1 /*
2  * Copyright (C) 2010 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 
17 package android.animation;
18 
19 import com.android.layoutlib.bridge.Bridge;
20 import com.android.layoutlib.bridge.impl.DelegateManager;
21 import com.android.tools.layoutlib.annotations.LayoutlibDelegate;
22 
23 import java.lang.reflect.InvocationTargetException;
24 import java.lang.reflect.Method;
25 import java.util.Arrays;
26 import java.util.HashMap;
27 import java.util.Map;
28 
29 /**
30  * Delegate implementing the native methods of android.animation.PropertyValuesHolder
31  *
32  * Through the layoutlib_create tool, the original native methods of PropertyValuesHolder have been
33  * replaced by calls to methods of the same name in this delegate class.
34  *
35  * Because it's a stateless class to start with, there's no need to keep a {@link DelegateManager}
36  * around to map int to instance of the delegate.
37  *
38  * The main goal of this class' methods are to provide a native way to access setters and getters
39  * on some object. We override these methods to use reflection since the original reflection
40  * implementation of the PropertyValuesHolder won't be able to access protected methods.
41  *
42  */
43 public class PropertyValuesHolder_Delegate {
44     // This code is copied from android.animation.PropertyValuesHolder and must be kept in sync
45     // We try several different types when searching for appropriate setter/getter functions.
46     // The caller may have supplied values in a type that does not match the setter/getter
47     // functions (such as the integers 0 and 1 to represent floating point values for alpha).
48     // Also, the use of generics in constructors means that we end up with the Object versions
49     // of primitive types (Float vs. float). But most likely, the setter/getter functions
50     // will take primitive types instead.
51     // So we supply an ordered array of other types to try before giving up.
52     private static Class[] FLOAT_VARIANTS = {float.class, Float.class, double.class, int.class,
53             Double.class, Integer.class};
54     private static Class[] INTEGER_VARIANTS = {int.class, Integer.class, float.class, double.class,
55             Float.class, Double.class};
56 
57     private static final Object sMethodIndexLock = new Object();
58     private static final Map<Long, Method> ID_TO_METHOD = new HashMap<Long, Method>();
59     private static final Map<String, Long> METHOD_NAME_TO_ID = new HashMap<String, Long>();
60     private static long sNextId = 1;
61 
registerMethod(Class<?> targetClass, String methodName, Class[] types, int nArgs)62     private static long registerMethod(Class<?> targetClass, String methodName, Class[] types,
63             int nArgs) {
64         // Encode the number of arguments in the method name
65         String methodIndexName = String.format("%1$s.%2$s#%3$d", targetClass.getSimpleName(),
66                 methodName, nArgs);
67         synchronized (sMethodIndexLock) {
68             Long methodId = METHOD_NAME_TO_ID.get(methodIndexName);
69 
70             if (methodId != null) {
71                 // The method was already registered, check whether the class loader has changed
72                 Method method = ID_TO_METHOD.get(methodId);
73                 if (targetClass.equals(method.getDeclaringClass())) {
74                     return methodId;
75                 }
76             }
77 
78             Class[] args = new Class[nArgs];
79             Method method = null;
80             for (Class typeVariant : types) {
81                 for (int i = 0; i < nArgs; i++) {
82                     args[i] = typeVariant;
83                 }
84                 try {
85                     method = targetClass.getDeclaredMethod(methodName, args);
86                 } catch (NoSuchMethodException ignore) {
87                 }
88             }
89 
90             if (method != null) {
91                 if (methodId == null) {
92                     methodId = sNextId++;
93                 }
94                 ID_TO_METHOD.put(methodId, method);
95                 METHOD_NAME_TO_ID.put(methodIndexName, methodId);
96 
97                 return methodId;
98             }
99         }
100 
101         // Method not found
102         return 0;
103     }
104 
callMethod(Object target, long methodID, Object... args)105     private static void callMethod(Object target, long methodID, Object... args) {
