PhotoView.java revision 413185316e9e6f0713185d9adc733b2768ab5aa1
1/* 2 * Copyright (C) 2011 Google Inc. 3 * Licensed to The Android Open Source Project. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18package com.android.ex.photo.views; 19 20import android.content.Context; 21import android.content.pm.PackageManager; 22import android.content.res.Resources; 23import android.graphics.Bitmap; 24import android.graphics.Canvas; 25import android.graphics.Matrix; 26import android.graphics.Paint; 27import android.graphics.Paint.Style; 28import android.graphics.Rect; 29import android.graphics.RectF; 30import android.graphics.drawable.BitmapDrawable; 31import android.support.v4.view.GestureDetectorCompat; 32import android.util.AttributeSet; 33import android.view.GestureDetector.OnGestureListener; 34import android.view.GestureDetector.OnDoubleTapListener; 35import android.view.MotionEvent; 36import android.view.ScaleGestureDetector; 37import android.view.View; 38 39import com.android.ex.photo.R; 40import com.android.ex.photo.fragments.PhotoViewFragment.HorizontallyScrollable; 41 42/** 43 * Layout for the photo list view header. 44 */ 45public class PhotoView extends View implements OnGestureListener, 46 OnDoubleTapListener, ScaleGestureDetector.OnScaleGestureListener, 47 HorizontallyScrollable { 48 /** Zoom animation duration; in milliseconds */ 49 private final static long ZOOM_ANIMATION_DURATION = 300L; 50 /** Rotate animation duration; in milliseconds */ 51 private final static long ROTATE_ANIMATION_DURATION = 500L; 52 /** Snap animation duration; in milliseconds */ 53 private static final long SNAP_DURATION = 100L; 54 /** Amount of time to wait before starting snap animation; in milliseconds */ 55 private static final long SNAP_DELAY = 250L; 56 /** By how much to scale the image when double click occurs */ 57 private final static float DOUBLE_TAP_SCALE_FACTOR = 1.5f; 58 /** Amount of translation needed before starting a snap animation */ 59 private final static float SNAP_THRESHOLD = 20.0f; 60 /** The width & height of the bitmap returned by {@link #getCroppedPhoto()} */ 61 private final static float CROPPED_SIZE = 256.0f; 62 63 /** If {@code true}, the static values have been initialized */ 64 private static boolean sInitialized; 65 66 // Various dimensions 67 /** Width & height of the crop region */ 68 private static int sCropSize; 69 70 // Bitmaps 71 /** Video icon */ 72 private static Bitmap sVideoImage; 73 /** Video icon */ 74 private static Bitmap sVideoNotReadyImage; 75 76 // Features 77 private static boolean sHasMultitouchDistinct; 78 79 // Paints 80 /** Paint to partially dim the photo during crop */ 81 private static Paint sCropDimPaint; 82 /** Paint to highlight the cropped portion of the photo */ 83 private static Paint sCropPaint; 84 85 /** The photo to display */ 86 private BitmapDrawable mDrawable; 87 /** The matrix used for drawing; this may be {@code null} */ 88 private Matrix mDrawMatrix; 89 /** A matrix to apply the scaling of the photo */ 90 private Matrix mMatrix = new Matrix(); 91 /** The original matrix for this image; used to reset any transformations applied by the user */ 92 private Matrix mOriginalMatrix = new Matrix(); 93 94 /** The fixed height of this view. If {@code -1}, calculate the height */ 95 private int mFixedHeight = -1; 96 /** When {@code true}, the view has been laid out */ 97 private boolean mHaveLayout; 98 /** Whether or not the photo is full-screen */ 99 private boolean mFullScreen; 100 /** Whether or not this is a still image of a video */ 101 private byte[] mVideoBlob; 102 /** Whether or not this is a still image of a video */ 103 private boolean mVideoReady; 104 105 /** Whether or not crop is allowed */ 106 private boolean mAllowCrop; 107 /** The crop region */ 108 private Rect mCropRect = new Rect(); 109 /** Actual crop size; may differ from {@link #sCropSize} if the screen is smaller */ 110 private int mCropSize; 111 /** The maximum amount of scaling to apply to images */ 112 private float mMaxInitialScaleFactor; 113 114 /** Gesture detector */ 115 private GestureDetectorCompat mGestureDetector; 116 /** Gesture detector that detects pinch gestures */ 117 private ScaleGestureDetector mScaleGetureDetector; 118 /** An external click listener */ 119 private OnClickListener mExternalClickListener; 120 /** When {@code true}, allows gestures to scale / pan the image */ 121 private boolean mTransformsEnabled; 122 123 // To support zooming 124 /** When {@code true}, a double tap scales the image by {@link #DOUBLE_TAP_SCALE_FACTOR} */ 125 private boolean mDoubleTapToZoomEnabled = true; 126 /** When {@code true}, prevents scale end gesture from falsely triggering a double click. */ 127 private boolean mDoubleTapDebounce; 128 /** When {@code false}, event is a scale gesture. Otherwise, event is a double touch. */ 129 private boolean