Adding TransformingTouchDelegate to allow transforming touch events before

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.graphics.Rect;

import android.os.Handler;

import android.os.Looper;

import android.support.v4.graphics.ColorUtils;

import android.util.AttributeSet;

import android.util.Log;

import android.util.Property;

import android.view.TouchDelegate;

import android.view.View;

import android.view.ViewConfiguration;

import com.android.launcher3.R;

import com.android.launcher3.Utilities;

import com.android.launcher3.dynamicui.ExtractedColors;

import com.android.launcher3.util.TransformingTouchDelegate;

/**

 * A PageIndicator that briefly shows a fraction of a line when moving between pages.

    private Paint mLinePaint;

    private Launcher mLauncher;

    private final int mLineHeight;

    private final Rect mTouchHitRect = new Rect();

    private final TransformingTouchDelegate mTouchDelegate;

    private final int mTouchExtensionHeight;

    private static final Property<PageIndicatorLineCaret, Integer> PAINT_ALPHA

        mLineHeight = res.getDimensionPixelSize(R.dimen.dynamic_grid_page_indicator_line_height);

        mTouchExtensionHeight = res.getDimensionPixelSize(

                R.dimen.dynamic_grid_page_indicator_extra_touch_height);

        mTouchDelegate = new TransformingTouchDelegate(this);

    }

    @Override

    protected void onAttachedToWindow() {

        super.onAttachedToWindow();

        mLauncher.getDragLayer().setTouchDelegate(mTouchDelegate);

    }

    @Override

        View parent = mLauncher.getDragLayer();

        sTempCoords[0] = sTempCoords[1] = 0;

        Utilities.getDescendantCoordRelativeToAncestor(this, parent, sTempCoords, true);

        mTouchHitRect.set(sTempCoords[0], sTempCoords[1], sTempCoords[0] + this.getWidth(),

        mTouchDelegate.setBounds(sTempCoords[0], sTempCoords[1], sTempCoords[0] + this.getWidth(),

                sTempCoords[1] + getHeight() + mTouchExtensionHeight);

        parent.setTouchDelegate(new TouchDelegate(mTouchHitRect, this));

    }

    @Override

/*

 * Copyright (C) 2016 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 com.android.launcher3.util;

import android.graphics.Rect;

import android.graphics.RectF;

import android.view.MotionEvent;

import android.view.TouchDelegate;

import android.view.View;

/**

 * This class differs from the framework {@link TouchDelegate} in that it transforms the

 * coordinates of the motion event to the provided bounds.

 *

 * You can also modify the bounds post construction. Since the bounds are available during layout,

 * this avoids new object creation during every layout.

 */

public class TransformingTouchDelegate extends TouchDelegate {

    private static final Rect sTempRect = new Rect();

    private final RectF mBounds;

    private View mDelegateView;

    private boolean mDelegateTargeted;

    public TransformingTouchDelegate(View delegateView) {

        super(sTempRect, delegateView);

        mDelegateView = delegateView;

        mBounds = new RectF();

    }

    public void setBounds(int left, int top, int right, int bottom) {

        mBounds.set(left, top, right, bottom);

    }

    public void setDelegateView(View view) {

        mDelegateView = view;

    }

    /**

     * Will forward touch events to the delegate view if the event is within the bounds

     * specified in the constructor.

     *

     * @param event The touch event to forward

     * @return True if the event was forwarded to the delegate, false otherwise.

     */

    public boolean onTouchEvent(MotionEvent event) {

        boolean sendToDelegate = false;

        switch (event.getAction()) {

            case MotionEvent.ACTION_DOWN:

                mDelegateTargeted = mBounds.contains(event.getX(), event.getY());

                if (mDelegateTargeted) {

                    sendToDelegate = true;

                }

                break;

            case MotionEvent.ACTION_MOVE:

                sendToDelegate = mDelegateTargeted;

                break;

            case MotionEvent.ACTION_UP:

            case MotionEvent.ACTION_CANCEL:

                sendToDelegate = mDelegateTargeted;

                mDelegateTargeted = false;

                break;

        }

        boolean handled = false;

        if (sendToDelegate) {

            event.offsetLocation(-mBounds.left, -mBounds.top);

            handled = mDelegateView.dispatchTouchEvent(event);

            event.offsetLocation(mBounds.left, mBounds.top);

        }

        return handled;

    }

}