Michael Jurka | 8c920dd | 2011-01-20 14:16:56 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2008 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.launcher2; |
| 18 | |
| 19 | import com.android.launcher.R; |
| 20 | |
| 21 | import android.content.Context; |
| 22 | import android.content.res.Resources; |
| 23 | import android.graphics.Bitmap; |
| 24 | import android.graphics.Canvas; |
| 25 | import android.graphics.Paint; |
| 26 | import android.graphics.Rect; |
| 27 | import android.graphics.Bitmap.Config; |
| 28 | import android.graphics.PorterDuff.Mode; |
Michael Jurka | cf6125c | 2011-01-28 15:20:01 -0800 | [diff] [blame] | 29 | import android.util.AttributeSet; |
Michael Jurka | 8c920dd | 2011-01-20 14:16:56 -0800 | [diff] [blame] | 30 | import android.view.View; |
| 31 | import android.view.ViewGroup; |
| 32 | |
| 33 | // This class caches the drawing of this View's children in a bitmap when the scale factor |
| 34 | // falls below a certain size. Only used by CellLayout, but in a separate class to keep cache |
| 35 | // logic separate from the other logic in CellLayout |
| 36 | public class CachedViewGroup extends ViewGroup implements VisibilityChangedListener { |
| 37 | static final String TAG = "CachedViewGroup"; |
| 38 | |
| 39 | private Bitmap mCache; |
| 40 | private Canvas mCacheCanvas; |
| 41 | private Rect mCacheRect; |
| 42 | private Paint mCachePaint; |
| 43 | |
| 44 | private boolean mIsCacheEnabled = true; |
| 45 | private boolean mDisableCacheUpdates = false; |
| 46 | private boolean mForceCacheUpdate = false; |
| 47 | private boolean isUpdatingCache = false; |
| 48 | private boolean mIsCacheDirty = true; |
| 49 | private float mBitmapCacheScale; |
| 50 | private float mMaxScaleForUsingBitmapCache; |
| 51 | |
| 52 | private Rect mBackgroundRect; |
| 53 | |
| 54 | public CachedViewGroup(Context context) { |
| 55 | super(context); |
Michael Jurka | cf6125c | 2011-01-28 15:20:01 -0800 | [diff] [blame] | 56 | init(); |
| 57 | } |
| 58 | |
| 59 | public CachedViewGroup(Context context, AttributeSet attrs, int defStyle) { |
| 60 | super(context, attrs, defStyle); |
| 61 | init(); |
| 62 | } |
| 63 | |
| 64 | private void init() { |
Michael Jurka | 8c920dd | 2011-01-20 14:16:56 -0800 | [diff] [blame] | 65 | mBackgroundRect = new Rect(); |
| 66 | mCacheRect = new Rect(); |
| 67 | final Resources res = getResources(); |
| 68 | mBitmapCacheScale = |
| 69 | res.getInteger(R.integer.config_workspaceScreenBitmapCacheScale) / 100.0f; |
| 70 | mMaxScaleForUsingBitmapCache = |
| 71 | res.getInteger(R.integer.config_maxScaleForUsingWorkspaceScreenBitmapCache) / 100.0f; |
| 72 | mCacheCanvas = new Canvas(); |
| 73 | } |
| 74 | |
| 75 | @Override |
| 76 | protected void onLayout(boolean changed, int l, int t, int r, int b) { |
| 77 | // sub-classes (namely CellLayout) will need to implement this |
| 78 | prepareCacheBitmap(); |
| 79 | invalidateCache(); |
| 80 | } |
| 81 | |
| 82 | private void invalidateIfNeeded() { |
| 83 | if (mIsCacheDirty) { |
| 84 | // Force a redraw to update the cache if it's dirty |
| 85 | invalidate(); |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | public void enableCache() { |
| 90 | mIsCacheEnabled = true; |
| 91 | invalidateIfNeeded(); |
| 92 | } |
| 93 | |
| 94 | public void disableCache() { |
| 95 | mIsCacheEnabled = false; |
| 96 | } |
| 97 | |
| 98 | public void disableCacheUpdates() { |
| 99 | mDisableCacheUpdates = true; |
| 100 | // Force just one update before we enter a period of no cache updates |
| 101 | mForceCacheUpdate = true; |
| 102 | } |
| 103 | |
| 104 | public void enableCacheUpdates() { |
| 105 | mDisableCacheUpdates = false; |
| 106 | invalidateIfNeeded(); |
| 107 | } |
| 108 | |
| 109 | private void invalidateCache() { |
| 110 | mIsCacheDirty = true; |
| 111 | invalidate(); |
| 112 | } |
| 113 | |
| 114 | public void receiveVisibilityChangedMessage(View v) { |
| 115 | invalidateCache(); |
| 116 | } |
| 117 | |
| 118 | private void prepareCacheBitmap() { |
| 119 | if (mCache == null) { |
| 120 | mCache = Bitmap.createBitmap((int) (getWidth() * mBitmapCacheScale), |
| 121 | (int) (getHeight() * mBitmapCacheScale), Config.ARGB_8888); |
| 122 | |
| 123 | mCachePaint = new Paint(); |
| 124 | mCachePaint.setFilterBitmap(true); |
| 125 | mCacheCanvas.setBitmap(mCache); |
| 126 | mCacheCanvas.scale(mBitmapCacheScale, mBitmapCacheScale); |
| 127 | } |
| 128 | } |
| 129 | |
| 130 | |
| 131 | public void updateCache() { |
| 132 | mCacheCanvas.drawColor(0, Mode.CLEAR); |
| 133 | |
| 134 | float alpha = getAlpha(); |