mIsDoubleTouch; 130 /** Runnable that scales the image */ 131 private ScaleRunnable mScaleRunnable; 132 /** Minimum scale the image can have. */ 133 private float mMinScale; 134 /** Maximum scale to limit scaling to, 0 means no limit. */ 135 private float mMaxScale; 136 137 // To support translation [i.e. panning] 138 /** Runnable that can move the image */ 139 private TranslateRunnable mTranslateRunnable; 140 private SnapRunnable mSnapRunnable; 141 142 // To support rotation 143 /** The rotate runnable used to animate rotations of the image */ 144 private RotateRunnable mRotateRunnable; 145 /** The current rotation amount, in degrees */ 146 private float mRotation; 147 148 // Convenience fields 149 // These are declared here not because they are important properties of the view. Rather, we 150 // declare them here to avoid object allocation during critical graphics operations; such as 151 // layout or drawing. 152 /** Source (i.e. the photo size) bounds */ 153 private RectF mTempSrc = new RectF(); 154 /** Destination (i.e. the display) bounds. The image is scaled to this size. */ 155 private RectF mTempDst = new RectF(); 156 /** Rectangle to handle translations */ 157 private RectF mTranslateRect = new RectF(); 158 /** Array to store a copy of the matrix values */ 159 private float[] mValues = new float[9]; 160 161 public PhotoView(Context context) { 162 super(context); 163 initialize(); 164 } 165 166 public PhotoView(Context context, AttributeSet attrs) { 167 super(context, attrs); 168 initialize(); 169 } 170 171 public PhotoView(Context context, AttributeSet attrs, int defStyle) { 172 super(context, attrs, defStyle); 173 initialize(); 174 } 175 176 @Override 177 public boolean onTouchEvent(MotionEvent event) { 178 if (mScaleGetureDetector == null || mGestureDetector == null) { 179 // We're being destroyed; ignore any touch events 180 return true; 181 } 182 183 mScaleGetureDetector.onTouchEvent(event); 184 mGestureDetector.onTouchEvent(event); 185 final int action = event.getAction(); 186 187 switch (action) { 188 case MotionEvent.ACTION_UP: 189 case MotionEvent.ACTION_CANCEL: 190 if (!mTranslateRunnable.mRunning) { 191 snap(); 192 } 193 break; 194 } 195 196 return true; 197 } 198 199 @Override 200 public boolean onDoubleTap(MotionEvent e) { 201 if (mDoubleTapToZoomEnabled && mTransformsEnabled) { 202 if (!mDoubleTapDebounce) { 203 float currentScale = getScale(); 204 float targetScale = currentScale * DOUBLE_TAP_SCALE_FACTOR; 205 206 // Ensure the target scale is within our bounds 207 targetScale = Math.max(mMinScale, targetScale); 208 targetScale = Math.min(mMaxScale, targetScale); 209 210 mScaleRunnable.start(currentScale, targetScale, e.getX(), e.getY()); 211 } 212 mDoubleTapDebounce = false; 213 } 214 return true; 215 } 216 217 @Override 218 public boolean onDoubleTapEvent(MotionEvent e) { 219 return true; 220 } 221 222 @Override 223 public boolean onSingleTapConfirmed(MotionEvent e) { 224 if (mExternalClickListener != null && !mIsDoubleTouch) { 225 mExternalClickListener.onClick(this); 226 } 227 mIsDoubleTouch = false; 228 return true; 229 } 230 231 @Override 232 public boolean onSingleTapUp(MotionEvent e) { 233 return false; 234 } 235 236 @Override 237 public void onLongPress(MotionEvent e) { 238 } 239 240 @Override 241 public void onShowPress(MotionEvent e) { 242 } 243 244 @Override 245 public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) { 246 if (mTransformsEnabled) { 247 translate(-distanceX, -distanceY); 248 } 249 return true; 250 } 251 252 @Override 253 public boolean onDown(MotionEvent e) { 254 if (mTransformsEnabled) { 255 mTranslateRunnable.stop(); 256 mSnapRunnable.stop(); 257 } 258 return true; 259 } 260 261 @Override 262 public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) { 263 if (mTransformsEnabled) { 264 mTranslateRunnable.start(velocityX, velocityY); 265 } 266 return true; 267 } 268 269 @Override 270 public boolean onScale(ScaleGestureDetector detector) { 271 if (mTransformsEnabled) { 272 mIsDoubleTouch = false; 273 float currentScale = getScale(); 274 float newScale = currentScale * detector.getScaleFactor(); 275 scale(newScale, detector.getFocusX(), detector.getFocusY()); 276 } 277 return true; 278 } 279 280 @Override 281 public boolean onScaleBegin(ScaleGestureDetector detector) { 282 if (mTransformsEnabled) { 283 mScaleRunnable.stop(); 284 mIsDoubleTouch = true; 285 } 286 return true; 287 } 288 289 @Override 290 public void onScaleEnd(ScaleGestureDetector detector) { 291 if (mTransformsEnabled && mIsDoubleTouch) { 292 mDoubleTapDebounce = true; 293 resetTransformations(); 294 } 295 } 296 297 @Override 298 public void setOnClickListener(OnClickListener listener) { 299 mExternalClickListener = listener; 300 } 301 302 @Override 303 public boolean interceptMoveLeft(float origX, float origY) { 304 if (!mTransformsEnabled) { 305 // Allow intercept if we're not in transform mode 306 return false; 307 } else if (mTranslateRunnable.mRunning) { 308 // Don't allow touch intercept until we've stopped flinging 309 return true; 310 } else { 311 mMatrix.getValues(mValues); 312 mTranslateRect.set(mTempSrc); 313 mMatrix.mapRect(mTranslateRect); 314 315 final float viewWidth = getWidth(); 316 final float transX = mValues[Matrix.MTRANS_X]; 317 final float drawWidth = mTranslateRect.right - mTranslateRect.left; 318 319 if (!mTransformsEnabled || drawWidth <= viewWidth) { 320 // Allow intercept if not in transform mode or the image is smaller than the view 321 return false; 322 } else if (transX == 0) { 323 // We're at the left-side of the image; allow intercepting movements to the right 324 return false; 325 } else if (viewWidth >= drawWidth + transX) { 326 // We're at the right-side of the image; allow intercepting movements to the left 327 return true; 328 } else { 329 // We're in the middle of the image; don't allow touch intercept 330 return true; 331 } 332 } 333 } 334 335 @Override 336 public boolean interceptMoveRight(float origX, float origY) { 337 if (!mTransformsEnabled) { 338 // Allow intercept if we're not in transform mode 339 return false; 340 } else if (mTranslateRunnable.mRunning) { 341 // Don't allow touch intercept until we've stopped flinging 342 return true; 343 } else { 344 mMatrix.getValues(mValues); 345 mTranslateRect.set(mTempSrc); 346 mMatrix.mapRect(mTranslateRect); 347 348 final float viewWidth = getWidth(); 349 final float transX = mValues[Matrix.MTRANS_X]; 350 final float drawWidth = mTranslateRect.right - mTranslateRect.left; 351 352 if (!mTransformsEnabled || drawWidth <= viewWidth) { 353 // Allow intercept if not in transform mode or the image is smaller than the view 354 return false; 355 } else if (transX == 0) { 356 // We're at the left-side of the image; allow intercepting movements to the right 357 return true; 358 } else if (viewWidth >= drawWidth + transX) { 359 // We're at the right-side of the image; allow intercepting movements to the left 360 return false; 361 } else { 362 // We're in the middle of the image; don't allow touch intercept 363 return true; 364 } 365 } 366 } 367 368 /** 369 * Free all resources held by this view. 370 * The view is on its way to be collected and will not be reused. 371 */ 372 public void clear() { 373 mGestureDetector = null; 374 mScaleGetureDetector = null; 375 mDrawable = null; 376 mScaleRunnable.stop(); 377 mScaleRunnable = null; 378 mTranslateRunnable.stop(); 379 mTranslateRunnable = null; 380 mSnapRunnable.stop(); 381 mSnapRunnable = null; 382 mRotateRunnable.stop(); 383 mRotateRunnable = null; 384 setOnClickListener(null); 385 mExternalClickListener = null; 386 } 387 388 /** 389 * Binds a bitmap to the view. 390 * 391 * @param photoBitmap the bitmap to bind. 392 */ 393 public void bindPhoto(Bitmap photoBitmap) { 394 boolean changed = false; 395 if (mDrawable != null) { 396 final Bitmap drawableBitmap = mDrawable.getBitmap(); 397 if (photoBitmap == drawableBitmap) { 398 // setting the same bitmap; do nothing 399 return; 400 } 401 402 changed = photoBitmap != null && 403 (mDrawable.getIntrinsicWidth() != photoBitmap.getWidth() || 404 mDrawable.getIntrinsicHeight() != photoBitmap.getHeight()); 405 406 // Reset mMinScale to ensure the bounds / matrix are recalculated 407 mMinScale = 0f; 408 mDrawable = null; 409 } 410 411 if (mDrawable == null && photoBitmap != null) { 412 mDrawable = new BitmapDrawable(getResources(), photoBitmap); 413 } 414 415 configureBounds(changed); 416 invalidate(); 417 } 418 419 /** 420 * Returns the bound photo data if set. Otherwise, {@code null}. 421 */ 422 public Bitmap getPhoto() { 423 if (mDrawable != null) { 424 return mDrawable.getBitmap(); 425 } 426 return null; 427 } 428 429 /** 430 * Gets video data associated with this item. Returns {@code null} if this is not a video. 431 */ 432 public byte[] getVideoData() { 433 return mVideoBlob; 434 } 435 436 /** 437 * Returns {@code true} if the photo represents a video. Otherwise, {@code false}. 438 */ 439 public boolean isVideo() { 440 return mVideoBlob != null; 441 } 442 443 /** 444 * Returns {@code true} if the video is ready to play. Otherwise, {@code false}. 445 */ 446 public boolean isVideoReady() { 447 return mVideoBlob != null && mVideoReady; 448 } 449 450 /** 451 * Returns {@code true} if a photo has been bound. Otherwise, {@code false}. 452 */ 453 public boolean isPhotoBound() { 454 return mDrawable != null; 455 } 456 457 /** 458 * Hides the photo info portion of the header. As a side effect, this automatically enables 459 * or disables image transformations [eg zoom, pan, etc...] depending upon the value of 460 * fullScreen. If this is not desirable, enable / disable image transformations manually. 