/**
* @param view The view to be dismissed
* @param velocity The desired pixels/second speed at which the view should move
*/
private void dismissChild(final SwipeableItemView view, float velocity) {
final View animView = mCurrView.getSwipeableView().getView();
final boolean canAnimViewBeDismissed = mCallback.canChildBeDismissed(view);
float newPos = determinePos(animView, velocity);
int duration = determineDuration(animView, newPos, velocity);
Utils.enableHardwareLayer(animView);
ObjectAnimator anim = createDismissAnimation(animView, newPos, duration);
anim.addListener(
new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
mCallback.onChildDismissed(mCurrView);
animView.setLayerType(View.LAYER_TYPE_NONE, null);
}
});
anim.addUpdateListener(
new AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
if (FADE_OUT_DURING_SWIPE && canAnimViewBeDismissed) {
animView.setAlpha(getAlphaForOffset(animView));
}
invalidateGlobalRegion(animView);
}
});
anim.start();
}
public void snapChild(final SwipeableItemView view) {
final View animView = view.getSwipeableView().getView();
final boolean canAnimViewBeDismissed = mCallback.canChildBeDismissed(view);
final ObjectAnimator anim = createTranslationAnimation(animView, 0);
final int duration = SNAP_ANIM_LEN;
anim.setDuration(duration);
anim.addUpdateListener(
new AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
if (FADE_OUT_DURING_SWIPE && canAnimViewBeDismissed) {
animView.setAlpha(getAlphaForOffset(animView));
}
invalidateGlobalRegion(animView);
}
});
anim.addListener(
new Animator.AnimatorListener() {
@Override
public void onAnimationStart(Animator animation) {}
@Override
public void onAnimationEnd(Animator animation) {
animView.setAlpha(1.0f);
mCallback.onDragCancelled(mCurrView);
}
@Override
public void onAnimationCancel(Animator animation) {}
@Override
public void onAnimationRepeat(Animator animation) {}
});
anim.start();
}
public boolean onTouchEvent(MotionEvent ev) {
if (!mDragging) {
return false;
}
mVelocityTracker.addMovement(ev);
final int action = ev.getAction();
switch (action) {
case MotionEvent.ACTION_OUTSIDE:
case MotionEvent.ACTION_MOVE:
if (mCurrView != null) {
float deltaX = ev.getX() - mInitialTouchPosX;
// If the swipe started in the dead region, ignore it.
if (mInitialTouchPosX <= (DEAD_REGION_FOR_SWIPE * mDensityScale)) {
return true;
}
// If the user has gone vertical and not gone horizontalish AT
// LEAST minBeforeLock, switch to scroll. Otherwise, cancel
// the swipe.
float minDistance = MIN_SWIPE;
if (Math.abs(deltaX) < minDistance) {
// Don't start the drag until at least X distance has
// occurred.
return true;
}
// don't let items that can't be dismissed be dragged more
// than maxScrollDistance
if (CONSTRAIN_SWIPE && !mCallback.canChildBeDismissed(mCurrView)) {
float size = getSize(mCurrAnimView);
float maxScrollDistance = 0.15f * size;
if (Math.abs(deltaX) >= size) {
deltaX = deltaX > 0 ? maxScrollDistance : -maxScrollDistance;
} else {
deltaX = maxScrollDistance * (float) Math.sin((deltaX / size) * (Math.PI / 2));
}
}
setTranslation(mCurrAnimView, deltaX);
if (FADE_OUT_DURING_SWIPE && mCanCurrViewBeDimissed) {
mCurrAnimView.setAlpha(getAlphaForOffset(mCurrAnimView));
if (mPrevView != null) {
// Base how much the text of the prev item is faded
// on how far the current item has moved.
