1 /* 2 * Copyright (C) 2013 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 package android.view; 17 18 import android.content.Context; 19 import android.graphics.drawable.Drawable; 20 21 /** 22 * A group overlay is an extra layer that sits on top of a ViewGroup 23 * (the "host view") which is drawn after all other content in that view 24 * (including the view group's children). Interaction with the overlay 25 * layer is done by adding and removing views and drawables. 26 * 27 * <p>ViewGroupOverlay is a subclass of {@link ViewOverlay}, adding the ability to 28 * manage views for overlays on ViewGroups, in addition to the drawable 29 * support in ViewOverlay.</p> 30 * 31 * @see ViewGroup#getOverlay() 32 */ 33 public class ViewGroupOverlay extends ViewOverlay { 34 ViewGroupOverlay(Context context, View hostView)35 ViewGroupOverlay(Context context, View hostView) { 36 super(context, hostView); 37 } 38 39 /** 40 * Adds a View to the overlay. The bounds of the added view should be 41 * relative to the host view. Any view added to the overlay should be 42 * removed when it is no longer needed or no longer visible. 43 * 44 * <p>Views in the overlay are visual-only; they do not receive input 45 * events and do not participate in focus traversal. Overlay views 46 * are intended to be transient, such as might be needed by a temporary 47 * animation effect.</p> 48 * 49 * <p>If the view has a parent, the view will be removed from that parent 50 * before being added to the overlay. Also, if that parent is attached 51 * in the current view hierarchy, the view will be repositioned 52 * such that it is in the same relative location inside the activity. For 53 * example, if the view's current parent lies 100 pixels to the right 54 * and 200 pixels down from the origin of the overlay's 55 * host view, then the view will be offset by (100, 200).</p> 56 * 57 * @param view The View to be added to the overlay. The added view will be 58 * drawn when the overlay is drawn. 59 * @see #remove(View) 60 * @see ViewOverlay#add(Drawable) 61 */ add(View view)62 public void add(View view) { 63 mOverlayViewGroup.add(view); 64 } 65 66 /** 67 * Removes the specified View from the overlay. 68 * 69 * @param view The View to be removed from the overlay. 70 * @see #add(View) 71 * @see ViewOverlay#remove(Drawable) 72 */ remove(View view)73 public void remove(View view) { 74 mOverlayViewGroup.remove(view); 75 } 76 } 77