461 */ 462 public void setFullScreen(boolean fullScreen, boolean animate) { 463 if (fullScreen != mFullScreen) { 464 mFullScreen = fullScreen; 465 requestLayout(); 466 invalidate(); 467 } 468 } 469 470 /** 471 * Enable or disable cropping of the displayed image. Cropping can only be enabled 472 * <em>before</em> the view has been laid out. Additionally, once cropping has been 473 * enabled, it cannot be disabled. 474 */ 475 public void enableAllowCrop(boolean allowCrop) { 476 if (allowCrop && mHaveLayout) { 477 throw new IllegalArgumentException("Cannot set crop after view has been laid out"); 478 } 479 if (!allowCrop && mAllowCrop) { 480 throw new IllegalArgumentException("Cannot unset crop mode"); 481 } 482 mAllowCrop = allowCrop; 483 } 484 485 /** 486 * Gets a bitmap of the cropped region. If cropping is not enabled, returns {@code null}. 487 */ 488 public Bitmap getCroppedPhoto() { 489 if (!mAllowCrop) { 490 return null; 491 } 492 493 final Bitmap croppedBitmap = Bitmap.createBitmap( 494 (int) CROPPED_SIZE, (int) CROPPED_SIZE, Bitmap.Config.ARGB_8888); 495 final Canvas croppedCanvas = new Canvas(croppedBitmap); 496 497 // scale for the final dimensions 498 final int cropWidth = mCropRect.right - mCropRect.left; 499 final float scaleWidth = CROPPED_SIZE / cropWidth; 500 final float scaleHeight = CROPPED_SIZE / cropWidth; 501 502 // translate to the origin & scale 503 final Matrix matrix = new Matrix(mDrawMatrix); 504 matrix.postTranslate(-mCropRect.left, -mCropRect.top); 505 matrix.postScale(scaleWidth, scaleHeight); 506 507 // draw the photo 508 if (mDrawable != null) { 509 croppedCanvas.concat(matrix); 510 mDrawable.draw(croppedCanvas); 511 } 512 return croppedBitmap; 513 } 514 515 /** 516 * Resets the image transformation to its original value. 517 */ 518 public void resetTransformations() { 519 // snap transformations; we don't animate 520 mMatrix.set(mOriginalMatrix); 521 522 // Invalidate the view because if you move off this PhotoView 523 // to another one and come back, you want it to draw from scratch 524 // in case you were zoomed in or translated (since those settings 525 // are not preserved and probably shouldn't be). 526 invalidate(); 527 } 528 529 /** 530 * Rotates the image 90 degrees, clockwise. 531 */ 532 public void rotateClockwise() { 533 rotate(90, true); 534 } 535 536 /** 537 * Rotates the image 90 degrees, counter clockwise. 538 */ 539 public void rotateCounterClockwise() { 540 rotate(-90, true); 541 } 542 543 @Override 544 protected void onDraw(Canvas canvas) { 545 super.onDraw(canvas); 546 547 // draw the photo 548 if (mDrawable != null) { 549 int saveCount = canvas.getSaveCount(); 550 canvas.save(); 551 552 if (mDrawMatrix != null) { 553 canvas.concat(mDrawMatrix); 554 } 555 mDrawable.draw(canvas); 556 557 canvas.restoreToCount(saveCount); 558 559 if (mVideoBlob != null) { 560 final Bitmap videoImage = (mVideoReady ? sVideoImage : sVideoNotReadyImage); 561 final int drawLeft = (getWidth() - videoImage.getWidth()) / 2; 562 final int drawTop = (getHeight() - videoImage.getHeight()) / 2; 563 canvas.drawBitmap(videoImage, drawLeft, drawTop, null); 564 } 565 566 // Extract the drawable's bounds (in our own copy, to not alter the image) 567 mTranslateRect.set(mDrawable.getBounds()); 568 if (mDrawMatrix != null) { 569 mDrawMatrix.mapRect(mTranslateRect); 570 } 571 572 if (mAllowCrop) { 573 int previousSaveCount = canvas.getSaveCount(); 574 canvas.drawRect(0, 0, getWidth(), getHeight(), sCropDimPaint); 575 canvas.save(); 576 canvas.clipRect(mCropRect); 577 578 if (mDrawMatrix != null) { 579 canvas.concat(mDrawMatrix); 580 } 581 582 mDrawable.draw(canvas); 583 canvas.restoreToCount(previousSaveCount); 584 canvas.drawRect(mCropRect, sCropPaint); 585 } 586 } 587 } 588 589 @Override 590 protected void onLayout(boolean changed, int left, int top, int right, int bottom) { 591 super.onLayout(changed, left, top, right, bottom); 592 mHaveLayout = true; 593 final int layoutWidth = getWidth(); 594 final int layoutHeight = getHeight(); 595 596 if (mAllowCrop) { 597 mCropSize = Math.min(sCropSize, Math.min(layoutWidth, layoutHeight)); 598 final int cropLeft = (layoutWidth - mCropSize) / 2; 599 final int cropTop = (layoutHeight - mCropSize) / 2; 600 final int cropRight = cropLeft + mCropSize; 601 final int cropBottom = cropTop + mCropSize; 602 603 // Create a crop region overlay. We need a separate canvas to be able to "punch 604 // a hole" through to the underlying image. 605 mCropRect.set(cropLeft, cropTop, cropRight, cropBottom); 606 } 607 configureBounds(changed); 608 } 609 610 @Override 611 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 612 if (mFixedHeight != -1) { 613 super.onMeasure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(mFixedHeight, 614 MeasureSpec.AT_MOST)); 615 setMeasuredDimension(getMeasuredWidth(), mFixedHeight); 616 } else { 617 super.onMeasure(widthMeasureSpec, heightMeasureSpec); 618 } 619 } 620 621 /** 622 * Forces a fixed height for this view. 623 * 624 * @param fixedHeight The height. If {@code -1}, use the measured height. 