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Diffstat (limited to 'android/source/src/java/org/mozilla/gecko/gfx/JavaPanZoomController.java')
| -rw-r--r-- | android/source/src/java/org/mozilla/gecko/gfx/JavaPanZoomController.java | 1094 |
1 files changed, 1094 insertions, 0 deletions
diff --git a/android/source/src/java/org/mozilla/gecko/gfx/JavaPanZoomController.java b/android/source/src/java/org/mozilla/gecko/gfx/JavaPanZoomController.java new file mode 100644 index 000000000..697980af3 --- /dev/null +++ b/android/source/src/java/org/mozilla/gecko/gfx/JavaPanZoomController.java @@ -0,0 +1,1094 @@ +/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*- + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +package org.mozilla.gecko.gfx; + +import android.graphics.PointF; +import android.graphics.RectF; +import android.os.Build; +import android.util.Log; +import android.view.GestureDetector; +import android.view.InputDevice; +import android.view.MotionEvent; +import android.view.View; + +import org.libreoffice.LOKitShell; +import org.libreoffice.LibreOfficeMainActivity; +import org.mozilla.gecko.ZoomConstraints; +import org.mozilla.gecko.util.FloatUtils; + +import java.util.Timer; +import java.util.TimerTask; + +/* + * Handles the kinetic scrolling and zooming physics for a layer controller. + * + * Many ideas are from Joe Hewitt's Scrollability: + * https://github.com/joehewitt/scrollability/ + */ +class JavaPanZoomController + extends GestureDetector.SimpleOnGestureListener + implements PanZoomController, SimpleScaleGestureDetector.SimpleScaleGestureListener +{ + private static final String LOGTAG = "GeckoPanZoomController"; + + // Animation stops if the velocity is below this value when overscrolled or panning. + private static final float STOPPED_THRESHOLD = 4.0f; + + // Animation stops is the velocity is below this threshold when flinging. + private static final float FLING_STOPPED_THRESHOLD = 0.1f; + + // The distance the user has to pan before we recognize it as such (e.g. to avoid 1-pixel pans + // between the touch-down and touch-up of a click). In units of density-independent pixels. + private final float PAN_THRESHOLD; + + // Angle from axis within which we stay axis-locked + private static final double AXIS_LOCK_ANGLE = Math.PI / 6.0; // 30 degrees + + // The maximum amount we allow you to zoom into a page + private static final float MAX_ZOOM = 4.0f; + + // The threshold zoom factor of whether a double tap triggers zoom-in or zoom-out + private static final float DOUBLE_TAP_THRESHOLD = 1.0f; + + // The maximum amount we would like to scroll with the mouse + private final float MAX_SCROLL; + + private enum PanZoomState { + NOTHING, /* no touch-start events received */ + FLING, /* all touches removed, but we're still scrolling page */ + TOUCHING, /* one touch-start event received */ + PANNING_LOCKED, /* touch-start followed by move (i.e. panning with axis lock) */ + PANNING, /* panning without axis lock */ + PANNING_HOLD, /* in panning, but not moving. + * similar to TOUCHING but after starting a pan */ + PANNING_HOLD_LOCKED, /* like PANNING_HOLD, but axis lock still in effect */ + PINCHING, /* nth touch-start, where n > 1. this mode allows pan and zoom */ + ANIMATED_ZOOM, /* animated zoom to a new rect */ + BOUNCE, /* in a bounce animation */ + + WAITING_LISTENERS, /* a state halfway between NOTHING and TOUCHING - the user has + put a finger down, but we don't yet know if a touch listener has + prevented the default actions yet. we still need to abort animations. */ + } + + private final PanZoomTarget mTarget; + private final SubdocumentScrollHelper mSubscroller; + private final Axis mX; + private final Axis mY; + private final TouchEventHandler mTouchEventHandler; + private Thread mMainThread; + private LibreOfficeMainActivity mContext; + + /* The timer that handles flings or bounces. */ + private Timer mAnimationTimer; + /* The runnable being scheduled by the animation timer. */ + private AnimationRunnable mAnimationRunnable; + /* The zoom focus at the first zoom event (in page coordinates). */ + private PointF mLastZoomFocus; + /* The time the last motion event took place. */ + private long mLastEventTime; + /* Current state the pan/zoom UI is in. */ + private PanZoomState mState; + /* Whether or not to wait for a double-tap before dispatching a single-tap */ + private boolean mWaitForDoubleTap; + + JavaPanZoomController(LibreOfficeMainActivity context, PanZoomTarget target, View view) { + mContext = context; + PAN_THRESHOLD = 1/16f * LOKitShell.getDpi(view.getContext()); + MAX_SCROLL = 0.075f * LOKitShell.getDpi(view.getContext()); + mTarget = target; + mSubscroller = new SubdocumentScrollHelper(); + mX = new AxisX(mSubscroller); + mY = new AxisY(mSubscroller); + mTouchEventHandler = new TouchEventHandler(view.getContext(), view, this); + + mMainThread = mContext.getMainLooper().getThread(); + checkMainThread(); + + setState(PanZoomState.NOTHING); + } + + public void destroy() { + mSubscroller.destroy(); + mTouchEventHandler.destroy(); + } + + private static float easeOut(float t) { + // ease-out approx. + // -(t-1)^2+1 + t = t-1; + return -t*t+1; + } + + private void setState(PanZoomState state) { + if (state != mState) { + mState = state; + } + } + + private ImmutableViewportMetrics getMetrics() { + return mTarget.getViewportMetrics(); + } + + // for debugging bug 713011; it can be taken out once that is resolved. + private void checkMainThread() { + if (mMainThread != Thread.currentThread()) { + // log with full stack trace + Log.e(LOGTAG, "Uh-oh, we're running on the wrong thread!", new Exception()); + } + } + + /** This function MUST be called on the UI thread */ + public boolean onMotionEvent(MotionEvent event) { + if ((event.getSource() & InputDevice.SOURCE_CLASS_MASK) == InputDevice.SOURCE_CLASS_POINTER + && (event.getAction() & MotionEvent.ACTION_MASK) == MotionEvent.ACTION_SCROLL) { + return handlePointerScroll(event); + } + return false; + } + + /** This function MUST be called on the UI thread */ + public boolean onTouchEvent(MotionEvent event) { + return mTouchEventHandler.handleEvent(event); + } + + boolean handleEvent(MotionEvent event) { + switch (event.getAction() & MotionEvent.ACTION_MASK) { + case MotionEvent.ACTION_DOWN: return handleTouchStart(event); + case MotionEvent.ACTION_MOVE: return handleTouchMove(event); + case MotionEvent.ACTION_UP: return handleTouchEnd(event); + case MotionEvent.ACTION_CANCEL: return handleTouchCancel(event); + } + return false; + } + + /** This function MUST be called on the UI thread */ + public void notifyDefaultActionPrevented(boolean prevented) { + mTouchEventHandler.handleEventListenerAction(!prevented); + } + + /** This function must be called from the UI thread. */ + public void abortAnimation() { + checkMainThread(); + // this happens when gecko changes the viewport on us or if the device is rotated. + // if that's the case, abort any animation in progress and re-zoom so that the page + // snaps to edges. for other cases (where the user's finger(s) are down) don't do + // anything special. + switch (mState) { + case FLING: + mX.stopFling(); + mY.stopFling(); + // fall through + case BOUNCE: + case ANIMATED_ZOOM: + // the zoom that's in progress likely makes no sense any more (such as if + // the screen orientation changed) so abort it + setState(PanZoomState.NOTHING); + // fall through + case NOTHING: + // Don't do animations here; they're distracting and can cause flashes on page + // transitions. + synchronized (mTarget.getLock()) { + mTarget.setViewportMetrics(getValidViewportMetrics()); + mTarget.forceRedraw(); + } + break; + } + } + + /** This function must be called on the UI thread. */ + void startingNewEventBlock(MotionEvent event, boolean waitingForTouchListeners) { + checkMainThread(); + mSubscroller.cancel(); + if (waitingForTouchListeners && (event.getAction() & MotionEvent.ACTION_MASK) == MotionEvent.ACTION_DOWN) { + // this is the first touch point going down, so we enter the pending state + // setting the state will kill any animations in progress, possibly leaving + // the page in overscroll + setState(PanZoomState.WAITING_LISTENERS); + } + } + + /** This function must be called on the UI thread. */ + void preventedTouchFinished() { + checkMainThread(); + if (mState == PanZoomState.WAITING_LISTENERS) { + // if we enter here, we just finished a block of events whose default actions + // were prevented by touch listeners. Now there are no touch points left, so + // we need to reset our state and re-bounce because we might be in overscroll + bounce(); + } + } + + /** This must be called on the UI thread. */ + public void pageRectUpdated() { + if (mState == PanZoomState.NOTHING) { + synchronized (mTarget.getLock()) { + ImmutableViewportMetrics validated = getValidViewportMetrics(); + if (!getMetrics().fuzzyEquals(validated)) { + // page size changed such that we are now in overscroll. snap to + // the nearest valid viewport + mTarget.setViewportMetrics(validated); + } + } + } + } + + /* + * Panning/scrolling + */ + + private boolean handleTouchStart(MotionEvent event) { + // user is taking control of movement, so stop + // any auto-movement we have going + stopAnimationTimer(); + + switch (mState) { + case ANIMATED_ZOOM: + // We just interrupted a double-tap animation, so force a redraw in + // case this touchstart is just a tap that doesn't end up triggering + // a redraw + mTarget.forceRedraw(); + // fall through + case FLING: + case BOUNCE: + case NOTHING: + case WAITING_LISTENERS: + startTouch(event.getX(0), event.getY(0), event.getEventTime()); + return false; + case TOUCHING: + case PANNING: + case PANNING_LOCKED: + case PANNING_HOLD: + case PANNING_HOLD_LOCKED: + case PINCHING: + Log.e(LOGTAG, "Received impossible touch down while in " + mState); + return false; + } + Log.e(LOGTAG, "Unhandled case " + mState + " in handleTouchStart"); + return false; + } + + private boolean handleTouchMove(MotionEvent event) { + if (mState == PanZoomState.PANNING_LOCKED || mState == PanZoomState.PANNING) { + if (getVelocity() > 18.0f) { + mContext.hideSoftKeyboard(); + } + } + + switch (mState) { + case FLING: + case BOUNCE: + case WAITING_LISTENERS: + // should never happen + Log.e(LOGTAG, "Received impossible touch move while in " + mState); + // fall through + case ANIMATED_ZOOM: + case NOTHING: + // may happen if user double-taps and drags without lifting after the + // second tap. ignore the move if this happens. + return false; + + case TOUCHING: + // Don't allow panning if there is an element in full-screen mode. See bug 775511. + if (mTarget.isFullScreen() || panDistance(event) < PAN_THRESHOLD) { + return false; + } + cancelTouch(); + startPanning(event.getX(0), event.getY(0), event.getEventTime()); + track(event); + return true; + + case PANNING_HOLD_LOCKED: + setState(PanZoomState.PANNING_LOCKED); + // fall through + case PANNING_LOCKED: + track(event); + return true; + + case PANNING_HOLD: + setState(PanZoomState.PANNING); + // fall through + case PANNING: + track(event); + return true; + + case PINCHING: + // scale gesture listener will handle this + return false; + } + Log.e(LOGTAG, "Unhandled case " + mState + " in handleTouchMove"); + return false; + } + + private boolean handleTouchEnd(MotionEvent event) { + + switch (mState) { + case FLING: + case BOUNCE: + case WAITING_LISTENERS: + // should never happen + Log.e(LOGTAG, "Received impossible touch end while in " + mState); + // fall through + case ANIMATED_ZOOM: + case NOTHING: + // may happen if user double-taps and drags without lifting after the + // second tap. ignore if this happens. + return false; + + case TOUCHING: + // the switch into TOUCHING might have happened while the page was + // snapping back after overscroll. we need to finish the snap if that + // was the case + bounce(); + return false; + + case PANNING: + case PANNING_LOCKED: + case PANNING_HOLD: + case PANNING_HOLD_LOCKED: + setState(PanZoomState.FLING); + fling(); + return true; + + case PINCHING: + setState(PanZoomState.NOTHING); + return true; + } + Log.e(LOGTAG, "Unhandled case " + mState + " in handleTouchEnd"); + return false; + } + + private boolean handleTouchCancel(MotionEvent event) { + cancelTouch(); + + if (mState == PanZoomState.WAITING_LISTENERS) { + // we might get a cancel event from the TouchEventHandler while in the + // WAITING_LISTENERS state if the touch listeners prevent-default the + // block of events. at this point being in WAITING_LISTENERS is equivalent + // to being in NOTHING with the exception of possibly being in overscroll. + // so here we don't want to do anything right now; the overscroll will be + // corrected in preventedTouchFinished(). + return false; + } + + // ensure we snap back if we're overscrolled + bounce(); + return false; + } + + private boolean handlePointerScroll(MotionEvent event) { + if (mState == PanZoomState.NOTHING || mState == PanZoomState.FLING) { + float scrollX = event.getAxisValue(MotionEvent.AXIS_HSCROLL); + float scrollY = event.getAxisValue(MotionEvent.AXIS_VSCROLL); + + scrollBy(scrollX * MAX_SCROLL, scrollY * MAX_SCROLL); + bounce(); + return true; + } + return false; + } + + private void startTouch(float x, float y, long time) { + mX.startTouch(x); + mY.startTouch(y); + setState(PanZoomState.TOUCHING); + mLastEventTime = time; + } + + private void startPanning(float x, float y, long time) { + float dx = mX.panDistance(x); + float dy = mY.panDistance(y); + double angle = Math.atan2(dy, dx); // range [-pi, pi] + angle = Math.abs(angle); // range [0, pi] + + // When the touch move breaks through the pan threshold, reposition the touch down origin + // so the page won't jump when we start panning. + mX.startTouch(x); + mY.startTouch(y); + mLastEventTime = time; + + if (!mX.scrollable() || !mY.scrollable()) { + setState(PanZoomState.PANNING); + } else if (angle < AXIS_LOCK_ANGLE || angle > (Math.PI - AXIS_LOCK_ANGLE)) { + mY.setScrollingDisabled(true); + setState(PanZoomState.PANNING_LOCKED); + } else if (Math.abs(angle - (Math.PI / 2)) < AXIS_LOCK_ANGLE) { + mX.setScrollingDisabled(true); + setState(PanZoomState.PANNING_LOCKED); + } else { + setState(PanZoomState.PANNING); + } + } + + private float panDistance(MotionEvent move) { + float dx = mX.panDistance(move.getX(0)); + float dy = mY.panDistance(move.getY(0)); + return (float) Math.sqrt(dx * dx + dy * dy); + } + + private void track(float x, float y, long time) { + float timeDelta = (float)(time - mLastEventTime); + if (FloatUtils.fuzzyEquals(timeDelta, 0)) { + // probably a duplicate event, ignore it. using a zero timeDelta will mess + // up our velocity + return; + } + mLastEventTime = time; + + mX.updateWithTouchAt(x, timeDelta); + mY.updateWithTouchAt(y, timeDelta); + } + + private void track(MotionEvent event) { + mX.saveTouchPos(); + mY.saveTouchPos(); + + for (int i = 0; i < event.getHistorySize(); i++) { + track(event.getHistoricalX(0, i), + event.getHistoricalY(0, i), + event.getHistoricalEventTime(i)); + } + track(event.getX(0), event.getY(0), event.getEventTime()); + + if (stopped()) { + if (mState == PanZoomState.PANNING) { + setState(PanZoomState.PANNING_HOLD); + } else if (mState == PanZoomState.PANNING_LOCKED) { + setState(PanZoomState.PANNING_HOLD_LOCKED); + } else { + // should never happen, but handle anyway for robustness + Log.e(LOGTAG, "Impossible case " + mState + " when stopped in track"); + setState(PanZoomState.PANNING_HOLD_LOCKED); + } + } + + mX.startPan(); + mY.startPan(); + updatePosition(); + } + + private void scrollBy(float dx, float dy) { + ImmutableViewportMetrics scrolled = getMetrics().offsetViewportBy(dx, dy); + mTarget.setViewportMetrics(scrolled); + } + + private void fling() { + updatePosition(); + + stopAnimationTimer(); + + boolean stopped = stopped(); + mX.startFling(stopped); + mY.startFling(stopped); + + startAnimationTimer(new FlingRunnable()); + } + + /* Performs a bounce-back animation to the given viewport metrics. */ + private void bounce(ImmutableViewportMetrics metrics, PanZoomState state) { + stopAnimationTimer(); + + ImmutableViewportMetrics bounceStartMetrics = getMetrics(); + if (bounceStartMetrics.fuzzyEquals(metrics)) { + setState(PanZoomState.NOTHING); + finishAnimation(); + return; + } + + setState(state); + + // At this point we have already set mState to BOUNCE or ANIMATED_ZOOM, so + // getRedrawHint() is returning false. This means we can safely call + // setAnimationTarget to set the new final display port and not have it get + // clobbered by display ports from intermediate animation frames. + mTarget.setAnimationTarget(metrics); + startAnimationTimer(new BounceRunnable(bounceStartMetrics, metrics)); + } + + /* Performs a bounce-back animation to the nearest valid viewport metrics. */ + private void bounce() { + bounce(getValidViewportMetrics(), PanZoomState.BOUNCE); + } + + /* Starts the fling or bounce animation. */ + private void startAnimationTimer(final AnimationRunnable runnable) { + if (mAnimationTimer != null) { + Log.e(LOGTAG, "Attempted to start a new fling without canceling the old one!"); + stopAnimationTimer(); + } + + mAnimationTimer = new Timer("Animation Timer"); + mAnimationRunnable = runnable; + mAnimationTimer.scheduleAtFixedRate(new TimerTask() { + @Override + public void run() { mTarget.post(runnable); } + }, 0, (int)Axis.MS_PER_FRAME); + } + + /* Stops the fling or bounce animation. */ + private void stopAnimationTimer() { + if (mAnimationTimer != null) { + mAnimationTimer.cancel(); + mAnimationTimer = null; + } + if (mAnimationRunnable != null) { + mAnimationRunnable.terminate(); + mAnimationRunnable = null; + } + } + + private float getVelocity() { + float xvel = mX.getRealVelocity(); + float yvel = mY.getRealVelocity(); + return (float) Math.sqrt(xvel * xvel + yvel * yvel); + } + + public PointF getVelocityVector() { + return new PointF(mX.getRealVelocity(), mY.getRealVelocity()); + } + + private boolean stopped() { + return getVelocity() < STOPPED_THRESHOLD; + } + + private