Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2011 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.gallery3d.ui; |
| 18 | |
| 19 | import com.android.gallery3d.R; |
| 20 | import com.android.gallery3d.app.GalleryActivity; |
| 21 | import com.android.gallery3d.common.Utils; |
| 22 | import com.android.gallery3d.data.Path; |
| 23 | import com.android.gallery3d.ui.PositionRepository.Position; |
Chih-Chung Chang | 8f568da | 2012-01-05 12:00:53 +0800 | [diff] [blame^] | 24 | import com.android.gallery3d.util.GalleryUtils; |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 25 | |
| 26 | import android.content.Context; |
| 27 | import android.graphics.Bitmap; |
| 28 | import android.graphics.Color; |
| 29 | import android.graphics.RectF; |
| 30 | import android.os.Message; |
| 31 | import android.os.SystemClock; |
| 32 | import android.view.GestureDetector; |
| 33 | import android.view.MotionEvent; |
| 34 | import android.view.ScaleGestureDetector; |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 35 | import android.widget.Scroller; |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 36 | |
| 37 | class PositionController { |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 38 | private static final String TAG = "PositionController"; |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 39 | private long mAnimationStartTime = NO_ANIMATION; |
| 40 | private static final long NO_ANIMATION = -1; |
| 41 | private static final long LAST_ANIMATION = -2; |
| 42 | |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 43 | private int mAnimationKind; |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 44 | private float mAnimationDuration; |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 45 | private final static int ANIM_KIND_SCROLL = 0; |
| 46 | private final static int ANIM_KIND_SCALE = 1; |
| 47 | private final static int ANIM_KIND_SNAPBACK = 2; |
| 48 | private final static int ANIM_KIND_SLIDE = 3; |
| 49 | private final static int ANIM_KIND_ZOOM = 4; |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 50 | private final static int ANIM_KIND_FLING = 5; |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 51 | |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 52 | // Animation time in milliseconds. The order must match ANIM_KIND_* above. |
| 53 | private final static int ANIM_TIME[] = { |
| 54 | 0, // ANIM_KIND_SCROLL |
| 55 | 50, // ANIM_KIND_SCALE |
| 56 | 600, // ANIM_KIND_SNAPBACK |
| 57 | 400, // ANIM_KIND_SLIDE |
| 58 | 300, // ANIM_KIND_ZOOM |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 59 | 0, // ANIM_KIND_FLING (the duration is calculated dynamically) |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 60 | }; |
| 61 | |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 62 | // We try to scale up the image to fill the screen. But in order not to |
| 63 | // scale too much for small icons, we limit the max up-scaling factor here. |
| 64 | private static final float SCALE_LIMIT = 4; |
Chih-Chung Chang | 8f568da | 2012-01-05 12:00:53 +0800 | [diff] [blame^] | 65 | private static final int sHorizontalSlack = GalleryUtils.dpToPixel(12); |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 66 | |
| 67 | private PhotoView mViewer; |
Chih-Chung Chang | 532d93c | 2011-10-12 17:10:33 +0800 | [diff] [blame] | 68 | private EdgeView mEdgeView; |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 69 | private int mImageW, mImageH; |
| 70 | private int mViewW, mViewH; |
| 71 | |
| 72 | // The X, Y are the coordinate on bitmap which shows on the center of |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 73 | // the view. We always keep the mCurrent{X,Y,Scale} sync with the actual |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 74 | // values used currently. |
| 75 | private int mCurrentX, mFromX, mToX; |
| 76 | private int mCurrentY, mFromY, mToY; |
| 77 | private float mCurrentScale, mFromScale, mToScale; |
| 78 | |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 79 | // The focus point of the scaling gesture (in bitmap coordinates). |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 80 | private int mFocusBitmapX; |
