public static boolean isChildInCenterY(RecyclerView recyclerView, View view) {
int childCount = recyclerView.getChildCount();
int[] rvLocationOnScreen = new int[2];
int[] vLocationOnScreen = new int[2];
recyclerView.getLocationOnScreen(rvLocationOnScreen);
int middleY =
(int) (rvLocationOnScreen[1] + recyclerView.getHeight() * recyclerView.getScaleY() / 2);
if (childCount > 0) {
view.getLocationOnScreen(vLocationOnScreen);
if (vLocationOnScreen[1] <= middleY
&& vLocationOnScreen[1] + view.getHeight() * view.getScaleY() >= middleY) {
return true;
}
}
return false;
}
public static boolean isChildInCenterX(RecyclerView recyclerView, View view) {
int childCount = recyclerView.getChildCount();
int[] lvLocationOnScreen = new int[2];
int[] vLocationOnScreen = new int[2];
recyclerView.getLocationOnScreen(lvLocationOnScreen);
int middleX =
(int) (lvLocationOnScreen[0] + recyclerView.getWidth() * recyclerView.getScaleX() / 2);
if (childCount > 0) {
view.getLocationOnScreen(vLocationOnScreen);
if (vLocationOnScreen[0] <= middleX
&& vLocationOnScreen[0] + view.getWidth() * view.getScaleX() >= middleX) {
return true;
}
}
return false;
}
/** 滑动开始准备 */
private void actionDown(MotionEvent motionEvent) {
if (mPaused) {
return;
}
// 找到被点击的 view 和位置（包括 top left right bottom）
Rect rect = new Rect();
int childCount = mRecyclerView.getChildCount();
// location 指的是 RecyclerView 左上角以整个屏幕的左上角为参照物的坐标
int[] location = new int[2];
mRecyclerView.getLocationOnScreen(location);
// 此处的 x y 指的是触摸点以 location 为参照物时的坐标
int x = (int) motionEvent.getRawX() - location[0];
int y = (int) motionEvent.getRawY() - location[1];
View child;
for (int i = 0; i < childCount; i++) {
child = mRecyclerView.getChildAt(i);
child.getHitRect(rect);
if (rect.contains(x, y)) {
mDownView = child;
break;
}
}
// 找到相应的 view 并且该 view 不处于执行动画状态
if (mDownView != null
&& mAnimatingPosition != mRecyclerView.getChildAdapterPosition(mDownView)) {
mAlpha = mDownView.getAlpha();
mDownX = motionEvent.getRawX();
mDownY = motionEvent.getRawY();
mDownPosition = mRecyclerView.getChildAdapterPosition(mDownView);
if (mSwipeListener.canSwipe(mDownPosition)) {
// ？添加速度追踪器
mVelocityTracker = VelocityTracker.obtain();
mVelocityTracker.addMovement(motionEvent);
} else {
mDownView = null;
}
}
}
private boolean handleTouchEvent(MotionEvent motionEvent) {
if (mViewWidth < 2) {
mViewWidth = mRecyclerView.getWidth();
}
switch (motionEvent.getActionMasked()) {
case MotionEvent.ACTION_DOWN:
{
if (mPaused) {
break;
}
// Find the child view that was touched (perform a hit test)
Rect rect = new Rect();
int childCount = mRecyclerView.getChildCount();
int[] listViewCoords = new int[2];
mRecyclerView.getLocationOnScreen(listViewCoords);
int x = (int) motionEvent.getRawX() - listViewCoords[0];
int y = (int) motionEvent.getRawY() - listViewCoords[1];
View child;
for (int i = 0; i < childCount; i++) {
child = mRecyclerView.getChildAt(i);
child.getHitRect(rect);
if (rect.contains(x, y)) {
mDownView = child;
break;
}
}
if (mDownView != null) {
mDownX = motionEvent.getRawX();
mDownY = motionEvent.getRawY();
mDownPosition = mRecyclerView.getChildAdapterPosition(mDownView);
mVelocityTracker = VelocityTracker.obtain();
mVelocityTracker.addMovement(motionEvent);
