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 
17 package com.android.layoutlib.bridge.android.support;
18 
19 import com.android.ide.common.rendering.api.ILayoutLog;
20 import com.android.ide.common.rendering.api.LayoutlibCallback;
21 import com.android.layoutlib.bridge.Bridge;
22 import com.android.layoutlib.bridge.android.BridgeContext;
23 import com.android.layoutlib.common.util.ReflectionUtils;
24 import com.android.layoutlib.common.util.ReflectionUtils.ReflectionException;
25 
26 import android.annotation.NonNull;
27 import android.annotation.Nullable;
28 import android.content.Context;
29 import android.view.View;
30 
31 import static com.android.layoutlib.common.util.ReflectionUtils.getCause;
32 import static com.android.layoutlib.common.util.ReflectionUtils.getMethod;
33 import static com.android.layoutlib.common.util.ReflectionUtils.invoke;
34 
35 /**
36  * Utility class for working with android.support.v7.widget.RecyclerView and
37  * androidx.widget.RecyclerView
38  */
39 public class RecyclerViewUtil {
40     public static final String[] CN_RECYCLER_VIEW = {
41             "android.support.v7.widget.RecyclerView",
42             "androidx.recyclerview.widget.RecyclerView"
43     };
44 
45     private static final Class<?>[] LLM_CONSTRUCTOR_SIGNATURE = new Class<?>[]{Context.class};
46 
47     /**
48      * Tries to create an Adapter ({@code android.support.v7.widget.RecyclerView.Adapter} and a
49      * LayoutManager {@code RecyclerView.LayoutManager} and assign these to the {@code RecyclerView}
50      * that is passed.
51      * <p/>
52      * Any exceptions thrown during the process are logged in {@link Bridge#getLog()}
53      */
setAdapter(@onNull View recyclerView, @NonNull BridgeContext context, @NonNull LayoutlibCallback layoutlibCallback, int adapterLayout, int itemCount)54     public static void setAdapter(@NonNull View recyclerView, @NonNull BridgeContext context,
55             @NonNull LayoutlibCallback layoutlibCallback, int adapterLayout, int itemCount) {
56         Class<?> recyclerViewClass =
57                 ReflectionUtils.getParentClass(recyclerView, RecyclerViewUtil.CN_RECYCLER_VIEW);
58         if (recyclerViewClass == null) {
59             Bridge.getLog().error(ILayoutLog.TAG_BROKEN,
60                     "Unable to setup RecyclerView. No parent found.", null, null, null);
61             return;
62         }
63         String recyclerViewClassName = recyclerViewClass.getName();
64         String recyclerViewPackageName = recyclerViewClass.getPackage().getName();
65         String adapterClassName = recyclerViewClassName + "$Adapter";
66         String layoutMgrClassName = recyclerViewClassName + "$LayoutManager";
67 
68         try {
69             setLayoutManager(recyclerView, recyclerViewPackageName, layoutMgrClassName, context, layoutlibCallback);
70             Object adapter = createAdapter(layoutlibCallback, adapterClassName);
71             if (adapter != null) {
72                 setProperty(recyclerView, adapterClassName, adapter, "setAdapter");
73                 setProperty(adapter, int.class, adapterLayout, "setLayoutId");
74 
75                 if (itemCount != -1) {
76                     setProperty(adapter, int.class, itemCount, "setItemCount");
77                 }
78             }
79         } catch (ReflectionException e) {
80             Throwable cause = getCause(e);
81             Bridge.getLog().error(ILayoutLog.TAG_BROKEN,
82                     "Error occurred while trying to setup RecyclerView.", cause, null, null);
83         }
84     }
85 
setLayoutManager(@onNull View recyclerView, @NonNull String recyclerViewPackageName, @NonNull String layoutMgrClassName, @NonNull BridgeContext context, @NonNull LayoutlibCallback callback)86     private static void setLayoutManager(@NonNull View recyclerView,
87             @NonNull String recyclerViewPackageName,
88             @NonNull String layoutMgrClassName, @NonNull BridgeContext context,
89             @NonNull LayoutlibCallback callback) throws ReflectionException {
90         if (getLayoutManager(recyclerView) == null) {
91             String linearLayoutMgrClassManager = recyclerViewPackageName + ".LinearLayoutManager";
92             // Only set the layout manager if not already set by the recycler view.
93             Object layoutManager =
94                     createLayoutManager(context, linearLayoutMgrClassManager, callback);
95             if (layoutManager != null) {
96                 setProperty(recyclerView, layoutMgrClassName, layoutManager, "setLayoutManager");
97             }
98         }
99     }
100 
101     /** Creates a LinearLayoutManager using the provided context. */
102     @Nullable
createLayoutManager(@onNull Context context, @NonNull String linearLayoutMgrClassName, @NonNull LayoutlibCallback callback)103     private static Object createLayoutManager(@NonNull Context context,
104             @NonNull String linearLayoutMgrClassName, @NonNull LayoutlibCallback callback)
105             throws ReflectionException {
106         try {
107             return callback.loadClass(linearLayoutMgrClassName, LLM_CONSTRUCTOR_SIGNATURE,
108                     new Object[]{context});
109         } catch (Exception e) {
110             throw new ReflectionException(e);
111         }
112     }
113 
114     @Nullable
getLayoutManager(View recyclerView)115     private static Object getLayoutManager(View recyclerView) throws ReflectionException {
116         return invoke(getMethod(recyclerView.getClass(), "getLayoutManager"), recyclerView);
117     }
118 
119     @Nullable
createAdapter(@onNull LayoutlibCallback layoutlibCallback, @NonNull String adapterClassName)120     private static Object createAdapter(@NonNull LayoutlibCallback layoutlibCallback,
121             @NonNull String adapterClassName) throws ReflectionException {
122         try {
123             return layoutlibCallback.loadClass(adapterClassName, new Class[0], new Object[0]);
124         } catch (Exception e) {
125             throw new ReflectionException(e);
126         }
127     }
128 
setProperty(@onNull Object object, @NonNull String propertyClassName, @NonNull Object propertyValue, @NonNull String propertySetter)129     private static void setProperty(@NonNull Object object, @NonNull String propertyClassName,
130             @NonNull Object propertyValue, @NonNull String propertySetter)
131             throws ReflectionException {
132         Class<?> propertyClass = ReflectionUtils.getClassInstance(propertyValue, propertyClassName);
133         setProperty(object, propertyClass, propertyValue, propertySetter);
134     }
135 
setProperty(@onNull Object object, @NonNull Class<?> propertyClass, @Nullable Object propertyValue, @NonNull String propertySetter)136     private static void setProperty(@NonNull Object object, @NonNull Class<?> propertyClass,
137             @Nullable Object propertyValue, @NonNull String propertySetter)
138             throws ReflectionException {
139         invoke(getMethod(object.getClass(), propertySetter, propertyClass), object, propertyValue);
140     }
141 
142 }
143