PopupWindowCompat.java revision 3ac77bf186f87ecad4bf0063b2f6c4384efbd56a 
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
17package android.support.v4.widget;
18
19import android.support.v4.view.GravityCompat;
20import android.support.v4.view.ViewCompat;
21import android.view.Gravity;
22import android.view.View;
23import android.view.WindowManager;
24import android.widget.PopupWindow;
25
26/**
27 * Helper for accessing features in PopupWindow introduced after API level 4
28 * in a backwards compatible fashion.
29 */
30public final class PopupWindowCompat {
31    /**
32     * Interface for the full API.
33     */
34    interface PopupWindowImpl {
35        void showAsDropDown(PopupWindow popup, View anchor, int xoff, int yoff, int gravity);
36        void setOverlapAnchor(PopupWindow popupWindow, boolean overlapAnchor);
37        boolean getOverlapAnchor(PopupWindow popupWindow);
38        void setWindowLayoutType(PopupWindow popupWindow, int layoutType);
39        int getWindowLayoutType(PopupWindow popupWindow);
40    }
41
42    /**
43     * Interface implementation that doesn't use anything above v4 APIs.
44     */
45    static class BasePopupWindowImpl implements PopupWindowImpl {
46        @Override
47        public void showAsDropDown(PopupWindow popup, View anchor, int xoff, int yoff,
48                int gravity) {
49            final int hgrav = GravityCompat.getAbsoluteGravity(gravity,
50                    ViewCompat.getLayoutDirection(anchor)) & Gravity.HORIZONTAL_GRAVITY_MASK;
51            if (hgrav == Gravity.RIGHT) {
52                // Flip the location to align the right sides of the popup and
53                // anchor instead of left.
54                xoff -= (popup.getWidth() - anchor.getWidth());
55            }
56            popup.showAsDropDown(anchor, xoff, yoff);
57        }
58
59        @Override
60        public void setOverlapAnchor(PopupWindow popupWindow, boolean overlapAnchor) {
61            // noop
62        }
63
64        @Override
65        public boolean getOverlapAnchor(PopupWindow popupWindow) {
66            return false;
67        }
68
69        @Override
70        public void setWindowLayoutType(PopupWindow popupWindow, int layoutType) {
71            // no-op
72        }
73
74        @Override
75        public int getWindowLayoutType(PopupWindow popupWindow) {
76            return 0;
77        }
78    }
79
80    /**
81     * Interface implementation that doesn't use anything above v4 APIs.
82     */
83    static class GingerbreadPopupWindowImpl extends BasePopupWindowImpl {
84        @Override
85        public void setWindowLayoutType(PopupWindow popupWindow, int layoutType) {
86            PopupWindowCompatGingerbread.setWindowLayoutType(popupWindow, layoutType);
87        }
88
89        @Override
90        public int getWindowLayoutType(PopupWindow popupWindow) {
91            return PopupWindowCompatGingerbread.getWindowLayoutType(popupWindow);
92        }
93    }
94
95    /**
96     * Interface implementation for devices with at least KitKat APIs.
97     */
98    static class KitKatPopupWindowImpl extends GingerbreadPopupWindowImpl {
99        @Override
100        public void showAsDropDown(PopupWindow popup, View anchor, int xoff, int yoff,
101                int gravity) {
102            PopupWindowCompatKitKat.showAsDropDown(popup, anchor, xoff, yoff, gravity);
103        }
104    }
105
106    static class Api21PopupWindowImpl extends KitKatPopupWindowImpl {
107        @Override
108        public void setOverlapAnchor(PopupWindow popupWindow, boolean overlapAnchor) {
109            PopupWindowCompatApi21.setOverlapAnchor(popupWindow, overlapAnchor);
110        }
111
112        @Override
113        public boolean getOverlapAnchor(PopupWindow popupWindow) {
114            return PopupWindowCompatApi21.getOverlapAnchor(popupWindow);
115        }
116    }
117
118    static class Api23PopupWindowImpl extends Api21PopupWindowImpl {
119        @Override
120        public void setOverlapAnchor(PopupWindow popupWindow, boolean overlapAnchor) {
121            PopupWindowCompatApi23.setOverlapAnchor(popupWindow, overlapAnchor);
122        }
123
124        @Override
125        public boolean getOverlapAnchor(PopupWindow popupWindow) {
126            return PopupWindowCompatApi23.getOverlapAnchor(popupWindow);
127        }
128
129        @Override
130        public void setWindowLayoutType(PopupWindow popupWindow, int layoutType) {
131            PopupWindowCompatApi23.setWindowLayoutType(popupWindow, layoutType);
132        }
133
134        @Override
135        public int getWindowLayoutType(PopupWindow popupWindow) {
136            return PopupWindowCompatApi23.getWindowLayoutType(popupWindow);
137        }
138    }
139
140    /**
141     * Select the correct implementation to use for the current platform.