mFgView = mDownView.findViewById(mFgID);
}
break;
}
case MotionEvent.ACTION_CANCEL:
{
if (mVelocityTracker == null) {
break;
}
if (mDownView != null && mSwiping) {
// cancel
mFgView.animate().translationX(0).setDuration(ANIMATION_FAST).setListener(null);
}
mVelocityTracker.recycle();
mVelocityTracker = null;
mDownX = 0;
mDownY = 0;
mDownView = null;
mDownPosition = ListView.INVALID_POSITION;
mSwiping = false;
mBgView = null;
break;
}
case MotionEvent.ACTION_UP:
{
if (mVelocityTracker == null) {
break;
}
mFinalDelta = motionEvent.getRawX() - mDownX;
mVelocityTracker.addMovement(motionEvent);
mVelocityTracker.computeCurrentVelocity(1000);
float velocityX = mVelocityTracker.getXVelocity();
float absVelocityX = Math.abs(velocityX);
float absVelocityY = Math.abs(mVelocityTracker.getYVelocity());
boolean dismiss = false;
boolean dismissRight = false;
if (Math.abs(mFinalDelta) > mViewWidth / 2 && mSwiping) {
dismiss = true;
dismissRight = mFinalDelta > 0;
} else if (mMinFlingVelocity <= absVelocityX
&& absVelocityX <= mMaxFlingVelocity
&& absVelocityY < absVelocityX
&& mSwiping) {
// dismiss only if flinging in the same direction as dragging
dismiss = (velocityX < 0) == (mFinalDelta < 0);
dismissRight = mVelocityTracker.getXVelocity() > 0;
}
if (dismiss
&& mDownPosition != ListView.INVALID_POSITION
&& mSwipeListener.canSwipe(mDownPosition)) {
// dismiss
++mDismissAnimationRefCount;
mBgView.animate().alpha(1).setDuration(ANIMATION_FAST);
mFgView
.animate()
.translationX(dismissRight ? mViewWidth : -mViewWidth)
.setDuration(ANIMATION_FAST)
.setListener(
new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
mFgView.animate().translationX(0); // Esto hace que regrese a su posision :)
}
});
} else {
// cancel
mFgView.animate().translationX(0).setDuration(ANIMATION_FAST).setListener(null);
}
mVelocityTracker.recycle();
mVelocityTracker = null;
mDownX = 0;
mDownY = 0;
mDownView = null;
mDownPosition = ListView.INVALID_POSITION;
mSwiping = false;
mBgView = null;
break;
}
case MotionEvent.ACTION_MOVE:
{
if (mVelocityTracker == null || mPaused) {
break;
}
mVelocityTracker.addMovement(motionEvent);
float deltaX = motionEvent.getRawX() - mDownX;
float deltaY = motionEvent.getRawY() - mDownY;
if (!mSwiping && Math.abs(deltaX) > mSlop && Math.abs(deltaY) < Math.abs(deltaX) / 2) {
mSwiping = true;
mSwipingSlop = (deltaX > 0 ? mSlop : -mSlop);
}
if (mSwiping) {
if (mBgView == null) {
mBgView = mDownView.findViewById(mBgID);
mBgView.setVisibility(View.VISIBLE);
listener.holaView((deltaX - mSwipingSlop) > 0, mBgView);
}
mFgView.setTranslationX(deltaX - mSwipingSlop);
return true;
}
break;
}
}
return false;
}
@TargetApi(Build.VERSION_CODES.HONEYCOMB_MR1)
private boolean handleTouchEvent(MotionEvent motionEvent) {
if (mViewWidth < 2) {
mViewWidth = mRecyclerView.getWidth();
}
switch (motionEvent.getActionMasked()) {
case MotionEvent.ACTION_DOWN:
{
if (mPaused) {
break;
}
// Find the child view that was touched (perform a hit test)
Rect rect = new Rect();
int childCount = mRecyclerView.getChildCount();
int[] listViewCoords = new int[2];
mRecyclerView.getLocationOnScreen(listViewCoords);
int x = (int) motionEvent.getRawX() - listViewCoords[0];
int y = (int) motionEvent.getRawY() - listViewCoords[1];