| 81 | private int mFocusBitmapY; |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 82 | private boolean mInScale; |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 83 | |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 84 | // The minimum and maximum scale we allow. |
| 85 | private float mScaleMin, mScaleMax = SCALE_LIMIT; |
| 86 | |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 87 | // This is used by the fling animation |
| 88 | private FlingScroller mScroller; |
| 89 | |
| 90 | // The bound of the stable region, see the comments above |
| 91 | // calculateStableBound() for details. |
| 92 | private int mBoundLeft, mBoundRight, mBoundTop, mBoundBottom; |
| 93 | |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 94 | // Assume the image size is the same as view size before we know the actual |
| 95 | // size of image. |
| 96 | private boolean mUseViewSize = true; |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 97 | |
| 98 | private RectF mTempRect = new RectF(); |
| 99 | private float[] mTempPoints = new float[8]; |
| 100 | |
Chih-Chung Chang | 532d93c | 2011-10-12 17:10:33 +0800 | [diff] [blame] | 101 | public PositionController(PhotoView viewer, Context context, |
| 102 | EdgeView edgeView) { |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 103 | mViewer = viewer; |
Chih-Chung Chang | 532d93c | 2011-10-12 17:10:33 +0800 | [diff] [blame] | 104 | mEdgeView = edgeView; |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 105 | mScroller = new FlingScroller(); |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 106 | } |
| 107 | |
| 108 | public void setImageSize(int width, int height) { |
| 109 | |
| 110 | // If no image available, use view size. |
| 111 | if (width == 0 || height == 0) { |
| 112 | mUseViewSize = true; |
| 113 | mImageW = mViewW; |
| 114 | mImageH = mViewH; |
| 115 | mCurrentX = mImageW / 2; |
| 116 | mCurrentY = mImageH / 2; |
| 117 | mCurrentScale = 1; |
| 118 | mScaleMin = 1; |
| 119 | mViewer.setPosition(mCurrentX, mCurrentY, mCurrentScale); |
| 120 | return; |
| 121 | } |
| 122 | |
| 123 | mUseViewSize = false; |
| 124 | |
| 125 | float ratio = Math.min( |
| 126 | (float) mImageW / width, (float) mImageH / height); |
| 127 | |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 128 | // See the comment above translate() for details. |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 129 | mCurrentX = translate(mCurrentX, mImageW, width, ratio); |
| 130 | mCurrentY = translate(mCurrentY, mImageH, height, ratio); |
| 131 | mCurrentScale = mCurrentScale * ratio; |
| 132 | |
| 133 | mFromX = translate(mFromX, mImageW, width, ratio); |
| 134 | mFromY = translate(mFromY, mImageH, height, ratio); |
| 135 | mFromScale = mFromScale * ratio; |
| 136 | |
| 137 | mToX = translate(mToX, mImageW, width, ratio); |
| 138 | mToY = translate(mToY, mImageH, height, ratio); |
| 139 | mToScale = mToScale * ratio; |
| 140 | |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 141 | mFocusBitmapX = translate(mFocusBitmapX, mImageW, width, ratio); |
| 142 | mFocusBitmapY = translate(mFocusBitmapY, mImageH, height, ratio); |
| 143 | |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 144 | mImageW = width; |
| 145 | mImageH = height; |
| 146 | |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 147 | mScaleMin = getMinimalScale(mImageW, mImageH); |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 148 | |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 149 | // Start animation from the saved position if we have one. |
| 150 | Position position = mViewer.retrieveSavedPosition(); |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 151 | if (position != null) { |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 152 | // The animation starts from 240 pixels and centers at the image |
| 153 | // at the saved position. |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 154 | float scale = 240f / Math.min(width, height); |
| 155 | mCurrentX = Math.round((mViewW / 2f - position.x) / scale) + mImageW / 2; |
| 156 | mCurrentY = Math.round((mViewH / 2f - position.y) / scale) + mImageH / 2; |
