UI preview of selected element

Summary:
This is a prototype for view preview within Flipper.
If enabled, a preview of the selected element is rendered in the attribute inspector.

Changelog: Add view preview/snapshot for the Layout plugin on Android.

Reviewed By: mweststrate

Differential Revision: D35009246

fbshipit-source-id: a442ff7f57093f463016811f0f451b52f579b448

android/src/test/java/com/facebook/flipper/plugins/inspector/DescriptorMappingTest.java

@@ -10,6 +10,7 @@ package com.facebook.flipper.plugins.inspector;
 import static org.hamcrest.CoreMatchers.equalTo;
 import static org.hamcrest.MatcherAssert.assertThat;
 
+import android.graphics.Bitmap;
 import com.facebook.flipper.core.FlipperConnection;
 import com.facebook.flipper.core.FlipperDynamic;
 import com.facebook.flipper.core.FlipperObject;
@@ -72,6 +73,11 @@ public class DescriptorMappingTest {
     @Override
     public void setHighlighted(T t, boolean b, boolean b1) throws Exception {}
 
+    @Override
+    public Bitmap getSnapshot(T t, boolean b) throws Exception {
+      return null;
+    }
+
     @Override
     public void hitTest(T node, Touch touch) {}
 

android/src/test/java/com/facebook/flipper/plugins/inspector/InspectorFlipperPluginTest.java

@@ -14,6 +14,7 @@ import static org.mockito.ArgumentMatchers.any;
 import static org.robolectric.annotation.LooperMode.Mode.LEGACY;
 
 import android.app.Application;
+import android.graphics.Bitmap;
 import android.graphics.Rect;
 import android.view.View;
 import android.view.ViewGroup;
@@ -415,6 +416,11 @@ public class InspectorFlipperPluginTest {
       testNode.highlighted = b;
     }
 
+    @Override
+    public Bitmap getSnapshot(TestNode testNode, boolean includeChildren) {
+      return null;
+    }
+
     @Override
     public void hitTest(TestNode node, Touch touch) {
       boolean finish = true;