Michael Jurka | d63497b | 2011-01-14 17:56:16 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2010 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 android.content.Context; |
| 20 | import android.graphics.Bitmap; |
Winson Chung | 97d85d2 | 2011-04-13 11:27:36 -0700 | [diff] [blame] | 21 | import android.graphics.Bitmap.Config; |
Michael Jurka | d63497b | 2011-01-14 17:56:16 -0800 | [diff] [blame] | 22 | import android.graphics.Canvas; |
| 23 | import android.graphics.Paint; |
Michael Jurka | d63497b | 2011-01-14 17:56:16 -0800 | [diff] [blame] | 24 | import android.graphics.PorterDuff.Mode; |
Winson Chung | 97d85d2 | 2011-04-13 11:27:36 -0700 | [diff] [blame] | 25 | import android.graphics.drawable.Drawable; |
Michael Jurka | d63497b | 2011-01-14 17:56:16 -0800 | [diff] [blame] | 26 | import android.text.Layout; |
| 27 | import android.util.AttributeSet; |
| 28 | import android.widget.TextView; |
| 29 | |
| 30 | /* |
| 31 | * This class is a bit of a hack, designed to speed up long text labels in Launcher. It caches the |
| 32 | * text in a TextView to a bitmap and then just draws that Bitmap instead afterward, speeding up |
| 33 | * rendering. Marquee scrolling is not currently supported. |
| 34 | * |
| 35 | */ |
| 36 | public class CachedTextView extends TextView { |
| 37 | private Bitmap mCache; |
| 38 | private final Paint mCachePaint = new Paint(); |
| 39 | private final Canvas mCacheCanvas = new Canvas(); |
| 40 | |
| 41 | private int mPrevAlpha = -1; |
| 42 | private boolean mIsBuildingCache; |
| 43 | boolean mIsTextCacheDirty; |
| 44 | float mTextCacheLeft; |
| 45 | float mTextCacheTop; |
| 46 | float mTextCacheScrollX; |
| 47 | float mRectLeft, mRectTop; |
| 48 | private float mPaddingH = 0; |
| 49 | private float mPaddingV = 0; |
| 50 | private CharSequence mText; |
Michael Jurka | c0759f5 | 2011-02-03 16:47:14 -0800 | [diff] [blame] | 51 | private boolean mEnabled = true; |
Michael Jurka | d63497b | 2011-01-14 17:56:16 -0800 | [diff] [blame] | 52 | |
| 53 | public CachedTextView(Context context) { |
| 54 | super(context); |
| 55 | } |
| 56 | |
| 57 | public CachedTextView(Context context, AttributeSet attrs) { |
| 58 | super(context, attrs); |
| 59 | } |
| 60 | |
| 61 | public CachedTextView(Context context, AttributeSet attrs, int defStyle) { |
| 62 | super(context, attrs, defStyle); |
| 63 | } |
| 64 | |
| 65 | protected int getCacheTopPadding() { |
| 66 | return 0; |
| 67 | } |
| 68 | protected int getCacheLeftPadding() { |
| 69 | return 0; |
| 70 | } |
| 71 | protected int getCacheRightPadding() { |
| 72 | return 0; |
| 73 | } |
| 74 | protected int getCacheBottomPadding() { |
| 75 | return 0; |
| 76 | } |
| 77 | |
Michael Jurka | c0759f5 | 2011-02-03 16:47:14 -0800 | [diff] [blame] | 78 | public void disableCache() { |
| 79 | mEnabled = false; |
| 80 | } |
| 81 | |
Michael Jurka | d63497b | 2011-01-14 17:56:16 -0800 | [diff] [blame] | 82 | public void setText(CharSequence text, BufferType type) { |
| 83 | super.setText(text, type); |
| 84 | mIsTextCacheDirty = true; |
| 85 | } |
| 86 | |
| 87 | private void buildAndUpdateCache() { |
| 88 | final Layout layout = getLayout(); |
| 89 | final int left = getCompoundPaddingLeft(); |
| 90 | final int top = getExtendedPaddingTop(); |
| 91 | final float prevAlpha = getAlpha(); |
| 92 | |
| 93 | mTextCacheLeft = layout.getLineLeft(0) - getCacheLeftPadding(); |