| 157 | mCurrentScale = scale; |
| 158 | mViewer.openAnimationStarted(); |
| 159 | startSnapback(); |
| 160 | } else if (mAnimationStartTime == NO_ANIMATION) { |
| 161 | mCurrentScale = Utils.clamp(mCurrentScale, mScaleMin, mScaleMax); |
| 162 | } |
| 163 | mViewer.setPosition(mCurrentX, mCurrentY, mCurrentScale); |
| 164 | } |
| 165 | |
| 166 | public void zoomIn(float tapX, float tapY, float targetScale) { |
| 167 | if (targetScale > mScaleMax) targetScale = mScaleMax; |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 168 | |
| 169 | // Convert the tap position to image coordinate |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 170 | int tempX = Math.round((tapX - mViewW / 2) / mCurrentScale + mCurrentX); |
| 171 | int tempY = Math.round((tapY - mViewH / 2) / mCurrentScale + mCurrentY); |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 172 | |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 173 | calculateStableBound(targetScale); |
| 174 | int targetX = Utils.clamp(tempX, mBoundLeft, mBoundRight); |
| 175 | int targetY = Utils.clamp(tempY, mBoundTop, mBoundBottom); |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 176 | |
| 177 | startAnimation(targetX, targetY, targetScale, ANIM_KIND_ZOOM); |
| 178 | } |
| 179 | |
| 180 | public void resetToFullView() { |
| 181 | startAnimation(mImageW / 2, mImageH / 2, mScaleMin, ANIM_KIND_ZOOM); |
| 182 | } |
| 183 | |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 184 | public float getMinimalScale(int w, int h) { |
| 185 | return Math.min(SCALE_LIMIT, |
| 186 | Math.min((float) mViewW / w, (float) mViewH / h)); |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 187 | } |
| 188 | |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 189 | // Translate a coordinate on bitmap if the bitmap size changes. |
| 190 | // If the aspect ratio doesn't change, it's easy: |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 191 | // |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 192 | // r = w / w' (= h / h') |
| 193 | // x' = x / r |
| 194 | // y' = y / r |
| 195 | // |
| 196 | // However the aspect ratio may change. That happens when the user slides |
| 197 | // a image before it's loaded, we don't know the actual aspect ratio, so |
| 198 | // we will assume one. When we receive the actual bitmap size, we need to |
| 199 | // translate the coordinate from the old bitmap into the new bitmap. |
| 200 | // |
| 201 | // What we want to do is center the bitmap at the original position. |
| 202 | // |
| 203 | // ...+--+... |
| 204 | // . | | . |
| 205 | // . | | . |
| 206 | // ...+--+... |
| 207 | // |
| 208 | // First we scale down the new bitmap by a factor r = min(w/w', h/h'). |
| 209 | // Overlay it onto the original bitmap. Now (0, 0) of the old bitmap maps |
| 210 | // to (-(w-w'*r)/2 / r, -(h-h'*r)/2 / r) in the new bitmap. So (x, y) of |
| 211 | // the old bitmap maps to (x', y') in the new bitmap, where |
| 212 | // x' = (x-(w-w'*r)/2) / r = w'/2 + (x-w/2)/r |
| 213 | // y' = (y-(h-h'*r)/2) / r = h'/2 + (y-h/2)/r |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 214 | private static int translate(int value, int size, int newSize, float ratio) { |
| 215 | return Math.round(newSize / 2f + (value - size / 2f) / ratio); |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 216 | } |
| 217 | |
| 218 | public void setViewSize(int viewW, int viewH) { |
| 219 | boolean needLayout = mViewW == 0 || mViewH == 0; |
| 220 | |
| 221 | mViewW = viewW; |
| 222 | mViewH = viewH; |
| 223 | |
| 224 | if (mUseViewSize) { |
| 225 | mImageW = viewW; |
| 226 | mImageH = viewH; |
| 227 | mCurrentX = mImageW / 2; |
| 228 | mCurrentY = mImageH / 2; |
| 229 | mCurrentScale = 1; |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 230 | mScaleMin = 1; |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 231 | mViewer.setPosition(mCurrentX, mCurrentY, mCurrentScale); |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 232 | return; |
| 233 | } |
| 234 | |
| 235 | // In most cases we want to keep the scaling factor intact when the |
| 236 | // view size changes. The cases we want to reset the scaling factor |
