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      1 /*
      2  * Copyright (C) 2014 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.launcher3;
     18 
     19 import android.content.Context;
     20 import android.graphics.Bitmap;
     21 import android.graphics.Canvas;
     22 import android.graphics.Color;
     23 import android.graphics.Paint;
     24 import android.view.View;
     25 import android.view.ViewGroup;
     26 
     27 public class ClickShadowView extends View {
     28 
     29     private static final int SHADOW_SIZE_FACTOR = 3;
     30     private static final int SHADOW_LOW_ALPHA = 30;
     31     private static final int SHADOW_HIGH_ALPHA = 60;
     32 
     33     private final Paint mPaint;
     34 
     35     private final float mShadowOffset;
     36     private final float mShadowPadding;
     37 
     38     private Bitmap mBitmap;
     39 
     40     public ClickShadowView(Context context) {
     41         super(context);
     42         mPaint = new Paint(Paint.FILTER_BITMAP_FLAG);
     43         mPaint.setColor(Color.BLACK);
     44 
     45         mShadowPadding = getResources().getDimension(R.dimen.blur_size_click_shadow);
     46         mShadowOffset = getResources().getDimension(R.dimen.click_shadow_high_shift);
     47     }
     48 
     49     /**
     50      * @return extra space required by the view to show the shadow.
     51      */
     52     public int getExtraSize() {
     53         return (int) (SHADOW_SIZE_FACTOR * mShadowPadding);
     54     }
     55 
     56     /**
     57      * Applies the new bitmap.
     58      * @return true if the view was invalidated.
     59      */
     60     public boolean setBitmap(Bitmap b) {
     61         if (b != mBitmap){
     62             mBitmap = b;
     63             invalidate();
     64             return true;
     65         }
     66         return false;
     67     }
     68 
     69     @Override
     70     protected void onDraw(Canvas canvas) {
     71         if (mBitmap != null) {
     72             mPaint.setAlpha(SHADOW_LOW_ALPHA);
     73             canvas.drawBitmap(mBitmap, 0, 0, mPaint);
     74             mPaint.setAlpha(SHADOW_HIGH_ALPHA);
     75             canvas.drawBitmap(mBitmap, 0, mShadowOffset, mPaint);
     76         }
     77     }
     78 
     79     public void animateShadow() {
     80         setAlpha(0);
     81         animate().alpha(1)
     82             .setDuration(FastBitmapDrawable.CLICK_FEEDBACK_DURATION)
     83             .setInterpolator(FastBitmapDrawable.CLICK_FEEDBACK_INTERPOLATOR)
     84             .start();
     85     }
     86 
     87     /**
     88      * Aligns the shadow with {@param view}
     89      * @param viewParent immediate parent of {@param view}. It must be a sibling of this view.
     90      */
     91     public void alignWithIconView(BubbleTextView view, ViewGroup viewParent) {
     92         float leftShift = view.getLeft() + viewParent.getLeft() - getLeft();
     93         float topShift = view.getTop() + viewParent.getTop() - getTop();
     94         int iconWidth = view.getRight() - view.getLeft();
     95         int iconHSpace = iconWidth - view.getCompoundPaddingRight() - view.getCompoundPaddingLeft();
     96         float drawableWidth = view.getIcon().getBounds().width();
     97 
     98         setTranslationX(leftShift
     99                 + viewParent.getTranslationX()
    100                 + view.getCompoundPaddingLeft() * view.getScaleX()
    101                 + (iconHSpace - drawableWidth) * view.getScaleX() / 2  /* drawable gap */
    102                 + iconWidth * (1 - view.getScaleX()) / 2  /* gap due to scale */
    103                 - mShadowPadding  /* extra shadow size */
    104                 );
    105         setTranslationY(topShift
    106                 + viewParent.getTranslationY()
    107                 + view.getPaddingTop() * view.getScaleY()  /* drawable gap */
    108                 + view.getHeight() * (1 - view.getScaleY()) / 2  /* gap due to scale */
    109                 - mShadowPadding  /* extra shadow size */
    110                 );
    111     }
    112 }
    113