionTopPadding;
        mSpinnerPadding.right = mPaddingRight > mSelectionRightPadding ? mPaddingRight
                : mSelectionRightPadding;
        mSpinnerPadding.bottom = mPaddingBottom > mSelectionBottomPadding ? mPaddingBottom
                : mSelectionBottomPadding;

        if (mDataChanged) {
            handleDataChanged();
        }

        int preferredHeight = 0;
        int preferredWidth = 0;
        boolean needsMeasuring = true;

        int selectedPosition = getSelectedItemPosition();
        if (selectedPosition >= 0 && mAdapter != null && selectedPosition < mAdapter.getCount()) {
            // Try looking in the recycler. (Maybe we were measured once already)
            View view = mRecycler.get(selectedPosition);
            if (view == null) {
                // Make a new one
                view = mAdapter.getView(selectedPosition, null, this);

                if (view.getImportantForAccessibility() == IMPORTANT_FOR_ACCESSIBILITY_AUTO) {
                    view.setImportantForAccessibility(IMPORTANT_FOR_ACCESSIBILITY_YES);
                }
            }

            if (view != null) {
                // Put in recycler for re-measuring and/or layout
                mRecycler.put(selectedPosition, view);

                if (view.getLayoutParams() == null) {
                    mBlockLayoutRequests = true;
                    view.setLayoutParams(generateDefaultLayoutParams());
                    mBlockLayoutRequests = false;
                }
                measureChild(view, widthMeasureSpec, heightMeasureSpec);

                preferredHeight = getChildHeight(view) + mSpinnerPadding.top + mSpinnerPadding.bottom;
                preferredWidth = getChildWidth(view) + mSpinnerPadding.left + mSpinnerPadding.right;

                needsMeasuring = false;
            }
        }

        if (needsMeasuring) {
            // No views -- just use padding
            preferredHeight = mSpinnerPadding.top + mSpinnerPadding.bottom;
            if (widthMode == MeasureSpec.UNSPECIFIED) {
                preferredWidth = mSpinnerPadding.left + mSpinnerPadding.right;
            }
        }

        preferredHeight = Math.max(preferredHeight, getSuggestedMinimumHeight());
        preferredWidth = Math.max(preferredWidth, getSuggestedMinimumWidth());

        heightSize = resolveSizeAndState(preferredHeight, heightMeasureSpec, 0);
        widthSize = resolveSizeAndState(preferredWidth, widthMeasureSpec, 0);

        setMeasuredDimension(widthSize, heightSize);
        mHeightMeasureSpec = heightMeasureSpec;
        mWidthMeasureSpec = widthMeasureSpec;
    }

    int getChildHeight(View child) {
        return child.getMeasuredHeight();
    }

    int getChildWidth(View child) {
        return child.getMeasuredWidth();
    }

    @Override
    protected ViewGroup.LayoutParams generateDefaultLayoutParams() {
        return new ViewGroup.LayoutParams(
                ViewGroup.LayoutParams.MATCH_PARENT,
                ViewGroup.LayoutParams.WRAP_CONTENT);
    }

    void recycleAllViews() {
        final int childCount = getChildCount();
        final AbsSpinner.RecycleBin recycleBin = mRecycler;
        final int position = mFirstPosition;

        // All views go in recycler
        for (int i = 0; i < childCount; i++) {
            View v = getChildAt(i);
            int index = position + i;
            recycleBin.put(index, v);
        }
    }

    
Jump directly to a specific item in the adapter data.
/**
     * Jump directly to a specific item in the adapter data.
     */
    public void setSelection(int position, boolean animate) {
        // Animate only if requested position is already on screen somewhere
        boolean shouldAnimate = animate && mFirstPosition <= position &&
                position <= mFirstPosition + getChildCount() - 1;
        setSelectionInt(position, shouldAnimate);
    }

    @Override
    public void setSelection(int position) {
        setNextSelectedPositionInt(position);
        requestLayout();
        invalidate();
    }


    
Makes the item at the supplied position selected.
Params:
position – Position to select
animate – Should the transition be animated/**
     * Makes the item at the supplied position selected.
     *
     * @param position Position to select
     * @param animate Should the transition be animated
     *
     */
    void setSelectionInt(int position, boolean animate) {
        if (position != mOldSelectedPosition) {
            mBlockLayoutRequests = true;
            int delta  = position - mSelectedPosition;
            setNextSelectedPositionInt(position);
            layout(delta, animate);
            mBlockLayoutRequests = false;
        }
    }

    abstract void layout(int delta, boolean animate);

    @Override
    public View getSelectedView() {
        if (mItemCount > 0 && mSelectedPosition >= 0) {
            return getChildAt(mSelectedPosition - mFirstPosition);
        } else {
            return null;
        }
    }

    
Override to prevent spamming ourselves with layout requests
as we place views
See Also:
requestLayout.requestLayout()/**
     * Override to prevent spamming ourselves with layout requests
     * as we place views
     *
     * @see android.view.View#requestLayout()
     */
    @Override
    public void requestLayout() {
        if (!mBlockLayoutRequests) {
            super.requestLayout();
        }
    }