View child;
for (int i = 0; i < childCount; i++) {
child = mRecyclerView.getChildAt(i);
child.getHitRect(rect);
if (rect.contains(x, y)) {
mDownView = child;
break;
}
}
if (mDownView != null
&& mAnimatingPosition != mRecyclerView.getChildPosition(mDownView)) {
mAlpha = mDownView.getAlpha();
mDownX = motionEvent.getRawX();
mDownY = motionEvent.getRawY();
mDownPosition = mRecyclerView.getChildPosition(mDownView);
if (mSwipeListener.canSwipe(mDownPosition)) {
mVelocityTracker = VelocityTracker.obtain();
mVelocityTracker.addMovement(motionEvent);
} else {
mDownView = null;
}
}
break;
}
case MotionEvent.ACTION_CANCEL:
{
if (mVelocityTracker == null) {
break;
}
if (mDownView != null && mSwiping) {
// cancel
mDownView
.animate()
.translationX(0)
.alpha(mAlpha)
.setDuration(mAnimationTime)
.setListener(null);
}
mVelocityTracker.recycle();
mVelocityTracker = null;
mDownX = 0;
mDownY = 0;
mDownView = null;
mDownPosition = ListView.INVALID_POSITION;
mSwiping = false;
break;
}
case MotionEvent.ACTION_UP:
{
if (mVelocityTracker == null) {
break;
}
mFinalDelta = motionEvent.getRawX() - mDownX;
mVelocityTracker.addMovement(motionEvent);
mVelocityTracker.computeCurrentVelocity(1000);
float velocityX = mVelocityTracker.getXVelocity();
float absVelocityX = Math.abs(velocityX);
float absVelocityY = Math.abs(mVelocityTracker.getYVelocity());
boolean dismiss = false;
boolean dismissRight = false;
if (Math.abs(mFinalDelta) > mViewWidth / 2 && mSwiping) {
dismiss = true;
dismissRight = mFinalDelta > 0;
} else if (mMinFlingVelocity <= absVelocityX
&& absVelocityX <= mMaxFlingVelocity
&& absVelocityY < absVelocityX
&& mSwiping) {
// dismiss only if flinging in the same direction as dragging
dismiss = (velocityX < 0) == (mFinalDelta < 0);
dismissRight = mVelocityTracker.getXVelocity() > 0;
}
if (dismiss
&& mDownPosition != mAnimatingPosition
&& mDownPosition != ListView.INVALID_POSITION) {
// dismiss
final View downView = mDownView; // mDownView gets null'd before animation ends
final int downPosition = mDownPosition;
++mDismissAnimationRefCount;
mAnimatingPosition = mDownPosition;
mDownView
.animate()
.translationX(dismissRight ? mViewWidth : -mViewWidth)
.alpha(0)
.setDuration(mAnimationTime)
.setListener(
new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
performDismiss(downView, downPosition);
}
});
} else {
// cancel
mDownView
.animate()
.translationX(0)
.alpha(mAlpha)
.setDuration(mAnimationTime)
.setListener(null);
}
mVelocityTracker.recycle();
mVelocityTracker = null;
mDownX = 0;
mDownY = 0;
mDownView = null;
mDownPosition = ListView.INVALID_POSITION;
mSwiping = false;
break;
}
case MotionEvent.ACTION_MOVE:
{
if (mVelocityTracker == null || mPaused) {
break;
}
mVelocityTracker.addMovement(motionEvent);
float deltaX = motionEvent.getRawX() - mDownX;
float deltaY = motionEvent.getRawY() - mDownY;
if (!mSwiping && Math.abs(deltaX) > mSlop && Math.abs(deltaY) < Math.abs(deltaX) / 2) {
mSwiping = true;
mSwipingSlop = (deltaX > 0 ? mSlop : -mSlop);
}
if (mSwiping) {
mDownView.setTranslationX(deltaX - mSwipingSlop);
mDownView.setAlpha(
Math.max(0f, Math.min(mAlpha, mAlpha * (1f - Math.abs(deltaX) / mViewWidth))));
return true;
}
break;
}
}
return false;
}