| /* |
| * 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.annotation.NonNull; |
| import android.content.Context; |
| import android.graphics.drawable.Drawable; |
| |
| /** |
| * A group overlay is an extra layer that sits on top of a ViewGroup |
| * (the "host view") which is drawn after all other content in that view |
| * (including the view group's children). Interaction with the overlay |
| * layer is done by adding and removing views and drawables. |
| * |
| * <p>ViewGroupOverlay is a subclass of {@link ViewOverlay}, adding the ability to |
| * manage views for overlays on ViewGroups, in addition to the drawable |
| * support in ViewOverlay.</p> |
| * |
| * @see ViewGroup#getOverlay() |
| */ |
| public class ViewGroupOverlay extends ViewOverlay { |
| |
| ViewGroupOverlay(Context context, View hostView) { |
| super(context, hostView); |
| } |
| |
| /** |
| * Adds a {@code View} to the overlay. The bounds of the added view should be |
| * relative to the host view. Any view added to the overlay should be |
| * removed when it is no longer needed or no longer visible. |
| * |
| * <p>Views in the overlay are visual-only; they do not receive input |
| * events and do not participate in focus traversal. Overlay views |
| * are intended to be transient, such as might be needed by a temporary |
| * animation effect.</p> |
| * |
| * <p>If the view has a parent, the view will be removed from that parent |
| * before being added to the overlay. Also, if that parent is attached |
| * in the current view hierarchy, the view will be repositioned |
| * such that it is in the same relative location inside the activity. For |
| * example, if the view's current parent lies 100 pixels to the right |
| * and 200 pixels down from the origin of the overlay's |
| * host view, then the view will be offset by (100, 200).</p> |
| * |
| * <p>{@code View}s added with this API will be drawn in the order they were |
| * added. Drawing of the overlay views will happen before drawing of any of the |
| * {@code Drawable}s added with {@link #add(Drawable)} API even if a call to |
| * this API happened after the call to {@link #add(Drawable)}.</p> |
| * |
| * <p>Passing <code>null</code> parameter will result in an |
| * {@link IllegalArgumentException} being thrown.</p> |
| * |
| * @param view The {@code View} to be added to the overlay. The added view will be |
| * drawn when the overlay is drawn. |
| * @see #remove(View) |
| * @see ViewOverlay#add(Drawable) |
| */ |
| public void add(@NonNull View view) { |
| mOverlayViewGroup.add(view); |
| } |
| |
| /** |
| * Removes the specified {@code View} from the overlay. Passing <code>null</code> parameter |
| * will result in an {@link IllegalArgumentException} being thrown. |
| * |
| * @param view The {@code View} to be removed from the overlay. |
| * @see #add(View) |
| * @see ViewOverlay#remove(Drawable) |
| */ |
| public void remove(@NonNull View view) { |
| mOverlayViewGroup.remove(view); |
| } |
| } |