| /* |
| * Copyright (C) 2013 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package android.view; |
| |
| import android.animation.LayoutTransition; |
| import android.content.Context; |
| import android.graphics.Canvas; |
| import android.graphics.Rect; |
| import android.graphics.drawable.Drawable; |
| |
| import java.util.ArrayList; |
| |
| /** |
| * An overlay is an extra layer that sits on top of a View (the "host view") |
| * which is drawn after all other content in that view (including children, |
| * if the view is a ViewGroup). Interaction with the overlay layer is done |
| * by adding and removing drawables. |
| * |
| * <p>An overlay requested from a ViewGroup is of type {@link ViewGroupOverlay}, |
| * which also supports adding and removing views.</p> |
| * |
| * @see View#getOverlay() View.getOverlay() |
| * @see ViewGroup#getOverlay() ViewGroup.getOverlay() |
| * @see ViewGroupOverlay |
| */ |
| public class ViewOverlay { |
| |
| /** |
| * The actual container for the drawables (and views, if it's a ViewGroupOverlay). |
| * All of the management and rendering details for the overlay are handled in |
| * OverlayViewGroup. |
| */ |
| OverlayViewGroup mOverlayViewGroup; |
| |
| ViewOverlay(Context context, View hostView) { |
| mOverlayViewGroup = new OverlayViewGroup(context, hostView); |
| } |
| |
| /** |
| * Used internally by View and ViewGroup to handle drawing and invalidation |
| * of the overlay |
| * @return |
| */ |
| ViewGroup getOverlayView() { |
| return mOverlayViewGroup; |
| } |
| |
| /** |
| * Adds a Drawable to the overlay. The bounds of the drawable should be relative to |
| * the host view. Any drawable added to the overlay should be removed when it is no longer |
| * needed or no longer visible. |
| * |
| * @param drawable The Drawable to be added to the overlay. This drawable will be |
| * drawn when the view redraws its overlay. |
| * @see #remove(Drawable) |
| */ |
| public void add(Drawable drawable) { |
| mOverlayViewGroup.add(drawable); |
| } |
| |
| /** |
| * Removes the specified Drawable from the overlay. |
| * |
| * @param drawable The Drawable to be removed from the overlay. |
| * @see #add(Drawable) |
| */ |
| public void remove(Drawable drawable) { |
| mOverlayViewGroup.remove(drawable); |
| } |
| |
| /** |
| * Removes all content from the overlay. |
| */ |
| public void clear() { |
| mOverlayViewGroup.clear(); |
| } |
| |
| boolean isEmpty() { |
| return mOverlayViewGroup.isEmpty(); |
| } |
| |
| /** |
| * OverlayViewGroup is a container that View and ViewGroup use to host |
| * drawables and views added to their overlays ({@link ViewOverlay} and |
| * {@link ViewGroupOverlay}, respectively). Drawables are added to the overlay |
| * via the add/remove methods in ViewOverlay, Views are added/removed via |
| * ViewGroupOverlay. These drawable and view objects are |
| * drawn whenever the view itself is drawn; first the view draws its own |
| * content (and children, if it is a ViewGroup), then it draws its overlay |
| * (if it has one). |
| * |
| * <p>Besides managing and drawing the list of drawables, this class serves |
| * two purposes: |
| * (1) it noops layout calls because children are absolutely positioned and |
| * (2) it forwards all invalidation calls to its host view. The invalidation |
| * redirect is necessary because the overlay is not a child of the host view |
| * and invalidation cannot therefore follow the normal path up through the |
| * parent hierarchy.</p> |
| * |
| * @see View#getOverlay() |
| * @see ViewGroup#getOverlay() |
| */ |
| static class OverlayViewGroup extends ViewGroup { |
| |
| /** |
| * The View for which this is an overlay. Invalidations of the overlay are redirected to |
| * this host view. |
| */ |
| View mHostView; |
| |
| /** |
| * The set of drawables to draw when the overlay is rendered. |
| */ |
| ArrayList<Drawable> mDrawables = null; |
| |
| OverlayViewGroup(Context context, View hostView) { |
| super(context); |
| mHostView = hostView; |
| mAttachInfo = mHostView.mAttachInfo; |
| mRight = hostView.getWidth(); |
| mBottom = hostView.getHeight(); |
| } |
| |
| public void add(Drawable drawable) { |
| if (mDrawables == null) { |
| |
| mDrawables = new ArrayList<Drawable>(); |
| } |
| if (!mDrawables.contains(drawable)) { |
| // Make each drawable unique in the overlay; can't add it more than once |
| mDrawables.add(drawable); |
| invalidate(drawable.getBounds()); |
| drawable.setCallback(this); |
| } |
| } |
| |
| public void remove(Drawable drawable) { |
| if (mDrawables != null) { |
| mDrawables.remove(drawable); |