mPrevView.setTextAlpha(getTextAlphaForOffset(mCurrAnimView));
}
}
invalidateGlobalRegion(mCurrView.getSwipeableView().getView());
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
if (mCurrView != null) {
float maxVelocity = MAX_DISMISS_VELOCITY * mDensityScale;
mVelocityTracker.computeCurrentVelocity(1000 /* px/sec */, maxVelocity);
float escapeVelocity = SWIPE_ESCAPE_VELOCITY * mDensityScale;
float velocity = getVelocity(mVelocityTracker);
float perpendicularVelocity = getPerpendicularVelocity(mVelocityTracker);
// Decide whether to dismiss the current view
// Tweak constants below as required to prevent erroneous
// swipe/dismiss
float translation = Math.abs(mCurrAnimView.getTranslationX());
float currAnimViewSize = getSize(mCurrAnimView);
// Long swipe = translation of .4 * width
boolean childSwipedFarEnough =
DISMISS_IF_SWIPED_FAR_ENOUGH && translation > 0.4 * currAnimViewSize;
// Fast swipe = > escapeVelocity and translation of .1 *
// width
boolean childSwipedFastEnough =
(Math.abs(velocity) > escapeVelocity)
&& (Math.abs(velocity) > Math.abs(perpendicularVelocity))
&& (velocity > 0) == (mCurrAnimView.getTranslationX() > 0)
&& translation > 0.05 * currAnimViewSize;
if (LOG_SWIPE_DISMISS_VELOCITY) {
LogUtils.v(
TAG,
"Swipe/Dismiss: "
+ velocity
+ "/"
+ escapeVelocity
+ "/"
+ perpendicularVelocity
+ ", x: "
+ translation
+ "/"
+ currAnimViewSize);
}
boolean dismissChild =
mCallback.canChildBeDismissed(mCurrView)
&& (childSwipedFastEnough || childSwipedFarEnough);
if (dismissChild) {
dismissChild(mCurrView, childSwipedFastEnough ? velocity : 0f);
} else {
snapChild(mCurrView);
}
}
break;
}
return true;
}
public boolean onInterceptTouchEvent(MotionEvent ev) {
final int action = ev.getAction();
switch (action) {
case MotionEvent.ACTION_DOWN:
mLastY = ev.getY();
mDragging = false;
View view = mCallback.getChildAtPosition(ev);
if (view instanceof SwipeableItemView) {
mCurrView = (SwipeableItemView) view;
} else {
// If the touched item is not a swipeable one, clean the cache in
// mCurrView to make sure nothing will be swiped for this action
mCurrView = null;
}
mVelocityTracker.clear();
if (mCurrView != null) {
mCurrAnimView = mCurrView.getSwipeableView().getView();
mCanCurrViewBeDimissed = mCallback.canChildBeDismissed(mCurrView);
mVelocityTracker.addMovement(ev);
mInitialTouchPosX = ev.getX();
mInitialTouchPosY = ev.getY();
}
mCallback.cancelDismissCounter();
break;
case MotionEvent.ACTION_MOVE:
if (mCurrView != null) {
// Check the movement direction.
if (mLastY >= 0 && !mDragging) {
float currY = ev.getY();
float currX = ev.getX();
float deltaY = Math.abs(currY - mInitialTouchPosY);
float deltaX = Math.abs(currX - mInitialTouchPosX);
if (deltaY > mCurrView.getMinAllowScrollDistance() && deltaY > (FACTOR * deltaX)) {
mLastY = ev.getY();
mCallback.onScroll();
return false;
}
}
mVelocityTracker.addMovement(ev);
float pos = ev.getX();
float delta = pos - mInitialTouchPosX;
if (Math.abs(delta) > mPagingTouchSlop) {
mCallback.onBeginDrag(mCurrView.getSwipeableView().getView());
mPrevView = mCallback.getLastSwipedItem();
mDragging = true;
mInitialTouchPosX = ev.getX() - mCurrAnimView.getTranslationX();
mInitialTouchPosY = ev.getY();
}
}
mLastY = ev.getY();
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
mDragging = false;
mCurrView = null;
mCurrAnimView = null;
mLastY = -1;
break;
}
return mDragging;
}