PointF resetDisplacement() { + return new PointF(mX.resetDisplacement(), mY.resetDisplacement()); + } + + private void updatePosition() { + mX.displace(); + mY.displace(); + PointF displacement = resetDisplacement(); + if (FloatUtils.fuzzyEquals(displacement.x, 0.0f) && FloatUtils.fuzzyEquals(displacement.y, 0.0f)) { + return; + } + if (! mSubscroller.scrollBy(displacement)) { + synchronized (mTarget.getLock()) { + scrollBy(displacement.x, displacement.y); + } + } + } + + private abstract class AnimationRunnable implements Runnable { + private boolean mAnimationTerminated; + + /* This should always run on the UI thread */ + public final void run() { + /* + * Since the animation timer queues this runnable on the UI thread, it + * is possible that even when the animation timer is cancelled, there + * are multiple instances of this queued, so we need to have another + * mechanism to abort. This is done by using the mAnimationTerminated flag. + */ + if (mAnimationTerminated) { + return; + } + animateFrame(); + } + + protected abstract void animateFrame(); + + /* This should always run on the UI thread */ + final void terminate() { + mAnimationTerminated = true; + } + } + + /* The callback that performs the bounce animation. */ + private class BounceRunnable extends AnimationRunnable { + /* The current frame of the bounce-back animation */ + private int mBounceFrame; + /* + * The viewport metrics that represent the start and end of the bounce-back animation, + * respectively. + */ + private ImmutableViewportMetrics mBounceStartMetrics; + private ImmutableViewportMetrics mBounceEndMetrics; + + BounceRunnable(ImmutableViewportMetrics startMetrics, ImmutableViewportMetrics endMetrics) { + mBounceStartMetrics = startMetrics; + mBounceEndMetrics = endMetrics; + } + + protected void animateFrame() { + /* + * The pan/zoom controller might have signaled to us that it wants to abort the + * animation by setting the state to PanZoomState.NOTHING. Handle this case and bail + * out. + */ + if (!(mState == PanZoomState.BOUNCE || mState == PanZoomState.ANIMATED_ZOOM)) { + finishAnimation(); + return; + } + + /* Perform the next frame of the bounce-back animation. */ + if (mBounceFrame < (int)(256f/Axis.MS_PER_FRAME)) { + advanceBounce(); + return; + } + + /* Finally, if there's nothing else to do, complete the animation and go to sleep. */ + finishBounce(); + finishAnimation(); + setState(PanZoomState.NOTHING); + } + + /* Performs one frame of a bounce animation. */ + private void advanceBounce() { + synchronized (mTarget.getLock()) { + float t = easeOut(mBounceFrame * Axis.MS_PER_FRAME / 256f); + ImmutableViewportMetrics newMetrics = mBounceStartMetrics.interpolate(mBounceEndMetrics, t); + mTarget.setViewportMetrics(newMetrics); + mBounceFrame++; + } + } + + /* Concludes a bounce animation and snaps the viewport into place. */ + private void finishBounce() { + synchronized (mTarget.getLock()) { + mTarget.setViewportMetrics(mBounceEndMetrics); + mBounceFrame = -1; + } + } + } + + // The callback that performs the fling animation. + private class FlingRunnable extends AnimationRunnable { + protected void animateFrame() { + /* + * The pan/zoom controller might have signaled to us that it wants to abort the + * animation by setting the state to PanZoomState.NOTHING. Handle this case and bail + * out. + */ + if (mState != PanZoomState.FLING) { + finishAnimation(); + return; + } + + /* Advance flings, if necessary. */ + boolean flingingX = mX.advanceFling(); + boolean flingingY = mY.advanceFling(); + + boolean overscrolled = (mX.overscrolled() || mY.overscrolled()); + + /* If we're still flinging in any direction, update the origin. */ + if (flingingX || flingingY) { + updatePosition(); + + /* + * Check to see if we're still flinging with an appreciable velocity. The threshold is + * higher in the case of overscroll, so we bounce back eagerly when overscrolling but + * coast smoothly to a stop when not. In other words, require a greater velocity to + * maintain the fling once we enter overscroll. + */ + float threshold = (overscrolled && !mSubscroller.scrolling() ? STOPPED_THRESHOLD : FLING_STOPPED_THRESHOLD); + if (getVelocity() >= threshold) { + mContext.getDocumentOverlay().showPageNumberRect(); + // we're still flinging + return; + } + + mX.stopFling(); + mY.stopFling(); + } + + /* Perform a bounce-back animation if overscrolled. */ + if (overscrolled) { + bounce(); + } else { + finishAnimation(); + setState(PanZoomState.NOTHING); + } + } + } + + private