ViewUtils.java revision 6f2135232bf216d194b049265f0b92f69e74c241 
1/*
2 * Copyright (C) 2014 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.v7.internal.widget;
18
19import android.content.Context;
20import android.content.res.TypedArray;
21import android.graphics.Rect;
22import android.os.Build;
23import android.support.v4.view.ViewCompat;
24import android.support.v7.appcompat.R;
25import android.support.v7.internal.view.ContextThemeWrapper;
26import android.util.AttributeSet;
27import android.util.Log;
28import android.view.View;
29
30import java.lang.reflect.InvocationTargetException;
31import java.lang.reflect.Method;
32
33/**
34 * @hide
35 */
36public class ViewUtils {
37    private static final String TAG = "ViewUtils";
38
39    private static Method sComputeFitSystemWindowsMethod;
40
41    static {
42        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
43            try {
44                sComputeFitSystemWindowsMethod = View.class.getDeclaredMethod(
45                        "computeFitSystemWindows", Rect.class, Rect.class);
46                if (!sComputeFitSystemWindowsMethod.isAccessible()) {
47                    sComputeFitSystemWindowsMethod.setAccessible(true);
48                }
49            } catch (NoSuchMethodException e) {
50                Log.d(TAG, "Could not find method computeFitSystemWindows. Oh well.");
51            }
52        }
53    }
54
55    private ViewUtils() {}
56
57    public static boolean isLayoutRtl(View view) {
58        return ViewCompat.getLayoutDirection(view) == ViewCompat.LAYOUT_DIRECTION_RTL;
59    }
60
61    /**
62     * Merge two states as returned by {@link ViewCompat#getMeasuredState(android.view.View)} ()}.
63     * @param curState The current state as returned from a view or the result
64     * of combining multiple views.
65     * @param newState The new view state to combine.
66     * @return Returns a new integer reflecting the combination of the two
67     * states.
68     */
69    public static int combineMeasuredStates(int curState, int newState) {
70        return curState | newState;
71    }
72
73    /**
74     * Allow calling the hidden method {@code computeFitSystemWindows(Rect, Rect)} through
75     * reflection on {@code view}.
76     */
77    public static void computeFitSystemWindows(View view, Rect inoutInsets, Rect outLocalInsets) {
78        if (sComputeFitSystemWindowsMethod != null) {
79            try {
80                sComputeFitSystemWindowsMethod.invoke(view, inoutInsets, outLocalInsets);
81            } catch (Exception e) {
82                Log.d(TAG, "Could not invoke computeFitSystemWindows", e);
83            }
84        }
85    }
86
87    /**
88     * Allow calling the hidden method {@code makeOptionalFitsSystem()} through reflection on
89     * {@code view}.
90     */
91    public static void makeOptionalFitsSystemWindows(View view) {
92        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
93            try {
94                // We need to use getMethod() for makeOptionalFitsSystemWindows since both View
95                // and ViewGroup implement the method
96                Method method = view.getClass().getMethod("makeOptionalFitsSystemWindows");
97                if (!method.isAccessible()) {
98                    method.setAccessible(true);
99                }
100                method.invoke(view);
101            } catch (NoSuchMethodException e) {
102                Log.d(TAG, "Could not find method makeOptionalFitsSystemWindows. Oh well...");
103            } catch (InvocationTargetException e) {
104                Log.d(TAG, "Could not invoke makeOptionalFitsSystemWindows", e);
105            } catch (IllegalAccessException e) {
106                Log.d(TAG, "Could not invoke makeOptionalFitsSystemWindows", e);
107            }
108        }
109    }
110
111    /**
112     * Allows us to emulate the {@code android:theme} attribute for devices before L.
113     */
114    public static Context themifyContext(Context context, AttributeSet attrs,
115            boolean useAndroidTheme, boolean useAppTheme) {
116        final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.View, 0, 0);
117        int themeId = 0;
118        if (useAndroidTheme) {
119            // First try reading android:theme if enabled
120            themeId = a.getResourceId(R.styleable.View_android_theme, 0);
121        }
122        if (useAppTheme && themeId == 0) {
123            // ...if that didn't work, try reading app:theme (for legacy reasons) if enabled
124            themeId = a.getResourceId(R.styleable.View_theme, 0);
125
126            if (themeId != 0) {
127                Log.i(TAG, "app:theme is now deprecated. Please move to using android:theme instead.");
128            }
129        }
130        a.recycle();
131
132        if (themeId != 0 && (!(context instanceof ContextThemeWrapper)
133                || ((ContextThemeWrapper) context).getThemeResId() != themeId)) {
134            // If the context isn't a ContextThemeWrapperCompat, or it is but does not have
135            // the same theme as we need, wrap it in a new wrapper
136            context = new ContextThemeWrapper(context, themeId);
137        }
138        return context;
139    }
140}
141