| 94 | mTextCacheTop = top + layout.getLineTop(0) - mPaddingV - getCacheTopPadding(); |
| 95 | |
| 96 | mRectLeft = mScrollX + getLeft(); |
| 97 | mRectTop = 0; |
| 98 | mTextCacheScrollX = mScrollX; |
| 99 | |
| 100 | final float textCacheRight = |
| 101 | Math.min(left + layout.getLineRight(0) + mPaddingH, mScrollX + mRight - mLeft) + |
| 102 | getCacheRightPadding(); |
| 103 | final float textCacheBottom = top + layout.getLineBottom(0) + mPaddingV + |
| 104 | getCacheBottomPadding(); |
| 105 | final float xCharWidth = getPaint().measureText("x"); |
| 106 | |
| 107 | int width = (int) (textCacheRight - mTextCacheLeft + (2 * xCharWidth)); |
| 108 | int height = (int) (textCacheBottom - mTextCacheTop); |
| 109 | |
| 110 | if (width != 0 && height != 0) { |
| 111 | if (mCache != null) { |
| 112 | if (mCache.getWidth() != width || mCache.getHeight() != height) { |
| 113 | mCache.recycle(); |
| 114 | mCache = null; |
| 115 | } |
| 116 | } |
| 117 | if (mCache == null) { |
| 118 | mCache = Bitmap.createBitmap(width, height, Config.ARGB_8888); |
| 119 | mCacheCanvas.setBitmap(mCache); |
| 120 | } else { |
| 121 | mCacheCanvas.drawColor(0, Mode.CLEAR); |
| 122 | } |
| 123 | |
| 124 | mCacheCanvas.save(); |
| 125 | mCacheCanvas.translate(-mTextCacheLeft, -mTextCacheTop); |
| 126 | |
| 127 | mIsBuildingCache = true; |
| 128 | setAlpha(1.0f); |
| 129 | draw(mCacheCanvas); |
| 130 | setAlpha(prevAlpha); |
| 131 | mIsBuildingCache = false; |
| 132 | mCacheCanvas.restore(); |
| 133 | |
| 134 | // A hack-- we set the text to be one space (we don't make it empty just to avoid any |
| 135 | // potential issues with text measurement, like line height, etc.) so that the text view |
| 136 | // doesn't draw it anymore, since it's been cached. |
| 137 | mText = getText(); |
| 138 | setText(" "); |
| 139 | } |
| 140 | } |
| 141 | |
| 142 | public CharSequence getText() { |
| 143 | return (mText == null) ? super.getText() : mText; |
| 144 | } |
| 145 | |
| 146 | public void draw(Canvas canvas) { |
Michael Jurka | c0759f5 | 2011-02-03 16:47:14 -0800 | [diff] [blame] | 147 | if (mEnabled && mIsTextCacheDirty && !mIsBuildingCache) { |
Michael Jurka | d63497b | 2011-01-14 17:56:16 -0800 | [diff] [blame] | 148 | buildAndUpdateCache(); |
| 149 | mIsTextCacheDirty = false; |
| 150 | } |
| 151 | if (mCache != null && !mIsBuildingCache) { |
| 152 | canvas.drawBitmap(mCache, mTextCacheLeft - mTextCacheScrollX + mScrollX, |
| 153 | mTextCacheTop, mCachePaint); |
| 154 | } |
| 155 | super.draw(canvas); |
| 156 | } |
| 157 | |
| 158 | protected boolean isBuildingCache() { |
| 159 | return mIsBuildingCache; |
| 160 | } |
| 161 | |
| 162 | @Override |
| 163 | protected boolean onSetAlpha(int alpha) { |
| 164 | if (mPrevAlpha != alpha) { |
| 165 | mPrevAlpha = alpha; |
| 166 | mCachePaint.setAlpha(alpha); |
Winson Chung | 97d85d2 | 2011-04-13 11:27:36 -0700 | [diff] [blame] | 167 | |
| 168 | // We manually update the drawables alpha since the default TextView implementation may |
| 169 | // not do this if there is a background set (which we may due to the focus bg) |
| 170 | final Drawable[] dr = getCompoundDrawables(); |
| 171 | for (int i = 0; i < dr.length; ++i) { |
| 172 | if (dr[i] != null) { |
| 173 | dr[i].mutate().setAlpha(alpha); |
| 174 | } |
| 175 | } |
| 176 | |
Michael Jurka | d63497b | 2011-01-14 17:56:16 -0800 | [diff] [blame] | 177 | super.onSetAlpha(alpha); |
| 178 | } |
| 179 | return true; |
| 180 | } |
| 181 | } |