| 135 | setAlpha(1.0f); |
| 136 | isUpdatingCache = true; |
Michael Jurka | cf6125c | 2011-01-28 15:20:01 -0800 | [diff] [blame] | 137 | drawChildren(mCacheCanvas); |
Michael Jurka | 8c920dd | 2011-01-20 14:16:56 -0800 | [diff] [blame] | 138 | isUpdatingCache = false; |
| 139 | setAlpha(alpha); |
| 140 | |
| 141 | mIsCacheDirty = false; |
| 142 | } |
| 143 | |
Michael Jurka | 8c920dd | 2011-01-20 14:16:56 -0800 | [diff] [blame] | 144 | public void drawChildren(Canvas canvas) { |
| 145 | super.dispatchDraw(canvas); |
| 146 | } |
| 147 | |
| 148 | @Override |
| 149 | public void removeAllViews() { |
| 150 | super.removeAllViews(); |
| 151 | invalidateCache(); |
| 152 | } |
| 153 | |
| 154 | @Override |
| 155 | public void removeAllViewsInLayout() { |
| 156 | super.removeAllViewsInLayout(); |
| 157 | invalidateCache(); |
| 158 | } |
| 159 | |
Michael Jurka | 8c920dd | 2011-01-20 14:16:56 -0800 | [diff] [blame] | 160 | @Override |
| 161 | public void removeView(View view) { |
| 162 | super.removeView(view); |
| 163 | invalidateCache(); |
| 164 | } |
| 165 | |
| 166 | @Override |
| 167 | public void removeViewAt(int index) { |
| 168 | super.removeViewAt(index); |
| 169 | invalidateCache(); |
| 170 | } |
| 171 | |
| 172 | @Override |
| 173 | public void removeViewInLayout(View view) { |
| 174 | super.removeViewInLayout(view); |
| 175 | invalidateCache(); |
| 176 | } |
| 177 | |
| 178 | @Override |
| 179 | public void removeViews(int start, int count) { |
| 180 | super.removeViews(start, count); |
| 181 | invalidateCache(); |
| 182 | } |
| 183 | |
| 184 | @Override |
| 185 | public void removeViewsInLayout(int start, int count) { |
| 186 | super.removeViewsInLayout(start, count); |
| 187 | invalidateCache(); |
| 188 | } |
| 189 | |
| 190 | @Override |
| 191 | public void dispatchDraw(Canvas canvas) { |
| 192 | final int count = getChildCount(); |
| 193 | |
| 194 | boolean useBitmapCache = false; |
| 195 | if (!isUpdatingCache) { |
| 196 | if (!mIsCacheDirty) { |
| 197 | // Check if one of the children (an icon or widget) is dirty |
| 198 | for (int i = 0; i < count; i++) { |
| 199 | final View child = getChildAt(i); |
| 200 | if (child.isDirty()) { |
| 201 | mIsCacheDirty = true; |
| 202 | break; |
| 203 | } |
| 204 | } |
| 205 | } |
| 206 | |
| 207 | useBitmapCache = mIsCacheEnabled && getScaleX() < mMaxScaleForUsingBitmapCache; |
| 208 | if (mForceCacheUpdate || |
| 209 | (useBitmapCache && !mDisableCacheUpdates)) { |
| 210 | // Sometimes we force a cache update-- this is used to make sure the cache will look as |
| 211 | // up-to-date as possible right when we disable cache updates |
| 212 | if (mIsCacheDirty) { |
| 213 | updateCache(); |
| 214 | } |
| 215 | mForceCacheUpdate = false; |
| 216 | } |
| 217 | } |
| 218 | |
| 219 | if (useBitmapCache) { |
| 220 | mCachePaint.setAlpha((int)(255*getAlpha())); |
| 221 | canvas.drawBitmap(mCache, mCacheRect, mBackgroundRect, mCachePaint); |
| 222 | } else { |
| 223 | super.dispatchDraw(canvas); |
| 224 | } |
| 225 | } |
| 226 | |
| 227 | @Override |
| 228 | public void addView(View child, int index, ViewGroup.LayoutParams params) { |
| 229 | super.addView(child, index, params); |
| 230 | |
| 231 | // invalidate the cache to have it reflect the new item |
| 232 | invalidateCache(); |
| 233 | |
| 234 | if (child instanceof VisibilityChangedBroadcaster) { |
| 235 | VisibilityChangedBroadcaster v = (VisibilityChangedBroadcaster) child; |
| 236 | v.setVisibilityChangedListener(this); |
| 237 | } |
| 238 | } |
| 239 | |
| 240 | |
| 241 | @Override |
| 242 | protected void onSizeChanged(int w, int h, int oldw, int oldh) { |
| 243 | super.onSizeChanged(w, h, oldw, oldh); |
| 244 | mBackgroundRect.set(0, 0, w, h); |
| 245 | mCacheRect.set(0, 0, (int) (mBitmapCacheScale * w), (int) (mBitmapCacheScale * h)); |
| 246 | mCache = null; |
| 247 | prepareCacheBitmap(); |
| 248 | invalidateCache(); |
| 249 | } |
| 250 | } |
| 251 | |
| 252 | |
| 253 | //Custom interfaces used to listen to "visibility changed" events of *children* of Views. Avoided |
| 254 | //using "onVisibilityChanged" in the names because there's a method of that name in framework |
| 255 | //(which can only can be used to listen to ancestors' "visibility changed" events) |
| 256 | interface VisibilityChangedBroadcaster { |
| 257 | public void setVisibilityChangedListener(VisibilityChangedListener listener); |
| 258 | } |
| 259 | |
| 260 | interface VisibilityChangedListener { |
| 261 | public void receiveVisibilityChangedMessage(View v); |
| 262 | } |