void finishAnimation() { + checkMainThread(); + + stopAnimationTimer(); + + mContext.getDocumentOverlay().hidePageNumberRect(); + + // Force a viewport synchronisation + mTarget.forceRedraw(); + } + + /* Returns the nearest viewport metrics with no overscroll visible. */ + private ImmutableViewportMetrics getValidViewportMetrics() { + return getValidViewportMetrics(getMetrics()); + } + + private ImmutableViewportMetrics getValidViewportMetrics(ImmutableViewportMetrics viewportMetrics) { + /* First, we adjust the zoom factor so that we can make no overscrolled area visible. */ + float zoomFactor = viewportMetrics.zoomFactor; + RectF pageRect = viewportMetrics.getPageRect(); + RectF viewport = viewportMetrics.getViewport(); + + float focusX = viewport.width() / 2.0f; + float focusY = viewport.height() / 2.0f; + + float minZoomFactor = 0.0f; + float maxZoomFactor = MAX_ZOOM; + + ZoomConstraints constraints = mTarget.getZoomConstraints(); + if (null == constraints) { + Log.e(LOGTAG, "ZoomConstraints not available - too impatient?"); + return viewportMetrics; + + } + if (constraints.getMinZoom() > 0) + minZoomFactor = constraints.getMinZoom(); + if (constraints.getMaxZoom() > 0) + maxZoomFactor = constraints.getMaxZoom(); + + if (!constraints.getAllowZoom()) { + // If allowZoom is false, clamp to the default zoom level. + maxZoomFactor = minZoomFactor = constraints.getDefaultZoom(); + } + + maxZoomFactor = Math.max(maxZoomFactor, minZoomFactor); + + if (zoomFactor < minZoomFactor) { + // if one (or both) of the page dimensions is smaller than the viewport, + // zoom using the top/left as the focus on that axis. this prevents the + // scenario where, if both dimensions are smaller than the viewport, but + // by different scale factors, we end up scrolled to the end on one axis + // after applying the scale + PointF center = new PointF(focusX, focusY); + viewportMetrics = viewportMetrics.scaleTo(minZoomFactor, center); + } else if (zoomFactor > maxZoomFactor) { + PointF center = new PointF(viewport.width() / 2.0f, viewport.height() / 2.0f); + viewportMetrics = viewportMetrics.scaleTo(maxZoomFactor, center); + } + + /* Now we pan to the right origin. */ + viewportMetrics = viewportMetrics.clamp(); + + viewportMetrics = pushPageToCenterOfViewport(viewportMetrics); + + return viewportMetrics; + } + + private ImmutableViewportMetrics pushPageToCenterOfViewport(ImmutableViewportMetrics viewportMetrics) { + RectF pageRect = viewportMetrics.getPageRect(); + RectF viewportRect = viewportMetrics.getViewport(); + + if (pageRect.width() < viewportRect.width()) { + float originX = (viewportRect.width() - pageRect.width()) / 2.0f; + viewportMetrics = viewportMetrics.setViewportOrigin(-originX, viewportMetrics.getOrigin().y); + } + + if (pageRect.height() < viewportRect.height()) { + float originY = (viewportRect.height() - pageRect.height()) / 2.0f; + viewportMetrics = viewportMetrics.setViewportOrigin(viewportMetrics.getOrigin().x, -originY); + } + + return viewportMetrics; + } + + private class AxisX extends Axis { + AxisX(SubdocumentScrollHelper subscroller) { super(subscroller); } + @Override + public float getOrigin() { return getMetrics().viewportRectLeft; } + @Override + protected float getViewportLength() { return getMetrics().getWidth(); } + @Override + protected float getPageStart() { return getMetrics().pageRectLeft; } + @Override + protected float getPageLength() { return getMetrics().getPageWidth(); } + } + + private class AxisY extends Axis { + AxisY(SubdocumentScrollHelper subscroller) { super(subscroller); } + @Override + public float getOrigin() { return getMetrics().viewportRectTop; } + @Override + protected float getViewportLength() { return getMetrics().getHeight(); } + @Override + protected float getPageStart() { return getMetrics().pageRectTop; } + @Override + protected float getPageLength() { return getMetrics().getPageHeight(); } + } + + /* + * Zooming + */ + @Override + public boolean onScaleBegin(SimpleScaleGestureDetector detector) { + if (mState == PanZoomState.ANIMATED_ZOOM) + return false; + + if (null == mTarget.getZoomConstraints() || !mTarget.getZoomConstraints().getAllowZoom()) + return false; + + setState(PanZoomState.PINCHING); + mLastZoomFocus = new PointF(detector.getFocusX(), detector.getFocusY()); + cancelTouch(); + + return true; + } + + @Override + public boolean onScale(SimpleScaleGestureDetector detector) { + if (mTarget.isFullScreen()) + return false; + + if (mState != PanZoomState.PINCHING) + return