Android Instrumentations tests are ready to be run in github/CI open source environment

Reviewed By: mkonicek

Differential Revision: D2769217

fb-gh-sync-id: 7469af816241d8b642753cca21f6542b971e9572

ReactAndroid/src/androidTest/java/com/facebook/react/testing/ScreenshotingFrameLayout.java

@@ -0,0 +1,71 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc.
+ * All rights reserved.
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+package com.facebook.react.testing;
+
+import javax.annotation.Nullable;
+
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.graphics.Canvas;
+import android.os.Looper;
+import android.widget.FrameLayout;
+
+/**
+ * A FrameLayout that allows you to access the result of the last time its hierarchy was drawn. It
+ * accomplishes this by drawing its hierarchy into a software Canvas, saving the resulting Bitmap
+ * and then drawing that Bitmap to the actual Canvas provided by the system.
+ */
+public class ScreenshotingFrameLayout extends FrameLayout {
+
+  private @Nullable Bitmap mBitmap;
+  private Canvas mCanvas;
+
+  public ScreenshotingFrameLayout(Context context) {
+    super(context);
+    mCanvas = new Canvas();
+  }
+
+  @Override
+  protected void dispatchDraw(Canvas canvas) {
+    if (mBitmap == null) {
+      mBitmap = createNewBitmap(canvas);
+      mCanvas.setBitmap(mBitmap);
+    } else if (mBitmap.getWidth() != canvas.getWidth() ||
+        mBitmap.getHeight() != canvas.getHeight()) {
+      mBitmap.recycle();
+      mBitmap = createNewBitmap(canvas);
+      mCanvas.setBitmap(mBitmap);
+    }
+
+    super.dispatchDraw(mCanvas);
+    canvas.drawBitmap(mBitmap, 0, 0, null);
+  }
+
+  private static Bitmap createNewBitmap(Canvas canvas) {
+    return Bitmap.createBitmap(canvas.getWidth(), canvas.getHeight(), Bitmap.Config.ARGB_8888);
+  }
+
+  public Bitmap getLastDrawnBitmap() {
+    if (mBitmap == null) {
+      throw new RuntimeException("View has not been drawn yet!");
+    }
+    if (Looper.getMainLooper() != Looper.myLooper()) {
+      throw new RuntimeException(
+          "Must access screenshots from main thread or you may get partially drawn Bitmaps");
+    }
+    if (!isScreenshotReady()) {
+      throw new RuntimeException("Trying to get screenshot, but the view is dirty or needs layout");
+    }
+    return Bitmap.createBitmap(mBitmap);
+  }
+
+  public boolean isScreenshotReady() {
+    return !isDirty() && !isLayoutRequested();
+  }
+}