625 */ 626 public void setFixedHeight(int fixedHeight) { 627 final boolean adjustBounds = (fixedHeight != mFixedHeight); 628 mFixedHeight = fixedHeight; 629 setMeasuredDimension(getMeasuredWidth(), mFixedHeight); 630 if (adjustBounds) { 631 configureBounds(true); 632 requestLayout(); 633 } 634 } 635 636 /** 637 * Enable or disable image transformations. When transformations are enabled, this view 638 * consumes all touch events. 639 */ 640 public void enableImageTransforms(boolean enable) { 641 mTransformsEnabled = enable; 642 if (!mTransformsEnabled) { 643 resetTransformations(); 644 } 645 } 646 647 /** 648 * Configures the bounds of the photo. The photo will always be scaled to fit center. 649 */ 650 private void configureBounds(boolean changed) { 651 if (mDrawable == null || !mHaveLayout) { 652 return; 653 } 654 final int dwidth = mDrawable.getIntrinsicWidth(); 655 final int dheight = mDrawable.getIntrinsicHeight(); 656 657 final int vwidth = getWidth(); 658 final int vheight = getHeight(); 659 660 final boolean fits = (dwidth < 0 || vwidth == dwidth) && 661 (dheight < 0 || vheight == dheight); 662 663 // We need to do the scaling ourself, so have the drawable use its native size. 664 mDrawable.setBounds(0, 0, dwidth, dheight); 665 666 // Create a matrix with the proper transforms 667 if (changed || (mMinScale == 0 && mDrawable != null && mHaveLayout)) { 668 generateMatrix(); 669 generateScale(); 670 } 671 672 if (fits || mMatrix.isIdentity()) { 673 // The bitmap fits exactly, no transform needed. 674 mDrawMatrix = null; 675 } else { 676 mDrawMatrix = mMatrix; 677 } 678 } 679 680 /** 681 * Generates the initial transformation matrix for drawing. Additionally, it sets the 682 * minimum and maximum scale values. 683 */ 684 private void generateMatrix() { 685 final int dwidth = mDrawable.getIntrinsicWidth(); 686 final int dheight = mDrawable.getIntrinsicHeight(); 687 688 final int vwidth = mAllowCrop ? sCropSize : getWidth(); 689 final int vheight = mAllowCrop ? sCropSize : getHeight(); 690 691 final boolean fits = (dwidth < 0 || vwidth == dwidth) && 692 (dheight < 0 || vheight == dheight); 693 694 if (fits && !mAllowCrop) { 695 mMatrix.reset(); 696 } else { 697 // Generate the required transforms for the photo 698 mTempSrc.set(0, 0, dwidth, dheight); 699 if (mAllowCrop) { 700 mTempDst.set(mCropRect); 701 } else { 702 mTempDst.set(0, 0, vwidth, vheight); 703 } 704 RectF scaledDestination = new RectF( 705 (vwidth / 2) - (dwidth * mMaxInitialScaleFactor / 2), 706 (vheight / 2) - (dheight * mMaxInitialScaleFactor / 2), 707 (vwidth / 2) + (dwidth * mMaxInitialScaleFactor / 2), 708 (vheight / 2) + (dheight * mMaxInitialScaleFactor / 2)); 709 if(mTempDst.contains(scaledDestination)) { 710 mMatrix.setRectToRect(mTempSrc, scaledDestination, Matrix.ScaleToFit.CENTER); 711 } else { 712 mMatrix.setRectToRect(mTempSrc, mTempDst, Matrix.ScaleToFit.CENTER); 713 } 714 } 715 mOriginalMatrix.set(mMatrix); 716 } 717 718 private void generateScale() { 719 final int dwidth = mDrawable.getIntrinsicWidth(); 720 final int dheight = mDrawable.getIntrinsicHeight(); 721 722 final int vwidth = mAllowCrop ? getCropSize() : getWidth(); 723 final int vheight = mAllowCrop ? getCropSize() : getHeight(); 724 725 if (dwidth < vwidth && dheight < vheight && !mAllowCrop) { 726 mMinScale = 1.0f; 727 } else { 728 mMinScale = getScale(); 729 } 730 mMaxScale = Math.max(mMinScale * 8, 8); 731 } 732 733 /** 734 * @return the size of the crop regions 735 */ 736 private int getCropSize() { 737 return mCropSize > 0 ? mCropSize : sCropSize; 738 } 739 740 /** 741 * Returns the currently applied scale factor for the image. 742 * <p> 743 * NOTE: This method overwrites any values stored in {@link #mValues}. 744 */ 745 private float getScale() { 746 mMatrix.getValues(mValues); 747 return mValues[Matrix.MSCALE_X]; 748 } 749 750 /** 751 * Scales the image while keeping the aspect ratio. 752 * 753 * The given scale is capped so that the resulting scale of the image always remains 754 * between {@link #mMinScale} and {@link #mMaxScale}. 755 * 756 * The scaled image is never allowed to be outside of the viewable area. If the image 757 * is smaller than the viewable area, it will be centered. 758 * 759 * @param newScale the new scale 760 * @param centerX the center horizontal point around which to scale 761 * @param centerY the center vertical point around which to scale 762 */ 763 private void scale(float newScale, float centerX, float centerY) { 764 // rotate back to the original orientation 765 mMatrix.postRotate(-mRotation, getWidth() / 2, getHeight() / 2); 766 767 // ensure that mMixScale <= newScale <= mMaxScale 768 newScale = Math.max(newScale, mMinScale); 769 newScale = Math.min(newScale, mMaxScale); 770 771 float currentScale = getScale(); 772 float factor = newScale / currentScale; 773 774 // apply the scale factor 775 mMatrix.postScale(factor, factor, centerX, centerY); 776 777 // ensure the image is within the view bounds 778 snap(); 779 780 // re-apply any rotation 781 mMatrix.postRotate(mRotation, getWidth() / 2, getHeight() / 2); 782 783 invalidate(); 784 } 785 786 /** 787 * Translates the image. 