false; + + float prevSpan = detector.getPreviousSpan(); + if (FloatUtils.fuzzyEquals(prevSpan, 0.0f)) { + // let's eat this one to avoid setting the new zoom to infinity (bug 711453) + return true; + } + + float spanRatio = detector.getCurrentSpan() / prevSpan; + + synchronized (mTarget.getLock()) { + float newZoomFactor = getMetrics().zoomFactor * spanRatio; + float minZoomFactor = 0.0f; // deliberately set to zero to allow big zoom out effect + float maxZoomFactor = MAX_ZOOM; + + ZoomConstraints constraints = mTarget.getZoomConstraints(); + + if (constraints.getMaxZoom() > 0) + maxZoomFactor = constraints.getMaxZoom(); + + if (newZoomFactor < minZoomFactor) { + // apply resistance when zooming past minZoomFactor, + // such that it asymptotically reaches minZoomFactor / 2.0 + // but never exceeds that + final float rate = 0.5f; // controls how quickly we approach the limit + float excessZoom = minZoomFactor - newZoomFactor; + excessZoom = 1.0f - (float)Math.exp(-excessZoom * rate); + newZoomFactor = minZoomFactor * (1.0f - excessZoom / 2.0f); + } + + if (newZoomFactor > maxZoomFactor) { + // apply resistance when zooming past maxZoomFactor, + // such that it asymptotically reaches maxZoomFactor + 1.0 + // but never exceeds that + float excessZoom = newZoomFactor - maxZoomFactor; + excessZoom = 1.0f - (float)Math.exp(-excessZoom); + newZoomFactor = maxZoomFactor + excessZoom; + } + + scrollBy(mLastZoomFocus.x - detector.getFocusX(), + mLastZoomFocus.y - detector.getFocusY()); + PointF focus = new PointF(detector.getFocusX(), detector.getFocusY()); + scaleWithFocus(newZoomFactor, focus); + } + + mLastZoomFocus.set(detector.getFocusX(), detector.getFocusY()); + + return true; + } + + @Override + public void onScaleEnd(SimpleScaleGestureDetector detector) { + if (mState == PanZoomState.ANIMATED_ZOOM) + return; + + // switch back to the touching state + startTouch(detector.getFocusX(), detector.getFocusY(), detector.getEventTime()); + + // Force a viewport synchronisation + mTarget.forceRedraw(); + + } + + /** + * Scales the viewport, keeping the given focus point in the same place before and after the + * scale operation. You must hold the monitor while calling this. + */ + private void scaleWithFocus(float zoomFactor, PointF focus) { + ImmutableViewportMetrics viewportMetrics = getMetrics(); + viewportMetrics = viewportMetrics.scaleTo(zoomFactor, focus); + mTarget.setViewportMetrics(viewportMetrics); + } + + public boolean getRedrawHint() { + switch (mState) { + case PINCHING: + case ANIMATED_ZOOM: + case BOUNCE: + // don't redraw during these because the zoom is (or might be, in the case + // of BOUNCE) be changing rapidly and gecko will have to redraw the entire + // display port area. we trigger a force-redraw upon exiting these states. + return false; + default: + // allow redrawing in other states + return true; + } + } + + @Override + public boolean onDown(MotionEvent motionEvent) { + if (mTarget.getZoomConstraints() != null) + mWaitForDoubleTap = mTarget.getZoomConstraints().getAllowDoubleTapZoom(); + else + mWaitForDoubleTap = false; + return false; + } + + @Override + public void onShowPress(MotionEvent motionEvent) { + // If we get this, it will be followed either by a call to + // onSingleTapUp (if the user lifts their finger before the + // long-press timeout) or a call to onLongPress (if the user + // does not). In the former case, we want to make sure it is + // treated as a click. (Note that if this is called, we will + // not get a call to onDoubleTap). + mWaitForDoubleTap = false; + } + + private PointF getMotionInDocumentCoordinates(MotionEvent motionEvent) { + RectF viewport = getValidViewportMetrics().getViewport(); + PointF viewPoint = new PointF(motionEvent.getX(0), motionEvent.getY(0)); + return mTarget.convertViewPointToLayerPoint(viewPoint); + } + + @Override + public void onLongPress(MotionEvent motionEvent) { + LOKitShell.sendTouchEvent("LongPress", getMotionInDocumentCoordinates(motionEvent)); + } + + @Override + public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) { + mContext.getDocumentOverlay().showPageNumberRect(); + return super.onScroll(e1, e2, distanceX, distanceY); + } + + @Override + public boolean onSingleTapUp(MotionEvent motionEvent) { + // When double-tapping is allowed, we have to wait to see if this is + // going to be a double-tap. + if (!mWaitForDoubleTap) { + LOKitShell.sendTouchEvent("SingleTap", getMotionInDocumentCoordinates(motionEvent)); + } + // return false