1 /*
2  * Copyright (C) 2016 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.graphics;
18 
19 import static com.android.launcher3.util.Executors.UI_HELPER_EXECUTOR;
20 
21 import android.content.Context;
22 import android.graphics.Bitmap;
23 import android.graphics.BlurMaskFilter;
24 import android.graphics.Canvas;
25 import android.graphics.Paint;
26 import android.graphics.PorterDuff;
27 import android.graphics.PorterDuffXfermode;
28 import android.graphics.Rect;
29 import android.graphics.drawable.Drawable;
30 import android.view.View;
31 
32 import com.android.launcher3.BubbleTextView;
33 import com.android.launcher3.FastBitmapDrawable;
34 import com.android.launcher3.Launcher;
35 import com.android.launcher3.R;
36 import com.android.launcher3.config.FeatureFlags;
37 import com.android.launcher3.folder.FolderIcon;
38 import com.android.launcher3.icons.BitmapRenderer;
39 import com.android.launcher3.widget.LauncherAppWidgetHostView;
40 import com.android.launcher3.widget.PendingAppWidgetHostView;
41 
42 import java.nio.ByteBuffer;
43 
44 /**
45  * A utility class to generate preview bitmap for dragging.
46  */
47 public class DragPreviewProvider {
48 
49     private final Rect mTempRect = new Rect();
50 
51     protected final View mView;
52 
53     // The padding added to the drag view during the preview generation.
54     public final int previewPadding;
55 
56     protected final int blurSizeOutline;
57 
58     private OutlineGeneratorCallback mOutlineGeneratorCallback;
59     public Bitmap generatedDragOutline;
60 
DragPreviewProvider(View view)61     public DragPreviewProvider(View view) {
62         this(view, view.getContext());
63     }
64 
DragPreviewProvider(View view, Context context)65     public DragPreviewProvider(View view, Context context) {
66         mView = view;
67         blurSizeOutline =
68                 context.getResources().getDimensionPixelSize(R.dimen.blur_size_medium_outline);
69 
70         if (mView instanceof BubbleTextView) {
71             Drawable d = ((BubbleTextView) mView).getIcon();
72             Rect bounds = getDrawableBounds(d);
73             previewPadding = blurSizeOutline - bounds.left - bounds.top;
74         } else {
75             previewPadding = blurSizeOutline;
76         }
77     }
78 
79     /**
80      * Draws the {@link #mView} into the given {@param destCanvas}.
81      */
drawDragView(Canvas destCanvas, float scale)82     protected void drawDragView(Canvas destCanvas, float scale) {
83         destCanvas.save();
84         destCanvas.scale(scale, scale);
85 
86         if (mView instanceof BubbleTextView) {
87             Drawable d = ((BubbleTextView) mView).getIcon();
88             Rect bounds = getDrawableBounds(d);
89             destCanvas.translate(blurSizeOutline / 2 - bounds.left,
90                     blurSizeOutline / 2 - bounds.top);
91             if (d instanceof FastBitmapDrawable) {
92                 ((FastBitmapDrawable) d).setScale(1);
93             }
94             d.draw(destCanvas);
95         } else {
96             final Rect clipRect = mTempRect;
97             mView.getDrawingRect(clipRect);
98 
99             boolean textVisible = false;
100             if (mView instanceof FolderIcon) {
101                 // For FolderIcons the text can bleed into the icon area, and so we need to
102                 // hide the text completely (which can't be achieved by clipping).
103                 if (((FolderIcon) mView).getTextVisible()) {
104                     ((FolderIcon) mView).setTextVisible(false);
105                     textVisible = true;
106                 }
107             }
108             destCanvas.translate(-mView.getScrollX() + blurSizeOutline / 2,
109                     -mView.getScrollY() + blurSizeOutline / 2);
110             destCanvas.clipRect(clipRect);
111             mView.draw(destCanvas);
112 
113             // Restore text visibility of FolderIcon if necessary
114             if (textVisible) {
115                 ((FolderIcon) mView).setTextVisible(true);
116             }
117         }
118         destCanvas.restore();
119     }
120 
121     /**
122      * Returns a new bitmap to show when the {@link #mView} is being dragged around.
