android.view.ViewGroupOverlay Maven / Gradle / Ivy
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/*
* 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.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.
*
* 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.
*
* @see ViewGroup#getOverlay()
*/
public class ViewGroupOverlay extends ViewOverlay {
ViewGroupOverlay(Context context, View hostView) {
super(context, hostView);
}
/**
* Adds a 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.
*
* 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.
*
* 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).
*
* @param view The 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(View view) {
mOverlayViewGroup.add(view);
}
/**
* Removes the specified View from the overlay.
*
* @param view The View to be removed from the overlay.
* @see #add(View)
* @see ViewOverlay#remove(Drawable)
*/
public void remove(View view) {
mOverlayViewGroup.remove(view);
}
}