| 237 | // (to fit the view if possible) are (1) the scaling factor is too |
| 238 | // small for the new view size (2) the scaling factor has not been |
| 239 | // changed by the user. |
| 240 | boolean wasMinScale = (mCurrentScale == mScaleMin); |
| 241 | mScaleMin = getMinimalScale(mImageW, mImageH); |
| 242 | |
| 243 | if (needLayout || mCurrentScale < mScaleMin || wasMinScale) { |
| 244 | mCurrentX = mImageW / 2; |
| 245 | mCurrentY = mImageH / 2; |
| 246 | mCurrentScale = mScaleMin; |
| 247 | mViewer.setPosition(mCurrentX, mCurrentY, mCurrentScale); |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 248 | } |
| 249 | } |
| 250 | |
| 251 | public void stopAnimation() { |
| 252 | mAnimationStartTime = NO_ANIMATION; |
| 253 | } |
| 254 | |
| 255 | public void skipAnimation() { |
| 256 | if (mAnimationStartTime == NO_ANIMATION) return; |
| 257 | mAnimationStartTime = NO_ANIMATION; |
| 258 | mCurrentX = mToX; |
| 259 | mCurrentY = mToY; |
| 260 | mCurrentScale = mToScale; |
| 261 | } |
| 262 | |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 263 | public void beginScale(float focusX, float focusY) { |
| 264 | mInScale = true; |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 265 | mFocusBitmapX = Math.round(mCurrentX + |
| 266 | (focusX - mViewW / 2f) / mCurrentScale); |
| 267 | mFocusBitmapY = Math.round(mCurrentY + |
| 268 | (focusY - mViewH / 2f) / mCurrentScale); |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 269 | } |
| 270 | |
| 271 | public void scaleBy(float s, float focusX, float focusY) { |
| 272 | |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 273 | // We want to keep the focus point (on the bitmap) the same as when |
| 274 | // we begin the scale guesture, that is, |
| 275 | // |
| 276 | // mCurrentX' + (focusX - mViewW / 2f) / scale = mFocusBitmapX |
| 277 | // |
| 278 | s *= getTargetScale(); |
| 279 | int x = Math.round(mFocusBitmapX - (focusX - mViewW / 2f) / s); |
| 280 | int y = Math.round(mFocusBitmapY - (focusY - mViewH / 2f) / s); |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 281 | |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 282 | startAnimation(x, y, s, ANIM_KIND_SCALE); |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 283 | } |
| 284 | |
| 285 | public void endScale() { |
| 286 | mInScale = false; |
| 287 | startSnapbackIfNeeded(); |
| 288 | } |
| 289 | |
| 290 | public float getCurrentScale() { |
| 291 | return mCurrentScale; |
| 292 | } |
| 293 | |
| 294 | public boolean isAtMinimalScale() { |
| 295 | return isAlmostEquals(mCurrentScale, mScaleMin); |
| 296 | } |
| 297 | |
| 298 | private static boolean isAlmostEquals(float a, float b) { |
| 299 | float diff = a - b; |
| 300 | return (diff < 0 ? -diff : diff) < 0.02f; |
| 301 | } |
| 302 | |
| 303 | public void up() { |
| 304 | startSnapback(); |
| 305 | } |
| 306 | |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 307 | // |<--| (1/2) * mImageW |
| 308 | // +-------+-------+-------+ |
| 309 | // | | | | |
| 310 | // | | o | | |
| 311 | // | | | | |
| 312 | // +-------+-------+-------+ |
| 313 | // |<----------| (3/2) * mImageW |
| 314 | // Slide in the image from left or right. |
| 315 | // Precondition: mCurrentScale = 1 (mView{W|H} == mImage{W|H}). |
| 316 | // Sliding from left: mCurrentX = (1/2) * mImageW |
| 317 | // right: mCurrentX = (3/2) * mImageW |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 318 | public void startSlideInAnimation(int direction) { |
| 319 | int fromX = (direction == PhotoView.TRANS_SLIDE_IN_LEFT) ? |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 320 | mImageW / 2 : 3 * mImageW / 2; |
| 321 | mFromX = Math.round(fromX); |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 322 | mFromY = Math.round(mImageH / 2f); |
| 323 | mCurrentX = mFromX; |
| 324 | mCurrentY = mFromY; |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 325 | startAnimation( |
| 326 | mImageW / 2, mImageH / 2, mCurrentScale, ANIM_KIND_SLIDE); |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 327 | } |
| 328 | |
| 329 | public void startHorizontalSlide(int distance) { |