123      * Responsibility for the bitmap is transferred to the caller.
124      */
createDragBitmap()125     public Bitmap createDragBitmap() {
126         int width = mView.getWidth();
127         int height = mView.getHeight();
128 
129         if (mView instanceof BubbleTextView) {
130             Drawable d = ((BubbleTextView) mView).getIcon();
131             Rect bounds = getDrawableBounds(d);
132             width = bounds.width();
133             height = bounds.height();
134         } else if (mView instanceof LauncherAppWidgetHostView) {
135             float scale = ((LauncherAppWidgetHostView) mView).getScaleToFit();
136             width = (int) (mView.getWidth() * scale);
137             height = (int) (mView.getHeight() * scale);
138 
139             if (mView instanceof PendingAppWidgetHostView) {
140                 // Use hardware renderer as the icon for the pending app widget may be a hw bitmap
141                 return BitmapRenderer.createHardwareBitmap(width + blurSizeOutline,
142                         height + blurSizeOutline, (c) -> drawDragView(c, scale));
143             } else {
144                 // Use software renderer for widgets as we know that they already work
145                 return BitmapRenderer.createSoftwareBitmap(width + blurSizeOutline,
146                         height + blurSizeOutline, (c) -> drawDragView(c, scale));
147             }
148         }
149 
150         return BitmapRenderer.createHardwareBitmap(width + blurSizeOutline,
151                 height + blurSizeOutline, (c) -> drawDragView(c, 1));
152     }
153 
generateDragOutline(Bitmap preview)154     public final void generateDragOutline(Bitmap preview) {
155         if (FeatureFlags.IS_DOGFOOD_BUILD && mOutlineGeneratorCallback != null) {
156             throw new RuntimeException("Drag outline generated twice");
157         }
158 
159         mOutlineGeneratorCallback = new OutlineGeneratorCallback(preview);
160         UI_HELPER_EXECUTOR.post(mOutlineGeneratorCallback);
161     }
162 
getDrawableBounds(Drawable d)163     protected static Rect getDrawableBounds(Drawable d) {
164         Rect bounds = new Rect();
165         d.copyBounds(bounds);
166         if (bounds.width() == 0 || bounds.height() == 0) {
167             bounds.set(0, 0, d.getIntrinsicWidth(), d.getIntrinsicHeight());
168         } else {
169             bounds.offsetTo(0, 0);
170         }
171         return bounds;
172     }
173 
getScaleAndPosition(Bitmap preview, int[] outPos)174     public float getScaleAndPosition(Bitmap preview, int[] outPos) {
175         float scale = Launcher.getLauncher(mView.getContext())
176                 .getDragLayer().getLocationInDragLayer(mView, outPos);
177         if (mView instanceof LauncherAppWidgetHostView) {
178             // App widgets are technically scaled, but are drawn at their expected size -- so the
179             // app widget scale should not affect the scale of the preview.