| invalidate(drawable.getBounds()); |
| drawable.setCallback(null); |
| } |
| } |
| |
| public void add(View child) { |
| if (child.getParent() instanceof ViewGroup) { |
| ViewGroup parent = (ViewGroup) child.getParent(); |
| if (parent != mHostView && parent.getParent() != null && |
| parent.mAttachInfo != null) { |
| // 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); |
| mHostView.getLocationOnScreen(hostViewLocation); |
| child.offsetLeftAndRight(parentLocation[0] - hostViewLocation[0]); |
| child.offsetTopAndBottom(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) { |
| child.mParent = null; |
| } |
| } |
| super.addView(child); |
| } |
| |
| public void remove(View view) { |
| super.removeView(view); |
| } |
| |
| public void clear() { |
| removeAllViews(); |
| if (mDrawables != null) { |
| mDrawables.clear(); |
| } |
| } |
| |
| boolean isEmpty() { |
| if (getChildCount() == 0 && |
| (mDrawables == null || mDrawables.size() == 0)) { |
| return true; |
| } |
| return false; |
| } |
| |
| @Override |
| public void invalidateDrawable(Drawable drawable) { |
| invalidate(drawable.getBounds()); |
| } |
| |
| @Override |
| protected void dispatchDraw(Canvas canvas) { |
| super.dispatchDraw(canvas); |
| final int numDrawables = (mDrawables == null) ? 0 : mDrawables.size(); |
| for (int i = 0; i < numDrawables; ++i) { |
| mDrawables.get(i).draw(canvas); |
| } |
| } |
| |
| @Override |
| protected void onLayout(boolean changed, int l, int t, int r, int b) { |
| // Noop: children are positioned absolutely |
| } |
| |
| /* |
| The following invalidation overrides exist for the purpose of redirecting invalidation to |
| the host view. The overlay is not parented to the host view (since a View cannot be a |
| parent), so the invalidation cannot proceed through the normal parent hierarchy. |
| There is a built-in assumption that the overlay exactly covers the host view, therefore |
| the invalidation rectangles received do not need to be adjusted when forwarded to |
| the host view. |
| */ |
| |
| @Override |
| public void invalidate(Rect dirty) { |
| super.invalidate(dirty); |
| if (mHostView != null) { |
| mHostView.invalidate(dirty); |
| } |
| } |
| |
| @Override |
| public void invalidate(int l, int t, int r, int b) { |
| super.invalidate(l, t, r, b); |
| if (mHostView != null) { |
| mHostView.invalidate(l, t, r, b); |
| } |
| } |
| |
| @Override |
| public void invalidate() { |
| super.invalidate(); |
| if (mHostView != null) { |
| mHostView.invalidate(); |
| } |
| } |
| |
| @Override |
| void invalidate(boolean invalidateCache) { |
| super.invalidate(invalidateCache); |
| if (mHostView != null) { |
| mHostView.invalidate(invalidateCache); |
| } |
| } |
| |
| @Override |
| void invalidateViewProperty(boolean invalidateParent, boolean forceRedraw) { |
| super.invalidateViewProperty(invalidateParent, forceRedraw); |
| if (mHostView != null) { |
| mHostView.invalidateViewProperty(invalidateParent, forceRedraw); |
| } |
| } |
| |
| @Override |
| protected void invalidateParentCaches() { |
| super.invalidateParentCaches(); |
| if (mHostView != null) { |
| mHostView.invalidateParentCaches(); |
| } |
| } |
| |
| @Override |
| protected void invalidateParentIfNeeded() { |
| super.invalidateParentIfNeeded(); |
| if (mHostView != null) { |
| mHostView.invalidateParentIfNeeded(); |
| } |
| } |
| |
| public void invalidateChildFast(View child, final Rect dirty) { |
| if (mHostView != null) { |
| // Note: This is not a "fast" invalidation. Would be nice to instead invalidate |
| // using DisplayList properties and a dirty rect instead of causing a real |
| // invalidation of the host view |
| int left = child.mLeft; |
| int top = child.mTop; |
| if (!child.getMatrix().isIdentity()) { |
| child.transformRect(dirty); |
| } |
| dirty.offset(left, top); |
| mHostView.invalidate(dirty); |
| } |
| } |
| |
| /** |
| * @hide |
| */ |
| @Override |
| protected ViewParent invalidateChildInParentFast(int left, int top, Rect dirty) { |
| if (mHostView instanceof ViewGroup) { |
| return ((ViewGroup) mHostView).invalidateChildInParentFast(left, top, dirty); |
| } |
| return null; |
| } |
| |
| @Override |
| public ViewParent invalidateChildInParent(int[] location, Rect dirty) { |
| if (mHostView != null) { |
| dirty.offset(location[0], location[1]); |
| if (mHostView instanceof ViewGroup) { |
| location[0] = 0; |
| location[1] = 0; |
| super.invalidateChildInParent(location, dirty); |
| return ((ViewGroup) mHostView).invalidateChildInParent(location, dirty); |
| } else { |
| invalidate(dirty); |
| } |
| } |
| return null; |
| } |
| } |
| |
| } |