| 330 | scrollBy(distance, 0, ANIM_KIND_SLIDE); |
| 331 | } |
| 332 | |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 333 | private void scrollBy(float dx, float dy, int type) { |
| 334 | startAnimation(getTargetX() + Math.round(dx / mCurrentScale), |
| 335 | getTargetY() + Math.round(dy / mCurrentScale), |
| 336 | mCurrentScale, type); |
| 337 | } |
| 338 | |
Chih-Chung Chang | 532d93c | 2011-10-12 17:10:33 +0800 | [diff] [blame] | 339 | public void startScroll(float dx, float dy, boolean hasNext, |
| 340 | boolean hasPrev) { |
| 341 | int x = getTargetX() + Math.round(dx / mCurrentScale); |
| 342 | int y = getTargetY() + Math.round(dy / mCurrentScale); |
| 343 | |
| 344 | calculateStableBound(mCurrentScale); |
| 345 | |
| 346 | // Vertical direction: If we have space to move in the vertical |
| 347 | // direction, we show the edge effect when scrolling reaches the edge. |
| 348 | if (mBoundTop != mBoundBottom) { |
| 349 | if (y < mBoundTop) { |
| 350 | mEdgeView.onPull(mBoundTop - y, EdgeView.TOP); |
| 351 | } else if (y > mBoundBottom) { |
| 352 | mEdgeView.onPull(y - mBoundBottom, EdgeView.BOTTOM); |
| 353 | } |
| 354 | } |
| 355 | |
| 356 | y = Utils.clamp(y, mBoundTop, mBoundBottom); |
| 357 | |
| 358 | // Horizontal direction: we show the edge effect when the scrolling |
| 359 | // tries to go left of the first image or go right of the last image. |
| 360 | if (!hasPrev && x < mBoundLeft) { |
| 361 | int pixels = Math.round((mBoundLeft - x) * mCurrentScale); |
| 362 | mEdgeView.onPull(pixels, EdgeView.LEFT); |
| 363 | x = mBoundLeft; |
| 364 | } else if (!hasNext && x > mBoundRight) { |
| 365 | int pixels = Math.round((x - mBoundRight) * mCurrentScale); |
| 366 | mEdgeView.onPull(pixels, EdgeView.RIGHT); |
| 367 | x = mBoundRight; |
| 368 | } |
| 369 | |
| 370 | startAnimation(x, y, mCurrentScale, ANIM_KIND_SCROLL); |
| 371 | } |
| 372 | |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 373 | public boolean fling(float velocityX, float velocityY) { |
| 374 | // We only want to do fling when the picture is zoomed-in. |
| 375 | if (mImageW * mCurrentScale <= mViewW && |
| 376 | mImageH * mCurrentScale <= mViewH) { |
| 377 | return false; |
| 378 | } |
| 379 | |
| 380 | calculateStableBound(mCurrentScale); |
| 381 | mScroller.fling(mCurrentX, mCurrentY, |
| 382 | Math.round(-velocityX / mCurrentScale), |
| 383 | Math.round(-velocityY / mCurrentScale), |
| 384 | mBoundLeft, mBoundRight, mBoundTop, mBoundBottom); |
| 385 | int targetX = mScroller.getFinalX(); |
| 386 | int targetY = mScroller.getFinalY(); |
| 387 | mAnimationDuration = mScroller.getDuration(); |
| 388 | startAnimation(targetX, targetY, mCurrentScale, ANIM_KIND_FLING); |
| 389 | return true; |
| 390 | } |
| 391 | |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 392 | private void startAnimation( |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 393 | int targetX, int targetY, float scale, int kind) { |
| 394 | if (targetX == mCurrentX && targetY == mCurrentY |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 395 | && scale == mCurrentScale) return; |
| 396 | |
| 397 | mFromX = mCurrentX; |
| 398 | mFromY = mCurrentY; |
| 399 | mFromScale = mCurrentScale; |
| 400 | |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 401 | mToX = targetX; |
| 402 | mToY = targetY; |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 403 | mToScale = Utils.clamp(scale, 0.6f * mScaleMin, 1.4f * mScaleMax); |
| 404 | |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 405 | // If the scaled height is smaller than the view height, |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 406 | // force it to be in the center. |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 407 | // (We do for height only, not width, because the user may |
| 408 | // want to scroll to the previous/next image.) |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 409 | if (Math.floor(mImageH * mToScale) <= mViewH) { |
| 410 | mToY = mImageH / 2; |
| 411 | } |
| 412 | |
| 413 | mAnimationStartTime = SystemClock.uptimeMillis(); |
| 414 | mAnimationKind = kind; |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 415 | if (mAnimationKind != ANIM_KIND_FLING) { |
