下面列出了android.view.ViewGroup#getLocationOnScreen ( ) 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。
/**
* Returns, whether a touch event at a specific position targets a view, which can be scrolled
* up.
*
* @param x
* The horizontal position of the touch event in pixels as a {@link Float} value
* @param y
* The vertical position of the touch event in pixels as a {@link Float} value
* @param viewGroup
* The view group, which should be used to search for scrollable child views, as an
* instance of the class {@link ViewGroup}. The view group may not be null
* @return True, if the touch event targets a view, which can be scrolled up, false otherwise
*/
private boolean isScrollUpEvent(final float x, final float y,
@NonNull final ViewGroup viewGroup) {
int location[] = new int[2];
viewGroup.getLocationOnScreen(location);
if (x >= location[0] && x <= location[0] + viewGroup.getWidth() && y >= location[1] &&
y <= location[1] + viewGroup.getHeight()) {
for (int i = 0; i < viewGroup.getChildCount(); i++) {
View view = viewGroup.getChildAt(i);
if (view.canScrollVertically(-1)) {
return true;
} else if (view instanceof ViewGroup) {
return isScrollUpEvent(x, y, (ViewGroup) view);
}
}
}
return false;
}
private ImageView addMirrorView(ViewGroup parent, RecyclerView recyclerView, View view) {
/**
* 我们要获取cache首先要通过setDrawingCacheEnable方法开启cache，然后再调用getDrawingCache方法就可以获得view的cache图片了。
buildDrawingCache方法可以不用调用，因为调用getDrawingCache方法时，若果cache没有建立，系统会自动调用buildDrawingCache方法生成cache。
若想更新cache, 必须要调用destoryDrawingCache方法把旧的cache销毁，才能建立新的。
当调用setDrawingCacheEnabled方法设置为false, 系统也会自动把原来的cache销毁。
*/
view.destroyDrawingCache();
view.setDrawingCacheEnabled(true);
final ImageView mirrorView = new ImageView(recyclerView.getContext());
Bitmap bitmap = Bitmap.createBitmap(view.getDrawingCache());
mirrorView.setImageBitmap(bitmap);
view.setDrawingCacheEnabled(false);
int[] locations = new int[2];
view.getLocationOnScreen(locations);
int[] parenLocations = new int[2];
parent.getLocationOnScreen(parenLocations);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(bitmap.getWidth(), bitmap.getHeight());
params.setMargins(locations[0], locations[1] - parenLocations[1], 0, 0);
parent.addView(mirrorView, params);
return mirrorView;
}
void drawViewGroup(Canvas canvas, ViewGroup viewGroup) {
drawView(canvas, viewGroup);
canvas.save();
int[] l = new int[2];
viewGroup.getLocationOnScreen(l);
rect.set(0, 0, viewGroup.getWidth(), viewGroup.getHeight());
rect.offset(l[0] - location[0], l[1] - location[1]);
canvas.clipRect(rect);
for (int i = 0; i < viewGroup.getChildCount(); i++) {
View v = viewGroup.getChildAt(i);
if (v instanceof ViewGroup) {
drawViewGroup(canvas, (ViewGroup) v);
} else {
drawView(canvas, v);
}
}
canvas.restore();
}
@Override
public long getStartDelay(ViewGroup sceneRoot, SceneVisibilityTransition transition, TransitionPropagationResult result, boolean appear) {
int directionMultiplier = 1;
Rect epicenter = transition.getEpicenter();
if (!appear) {
directionMultiplier = -1;
}
int viewCenterX = getViewX(result);
int viewCenterY = getViewY(result);
int[] loc = new int[2];
sceneRoot.getLocationOnScreen(loc);
int left = loc[0] + Math.round(sceneRoot.getTranslationX());
int top = loc[1] + Math.round(sceneRoot.getTranslationY());
int right = left + sceneRoot.getWidth();
int bottom = top + sceneRoot.getHeight();
int epicenterX;
int epicenterY;
if (epicenter != null) {
epicenterX = epicenter.centerX();
epicenterY = epicenter.centerY();
} else {
epicenterX = (left + right) / 2;
epicenterY = (top + bottom) / 2;
}
float distance = distance(sceneRoot, viewCenterX, viewCenterY, epicenterX, epicenterY,
left, top, right, bottom);
float maxDistance = getMaxDistance(sceneRoot);
float distanceFraction = distance / maxDistance;
long duration = transition.getDuration();