788 * 789 * This method will not allow the image to be translated outside of the visible area. 790 * 791 * @param tx how many pixels to translate horizontally 792 * @param ty how many pixels to translate vertically 793 * @return {@code true} if the translation was applied as specified. Otherwise, {@code false} 794 * if the translation was modified. 795 */ 796 private boolean translate(float tx, float ty) { 797 mTranslateRect.set(mTempSrc); 798 mMatrix.mapRect(mTranslateRect); 799 800 final float maxLeft = mAllowCrop ? mCropRect.left : 0.0f; 801 final float maxRight = mAllowCrop ? mCropRect.right : getWidth(); 802 float l = mTranslateRect.left; 803 float r = mTranslateRect.right; 804 805 final float translateX; 806 if (mAllowCrop) { 807 // If we're cropping, allow the image to scroll off the edge of the screen 808 translateX = Math.max(maxLeft - mTranslateRect.right, 809 Math.min(maxRight - mTranslateRect.left, tx)); 810 } else { 811 // Otherwise, ensure the image never leaves the screen 812 if (r - l < maxRight - maxLeft) { 813 translateX = maxLeft + ((maxRight - maxLeft) - (r + l)) / 2; 814 } else { 815 translateX = Math.max(maxRight - r, Math.min(maxLeft - l, tx)); 816 } 817 } 818 819 float maxTop = mAllowCrop ? mCropRect.top: 0.0f; 820 float maxBottom = mAllowCrop ? mCropRect.bottom : getHeight(); 821 float t = mTranslateRect.top; 822 float b = mTranslateRect.bottom; 823 824 final float translateY; 825 826 if (mAllowCrop) { 827 // If we're cropping, allow the image to scroll off the edge of the screen 828 translateY = Math.max(maxTop - mTranslateRect.bottom, 829 Math.min(maxBottom - mTranslateRect.top, ty)); 830 } else { 831 // Otherwise, ensure the image never leaves the screen 832 if (b - t < maxBottom - maxTop) { 833 translateY = maxTop + ((maxBottom - maxTop) - (b + t)) / 2; 834 } else { 835 translateY = Math.max(maxBottom - b, Math.min(maxTop - t, ty)); 836 } 837 } 838 839 // Do the translation 840 mMatrix.postTranslate(translateX, translateY); 841 invalidate(); 842 843 return (translateX == tx) && (translateY == ty); 844 } 845 846 /** 847 * Snaps the image so it touches all edges of the view. 848 */ 849 private void snap() { 850 mTranslateRect.set(mTempSrc); 851 mMatrix.mapRect(mTranslateRect); 852 853 // Determine how much to snap in the horizontal direction [if any] 854 float maxLeft = mAllowCrop ? mCropRect.left : 0.0f; 855 float maxRight = mAllowCrop ? mCropRect.right : getWidth(); 856 float l = mTranslateRect.left; 857 float r = mTranslateRect.right; 858 859 final float translateX; 860 if (r - l < maxRight - maxLeft) { 861 // Image is narrower than view; translate to the center of the view 862 translateX = maxLeft + ((maxRight - maxLeft) - (r + l)) / 2; 863 } else if (l > maxLeft) { 864 // Image is off right-edge of screen; bring it into view 865 translateX = maxLeft - l; 866 } else if (r < maxRight) { 867 // Image is off left-edge of screen; bring it into view 868 translateX = maxRight - r; 869 } else { 870 translateX = 0.0f; 871 } 872 873 // Determine how much to snap in the vertical direction [if any] 874 float maxTop = mAllowCrop ? mCropRect.top : 0.0f; 875 float maxBottom = mAllowCrop ? mCropRect.bottom : getHeight(); 876 float t = mTranslateRect.top; 877 float b = mTranslateRect.bottom; 878 879 final float translateY; 880 if (b - t < maxBottom - maxTop) { 881 // Image is shorter than view; translate to the bottom edge of the view 882 translateY = maxTop + ((maxBottom - maxTop) - (b + t)) / 2; 883 } else if (t > maxTop) { 884 // Image is off bottom-edge of screen; bring it into view 885 translateY = maxTop - t; 886 } else if (b < maxBottom) { 887 // Image is off top-edge of screen; bring it into view 888 translateY = maxBottom - b; 889 } else { 890 translateY = 0.0f; 891 } 892 893 if (Math.abs(translateX) > SNAP_THRESHOLD || Math.abs(translateY) > SNAP_THRESHOLD) { 894 mSnapRunnable.start(translateX, translateY); 895 } else { 896 mMatrix.postTranslate(translateX, translateY); 897 invalidate(); 898 } 899 } 900 901 /** 902 * Rotates the image, either instantly or gradually 903 * 904 * @param degrees how many degrees to rotate the image, positive rotates clockwise 905 * @param animate if {@code true}, animate during the rotation. Otherwise, snap rotate. 