The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2006 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 android.widget; |
| 18 | |
| 19 | import android.graphics.Canvas; |
| 20 | import android.graphics.ColorFilter; |
| 21 | import android.graphics.PixelFormat; |
| 22 | import android.graphics.Rect; |
| 23 | import android.graphics.drawable.Drawable; |
| 24 | |
| 25 | /** |
| 26 | * This is only used by View for displaying its scroll bars. It should probably |
| 27 | * be moved in to the view package since it is used in that lower-level layer. |
| 28 | * For now, we'll hide it so it can be cleaned up later. |
| 29 | * {@hide} |
| 30 | */ |
| 31 | public class ScrollBarDrawable extends Drawable { |
| 32 | private Drawable mVerticalTrack; |
| 33 | private Drawable mHorizontalTrack; |
| 34 | private Drawable mVerticalThumb; |
| 35 | private Drawable mHorizontalThumb; |
| 36 | private int mRange; |
| 37 | private int mOffset; |
| 38 | private int mExtent; |
| 39 | private boolean mVertical; |
| 40 | private boolean mChanged; |
| 41 | private boolean mRangeChanged; |
| 42 | private final Rect mTempBounds = new Rect(); |
| 43 | private boolean mAlwaysDrawHorizontalTrack; |
| 44 | private boolean mAlwaysDrawVerticalTrack; |
| 45 | |
| 46 | public ScrollBarDrawable() { |
| 47 | } |
| 48 | |
| 49 | /** |
| 50 | * Indicate whether the horizontal scrollbar track should always be drawn regardless of the |
| 51 | * extent. Defaults to false. |
| 52 | * |
| 53 | * @param alwaysDrawTrack Set to true if the track should always be drawn |
| 54 | */ |
| 55 | public void setAlwaysDrawHorizontalTrack(boolean alwaysDrawTrack) { |
| 56 | mAlwaysDrawHorizontalTrack = alwaysDrawTrack; |
| 57 | } |
| 58 | |
| 59 | /** |
| 60 | * Indicate whether the vertical scrollbar track should always be drawn regardless of the |
| 61 | * extent. Defaults to false. |
| 62 | * |
| 63 | * @param alwaysDrawTrack Set to true if the track should always be drawn |
| 64 | */ |
| 65 | public void setAlwaysDrawVerticalTrack(boolean alwaysDrawTrack) { |
| 66 | mAlwaysDrawVerticalTrack = alwaysDrawTrack; |
| 67 | } |
| 68 | |
| 69 | /** |
| 70 | * Indicates whether the vertical scrollbar track should always be drawn regardless of the |
| 71 | * extent. |
| 72 | */ |
| 73 | public boolean getAlwaysDrawVerticalTrack() { |
| 74 | return mAlwaysDrawVerticalTrack; |
| 75 | } |
| 76 | |
| 77 | /** |
| 78 | * Indicates whether the horizontal scrollbar track should always be drawn regardless of the |
| 79 | * extent. |
| 80 | */ |
| 81 | public boolean getAlwaysDrawHorizontalTrack() { |
| 82 | return mAlwaysDrawHorizontalTrack; |
| 83 | } |
| 84 | |
| 85 | public void setParameters(int range, int offset, int extent, boolean vertical) { |
| 86 | if (mVertical != vertical) { |
| 87 | mChanged = true; |
| 88 | } |
| 89 | |
| 90 | if (mRange != range || mOffset != offset || mExtent != extent) { |
| 91 | mRangeChanged = true; |
| 92 | } |
| 93 | |
| 94 | mRange = range; |
| 95 | mOffset = offset; |
| 96 | mExtent = extent; |
| 97 | mVertical = vertical; |
| 98 | } |
| 99 | |
| 100 | @Override |
| 101 | public void draw(Canvas canvas) { |
| 102 | final boolean vertical = mVertical; |
| 103 | final int extent = mExtent; |
| 104 | final int range = mRange; |
| 105 | |
| 106 | boolean drawTrack = true; |
| 107 | boolean drawThumb = true; |
| 108 | if (extent <= 0 || range <= extent) { |
| 109 | drawTrack = vertical ? mAlwaysDrawVerticalTrack : mAlwaysDrawHorizontalTrack; |
| 110 | drawThumb = false; |
| 111 | } |
| 112 | |
| 113 | Rect r = getBounds(); |
Romain Guy | 8fb9542 | 2010-08-17 18:38:51 -0700 | [diff] [blame] | 114 | if (canvas.quickReject(r.left, r.top, r.right, r.bottom, Canvas.EdgeType.AA)) { |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 115 | return; |
| 116 | } |
| 117 | if (drawTrack) { |
| 118 | drawTrack(canvas, r, vertical); |
| 119 | } |
| 120 | |
| 121 | if (drawThumb) { |
| 122 | int size = vertical ? r.height() : r.width(); |
| 123 | int thickness = vertical ? r.width() : r.height(); |
| 124 | int length = Math.round((float) size * extent / range); |
| 125 | int offset = Math.round((float) (size - length) * mOffset / (range - extent)); |
