RoundedRectHelper.java revision a76db0cf97b5f05ef0a5e1f6d999933f738f4a3e 
1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
5 * in compliance with the License. You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software distributed under the License
10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
11 * or implied. See the License for the specific language governing permissions and limitations under
12 * the License.
13 */
14package android.support.v17.leanback.widget;
15
16import android.graphics.Color;
17import android.graphics.drawable.ColorDrawable;
18import android.os.Build;
19import android.view.View;
20
21/**
22 * Helper for setting rounded rectangle backgrounds on a view.
23 */
24final class RoundedRectHelper {
25
26    private final static RoundedRectHelper sInstance = new RoundedRectHelper();
27    private Impl mImpl;
28
29    /**
30     * Returns an instance of the helper.
31     */
32    public static RoundedRectHelper getInstance() {
33        return sInstance;
34    }
35
36    /**
37     * Sets or removes a rounded rectangle outline on the given view.
38     */
39    public void setClipToRoundedOutline(View view, boolean clip) {
40        mImpl.setClipToRoundedOutline(view, clip);
41    }
42
43    /**
44     * Sets a rounded rectangle background on the given view, and clips the view to the
45     * background.  If clipping isn't supported on the android runtime, a simple rectangle
46     * background is set instead.
47     *
48     * @param view The view to be modified
49     * @param color The color of the background
50     */
51    public void setRoundedRectBackground(View view, int color) {
52        mImpl.setRoundedRectBackground(view, color);
53    }
54
55    /**
56     * Clears the background of the view to transparent.
57     *
58     * @param view The view to be modified
59     */
60    public void clearBackground(View view) {
61        mImpl.clearBackground(view);
62    }
63
64    static interface Impl {
65        public void setClipToRoundedOutline(View view, boolean clip);
66        public void setRoundedRectBackground(View view, int color);
67        public void clearBackground(View view);
68    }
69
70    /**
71     * Implementation used prior to L.
72     */
73    private static final class StubImpl implements Impl {
74        @Override
75        public void setClipToRoundedOutline(View view, boolean clip) {
76            // Not supported
77        }
78
79        @Override
80        public void setRoundedRectBackground(View view, int color) {
81            // We could set a rounded rect background, but we don't
82            // because we can't do setClipToOutline.
83            // So just set a regular rectangle.
84            view.setBackgroundColor(color);
85        }
86
87        @Override
88        public void clearBackground(View view) {
89            view.setBackground(null);
90        }
91    }
92
93    /**
94     * Implementation used on api 21 (and above).
95     */
96    private static final class Api21Impl implements Impl {
97        @Override
98        public void setClipToRoundedOutline(View view, boolean clip) {
99            RoundedRectHelperApi21.setClipToRoundedOutline(view, clip);
100        }
101
102        @Override
103        public void setRoundedRectBackground(View view, int color) {
104            RoundedRectHelperApi21.setRoundedRectBackground(view, color);
105        }
106
107        @Override
108        public void clearBackground(View view) {
109            RoundedRectHelperApi21.clearBackground(view);
110        }
111    }
112
113    private RoundedRectHelper() {
114        if (Build.VERSION.SDK_INT >= 21) {
115            mImpl = new Api21Impl();
116        } else {
117            mImpl = new StubImpl();
118        }
119    }
120}
121