906 */ 907 private void rotate(float degrees, boolean animate) { 908 if (animate) { 909 mRotateRunnable.start(degrees); 910 } else { 911 mRotation += degrees; 912 mMatrix.postRotate(degrees, getWidth() / 2, getHeight() / 2); 913 invalidate(); 914 } 915 } 916 917 /** 918 * Initializes the header and any static values 919 */ 920 private void initialize() { 921 Context context = getContext(); 922 923 if (!sInitialized) { 924 sInitialized = true; 925 926 Resources resources = context.getApplicationContext().getResources(); 927 928 sCropSize = resources.getDimensionPixelSize(R.dimen.photo_crop_width); 929 930 sCropDimPaint = new Paint(); 931 sCropDimPaint.setAntiAlias(true); 932 sCropDimPaint.setColor(resources.getColor(R.color.photo_crop_dim_color)); 933 sCropDimPaint.setStyle(Style.FILL); 934 935 sCropPaint = new Paint(); 936 sCropPaint.setAntiAlias(true); 937 sCropPaint.setColor(resources.getColor(R.color.photo_crop_highlight_color)); 938 sCropPaint.setStyle(Style.STROKE); 939 sCropPaint.setStrokeWidth(resources.getDimension(R.dimen.photo_crop_stroke_width)); 940 } 941 942 mGestureDetector = new GestureDetectorCompat(context, this, null); 943 mScaleGetureDetector = new ScaleGestureDetector(context, this); 944 mScaleRunnable = new ScaleRunnable(this); 945 mTranslateRunnable = new TranslateRunnable(this); 946 mSnapRunnable = new SnapRunnable(this); 947 mRotateRunnable = new RotateRunnable(this); 948 } 949 950 /** 951 * Runnable that animates an image scale operation. 952 */ 953 private static class ScaleRunnable implements Runnable { 954 955 private final PhotoView mHeader; 956 957 private float mCenterX; 958 private float mCenterY; 959 960 private boolean mZoomingIn; 961 962 private float mTargetScale; 963 private float mStartScale; 964 private float mVelocity; 965 private long mStartTime; 966 967 private boolean mRunning; 968 private boolean mStop; 969 970 public ScaleRunnable(PhotoView header) { 971 mHeader = header; 972 } 973 974 /** 975 * Starts the animation. There is no target scale bounds check. 976 */ 977 public boolean start(float startScale, float targetScale, float centerX, float centerY) { 978 if (mRunning) { 979 return false; 980 } 981 982 mCenterX = centerX; 983 mCenterY = centerY; 984 985 // Ensure the target scale is within the min/max bounds 986 mTargetScale = targetScale; 987 mStartTime = System.currentTimeMillis(); 988 mStartScale = startScale; 989 mZoomingIn = mTargetScale > mStartScale; 990 mVelocity = (mTargetScale - mStartScale) / ZOOM_ANIMATION_DURATION; 991 mRunning = true; 992 mStop = false; 993 mHeader.post(this); 994 return true; 995 } 996 997 /** 998 * Stops the animation in place. It does not snap the image to its final zoom. 999 */ 1000 public void stop() { 1001 mRunning = false; 1002 mStop = true; 1003 } 1004 1005 @Override 1006 public void run() { 1007 if (mStop) { 1008 return; 1009 } 1010 1011 // Scale 1012 long now = System.currentTimeMillis(); 1013 long ellapsed = now - mStartTime; 1014 float newScale = (mStartScale + mVelocity * ellapsed); 1015 mHeader.scale(newScale, mCenterX, mCenterY); 1016 1017 // Stop when done 1018 if (newScale == mTargetScale || (mZoomingIn == (newScale > mTargetScale))) { 1019 mHeader.scale(mTargetScale, mCenterX, mCenterY); 1020 stop(); 1021 } 1022 1023 if (!mStop) { 1024 mHeader.post(this); 1025 } 1026 } 1027 } 1028 1029 /** 1030 * Runnable that animates an image translation operation. 1031 */ 1032 private static class TranslateRunnable implements Runnable { 1033 1034 private static final float DECELERATION_RATE = 1000f; 1035 private static final long NEVER = -1L; 1036 1037 private final PhotoView mHeader; 1038 1039 private float mVelocityX; 1040 private float mVelocityY; 1041 1042 private long mLastRunTime; 1043 private boolean mRunning; 1044 private boolean mStop; 1045 1046 public TranslateRunnable(PhotoView header) { 1047 mLastRunTime = NEVER; 1048 mHeader = header; 1049 } 1050 1051 /** 1052 * Starts the animation. 1053 */ 1054 public boolean start(float velocityX, float velocityY) { 1055 if (mRunning) { 1056 return false; 1057 } 1058 mLastRunTime = NEVER; 1059 mVelocityX = velocityX; 1060 mVelocityY = velocityY; 1061 mStop = false; 1062 mRunning = true; 1063 mHeader.post(this); 1064 return true; 1065 } 1066 1067 /** 1068 * Stops the animation in place. It does not snap the image to its final translation. 