106         Method method = ID_TO_METHOD.get(methodID);
107         assert method != null;
108 
109         try {
110             method.setAccessible(true);
111             method.invoke(target, args);
112         } catch (IllegalAccessException | InvocationTargetException e) {
113             Bridge.getLog().error(null, "Unable to update property during animation", e, null,
114                     null);
115         }
116     }
117 
118     @LayoutlibDelegate
nGetIntMethod(Class<?> targetClass, String methodName)119     /*package*/ static long nGetIntMethod(Class<?> targetClass, String methodName) {
120         return nGetMultipleIntMethod(targetClass, methodName, 1);
121     }
122 
123     @LayoutlibDelegate
nGetFloatMethod(Class<?> targetClass, String methodName)124     /*package*/ static long nGetFloatMethod(Class<?> targetClass, String methodName) {
125         return nGetMultipleFloatMethod(targetClass, methodName, 1);
126     }
127 
128     @LayoutlibDelegate
nGetMultipleIntMethod(Class<?> targetClass, String methodName, int numParams)129     /*package*/ static long nGetMultipleIntMethod(Class<?> targetClass, String methodName,
130             int numParams) {
131         return registerMethod(targetClass, methodName, INTEGER_VARIANTS, numParams);
132     }
133 
134     @LayoutlibDelegate
nGetMultipleFloatMethod(Class<?> targetClass, String methodName, int numParams)135     /*package*/ static long nGetMultipleFloatMethod(Class<?> targetClass, String methodName,
136             int numParams) {
137         return registerMethod(targetClass, methodName, FLOAT_VARIANTS, numParams);
138     }
139 
140     @LayoutlibDelegate
nCallIntMethod(Object target, long methodID, int arg)141     /*package*/ static void nCallIntMethod(Object target, long methodID, int arg) {
142         callMethod(target, methodID, arg);
143     }
144 
145     @LayoutlibDelegate
nCallFloatMethod(Object target, long methodID, float arg)146     /*package*/ static void nCallFloatMethod(Object target, long methodID, float arg) {
147         callMethod(target, methodID, arg);
148     }
149 
150     @LayoutlibDelegate
nCallTwoIntMethod(Object target, long methodID, int arg1, int arg2)151     /*package*/ static void nCallTwoIntMethod(Object target, long methodID, int arg1,
152             int arg2) {
153         callMethod(target, methodID, arg1, arg2);
154     }
155 
156     @LayoutlibDelegate
nCallFourIntMethod(Object target, long methodID, int arg1, int arg2, int arg3, int arg4)157     /*package*/ static void nCallFourIntMethod(Object target, long methodID, int arg1,
158             int arg2, int arg3, int arg4) {
159         callMethod(target, methodID, arg1, arg2, arg3, arg4);
160     }
161 
162     @LayoutlibDelegate
nCallMultipleIntMethod(Object target, long methodID, int[] args)163     /*package*/ static void nCallMultipleIntMethod(Object target, long methodID,
164             int[] args) {
165         assert args != null;
166 
167         // Box parameters
168         Object[] params = new Object[args.length];
169         for (int i = 0; i < args.length; i++) {
170             params[i] = args;
171         }
172         callMethod(target, methodID, params);
173     }
174 
175     @LayoutlibDelegate
nCallTwoFloatMethod(Object target, long methodID, float arg1, float arg2)176     /*package*/ static void nCallTwoFloatMethod(Object target, long methodID, float arg1,
177             float arg2) {
178         callMethod(target, methodID, arg1, arg2);
179     }
180 
181     @LayoutlibDelegate
nCallFourFloatMethod(Object target, long methodID, float arg1, float arg2, float arg3, float arg4)182     /*package*/ static void nCallFourFloatMethod(Object target, long methodID, float arg1,
183             float arg2, float arg3, float arg4) {
184         callMethod(target, methodID, arg1, arg2, arg3, arg4);
185     }
186 
187     @LayoutlibDelegate
nCallMultipleFloatMethod(Object target, long methodID, float[] args)188     /*package*/ static void nCallMultipleFloatMethod(Object target, long methodID,
189             float[] args) {
190         assert args != null;
191 
192         // Box parameters
193         Object[] params = new Object[args.length];
194         for (int i = 0; i < args.length; i++) {
195             params[i] = args;
196         }
197         callMethod(target, methodID, params);
198     }
199 
clearCaches()200     public static void clearCaches() {
201         ID_TO_METHOD.clear();
202         METHOD_NAME_TO_ID.clear();
203     }
204 }
205