| 416 | mAnimationDuration = ANIM_TIME[mAnimationKind]; |
| 417 | } |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 418 | if (advanceAnimation()) mViewer.invalidate(); |
| 419 | } |
| 420 | |
| 421 | // Returns true if redraw is needed. |
| 422 | public boolean advanceAnimation() { |
| 423 | if (mAnimationStartTime == NO_ANIMATION) { |
| 424 | return false; |
| 425 | } else if (mAnimationStartTime == LAST_ANIMATION) { |
| 426 | mAnimationStartTime = NO_ANIMATION; |
| 427 | if (mViewer.isInTransition()) { |
| 428 | mViewer.notifyTransitionComplete(); |
| 429 | return false; |
| 430 | } else { |
| 431 | return startSnapbackIfNeeded(); |
| 432 | } |
| 433 | } |
| 434 | |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 435 | long now = SystemClock.uptimeMillis(); |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 436 | float progress; |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 437 | if (mAnimationDuration == 0) { |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 438 | progress = 1; |
| 439 | } else { |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 440 | progress = (now - mAnimationStartTime) / mAnimationDuration; |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 441 | } |
| 442 | |
| 443 | if (progress >= 1) { |
| 444 | progress = 1; |
| 445 | mCurrentX = mToX; |
| 446 | mCurrentY = mToY; |
| 447 | mCurrentScale = mToScale; |
| 448 | mAnimationStartTime = LAST_ANIMATION; |
| 449 | } else { |
| 450 | float f = 1 - progress; |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 451 | switch (mAnimationKind) { |
| 452 | case ANIM_KIND_SCROLL: |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 453 | case ANIM_KIND_FLING: |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 454 | progress = 1 - f; // linear |
| 455 | break; |
| 456 | case ANIM_KIND_SCALE: |
| 457 | progress = 1 - f * f; // quadratic |
| 458 | break; |
| 459 | case ANIM_KIND_SNAPBACK: |
| 460 | case ANIM_KIND_ZOOM: |
| 461 | case ANIM_KIND_SLIDE: |
| 462 | progress = 1 - f * f * f * f * f; // x^5 |
| 463 | break; |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 464 | } |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 465 | if (mAnimationKind == ANIM_KIND_FLING) { |
| 466 | flingInterpolate(progress); |
| 467 | } else { |
| 468 | linearInterpolate(progress); |
| 469 | } |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 470 | } |
| 471 | mViewer.setPosition(mCurrentX, mCurrentY, mCurrentScale); |
| 472 | return true; |
| 473 | } |
| 474 | |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 475 | private void flingInterpolate(float progress) { |
| 476 | mScroller.computeScrollOffset(progress); |
Chih-Chung Chang | 532d93c | 2011-10-12 17:10:33 +0800 | [diff] [blame] | 477 | int oldX = mCurrentX; |
| 478 | int oldY = mCurrentY; |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 479 | mCurrentX = mScroller.getCurrX(); |
| 480 | mCurrentY = mScroller.getCurrY(); |
Chih-Chung Chang | 532d93c | 2011-10-12 17:10:33 +0800 | [diff] [blame] | 481 | |
| 482 | // Check if we hit the edges; show edge effects if we do. |
| 483 | if (oldX > mBoundLeft && mCurrentX == mBoundLeft) { |
| 484 | int v = Math.round(-mScroller.getCurrVelocityX() * mCurrentScale); |
| 485 | mEdgeView.onAbsorb(v, EdgeView.LEFT); |
| 486 | } else if (oldX < mBoundRight && mCurrentX == mBoundRight) { |
| 487 | int v = Math.round(mScroller.getCurrVelocityX() * mCurrentScale); |
| 488 | mEdgeView.onAbsorb(v, EdgeView.RIGHT); |
| 489 | } |
| 490 | |
| 491 | if (oldY > mBoundTop && mCurrentY == mBoundTop) { |
| 492 | int v = Math.round(-mScroller.getCurrVelocityY() * mCurrentScale); |
| 493 | mEdgeView.onAbsorb(v, EdgeView.TOP); |
| 494 | } else if (oldY < mBoundBottom && mCurrentY == mBoundBottom) { |
| 495 | int v = Math.round(mScroller.getCurrVelocityY() * mCurrentScale); |
| 496 | mEdgeView.onAbsorb(v, EdgeView.BOTTOM); |
| 497 | } |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 498 | } |