1069 */ 1070 public void stop() { 1071 mRunning = false; 1072 mStop = true; 1073 } 1074 1075 @Override 1076 public void run() { 1077 // See if we were told to stop: 1078 if (mStop) { 1079 return; 1080 } 1081 1082 // Translate according to current velocities and time delta: 1083 long now = System.currentTimeMillis(); 1084 float delta = (mLastRunTime != NEVER) ? (now - mLastRunTime) / 1000f : 0f; 1085 final boolean didTranslate = mHeader.translate(mVelocityX * delta, mVelocityY * delta); 1086 mLastRunTime = now; 1087 // Slow down: 1088 float slowDown = DECELERATION_RATE * delta; 1089 if (mVelocityX > 0f) { 1090 mVelocityX -= slowDown; 1091 if (mVelocityX < 0f) { 1092 mVelocityX = 0f; 1093 } 1094 } else { 1095 mVelocityX += slowDown; 1096 if (mVelocityX > 0f) { 1097 mVelocityX = 0f; 1098 } 1099 } 1100 if (mVelocityY > 0f) { 1101 mVelocityY -= slowDown; 1102 if (mVelocityY < 0f) { 1103 mVelocityY = 0f; 1104 } 1105 } else { 1106 mVelocityY += slowDown; 1107 if (mVelocityY > 0f) { 1108 mVelocityY = 0f; 1109 } 1110 } 1111 1112 // Stop when done 1113 if ((mVelocityX == 0f && mVelocityY == 0f) || !didTranslate) { 1114 stop(); 1115 mHeader.snap(); 1116 } 1117 1118 // See if we need to continue flinging: 1119 if (mStop) { 1120 return; 1121 } 1122 mHeader.post(this); 1123 } 1124 } 1125 1126 /** 1127 * Runnable that animates an image translation operation. 1128 */ 1129 private static class SnapRunnable implements Runnable { 1130 1131 private static final long NEVER = -1L; 1132 1133 private final PhotoView mHeader; 1134 1135 private float mTranslateX; 1136 private float mTranslateY; 1137 1138 private long mStartRunTime; 1139 private boolean mRunning; 1140 private boolean mStop; 1141 1142 public SnapRunnable(PhotoView header) { 1143 mStartRunTime = NEVER; 1144 mHeader = header; 1145 } 1146 1147 /** 1148 * Starts the animation. 1149 */ 1150 public boolean start(float translateX, float translateY) { 1151 if (mRunning) { 1152 return false; 1153 } 1154 mStartRunTime = NEVER; 1155 mTranslateX = translateX; 1156 mTranslateY = translateY; 1157 mStop = false; 1158 mRunning = true; 1159 mHeader.postDelayed(this, SNAP_DELAY); 1160 return true; 1161 } 1162 1163 /** 1164 * Stops the animation in place. It does not snap the image to its final translation. 1165 */ 1166 public void stop() { 1167 mRunning = false; 1168 mStop = true; 1169 } 1170 1171 @Override 1172 public void run() { 1173 // See if we were told to stop: 1174 if (mStop) { 1175 return; 1176 } 1177 1178 // Translate according to current velocities and time delta: 1179 long now = System.currentTimeMillis(); 1180 float delta = (mStartRunTime != NEVER) ? (now - mStartRunTime) : 0f; 1181 1182 if (mStartRunTime == NEVER) { 1183 mStartRunTime = now; 1184 } 1185 1186 float transX; 1187 float transY; 1188 if (delta >= SNAP_DURATION) { 1189 transX = mTranslateX; 1190 transY = mTranslateY; 1191 } else { 1192 transX = (mTranslateX / (SNAP_DURATION - delta)) * 10f; 1193 transY = (mTranslateY / (SNAP_DURATION - delta)) * 10f; 1194 if (Math.abs(transX) > Math.abs(mTranslateX) || transX == Float.NaN) { 1195 transX = mTranslateX; 1196 } 1197 if (Math.abs(transY) > Math.abs(mTranslateY) || transY == Float.NaN) { 1198 transY = mTranslateY; 1199 } 1200 } 1201 1202 mHeader.translate(transX, transY); 1203 mTranslateX -= transX; 1204 mTranslateY -= transY; 1205 1206 if (mTranslateX == 0 && mTranslateY == 0) { 1207 stop(); 1208 } 1209 1210 // See if we need to continue flinging: 1211 if (mStop) { 1212 return; 1213 } 1214 mHeader.post(this); 1215 } 1216 } 1217 1218 /** 1219 * Runnable that animates an image rotation operation. 1220 */ 1221 private static class RotateRunnable implements Runnable { 1222 1223 private static final long NEVER = -1L; 1224 1225 private final PhotoView mHeader; 1226 1227 private float mTargetRotation; 1228 private float mAppliedRotation; 1229 private float mVelocity; 1230 private long mLastRuntime; 1231 1232 private boolean mRunning; 1233 private boolean mStop; 1234 1235 public RotateRunnable(PhotoView header) { 1236 mHeader = header; 1237 } 1238 1239 /** 1240 * Starts the animation. 1241 */ 1242 public void start(float rotation) { 1243 if (mRunning) { 1244 return; 1245 } 1246 1247 mTargetRotation = rotation; 1248 mVelocity = mTargetRotation / ROTATE_ANIMATION_DURATION; 1249 mAppliedRotation = 0f; 1250 mLastRuntime = NEVER; 1251 mStop = false; 1252 mRunning = true; 1253 mHeader.post(this); 1254 } 1255 1256 /** 1257 * Stops the animation in place. It does not snap the image to its final rotation. 1258 */ 1259 public void stop() { 1260 mRunning = false; 1261 mStop = true; 1262 } 1263 1264 @Override 1265 public void run() { 1266 if (mStop) { 1267 return; 1268 } 1269 1270 if (mAppliedRotation != mTargetRotation) { 1271 long now = System.currentTimeMillis(); 1272 long delta = mLastRuntime != NEVER ? now - mLastRuntime : 0L; 1273 float rotationAmount = mVelocity * delta; 1274 if (mAppliedRotation < mTargetRotation 1275 && mAppliedRotation + rotationAmount > mTargetRotation 1276 || mAppliedRotation > mTargetRotation 1277 && mAppliedRotation + rotationAmount < mTargetRotation) { 1278 rotationAmount = mTargetRotation - mAppliedRotation; 1279 } 1280 mHeader.rotate(rotationAmount, false); 1281 mAppliedRotation += rotationAmount; 1282 if (mAppliedRotation == mTargetRotation) { 1283 stop(); 1284 } 1285 mLastRuntime = now; 1286 } 1287 1288 if (mStop) { 1289 return; 1290 } 1291 mHeader.post(this); 1292 } 1293 } 1294 1295 public void setMaxInitialScale(float f) { 1296 mMaxInitialScaleFactor = f; 1297 } 1298} 1299