Java Code Examples for android.view.ViewGroup#getLocationOnScreen()

/**
 * 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);
}