/**
* Scroll to the child at the position passed.
*
* @param childPosition the child's position
* @return if scrolling to the child is starting, false otherwise
*/
private boolean scrollToChild(final int childPosition) {
final View child = getChildAt(childPosition);
if (child != null) {
final int distance = getGalleryLockPoint() - getLeftOfView(child);
mFlingRunnable.startUsingDistance(distance);
return true;
}
return false;
}
@Override
public void onFling(float startX, float startY, float velocityX, float velocityY) {
DraweeView<GenericDraweeHierarchy> draweeView = getDraweeView();
if (draweeView == null) {
return;
}
mCurrentFlingRunnable = new FlingRunnable(draweeView.getContext());
mCurrentFlingRunnable.fling(getViewWidth(), getViewHeight(), (int) velocityX, (int) velocityY);
draweeView.post(mCurrentFlingRunnable);
}
/**
* Scrolls the items so that the selected item is in its 'slot' (its center is the Gallery's
* center).
*
* <p>Note: modifed to snap the left of a view rather than the center
*/
private void scrollIntoSlots() {
if (getChildCount() == 0 || mSelectedChild == null) {
return;
}
final int selectedCenter = getLeftOfView(mSelectedChild);
final int targetCenter = getGalleryLockPoint();
final int scrollAmount = targetCenter - selectedCenter;
if (scrollAmount != 0) {
mFlingRunnable.startUsingDistance(scrollAmount);
} else {
onFinishedMovement();
}
}
@Override
public final void onFling(float startX, float startY, float velocityX, float velocityY) {
if (DEBUG) {
Log.d(
LOG_TAG,
"onFling. sX: " + startX + " sY: " + startY + " Vx: " + velocityX + " Vy: " + velocityY);
}
ImageView imageView = getImageView();
if (hasDrawable(imageView)) {
mCurrentFlingRunnable = new FlingRunnable(imageView.getContext());
mCurrentFlingRunnable.fling(
imageView.getWidth(), imageView.getHeight(), (int) velocityX, (int) velocityY);
imageView.post(mCurrentFlingRunnable);
}
}
@Override
public final boolean onTouch(View v, MotionEvent ev) {
boolean handled = false;
if (isZoomEnabled) {
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
// First, disable the Parent from intercepting the touch
// event
if (v.getParent() != null) {
v.getParent().requestDisallowInterceptTouchEvent(true);
}
// If we're flinging, and the user presses down, cancel
// fling
if (currentFlingRunnable != null) {
currentFlingRunnable.cancelFling();
currentFlingRunnable = null;
}
break;
case MotionEvent.ACTION_CANCEL:
case MotionEvent.ACTION_UP:
// If the user has zoomed less than min scale, zoom back
// to min scale
if (getScale() < minScale) {
RectF rect = getDisplayRect();
if (null != rect) {
v.post(
new AnimatedZoomRunnable(getScale(), minScale, rect.centerX(), rect.centerY()));
handled = true;
}
}
break;
}
// Finally, try the scale/drag/tap detector
if ((multiGestureDetector != null) && multiGestureDetector.onTouchEvent(ev)) {
handled = true;
}
}
return handled;
}
@Override
public boolean onDown(final MotionEvent e) {
// Kill any existing fling/scroll
mFlingRunnable.stop(false);
// Get the item's view that was touched
mDownTouchPosition = pointToPosition((int) e.getX(), (int) e.getY());
if (mDownTouchPosition >= 0) {
mDownTouchView = getChildAt(mDownTouchPosition - mFirstPosition);
mDownTouchView.setPressed(true);
}
// Reset the multiple-scroll tracking state
mIsFirstScroll = true;
// Must return true to get matching events for this down event.
return true;
}
@Override
public boolean onFling(
final MotionEvent e1, final MotionEvent e2, final float velocityX, final float velocityY) {
if (!mShouldCallbackDuringFling) {
// We want to suppress selection changes
// Remove any future code to set mSuppressSelectionChanged = false
removeCallbacks(mDisableSuppressSelectionChangedRunnable);
// This will get reset once we scroll into slots
if (!mSuppressSelectionChanged) {
mSuppressSelectionChanged = true;
}
}
// Fling the Gallery!
mFlingRunnable.startUsingVelocity((int) -velocityX);
return true;
}
@Override
public void onFling(float startX, float startY, float velocityX, float velocityY) {
if (DEBUG) {
LogManager.getLogger()
.d(
LOG_TAG,
"onFling. sX: "
+ startX
+ " sY: "
+ startY
+ " Vx: "
+ velocityX
+ " Vy: "
+ velocityY);
}
ImageView imageView = getImageView();
mCurrentFlingRunnable = new FlingRunnable(imageView.getContext());
mCurrentFlingRunnable.fling(
getImageViewWidth(imageView),
getImageViewHeight(imageView),
(int) velocityX,
(int) velocityY);
imageView.post(mCurrentFlingRunnable);
}
/**
* Tracks a motion scroll. In reality, this is used to do just about any movement to items (touch
* scroll, arrow-key scroll, set an item as selected).
*
* @param deltaX Change in X from the previous event.
*/
void trackMotionScroll(final int deltaX) {
if (getChildCount() == 0) {
return;
}
final boolean toLeft = deltaX < 0;
final int limitedDeltaX = getLimitedMotionScrollAmount(toLeft, deltaX);
if (limitedDeltaX != deltaX) {
// The above call returned a limited amount, so stop any scrolls/flings
mFlingRunnable.endFling(false);
onFinishedMovement();
}
offsetChildrenLeftAndRight(limitedDeltaX);
detachOffScreenChildren(toLeft);
if (toLeft) {
// If moved left, there will be empty space on the right
fillToGalleryRight();
} else {
// Similarly, empty space on the left
fillToGalleryLeft();
}
// Clear unused views
mRecycler.clear();
setSelectionToChildClosestToLockPoint();
onScrollChanged(0, 0, 0, 0); // Dummy values, View's implementation does not use these.
invalidate();
}
private void cancelFling() {
if (null != mCurrentFlingRunnable) {
mCurrentFlingRunnable.cancelFling();
mCurrentFlingRunnable = null;
}
}
private void cancelFling() {
if (mCurrentFlingRunnable != null) {
mCurrentFlingRunnable.cancelFling();
mCurrentFlingRunnable = null;
}
}
