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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.support.v4.widget;
import android.view.View;
import android.view.View.OnTouchListener;
/**
* Helper for accessing features in ListPopupWindow introduced after API level 4
* in a backwards compatible fashion.
*/
public final class ListPopupWindowCompat {
/**
* Interface for the full API.
*/
interface ListPopupWindowImpl {
public OnTouchListener createDragToOpenListener(Object listPopupWindow, View src);
}
/**
* Interface implementation that doesn't use anything above v4 APIs.
*/
static class BaseListPopupWindowImpl implements ListPopupWindowImpl {
@Override
public OnTouchListener createDragToOpenListener(Object listPopupWindow, View src) {
return null;
}
}
/**
* Interface implementation for devices with at least KitKat APIs.
*/
static class KitKatListPopupWindowImpl extends BaseListPopupWindowImpl {
@Override
public OnTouchListener createDragToOpenListener(Object listPopupWindow, View src) {
return ListPopupWindowCompatKitKat.createDragToOpenListener(listPopupWindow, src);
}
}
/**
* Select the correct implementation to use for the current platform.
*/
static final ListPopupWindowImpl IMPL;
static {
final int version = android.os.Build.VERSION.SDK_INT;
if (version >= 19) {
IMPL = new KitKatListPopupWindowImpl();
} else {
IMPL = new BaseListPopupWindowImpl();
}
}
private ListPopupWindowCompat() {
// This class is not publicly instantiable.
}
/**
* On API {@link android.os.Build.VERSION_CODES#KITKAT} and higher, returns
* an {@link OnTouchListener} that can be added to the source view to
* implement drag-to-open behavior. Generally, the source view should be the
* same view that was passed to ListPopupWindow.setAnchorView(View).
* <p>
* When the listener is set on a view, touching that view and dragging
* outside of its bounds will open the popup window. Lifting will select the
* currently touched list item.
* <p>
* Example usage:
*
* <pre>
* ListPopupWindow myPopup = new ListPopupWindow(context);
* myPopup.setAnchor(myAnchor);
* OnTouchListener dragListener = myPopup.createDragToOpenListener(myAnchor);
* myAnchor.setOnTouchListener(dragListener);
* </pre>
*
* @param listPopupWindow the ListPopupWindow against which to invoke the
* method
* @param src the view on which the resulting listener will be set
* @return a touch listener that controls drag-to-open behavior, or null on
* unsupported APIs
*/
public static OnTouchListener createDragToOpenListener(Object listPopupWindow, View src) {
return IMPL.createDragToOpenListener(listPopupWindow, src);
}
}