下面列出了android.view.MotionEvent#getHistoricalEventTime ( ) 实例代码,或者点击链接到github查看源代码,也可以在右侧发表评论。
/**
* <p>Calculates the pinch velocity for the last <code>timeWindow</code> milliseconds.</p>
* @param event
* @param pointerA id of pointer A
* @param pointerB id of pointer B
* @param timeWindow
* @return spacing between both pointers
*/
public static final float pinchVelocity(MotionEvent event, int pointerA, int pointerB, long timeWindow) {
int indexA = event.findPointerIndex(pointerA);
int indexB = event.findPointerIndex(pointerB);
long eventTime = event.getEventTime();
long timeDelta = 0;
float previousSpacing = spacingByIndex(event, indexA, indexB);
float scale = 1;
for(int i = 0, n = event.getHistorySize(); i < n && timeDelta < timeWindow; i++) {
int index = (n - 1) - i;
float x = event.getHistoricalX(indexA, index) - event.getHistoricalX(indexB, index);
float y = event.getHistoricalY(indexA, index) - event.getHistoricalY(indexB, index);
float spacing = (float) Math.sqrt(x * x + y * y);
scale *= previousSpacing / spacing;
previousSpacing = spacing;
timeDelta = eventTime - event.getHistoricalEventTime(index);
}
return (float) Math.pow(Math.pow(scale, 1d / timeWindow), 1000d);
}
private void onMoveEvent(final int x, final int y, final long eventTime, final MotionEvent me) {
if (DEBUG_MOVE_EVENT) {
printTouchEvent("onMoveEvent:", x, y, eventTime);
}
if (mIsTrackingForActionDisabled) {
return;
}
if (sGestureEnabler.shouldHandleGesture() && me != null) {
// Add historical points to gesture path.
final int pointerIndex = me.findPointerIndex(mPointerId);
final int historicalSize = me.getHistorySize();
for (int h = 0; h < historicalSize; h++) {
final int historicalX = (int)me.getHistoricalX(pointerIndex, h);
final int historicalY = (int)me.getHistoricalY(pointerIndex, h);
final long historicalTime = me.getHistoricalEventTime(h);
onGestureMoveEvent(historicalX, historicalY, historicalTime,
false /* isMajorEvent */, null);
}
}
if (isShowingMoreKeysPanel()) {
final int translatedX = mMoreKeysPanel.translateX(x);
final int translatedY = mMoreKeysPanel.translateY(y);
mMoreKeysPanel.onMoveEvent(translatedX, translatedY, mPointerId, eventTime);
onMoveKey(x, y);
if (mIsInSlidingKeyInput) {
sDrawingProxy.showSlidingKeyInputPreview(this);
}
return;
}
onMoveEventInternal(x, y, eventTime);
}
private void onMoveEvent(final int x, final int y, final long eventTime, final MotionEvent me) {
if (DEBUG_MOVE_EVENT) {
printTouchEvent("onMoveEvent:", x, y, eventTime);
}
if (mIsTrackingForActionDisabled) {
return;
}
if (sGestureEnabler.shouldHandleGesture() && me != null) {
// Add historical points to gesture path.
final int pointerIndex = me.findPointerIndex(mPointerId);
final int historicalSize = me.getHistorySize();
for (int h = 0; h < historicalSize; h++) {
final int historicalX = (int)me.getHistoricalX(pointerIndex, h);
final int historicalY = (int)me.getHistoricalY(pointerIndex, h);
final long historicalTime = me.getHistoricalEventTime(h);
onGestureMoveEvent(historicalX, historicalY, historicalTime,
false /* isMajorEvent */, null);
}
}
if (isShowingMoreKeysPanel()) {
final int translatedX = mMoreKeysPanel.translateX(x);
final int translatedY = mMoreKeysPanel.translateY(y);
mMoreKeysPanel.onMoveEvent(translatedX, translatedY, mPointerId, eventTime);
onMoveKey(x, y);
if (mIsInSlidingKeyInput) {
sDrawingProxy.showSlidingKeyInputPreview(this);
}
return;
}
onMoveEventInternal(x, y, eventTime);
}
private void onMoveEvent(final int x, final int y, final long eventTime, final MotionEvent me) {
if (DEBUG_MOVE_EVENT) {
printTouchEvent("onMoveEvent:", x, y, eventTime);
}
if (mIsTrackingForActionDisabled) {
return;
}
if (sGestureEnabler.shouldHandleGesture() && me != null) {
// Add historical points to gesture path.
