/*
* Determines if we should change the touch state to start dragging after the
* user moves their touch point far enough.
*/
protected void determineDraggingStart(MotionEvent ev) {
/*
* Locally do absolute value. mLastMotionX is set to the y value
* of the down event.
*/
final int pointerIndex = ev.findPointerIndex(mActivePointerId);
final float x = ev.getX(pointerIndex);
final float y = ev.getY(pointerIndex);
final int xDiff = (int) Math.abs(x - mLastMotionX);
final int yDiff = (int) Math.abs(y - mLastMotionY);
final int touchSlop = mTouchSlop;
boolean yMoved = yDiff > touchSlop;
boolean isUpwardMotion = (yDiff / (float) xDiff) > mDragSlopeThreshold;
if (isUpwardMotion && yMoved && mLastTouchedItem != null) {
// Drag if the user moved far enough along the Y axis
beginDragging(mLastTouchedItem);
// Cancel any pending long press
if (mAllowLongPress) {
mAllowLongPress = false;
// Try canceling the long press. It could also have been scheduled
// by a distant descendant, so use the mAllowLongPress flag to block
// everything
final View currentPage = getPageAt(mCurrentPage);
if (currentPage != null) {
currentPage.cancelLongPress();
}
}
}
}
private void checkStartScroll(float x, float y) {
/*
* Locally do absolute value. mLastMotionX is set to the y value
* of the down event.
*/
final int xDiff = (int) Math.abs(x - mLastMotionX);
final int yDiff = (int) Math.abs(y - mLastMotionY);
boolean xMoved = xDiff > mTouchSlop;
boolean yMoved = yDiff > mTouchSlop;
if (xMoved || yMoved) {
if (yMoved) {
// Scroll if the user moved far enough along the X axis
mTouchState = TOUCH_STATE_SCROLLING;
enableChildrenCache();
}
// Either way, cancel any pending longpress
if (mAllowLongPress) {
mAllowLongPress = false;
// Try canceling the long press. It could also have been scheduled
// by a distant descendant, so use the mAllowLongPress flag to block
// everything
final View currentScreen = getChildAt(mCurrentPage);
currentScreen.cancelLongPress();
}
}
}
@Override
public void cancelLongPress() {
super.cancelLongPress();
final int count = getChildCount();
for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
child.cancelLongPress();
}
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
if (mLocked) {
return true;
}
final int action = ev.getAction();
if ((action == MotionEvent.ACTION_MOVE) && (mTouchState != TOUCH_STATE_REST)) {
return true;
}
final float x = ev.getX();
final float y = ev.getY();
switch (action) {
case MotionEvent.ACTION_MOVE:
final int xDiff = (int) Math.abs(x - mLastMotionX);
final int yDiff = (int) Math.abs(y - mLastMotionY);
final int touchSlop = mTouchSlop;
boolean xMoved = xDiff > touchSlop;
boolean yMoved = yDiff > touchSlop;
if (xMoved || yMoved) {
if (xMoved) {
// Scroll if the user moved far enough along the X axis
mTouchState = TOUCH_STATE_SCROLLING;
enableChildrenCache();
}
// Either way, cancel any pending longpress
if (mAllowLongPress) {
mAllowLongPress = false;
// Try canceling the long press. It could also have been scheduled
// by a distant descendant, so use the mAllowLongPress flag to block
// everything
final View currentScreen = getChildAt(mCurrentScreen);
currentScreen.cancelLongPress();
}
}
break;
case MotionEvent.ACTION_DOWN:
// Remember location of down touch
mLastMotionX = x;
mLastMotionY = y;
mAllowLongPress = true;
mTouchState = mScroller.isFinished() ? TOUCH_STATE_REST : TOUCH_STATE_SCROLLING;
break;
case MotionEvent.ACTION_CANCEL:
case MotionEvent.ACTION_UP:
// Release the drag
clearChildrenCache();
mTouchState = TOUCH_STATE_REST;
mAllowLongPress = false;
break;
}
/*
* The only time we want to intercept motion events is if we are in the
* drag mode.
*/
return mTouchState != TOUCH_STATE_REST;
}