| 126 | |
| 127 | // avoid the tiny thumb |
| 128 | int minLength = thickness * 2; |
| 129 | if (length < minLength) { |
| 130 | length = minLength; |
| 131 | } |
| 132 | // avoid the too-big thumb |
| 133 | if (offset + length > size) { |
| 134 | offset = size - length; |
| 135 | } |
| 136 | |
| 137 | drawThumb(canvas, r, offset, length, vertical); |
| 138 | } |
| 139 | } |
| 140 | |
| 141 | @Override |
| 142 | protected void onBoundsChange(Rect bounds) { |
| 143 | super.onBoundsChange(bounds); |
| 144 | mChanged = true; |
| 145 | } |
| 146 | |
| 147 | protected void drawTrack(Canvas canvas, Rect bounds, boolean vertical) { |
| 148 | Drawable track; |
| 149 | if (vertical) { |
| 150 | track = mVerticalTrack; |
| 151 | } else { |
| 152 | track = mHorizontalTrack; |
| 153 | } |
| 154 | if (track != null) { |
| 155 | if (mChanged) { |
| 156 | track.setBounds(bounds); |
| 157 | } |
| 158 | track.draw(canvas); |
| 159 | } |
| 160 | } |
| 161 | |
| 162 | protected void drawThumb(Canvas canvas, Rect bounds, int offset, int length, boolean vertical) { |
| 163 | final Rect thumbRect = mTempBounds; |
| 164 | final boolean changed = mRangeChanged || mChanged; |
| 165 | if (changed) { |
| 166 | if (vertical) { |
| 167 | thumbRect.set(bounds.left, bounds.top + offset, |
| 168 | bounds.right, bounds.top + offset + length); |
| 169 | } else { |
| 170 | thumbRect.set(bounds.left + offset, bounds.top, |
| 171 | bounds.left + offset + length, bounds.bottom); |
| 172 | } |
| 173 | } |
| 174 | |
| 175 | if (vertical) { |
| 176 | final Drawable thumb = mVerticalThumb; |
| 177 | if (changed) thumb.setBounds(thumbRect); |
| 178 | thumb.draw(canvas); |
| 179 | } else { |
| 180 | final Drawable thumb = mHorizontalThumb; |
| 181 | if (changed) thumb.setBounds(thumbRect); |
| 182 | thumb.draw(canvas); |
| 183 | } |
| 184 | } |
| 185 | |
| 186 | public void setVerticalThumbDrawable(Drawable thumb) { |
| 187 | if (thumb != null) { |
| 188 | mVerticalThumb = thumb; |
| 189 | } |
| 190 | } |
| 191 | |
| 192 | public void setVerticalTrackDrawable(Drawable track) { |
| 193 | mVerticalTrack = track; |
| 194 | } |
| 195 | |
| 196 | public void setHorizontalThumbDrawable(Drawable thumb) { |
| 197 | if (thumb != null) { |
| 198 | mHorizontalThumb = thumb; |
| 199 | } |
| 200 | } |
| 201 | |
| 202 | public void setHorizontalTrackDrawable(Drawable track) { |
| 203 | mHorizontalTrack = track; |
| 204 | } |
| 205 | |
| 206 | public int getSize(boolean vertical) { |
| 207 | if (vertical) { |
| 208 | return (mVerticalTrack != null ? |
| 209 | mVerticalTrack : mVerticalThumb).getIntrinsicWidth(); |
| 210 | } else { |
| 211 | return (mHorizontalTrack != null ? |
| 212 | mHorizontalTrack : mHorizontalThumb).getIntrinsicHeight(); |
| 213 | } |
| 214 | } |
| 215 | |
| 216 | @Override |
| 217 | public void setAlpha(int alpha) { |
| 218 | if (mVerticalTrack != null) { |
| 219 | mVerticalTrack.setAlpha(alpha); |
| 220 | } |
| 221 | mVerticalThumb.setAlpha(alpha); |
| 222 | if (mHorizontalTrack != null) { |
| 223 | mHorizontalTrack.setAlpha(alpha); |
| 224 | } |
| 225 | mHorizontalThumb.setAlpha(alpha); |
| 226 | } |
| 227 | |
| 228 | @Override |
Chet Haase | b1af7f3 | 2013-03-08 14:02:04 -0800 | [diff] [blame] | 229 | public int getAlpha() { |
| 230 | // All elements should have same alpha, just return one of them |
| 231 | return mVerticalThumb.getAlpha(); |
| 232 | } |
| 233 | |
| 234 | @Override |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 235 | public void setColorFilter(ColorFilter cf) { |
| 236 | if (mVerticalTrack != null) { |
| 237 | mVerticalTrack.setColorFilter(cf); |
| 238 | } |
| 239 | mVerticalThumb.setColorFilter(cf); |
| 240 | if (mHorizontalTrack != null) { |
| 241 | mHorizontalTrack.setColorFilter(cf); |
| 242 | } |
| 243 | mHorizontalThumb.setColorFilter(cf); |
| 244 | } |
| 245 | |
| 246 | @Override |
| 247 | public int getOpacity() { |
| 248 | return PixelFormat.TRANSLUCENT; |
| 249 | } |
| 250 | |
| 251 | @Override |
| 252 | public String toString() { |
| 253 | return "ScrollBarDrawable: range=" + mRange + " offset=" + mOffset + |
| 254 | " extent=" + mExtent + (mVertical ? " V" : " H"); |
| 255 | } |
| 256 | } |
| 257 | |
| 258 | |