if (duration < 0) {
duration = 300;
}
return Math.round(duration * directionMultiplier / mPropagationSpeed * distanceFraction);
}
@Override
public long getStartDelay(ViewGroup sceneRoot, SceneVisibilityTransition transition, TransitionPropagationResult result, boolean appear) {
int directionMultiplier = 1;
TransitionValues positionValues;
if (!appear) {
directionMultiplier = -1;
}
int viewCenterX = getViewX(result);
int viewCenterY = getViewY(result);
Rect epicenter = transition.getEpicenter();
int epicenterX;
int epicenterY;
if (epicenter != null) {
epicenterX = epicenter.centerX();
epicenterY = epicenter.centerY();
} else {
int[] loc = new int[2];
sceneRoot.getLocationOnScreen(loc);
epicenterX = Math.round(loc[0] + (sceneRoot.getWidth() / 2)
+ sceneRoot.getTranslationX());
epicenterY = Math.round(loc[1] + (sceneRoot.getHeight() / 2)
+ sceneRoot.getTranslationY());
}
float distance = distance(viewCenterX, viewCenterY, epicenterX, epicenterY);
float maxDistance = distance(0, 0, sceneRoot.getWidth(), sceneRoot.getHeight());
float distanceFraction = distance / maxDistance;
long duration = transition.getDuration();
if (duration < 0) {
duration = 300;
}
return Math.round(duration * directionMultiplier / mPropagationSpeed * distanceFraction);
}
protected ArrayList<View> createSnapshots(Bundle state, Collection<String> names) {
int numSharedElements = names.size();
ArrayList<View> snapshots = new ArrayList<View>(numSharedElements);
if (numSharedElements == 0) {
return snapshots;
}
Context context = getWindow().getContext();
int[] decorLoc = new int[2];
ViewGroup decorView = getDecor();
if (decorView != null) {
decorView.getLocationOnScreen(decorLoc);
}
Matrix tempMatrix = new Matrix();
for (String name: names) {
Bundle sharedElementBundle = state.getBundle(name);
View snapshot = null;
if (sharedElementBundle != null) {
Parcelable parcelable = sharedElementBundle.getParcelable(KEY_SNAPSHOT);
if (parcelable != null && mListener != null) {
snapshot = mListener.onCreateSnapshotView(context, parcelable);
}
if (snapshot != null) {
setSharedElementState(snapshot, name, state, tempMatrix, null, decorLoc);
}
}
// Even null snapshots are added so they remain in the same order as shared elements.
snapshots.add(snapshot);
}
return snapshots;
}
@SuppressWarnings("RestrictTo")
private static boolean shouldApplyBottomInset(ViewGroup scrollView, int systemWindowInsetBottom) {
View scrollableContent = scrollView.getChildAt(0);
int scrollableContentHeight = scrollableContent.getHeight();
int scrollViewHeight = scrollView.getHeight();
int[] scrollViewLocation = new int[2];
scrollView.getLocationOnScreen(scrollViewLocation);
Context context = scrollView.getContext();
Activity activity = ContextUtils.getActivity(context);
return scrollViewHeight + scrollViewLocation[1] >= getContentViewHeight(activity)
&& scrollableContentHeight + systemWindowInsetBottom >= scrollViewHeight;
}
public void add(View child) {
assertNotDisposed();
if (child.getParent() instanceof ViewGroup) {
ViewGroup parent = (ViewGroup) child.getParent();
if (parent != hostView
&& parent.getParent() != null
&& ViewCompat.isAttachedToWindow(parent)) {
// Moving to different container; figure out how to position child such that
// it is in the same location on the screen
int[] parentLocation = new int[2];
int[] hostViewLocation = new int[2];
parent.getLocationOnScreen(parentLocation);
hostView.getLocationOnScreen(hostViewLocation);
ViewCompat.offsetLeftAndRight(child, parentLocation[0] - hostViewLocation[0]);
ViewCompat.offsetTopAndBottom(child, parentLocation[1] - hostViewLocation[1]);
}
parent.removeView(child);
// if (parent.getLayoutTransition() != null) {
// // LayoutTransition will cause the child to delay removal - cancel it
// parent.getLayoutTransition().cancel(LayoutTransition.DISAPPEARING);