142     */
143    static final PopupWindowImpl IMPL;
144    static {
145        final int version = android.os.Build.VERSION.SDK_INT;
146        if (version >= 23) {
147            IMPL = new Api23PopupWindowImpl();
148        } else if (version >= 21) {
149            IMPL = new Api21PopupWindowImpl();
150        } else if (version >= 19) {
151            IMPL = new KitKatPopupWindowImpl();
152        } else if (version >= 9) {
153            IMPL = new GingerbreadPopupWindowImpl();
154        } else {
155            IMPL = new BasePopupWindowImpl();
156        }
157    }
158
159    private PopupWindowCompat() {
160        // This class is not publicly instantiable.
161    }
162
163    /**
164     * <p>Display the content view in a popup window anchored to the bottom-left
165     * corner of the anchor view offset by the specified x and y coordinates.
166     * If there is not enough room on screen to show
167     * the popup in its entirety, this method tries to find a parent scroll
168     * view to scroll. If no parent scroll view can be scrolled, the bottom-left
169     * corner of the popup is pinned at the top left corner of the anchor view.</p>
170     * <p>If the view later scrolls to move <code>anchor</code> to a different
171     * location, the popup will be moved correspondingly.</p>
172     *
173     * @param popup the PopupWindow to show
174     * @param anchor the view on which to pin the popup window
175     * @param xoff A horizontal offset from the anchor in pixels
176     * @param yoff A vertical offset from the anchor in pixels
177     * @param gravity Alignment of the popup relative to the anchor
178     */
179    public static void showAsDropDown(PopupWindow popup, View anchor, int xoff, int yoff,
180            int gravity) {
181        IMPL.showAsDropDown(popup, anchor, xoff, yoff, gravity);
182    }
183
184    /**
185     * Sets whether the popup window should overlap its anchor view when
186     * displayed as a drop-down.
187     *
188     * @param overlapAnchor Whether the popup should overlap its anchor.
189     */
190    public static void setOverlapAnchor(PopupWindow popupWindow, boolean overlapAnchor) {
191        IMPL.setOverlapAnchor(popupWindow, overlapAnchor);
192    }
193
194    /**
195     * Returns whether the popup window should overlap its anchor view when
196     * displayed as a drop-down.
197     *
198     * @return Whether the popup should overlap its anchor.
199     */
200    public static boolean getOverlapAnchor(PopupWindow popupWindow) {
201        return IMPL.getOverlapAnchor(popupWindow);
202    }
203
204    /**
205     * Set the layout type for this window. This value will be passed through to
206     * {@link WindowManager.LayoutParams#type} therefore the value should match any value
207     * {@link WindowManager.LayoutParams#type} accepts.
208     *
209     * @param layoutType Layout type for this window.
210     *
211     * @see WindowManager.LayoutParams#type
212     */
213    public static void setWindowLayoutType(PopupWindow popupWindow, int layoutType) {
214        IMPL.setWindowLayoutType(popupWindow, layoutType);
215    }
216
217    /**
218     * Returns the layout type for this window.
219     *
220     * @see #setWindowLayoutType(PopupWindow popupWindow, int)
221     */
222    public static int getWindowLayoutType(PopupWindow popupWindow) {
223        return IMPL.getWindowLayoutType(popupWindow);
224    }
225}
226