1/*
2 * Copyright (C) 2015 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.design.widget;
18
19import android.graphics.drawable.Drawable;
20import android.graphics.drawable.DrawableContainer;
21import android.util.Log;
22
23import java.lang.reflect.Method;
24
25/**
26 * Caution. Gross hacks ahead.
27 */
28class DrawableUtils {
29
30    private static final String LOG_TAG = "DrawableUtils";
31
32    private static Method sSetConstantStateMethod;
33    private static boolean sSetConstantStateMethodFetched;
34
35    private DrawableUtils() {}
36
37    static boolean setContainerConstantState(DrawableContainer drawable,
38            Drawable.ConstantState constantState) {
39        // We can use getDeclaredMethod() on v9+
40        return setContainerConstantStateV9(drawable, constantState);
41    }
42
43    private static boolean setContainerConstantStateV9(DrawableContainer drawable,
44            Drawable.ConstantState constantState) {
45        if (!sSetConstantStateMethodFetched) {
46            try {
47                sSetConstantStateMethod = DrawableContainer.class.getDeclaredMethod(
48                        "setConstantState", DrawableContainer.DrawableContainerState.class);
49                sSetConstantStateMethod.setAccessible(true);
50            } catch (NoSuchMethodException e) {
51                Log.e(LOG_TAG, "Could not fetch setConstantState(). Oh well.");
52            }
53            sSetConstantStateMethodFetched = true;
54        }
55        if (sSetConstantStateMethod != null) {
56            try {
57                sSetConstantStateMethod.invoke(drawable, constantState);
58                return true;
59            } catch (Exception e) {
60                Log.e(LOG_TAG, "Could not invoke setConstantState(). Oh well.");
61            }
62        }
63        return false;
64    }
65}
66