// }
// fail-safe if view is still attached for any reason
if (child.getParent() != null) {
parent.removeView(child);
}
}
super.addView(child);
}
@Override
public void moveViewInOverlay(@NonNull ViewGroup sceneRoot, @NonNull View overlayView, int screenX, int screenY) {
if (screenX != 0 || screenY != 0) {
int[] loc = new int[2];
sceneRoot.getLocationOnScreen(loc);
overlayView.offsetLeftAndRight((screenX - loc[0]) - overlayView.getLeft());
overlayView.offsetTopAndBottom((screenY - loc[1]) - overlayView.getTop());
}
}
@NonNull
@Override
public int[] getLocationOnScreenOfOverlayView(@NonNull ViewGroup sceneRoot, @NonNull View overlayView) {
int[] location = new int[2];
sceneRoot.getLocationOnScreen(location);
location[0] += overlayView.getLeft();
location[1] += overlayView.getTop();
return location;
}
@Override
public long getStartDelay(ViewGroup sceneRoot, Transition transition,
TransitionValues startValues, TransitionValues endValues) {
if (startValues == null && endValues == null) {
return 0;
}
int directionMultiplier = 1;
Rect epicenter = transition.getEpicenter();
TransitionValues positionValues;
if (endValues == null || getViewVisibility(startValues) == View.VISIBLE) {
positionValues = startValues;
directionMultiplier = -1;
} else {
positionValues = endValues;
}
int viewCenterX = getViewX(positionValues);
int viewCenterY = getViewY(positionValues);
int[] loc = new int[2];
sceneRoot.getLocationOnScreen(loc);
int left = loc[0] + Math.round(sceneRoot.getTranslationX());
int top = loc[1] + Math.round(sceneRoot.getTranslationY());
int right = left + sceneRoot.getWidth();
int bottom = top + sceneRoot.getHeight();
int epicenterX;
int epicenterY;
if (epicenter != null) {
epicenterX = epicenter.centerX();
epicenterY = epicenter.centerY();
} else {
epicenterX = (left + right) / 2;
epicenterY = (top + bottom) / 2;
}
float distance = distance(sceneRoot, viewCenterX, viewCenterY, epicenterX, epicenterY,
left, top, right, bottom);
float maxDistance = getMaxDistance(sceneRoot);
float distanceFraction = distance/maxDistance;
long duration = transition.getDuration();
if (duration < 0) {
duration = 300;
}
return Math.round(duration * directionMultiplier / mPropagationSpeed * distanceFraction);
}
@Override
public long getStartDelay(ViewGroup sceneRoot, Transition transition,
TransitionValues startValues, TransitionValues endValues) {
if (startValues == null && endValues == null) {
return 0;
}
int directionMultiplier = 1;
TransitionValues positionValues;
if (endValues == null || getViewVisibility(startValues) == View.VISIBLE) {
positionValues = startValues;
directionMultiplier = -1;
} else {
positionValues = endValues;
}
int viewCenterX = getViewX(positionValues);
int viewCenterY = getViewY(positionValues);
Rect epicenter = transition.getEpicenter();
int epicenterX;
int epicenterY;
if (epicenter != null) {
epicenterX = epicenter.centerX();
epicenterY = epicenter.centerY();
} else {
int[] loc = new int[2];
sceneRoot.getLocationOnScreen(loc);
epicenterX = Math.round(loc[0] + (sceneRoot.getWidth() / 2)
+ sceneRoot.getTranslationX());
epicenterY = Math.round(loc[1] + (sceneRoot.getHeight() / 2)
+ sceneRoot.getTranslationY());
}
double distance = distance(viewCenterX, viewCenterY, epicenterX, epicenterY);
double maxDistance = distance(0, 0, sceneRoot.getWidth(), sceneRoot.getHeight());
double distanceFraction = distance/maxDistance;
long duration = transition.getDuration();
if (duration < 0) {
duration = 300;
}
return Math.round(duration * directionMultiplier / mPropagationSpeed * distanceFraction);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
if (mDragListener != null || mDropListener != null) {
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
int x = (int) ev.getX();
int y = (int) ev.getY();
int itemnum = pointToPosition(x, y);
