Make Context.getClassLoader() work.

Context.getClassLoader() is used by the LayoutInflater and can be used
by custom views. However, when called from the LayoutInflater, this
needs to return only the Framework classes. This is so that the IDE gets
a chance to instantiate the custom views, which helps in better error
reporting and better fallback in case of exceptions, like MockView.

To workaround this need of the same method returning different results
based on where it's called from, the method call in LayoutInflater is
renamed to getFrameworkClassLoader() and the new method is injected in
Context. The implementation of getFrameworkClassLoader() maintains the
existing behaviour of getClassLoader().

Context.getClassLoader() is now modified to return classes from both
Framework and the app namespace.

Also, update the list of packages to search for Framework views.

Change-Id: I1a6be4aa1fc5c1c5520b5440a348a52f10b6eb3b

3 files changed, 23 insertions, 4 deletions

diff --git a/tools/layoutlib/bridge/src/android/view/BridgeInflater.java b/tools/layoutlib/bridge/src/android/view/BridgeInflater.java
index 87762a6..32ee9e8 100644
--- a/tools/layoutlib/bridge/src/android/view/BridgeInflater.java
+++ b/tools/layoutlib/bridge/src/android/view/BridgeInflater.java
@@ -53,9 +53,14 @@ public final class BridgeInflater extends LayoutInflater {
      */
     private static final String[] sClassPrefixList = {
         "android.widget.",
-        "android.webkit."
+        "android.webkit.",
+        "android.app."
     };
 
+    public static String[] getClassPrefixList() {
+        return sClassPrefixList;
+    }
+
     protected BridgeInflater(LayoutInflater original, Context newContext) {
         super(original, newContext);
         newContext = getBaseContext(newContext);
diff --git a/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/android/BridgeContext.java b/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/android/BridgeContext.java
index eb5f597..59f07a7 100644
--- a/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/android/BridgeContext.java
+++ b/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/android/BridgeContext.java
@@ -138,8 +138,9 @@ public final class BridgeContext extends Context {
 
     private final Stack<BridgeXmlBlockParser> mParserStack = new Stack<BridgeXmlBlockParser>();
     private SharedPreferences mSharedPreferences;
+    private ClassLoader mClassLoader;
 
-  /**
+    /**
      * @param projectKey An Object identifying the project. This is used for the cache mechanism.
      * @param metrics the {@link DisplayMetrics}.
      * @param renderResources the configured resources (both framework and projects) for this
@@ -462,7 +463,21 @@ public final class BridgeContext extends Context {
 
     @Override
     public ClassLoader getClassLoader() {
-        return this.getClass().getClassLoader();
+        if (mClassLoader == null) {
+            mClassLoader = new ClassLoader(getClass().getClassLoader()) {
+                @Override
+                protected Class<?> findClass(String name) throws ClassNotFoundException {
+                    for (String prefix : BridgeInflater.getClassPrefixList()) {
+                        if (name.startsWith(prefix)) {
+                            // These are framework classes and should not be loaded from the app.
+                            throw new ClassNotFoundException(name + " not found");
+                        }
+                    }
+                    return BridgeContext.this.mLayoutlibCallback.findClass(name);
+                }
+            };
+        }
+        return mClassLoader;
     }
 
     @Override
diff --git a/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/impl/RenderAction.java b/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/impl/RenderAction.java
index 2b95488..f3a0d58 100644
--- a/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/impl/RenderAction.java
+++ b/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/impl/RenderAction.java
@@ -275,7 +275,6 @@ public abstract class RenderAction<T extends RenderParams> extends FrameworkReso
             mContext.getRenderResources().setLogger(null);
         }
         ParserFactory.setParserFactory(null);
-
     }
 
     public static BridgeContext getCurrentContext() {