Improve error reporting on Exceptions in fw views.

When there's an exception during the inflation of a framework view (for
example invalid attributes), report the exception correctly. The earlier
behaviour assumed the exception to be a ClassNotFoundException and tried
to load it from the user's project. This is not longer the case.

Also, update the MockView class to a FrameLayout with a single TextView.
This means that the MockView is a ViewGroup and will not choke when
someone attempts to add a View to it (although, the view will be
silently dropped).

Change-Id: Ice003817ceb627ebfbbbb245ab6be10f9141e728

2 files changed, 91 insertions, 29 deletions

diff --git a/tools/layoutlib/bridge/src/android/view/BridgeInflater.java b/tools/layoutlib/bridge/src/android/view/BridgeInflater.java
index 5db1bde..723e827 100644
--- a/tools/layoutlib/bridge/src/android/view/BridgeInflater.java
+++ b/tools/layoutlib/bridge/src/android/view/BridgeInflater.java
@@ -23,6 +23,7 @@ import com.android.ide.common.rendering.api.ResourceReference;
 import com.android.ide.common.rendering.api.ResourceValue;
 import com.android.layoutlib.bridge.Bridge;
 import com.android.layoutlib.bridge.BridgeConstants;
+import com.android.layoutlib.bridge.MockView;
 import com.android.layoutlib.bridge.android.BridgeContext;
 import com.android.layoutlib.bridge.android.BridgeXmlBlockParser;
 import com.android.layoutlib.bridge.android.support.DrawerLayoutUtil;
@@ -126,6 +127,9 @@ public final class BridgeInflater extends LayoutInflater {
             if (view == null) {
                 view = loadCustomView(name, attrs);
             }
+        } catch (InflateException e) {
+            // Don't catch the InflateException below as that results in hiding the real cause.
+            throw e;
         } catch (Exception e) {
             // Wrap the real exception in a ClassNotFoundException, so that the calling method
             // can deal with it.
@@ -154,23 +158,30 @@ public final class BridgeInflater extends LayoutInflater {
                 }
                 ta.recycle();
             }
-            final Object lastContext = mConstructorArgs[0];
-            mConstructorArgs[0] = context;
-            // try to load the class from using the custom view loader
-            try {
-                view = loadCustomView(name, attrs);
-            } catch (Exception e2) {
-                // Wrap the real exception in an InflateException so that the calling
-                // method can deal with it.
-                InflateException exception = new InflateException();
-                if (!e2.getClass().equals(ClassNotFoundException.class)) {
-                    exception.initCause(e2);
-                } else {
-                    exception.initCause(e);
+            if (!(e.getCause() instanceof ClassNotFoundException)) {
+                // There is some unknown inflation exception in inflating a View that was found.
+                view = new MockView(context, attrs);
+                ((MockView) view).setText(name);
+                Bridge.getLog().error(LayoutLog.TAG_BROKEN, e.getMessage(), e, null);
+            } else {
+                final Object lastContext = mConstructorArgs[0];
+                mConstructorArgs[0] = context;
+                // try to load the class from using the custom view loader
+                try {
+                    view = loadCustomView(name, attrs);
+                } catch (Exception e2) {
+                    // Wrap the real exception in an InflateException so that the calling
+                    // method can deal with it.
+                    InflateException exception = new InflateException();
+                    if (!e2.getClass().equals(ClassNotFoundException.class)) {
+                        exception.initCause(e2);
+                    } else {
+                        exception.initCause(e);
+                    }
+                    throw exception;
+                } finally {
+                    mConstructorArgs[0] = lastContext;
                 }
-                throw exception;
-            } finally {
-                mConstructorArgs[0] = lastContext;
             }
         }
 
diff --git a/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/MockView.java b/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/MockView.java
index 44a9aad..d392f21 100644
--- a/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/MockView.java
+++ b/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/MockView.java
@@ -17,39 +17,90 @@
 package com.android.layoutlib.bridge;
 
 import android.content.Context;
-import android.graphics.Canvas;
 import android.util.AttributeSet;
 import android.view.Gravity;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.FrameLayout;
 import android.widget.TextView;
 
 /**
  * Base class for mocked views.
- *
- * TODO: implement onDraw and draw a rectangle in a random color with the name of the class
- * (or better the id of the view).
+ * <p/>
+ * FrameLayout with a single TextView. Doesn't allow adding any other views to itself.
  */
-public class MockView extends TextView {
+public class MockView extends FrameLayout {
+
+    private final TextView mView;
+
+    public MockView(Context context) {
+        this(context, null);
+    }
 
     public MockView(Context context, AttributeSet attrs) {
         this(context, attrs, 0);
     }
 
-    public MockView(Context context, AttributeSet attrs, int defStyle) {
-        this(context, attrs, defStyle, 0);
+    public MockView(Context context, AttributeSet attrs, int defStyleAttr) {
+        this(context, attrs, defStyleAttr, 0);
     }
 
     public MockView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
         super(context, attrs, defStyleAttr, defStyleRes);
-
-        setText(this.getClass().getSimpleName());
-        setTextColor(0xFF000000);
+        mView = new TextView(context, attrs);
+        mView.setTextColor(0xFF000000);
         setGravity(Gravity.CENTER);
+        setText(getClass().getSimpleName());
+        addView(mView);
+        setBackgroundColor(0xFF7F7F7F);
+    }
+
+    // Only allow adding one TextView.
+    @Override
+    public void addView(View child) {
+        if (child == mView) {
+            super.addView(child);
+        }
+    }
+
+    @Override
+    public void addView(View child, int index) {
+        if (child == mView) {
+            super.addView(child, index);
+        }
     }
 
     @Override
-    public void onDraw(Canvas canvas) {
-        canvas.drawARGB(0xFF, 0x7F, 0x7F, 0x7F);
+    public void addView(View child, int width, int height) {
+        if (child == mView) {
+            super.addView(child, width, height);
+        }
+    }
+
+    @Override
+    public void addView(View child, ViewGroup.LayoutParams params) {
+        if (child == mView) {
+            super.addView(child, params);
+        }
+    }
+
+    @Override
+    public void addView(View child, int index, ViewGroup.LayoutParams params) {
+        if (child == mView) {
+            super.addView(child, index, params);
+        }
+    }
+
+    // The following methods are called by the IDE via reflection, and should be considered part
+    // of the API.
+    // Historically, MockView used to be a textView and had these methods. Now, we simply delegate
+    // them to the contained textView.
+
+    public void setText(CharSequence text) {
+        mView.setText(text);
+    }
 
-        super.onDraw(canvas);
+    public void setGravity(int gravity) {
+        mView.setGravity(gravity);
     }
 }