if (itemnum == AdapterView.INVALID_POSITION) {
break;
}
ViewGroup item = (ViewGroup) getChildAt(itemnum - getFirstVisiblePosition());
mDragPoint = y - item.getTop();
mCoordOffset = ((int) ev.getRawY()) - y;
View dragger = item.findViewById(R.id.grabber);
Rect r = mTempRect;
dragger.getDrawingRect(r);
if (shouldStartDragging(x, r.width())) {
// Fix x position while dragging
int[] itemPos = new int[2];
item.getLocationOnScreen(itemPos);
item.setDrawingCacheEnabled(true);
// Create a copy of the drawing cache so that it does
// not get recycled
// by the framework when the list tries to clean up
// memory
Bitmap bitmap = Bitmap.createBitmap(item.getDrawingCache());
startDragging(bitmap, itemPos[0], y);
mDragPos = itemnum;
mFirstDragPos = mDragPos;
mHeight = getHeight();
int touchSlop = mTouchSlop;
mUpperBound = Math.min(y - touchSlop, mHeight / 3);
mLowerBound = Math.max(y + touchSlop, mHeight * 2 / 3);
return false;
}
stopDragging();
break;
}
}
return super.onInterceptTouchEvent(ev);
}
@Override
public long getStartDelay(@NonNull ViewGroup sceneRoot, @NonNull Transition transition,
@Nullable TransitionValues startValues, @Nullable TransitionValues endValues) {
if (startValues == null && endValues == null) {
return 0;
}
int directionMultiplier = 1;
Rect epicenter = transition.getEpicenter();
TransitionValues positionValues;
if (endValues == null || getViewVisibility(startValues) == View.VISIBLE) {
positionValues = startValues;
directionMultiplier = -1;
} else {
positionValues = endValues;
}
int viewCenterX = getViewX(positionValues);
int viewCenterY = getViewY(positionValues);
int[] loc = new int[2];
sceneRoot.getLocationOnScreen(loc);
int left = loc[0] + Math.round(sceneRoot.getTranslationX());
int top = loc[1] + Math.round(sceneRoot.getTranslationY());
int right = left + sceneRoot.getWidth();
int bottom = top + sceneRoot.getHeight();
int epicenterX;
int epicenterY;
if (epicenter != null) {
epicenterX = epicenter.centerX();
epicenterY = epicenter.centerY();
} else {
epicenterX = (left + right) / 2;
epicenterY = (top + bottom) / 2;
}
float distance = distance(sceneRoot, viewCenterX, viewCenterY, epicenterX, epicenterY,
left, top, right, bottom);
float maxDistance = getMaxDistance(sceneRoot);
float distanceFraction = distance/maxDistance;
long duration = transition.getDuration();
if (duration < 0) {
duration = 300;
}
return Math.round(duration * directionMultiplier / mPropagationSpeed * distanceFraction);
}
@Override
public long getStartDelay(@NonNull ViewGroup sceneRoot, @NonNull Transition transition,
@Nullable TransitionValues startValues, @Nullable TransitionValues endValues) {
if (startValues == null && endValues == null) {
return 0;
}
int directionMultiplier = 1;
TransitionValues positionValues;
if (endValues == null || getViewVisibility(startValues) == View.VISIBLE) {
positionValues = startValues;
directionMultiplier = -1;
} else {
positionValues = endValues;
}
int viewCenterX = getViewX(positionValues);
int viewCenterY = getViewY(positionValues);
Rect epicenter = transition.getEpicenter();
int epicenterX;
int epicenterY;
if (epicenter != null) {
epicenterX = epicenter.centerX();
epicenterY = epicenter.centerY();
} else {
int[] loc = new int[2];
sceneRoot.getLocationOnScreen(loc);
epicenterX = Math.round(loc[0] + (sceneRoot.getWidth() / 2)
+ sceneRoot.getTranslationX());
epicenterY = Math.round(loc[1] + (sceneRoot.getHeight() / 2)
+ sceneRoot.getTranslationY());
}
double distance = distance(viewCenterX, viewCenterY, epicenterX, epicenterY);
double maxDistance = distance(0, 0, sceneRoot.getWidth(), sceneRoot.getHeight());
double distanceFraction = distance/maxDistance;
long duration = transition.getDuration();
if (duration < 0) {
duration = 300;
}
return Math.round(duration * directionMultiplier / mPropagationSpeed * distanceFraction);
}