180             scale /= ((LauncherAppWidgetHostView) mView).getScaleToFit();
181         }
182 
183         outPos[0] = Math.round(outPos[0] -
184                 (preview.getWidth() - scale * mView.getWidth() * mView.getScaleX()) / 2);
185         outPos[1] = Math.round(outPos[1] - (1 - scale) * preview.getHeight() / 2
186                 - previewPadding / 2);
187         return scale;
188     }
189 
convertPreviewToAlphaBitmap(Bitmap preview)190     protected Bitmap convertPreviewToAlphaBitmap(Bitmap preview) {
191         return preview.copy(Bitmap.Config.ALPHA_8, true);
192     }
193 
194     private class OutlineGeneratorCallback implements Runnable {
195 
196         private final Bitmap mPreviewSnapshot;
197         private final Context mContext;
198         private final boolean mIsIcon;
199 
OutlineGeneratorCallback(Bitmap preview)200         OutlineGeneratorCallback(Bitmap preview) {
201             mPreviewSnapshot = preview;
202             mContext = mView.getContext();
203             mIsIcon = mView instanceof BubbleTextView;
204         }
205 
206         @Override
run()207         public void run() {
208             Bitmap preview = convertPreviewToAlphaBitmap(mPreviewSnapshot);
209             if (mIsIcon) {
210                 int size = Launcher.getLauncher(mContext).getDeviceProfile().iconSizePx;
211                 preview = Bitmap.createScaledBitmap(preview, size, size, false);
212             }
213             //else case covers AppWidgetHost (doesn't drag/drop across different device profiles)
214 
215             // We start by removing most of the alpha channel so as to ignore shadows, and
216             // other types of partial transparency when defining the shape of the object
217             byte[] pixels = new byte[preview.getWidth() * preview.getHeight()];
218             ByteBuffer buffer = ByteBuffer.wrap(pixels);
219             buffer.rewind();
220             preview.copyPixelsToBuffer(buffer);
221 
222             for (int i = 0; i < pixels.length; i++) {
223                 if ((pixels[i] & 0xFF) < 188) {
224                     pixels[i] = 0;
225                 }
226             }
227 
228             buffer.rewind();
229             preview.copyPixelsFromBuffer(buffer);
230 
231             final Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG);
232             Canvas canvas = new Canvas();
233 
234             // calculate the outer blur first
235             paint.setMaskFilter(new BlurMaskFilter(blurSizeOutline, BlurMaskFilter.Blur.OUTER));
236             int[] outerBlurOffset = new int[2];
237             Bitmap thickOuterBlur = preview.extractAlpha(paint, outerBlurOffset);
238 
239             paint.setMaskFilter(new BlurMaskFilter(
240                     mContext.getResources().getDimension(R.dimen.blur_size_thin_outline),
241                     BlurMaskFilter.Blur.OUTER));
242             int[] brightOutlineOffset = new int[2];
243             Bitmap brightOutline = preview.extractAlpha(paint, brightOutlineOffset);
244 
245             // calculate the inner blur
246             canvas.setBitmap(preview);
247             canvas.drawColor(0xFF000000, PorterDuff.Mode.SRC_OUT);
248             paint.setMaskFilter(new BlurMaskFilter(blurSizeOutline, BlurMaskFilter.Blur.NORMAL));
249             int[] thickInnerBlurOffset = new int[2];
250             Bitmap thickInnerBlur = preview.extractAlpha(paint, thickInnerBlurOffset);
251 
252             // mask out the inner blur
253             paint.setMaskFilter(null);
254             paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));
255             canvas.setBitmap(thickInnerBlur);
256             canvas.drawBitmap(preview, -thickInnerBlurOffset[0],
257                     -thickInnerBlurOffset[1], paint);
258             canvas.drawRect(0, 0, -thickInnerBlurOffset[0], thickInnerBlur.getHeight(), paint);
259             canvas.drawRect(0, 0, thickInnerBlur.getWidth(), -thickInnerBlurOffset[1], paint);
260 
261             // draw the inner and outer blur
262             paint.setXfermode(null);
263             canvas.setBitmap(preview);
264             canvas.drawColor(0, PorterDuff.Mode.CLEAR);
265             canvas.drawBitmap(thickInnerBlur, thickInnerBlurOffset[0], thickInnerBlurOffset[1],
266                     paint);
267             canvas.drawBitmap(thickOuterBlur, outerBlurOffset[0], outerBlurOffset[1], paint);
268 
269             // draw the bright outline
270             canvas.drawBitmap(brightOutline, brightOutlineOffset[0], brightOutlineOffset[1], paint);
271 
272             // cleanup
273             canvas.setBitmap(null);
274             brightOutline.recycle();
275             thickOuterBlur.recycle();
276             thickInnerBlur.recycle();
277 
278             generatedDragOutline = preview;
279         }
280     }
281 }
282