| 499 | |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 500 | // Interpolates mCurrent{X,Y,Scale} given the progress in [0, 1]. |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 501 | private void linearInterpolate(float progress) { |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 502 | // To linearly interpolate the position on view coordinates, we do the |
| 503 | // following steps: |
| 504 | // (1) convert a bitmap position (x, y) to view coordinates: |
| 505 | // from: (x - mFromX) * mFromScale + mViewW / 2 |
| 506 | // to: (x - mToX) * mToScale + mViewW / 2 |
| 507 | // (2) interpolate between the "from" and "to" coordinates: |
| 508 | // (x - mFromX) * mFromScale * (1 - p) + (x - mToX) * mToScale * p |
| 509 | // + mViewW / 2 |
| 510 | // should be equal to |
| 511 | // (x - mCurrentX) * mCurrentScale + mViewW / 2 |
| 512 | // (3) The x-related terms in the above equation can be removed because |
| 513 | // mFromScale * (1 - p) + ToScale * p = mCurrentScale |
| 514 | // (4) Solve for mCurrentX, we have mCurrentX = |
| 515 | // (mFromX * mFromScale * (1 - p) + mToX * mToScale * p) / mCurrentScale |
| 516 | float fromX = mFromX * mFromScale; |
| 517 | float toX = mToX * mToScale; |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 518 | float currentX = fromX + progress * (toX - fromX); |
| 519 | |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 520 | float fromY = mFromY * mFromScale; |
| 521 | float toY = mToY * mToScale; |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 522 | float currentY = fromY + progress * (toY - fromY); |
| 523 | |
| 524 | mCurrentScale = mFromScale + progress * (mToScale - mFromScale); |
Chih-Chung Chang | 676170e | 2011-09-30 18:33:17 +0800 | [diff] [blame] | 525 | mCurrentX = Math.round(currentX / mCurrentScale); |
| 526 | mCurrentY = Math.round(currentY / mCurrentScale); |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 527 | } |
| 528 | |
| 529 | // Returns true if redraw is needed. |
| 530 | private boolean startSnapbackIfNeeded() { |
| 531 | if (mAnimationStartTime != NO_ANIMATION) return false; |
| 532 | if (mInScale) return false; |
| 533 | if (mAnimationKind == ANIM_KIND_SCROLL && mViewer.isDown()) { |
| 534 | return false; |
| 535 | } |
| 536 | return startSnapback(); |
| 537 | } |
| 538 | |
| 539 | public boolean startSnapback() { |
| 540 | boolean needAnimation = false; |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 541 | float scale = mCurrentScale; |
| 542 | |
| 543 | if (mCurrentScale < mScaleMin || mCurrentScale > mScaleMax) { |
| 544 | needAnimation = true; |
| 545 | scale = Utils.clamp(mCurrentScale, mScaleMin, mScaleMax); |
| 546 | } |
| 547 | |
Chih-Chung Chang | 8f568da | 2012-01-05 12:00:53 +0800 | [diff] [blame^] | 548 | calculateStableBound(scale, sHorizontalSlack); |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 549 | int x = Utils.clamp(mCurrentX, mBoundLeft, mBoundRight); |
| 550 | int y = Utils.clamp(mCurrentY, mBoundTop, mBoundBottom); |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 551 | |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 552 | if (mCurrentX != x || mCurrentY != y || mCurrentScale != scale) { |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 553 | needAnimation = true; |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 554 | } |
| 555 | |
| 556 | if (needAnimation) { |
| 557 | startAnimation(x, y, scale, ANIM_KIND_SNAPBACK); |
| 558 | } |
| 559 | |
| 560 | return needAnimation; |
| 561 | } |
| 562 | |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 563 | // Calculates the stable region of mCurrent{X/Y}, where "stable" means |
| 564 | // |
| 565 | // (1) If the dimension of scaled image >= view dimension, we will not |
| 566 | // see black region outside the image (at that dimension). |
| 567 | // (2) If the dimension of scaled image < view dimension, we will center |
| 568 | // the scaled image. |
| 569 | // |
| 570 | // We might temporarily go out of this stable during user interaction, |
| 571 | // but will "snap back" after user stops interaction. |
| 572 | // |
| 573 | // The results are stored in mBound{Left/Right/Top/Bottom}. |
| 574 | // |
Chih-Chung Chang | 8f568da | 2012-01-05 12:00:53 +0800 | [diff] [blame^] | 575 | // An extra parameter "horizontalSlack" (which has the value of 0 usually) |
