Add support for RCTImageView in FlatShadowHierarchyManager

Summary: @public This patch adds basic support for RCTImageView (only 'src', 'tintColor' and 'resizeMode' properties are supported for now), and a concept of AttachDetachListener that is required to support it to FlatUIImplementations.

Reviewed By: sriramramani

Differential Revision: D2564389

ReactAndroid/src/main/java/com/facebook/react/flat/DrawImage.java

@@ -0,0 +1,46 @@
+/**
+ * Copyright (c) 2015-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.flat;
+
+import javax.annotation.Nullable;
+
+import com.facebook.drawee.drawable.ScalingUtils.ScaleType;
+import com.facebook.imagepipeline.request.ImageRequest;
+
+/**
+ * Common interface for DrawImageWithPipeline and DrawImageWithDrawee.
+ */
+/* package */ interface DrawImage extends DrawCommand, AttachDetachListener {
+  /**
+   * Returns true if an image source was assigned to the DrawImage.
+   * A DrawImage with no source will not draw anything.
+   */
+  public boolean hasImageRequest();
+
+  /**
+   * Assigns a new image request to the DrawImage, or null to clear the image request.
+   */
+  public void setImageRequest(@Nullable ImageRequest imageRequest);
+
+  /**
+   * Assigns a tint color to apply to the image drawn.
+   */
+  public void setTintColor(int tintColor);
+
+  /**
+   * Assigns a scale type to draw to the image with.
+   */
+  public void setScaleType(ScaleType scaleType);
+
+  /**
+   * Returns a scale type to draw to the image with.
+   */
+  public ScaleType getScaleType();
+}