final int pointerIndex = me.findPointerIndex(mPointerId);
final int historicalSize = me.getHistorySize();
for (int h = 0; h < historicalSize; h++) {
final int historicalX = (int)me.getHistoricalX(pointerIndex, h);
final int historicalY = (int)me.getHistoricalY(pointerIndex, h);
final long historicalTime = me.getHistoricalEventTime(h);
onGestureMoveEvent(historicalX, historicalY, historicalTime,
false /* isMajorEvent */, null);
}
}
if (isShowingMoreKeysPanel()) {
final int translatedX = mMoreKeysPanel.translateX(x);
final int translatedY = mMoreKeysPanel.translateY(y);
mMoreKeysPanel.onMoveEvent(translatedX, translatedY, mPointerId, eventTime);
onMoveKey(x, y);
if (mIsInSlidingKeyInput) {
sDrawingProxy.showSlidingKeyInputPreview(this);
}
return;
}
onMoveEventInternal(x, y, eventTime);
}
@Override
public boolean handleMoveTouchEvent(MotionEvent event) {
// Switching 'pointers' (e.g. fingers) on-the-fly isn't supported -- abort over-scroll
// smoothly using the default bounce-back animation in this case.
if (mOverScrollStartAttr.mPointerId != event.getPointerId(0)) {
issueStateTransition(mBounceBackState);
return true;
}
final View view = mViewAdapter.getView();
if (!mMoveAttr.init(view, event)) {
// Keep intercepting the touch event as long as we're still over-scrolling...
return true;
}
float deltaOffset = mMoveAttr.mDeltaOffset / (mMoveAttr.mDir == mOverScrollStartAttr.mDir ? mTouchDragRatioFwd : mTouchDragRatioBck);
float newOffset = mMoveAttr.mAbsOffset + deltaOffset;
// If moved in counter direction onto a potential under-scroll state -- don't. Instead, abort
// over-scrolling abruptly, thus returning control to which-ever touch handlers there
// are waiting (e.g. regular scroller handlers).
if ((mOverScrollStartAttr.mDir && !mMoveAttr.mDir && (newOffset <= mOverScrollStartAttr.mAbsOffset)) ||
(!mOverScrollStartAttr.mDir && mMoveAttr.mDir && (newOffset >= mOverScrollStartAttr.mAbsOffset))) {
translateViewAndEvent(view, mOverScrollStartAttr.mDir, mOverScrollStartAttr.mAbsOffset, event);
mUpdateListener.onOverScrollUpdate(ElasticityBounceEffectBase.this, mCurrDragState, 0);
issueStateTransition(mIdleState);
return true;
}
if (view.getParent() != null) {
view.getParent().requestDisallowInterceptTouchEvent(true);
}
long dt = event.getEventTime() - event.getHistoricalEventTime(0);
if (dt > 0) { // Sometimes (though rarely) dt==0 cause originally timing is in nanos, but is presented in millis.
mVelocity = deltaOffset / dt;
}
translateView(view, mOverScrollStartAttr.mDir, newOffset);
mUpdateListener.onOverScrollUpdate(ElasticityBounceEffectBase.this, mCurrDragState, newOffset);
return true;
}
@Override
public boolean handleMoveTouchEvent(MotionEvent event) {
// Switching 'pointers' (e.g. fingers) on-the-fly isn't supported -- abort over-scroll
// smoothly using the default bounce-back animation in this case.
if (mStartAttr.mPointerId != event.getPointerId(0)) {
issueStateTransition(mBounceBackState);
return true;
}
final View view = mViewAdapter.getView();
if (!mMoveAttr.init(view, event)) {
// Keep intercepting the touch event as long as we're still over-scrolling...
return true;
}
float deltaOffset = mMoveAttr.mDeltaOffset / (mMoveAttr.mDir == mStartAttr.mDir ? mTouchDragRatioFwd : mTouchDragRatioBck);
float newOffset = mMoveAttr.mAbsOffset + deltaOffset;
// If moved in counter direction onto a potential under-scroll state -- don't. Instead, abort
// over-scrolling abruptly, thus returning control to which-ever touch handlers there
// are waiting (e.g. regular scroller handlers).
if ( (mStartAttr.mDir && !mMoveAttr.mDir && (newOffset <= mStartAttr.mAbsOffset)) ||
(!mStartAttr.mDir && mMoveAttr.mDir && (newOffset >= mStartAttr.mAbsOffset)) ) {
translateViewAndEvent(view, mStartAttr.mAbsOffset, event);
mUpdateListener.onOverScrollUpdate(OverScrollBounceEffectDecoratorBase.this, mCurrDragState, 0);
issueStateTransition(mIdleState);
return true;
}
if (view.getParent() != null) {
view.getParent().requestDisallowInterceptTouchEvent(true);
}
long dt = event.getEventTime() - event.getHistoricalEventTime(0);
if (dt > 0) { // Sometimes (though rarely) dt==0 cause originally timing is in nanos, but is presented in millis.
mVelocity = deltaOffset / dt;
}
translateView(view, newOffset);
mUpdateListener.onOverScrollUpdate(OverScrollBounceEffectDecoratorBase.this, mCurrDragState, newOffset);
return true;
}