because we still want to get the ACTION_UP event that triggers this + return false; + } + + @Override + public boolean onSingleTapConfirmed(MotionEvent motionEvent) { + // In cases where we don't wait for double-tap, we handle this in onSingleTapUp. + if (mWaitForDoubleTap) { + LOKitShell.sendTouchEvent("SingleTap", getMotionInDocumentCoordinates(motionEvent)); + } + return true; + } + + @Override + public boolean onDoubleTap(MotionEvent motionEvent) { + if (null == mTarget.getZoomConstraints() || !mTarget.getZoomConstraints().getAllowDoubleTapZoom()) { + return true; + } + // Double tap zooms in or out depending on the current zoom factor + PointF pointOfTap = getMotionInDocumentCoordinates(motionEvent); + ImmutableViewportMetrics metrics = getMetrics(); + float newZoom = metrics.getZoomFactor() >= + DOUBLE_TAP_THRESHOLD ? mTarget.getZoomConstraints().getMinZoom() : DOUBLE_TAP_THRESHOLD; + // calculate new top_left point from the point of tap + float ratio = newZoom/metrics.getZoomFactor(); + float newLeft = pointOfTap.x - 1/ratio * (pointOfTap.x - metrics.getOrigin().x / metrics.getZoomFactor()); + float newTop = pointOfTap.y - 1/ratio * (pointOfTap.y - metrics.getOrigin().y / metrics.getZoomFactor()); + // animate move to the new view + animatedMove(new PointF(newLeft, newTop), newZoom); + + LOKitShell.sendTouchEvent("DoubleTap", pointOfTap); + return true; + } + + private void cancelTouch() { + //GeckoEvent e = GeckoEvent.createBroadcastEvent("Gesture:CancelTouch", ""); + //GeckoAppShell.sendEventToGecko(e); + } + + /** + * Zoom to a specified rect IN CSS PIXELS. + * + * While we usually use device pixels, zoomToRect must be specified in CSS + * pixels. + */ + boolean animatedZoomTo(RectF zoomToRect) { + final float startZoom = getMetrics().zoomFactor; + + RectF viewport = getMetrics().getViewport(); + // 1. adjust the aspect ratio of zoomToRect to match that of the current viewport, + // enlarging as necessary (if it gets too big, it will get shrunk in the next step). + // while enlarging make sure we enlarge equally on both sides to keep the target rect + // centered. + float targetRatio = viewport.width() / viewport.height(); + float rectRatio = zoomToRect.width() / zoomToRect.height(); + if (FloatUtils.fuzzyEquals(targetRatio, rectRatio)) { + // all good, do nothing + } else if (targetRatio < rectRatio) { + // need to increase zoomToRect height + float newHeight = zoomToRect.width() / targetRatio; + zoomToRect.top -= (newHeight - zoomToRect.height()) / 2; + zoomToRect.bottom = zoomToRect.top + newHeight; + } else { // targetRatio > rectRatio) { + // need to increase zoomToRect width + float newWidth = targetRatio * zoomToRect.height(); + zoomToRect.left -= (newWidth - zoomToRect.width()) / 2; + zoomToRect.right = zoomToRect.left + newWidth; + } + + float finalZoom = viewport.width() / zoomToRect.width(); + + ImmutableViewportMetrics finalMetrics = getMetrics(); + finalMetrics = finalMetrics.setViewportOrigin( + zoomToRect.left * finalMetrics.zoomFactor, + zoomToRect.top * finalMetrics.zoomFactor); + finalMetrics = finalMetrics.scaleTo(finalZoom, new PointF(0.0f, 0.0f)); + + // 2. now run getValidViewportMetrics on it, so that the target viewport is + // clamped down to prevent overscroll, over-zoom, and other bad conditions. + finalMetrics = getValidViewportMetrics(finalMetrics); + + bounce(finalMetrics, PanZoomState.ANIMATED_ZOOM); + return true; + } + + /** + * Move the viewport to the top-left point to and zoom to the desired + * zoom factor. Input zoom factor can be null, in this case leave the zoom unchanged. + */ + boolean animatedMove(PointF topLeft, Float zoom) { + RectF moveToRect = getMetrics().getCssViewport(); + moveToRect.offsetTo(topLeft.x, topLeft.y); + + ImmutableViewportMetrics finalMetrics = getMetrics(); + + finalMetrics = finalMetrics.setViewportOrigin( + moveToRect.left * finalMetrics.zoomFactor, + moveToRect.top * finalMetrics.zoomFactor); + + if (zoom != null) { + finalMetrics = finalMetrics.scaleTo(zoom, new PointF(0.0f, 0.0f)); + } + finalMetrics = getValidViewportMetrics(finalMetrics); + + bounce(finalMetrics, PanZoomState.ANIMATED_ZOOM); + return true; + } + + /** This function must be called from the UI thread. */ + public void abortPanning() { + checkMainThread(); + bounce(); + } + + public void setOverScrollMode(int overscrollMode) { + mX.setOverScrollMode(overscrollMode); + mY.setOverScrollMode(overscrollMode); + } + + public int getOverScrollMode() { + return mX.getOverScrollMode(); + } +} |