    @Override
    public SpinnerAdapter getAdapter() {
        return mAdapter;
    }

    @Override
    public int getCount() {
        return mItemCount;
    }

    
Maps a point to a position in the list.
Params:
x – X in local coordinate
y – Y in local coordinate
Returns:
The position of the item which contains the specified point, or AdapterView<SpinnerAdapter>.INVALID_POSITION if the point does not intersect an item./**
     * Maps a point to a position in the list.
     *
     * @param x X in local coordinate
     * @param y Y in local coordinate
     * @return The position of the item which contains the specified point, or
     *         {@link #INVALID_POSITION} if the point does not intersect an item.
     */
    public int pointToPosition(int x, int y) {
        Rect frame = mTouchFrame;
        if (frame == null) {
            mTouchFrame = new Rect();
            frame = mTouchFrame;
        }

        final int count = getChildCount();
        for (int i = count - 1; i >= 0; i--) {
            View child = getChildAt(i);
            if (child.getVisibility() == View.VISIBLE) {
                child.getHitRect(frame);
                if (frame.contains(x, y)) {
                    return mFirstPosition + i;
                }
            }
        }
        return INVALID_POSITION;
    }

    @Override
    protected void dispatchRestoreInstanceState(SparseArray<Parcelable> container) {
        super.dispatchRestoreInstanceState(container);
        // Restores the selected position when Spinner gets restored,
        // rather than wait until the next measure/layout pass to do it.
        handleDataChanged();
    }

    static class SavedState extends BaseSavedState {
        long selectedId;
        int position;

        
Constructor called from AbsSpinner.onSaveInstanceState() /**
         * Constructor called from {@link AbsSpinner#onSaveInstanceState()}
         */
        SavedState(Parcelable superState) {
            super(superState);
        }

        
Constructor called from CREATOR /**
         * Constructor called from {@link #CREATOR}
         */
        SavedState(Parcel in) {
            super(in);
            selectedId = in.readLong();
            position = in.readInt();
        }

        @Override
        public void writeToParcel(Parcel out, int flags) {
            super.writeToParcel(out, flags);
            out.writeLong(selectedId);
            out.writeInt(position);
        }

        @Override
        public String toString() {
            return "AbsSpinner.SavedState{"
                    + Integer.toHexString(System.identityHashCode(this))
                    + " selectedId=" + selectedId
                    + " position=" + position + "}";
        }

        public static final Parcelable.Creator<SavedState> CREATOR
                = new Parcelable.Creator<SavedState>() {
            public SavedState createFromParcel(Parcel in) {
                return new SavedState(in);
            }

            public SavedState[] newArray(int size) {
                return new SavedState[size];
            }
        };
    }

    @Override
    public Parcelable onSaveInstanceState() {
        Parcelable superState = super.onSaveInstanceState();
        SavedState ss = new SavedState(superState);
        ss.selectedId = getSelectedItemId();
        if (ss.selectedId >= 0) {
            ss.position = getSelectedItemPosition();
        } else {
            ss.position = INVALID_POSITION;
        }
        return ss;
    }

    @Override
    public void onRestoreInstanceState(Parcelable state) {
        SavedState ss = (SavedState) state;

        super.onRestoreInstanceState(ss.getSuperState());

        if (ss.selectedId >= 0) {
            mDataChanged = true;
            mNeedSync = true;
            mSyncRowId = ss.selectedId;
            mSyncPosition = ss.position;
            mSyncMode = SYNC_SELECTED_POSITION;
            requestLayout();
        }
    }

    class RecycleBin {
        private final SparseArray<View> mScrapHeap = new SparseArray<View>();

        public void put(int position, View v) {
            mScrapHeap.put(position, v);
        }

        View get(int position) {
            // System.out.print("Looking for " + position);
            View result = mScrapHeap.get(position);
            if (result != null) {
                // System.out.println(" HIT");
                mScrapHeap.delete(position);
            } else {
                // System.out.println(" MISS");
            }
            return result;
        }

        void clear() {
            final SparseArray<View> scrapHeap = mScrapHeap;
            final int count = scrapHeap.size();
            for (int i = 0; i < count; i++) {
                final View view = scrapHeap.valueAt(i);
                if (view != null) {
                    removeDetachedView(view, true);
                }
            }
            scrapHeap.clear();
        }
    }

    @Override
    public CharSequence getAccessibilityClassName() {
        return AbsSpinner.class.getName();
    }

    @Override
    public void autofill(AutofillValue value) {
        if (!isEnabled()) return;

        if (!value.isList()) {
            Log.w(LOG_TAG, value + " could not be autofilled into " + this);
            return;
        }

        setSelection(value.getListValue());
    }

    @Override
    public @AutofillType int getAutofillType() {
        return isEnabled() ? AUTOFILL_TYPE_LIST : AUTOFILL_TYPE_NONE;
    }

    @Override
    public AutofillValue getAutofillValue() {
        return isEnabled() ? AutofillValue.forList(getSelectedItemPosition()) : null;
    }
}