| 576 | // is used to extend the stable region by some pixels on each side |
| 577 | // horizontally. |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 578 | private void calculateStableBound(float scale) { |
Chih-Chung Chang | 8f568da | 2012-01-05 12:00:53 +0800 | [diff] [blame^] | 579 | calculateStableBound(scale, 0f); |
| 580 | } |
| 581 | |
| 582 | private void calculateStableBound(float scale, float horizontalSlack) { |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 583 | // The number of pixels between the center of the view |
| 584 | // and the edge when the edge is aligned. |
Chih-Chung Chang | 8f568da | 2012-01-05 12:00:53 +0800 | [diff] [blame^] | 585 | mBoundLeft = (int) Math.ceil((mViewW - horizontalSlack) / (2 * scale)); |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 586 | mBoundRight = mImageW - mBoundLeft; |
| 587 | mBoundTop = (int) Math.ceil(mViewH / (2 * scale)); |
| 588 | mBoundBottom = mImageH - mBoundTop; |
| 589 | |
| 590 | // If the scaled height is smaller than the view height, |
| 591 | // force it to be in the center. |
| 592 | if (Math.floor(mImageH * scale) <= mViewH) { |
| 593 | mBoundTop = mBoundBottom = mImageH / 2; |
| 594 | } |
| 595 | |
| 596 | // Same for width |
| 597 | if (Math.floor(mImageW * scale) <= mViewW) { |
| 598 | mBoundLeft = mBoundRight = mImageW / 2; |
| 599 | } |
| 600 | } |
| 601 | |
| 602 | private boolean useCurrentValueAsTarget() { |
| 603 | return mAnimationStartTime == NO_ANIMATION || |
| 604 | mAnimationKind == ANIM_KIND_SNAPBACK || |
| 605 | mAnimationKind == ANIM_KIND_FLING; |
| 606 | } |
| 607 | |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 608 | private float getTargetScale() { |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 609 | return useCurrentValueAsTarget() ? mCurrentScale : mToScale; |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 610 | } |
| 611 | |
| 612 | private int getTargetX() { |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 613 | return useCurrentValueAsTarget() ? mCurrentX : mToX; |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 614 | } |
| 615 | |
| 616 | private int getTargetY() { |
Chih-Chung Chang | b3aab90 | 2011-10-03 21:11:39 +0800 | [diff] [blame] | 617 | return useCurrentValueAsTarget() ? mCurrentY : mToY; |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 618 | } |
| 619 | |
| 620 | public RectF getImageBounds() { |
| 621 | float points[] = mTempPoints; |
| 622 | |
| 623 | /* |
| 624 | * (p0,p1)----------(p2,p3) |
| 625 | * | | |
| 626 | * | | |
| 627 | * (p4,p5)----------(p6,p7) |
| 628 | */ |
| 629 | points[0] = points[4] = -mCurrentX; |
| 630 | points[1] = points[3] = -mCurrentY; |
| 631 | points[2] = points[6] = mImageW - mCurrentX; |
| 632 | points[5] = points[7] = mImageH - mCurrentY; |
| 633 | |
| 634 | RectF rect = mTempRect; |
| 635 | rect.set(Float.POSITIVE_INFINITY, Float.POSITIVE_INFINITY, |
| 636 | Float.NEGATIVE_INFINITY, Float.NEGATIVE_INFINITY); |
| 637 | |
| 638 | float scale = mCurrentScale; |
| 639 | float offsetX = mViewW / 2; |
| 640 | float offsetY = mViewH / 2; |
| 641 | for (int i = 0; i < 4; ++i) { |
| 642 | float x = points[i + i] * scale + offsetX; |
| 643 | float y = points[i + i + 1] * scale + offsetY; |
| 644 | if (x < rect.left) rect.left = x; |
| 645 | if (x > rect.right) rect.right = x; |
| 646 | if (y < rect.top) rect.top = y; |
| 647 | if (y > rect.bottom) rect.bottom = y; |
| 648 | } |
| 649 | return rect; |
| 650 | } |
| 651 | |
| 652 | public int getImageWidth() { |
| 653 | return mImageW; |
| 654 | } |
| 655 | |
| 656 | public int getImageHeight() { |
| 657 | return mImageH; |
| 658 | } |
Chih-Chung Chang | 532d93c | 2011-10-12 17:10:33 +0800 | [diff] [blame] | 659 | |
| 660 | public boolean isAtLeftEdge() { |
| 661 | calculateStableBound(mCurrentScale); |
| 662 | return mCurrentX <= mBoundLeft; |
| 663 | } |
| 664 | |
| 665 | public boolean isAtRightEdge() { |
| 666 | calculateStableBound(mCurrentScale); |
| 667 | return mCurrentX >= mBoundRight; |
| 668 | } |
Chih-Chung Chang | ec41254 | 2011-09-26 17:34:06 +0800 | [diff] [blame] | 669 | } |