[Remoting Android] Refactor GlDesktopView

remoting/android/java/src/org/chromium/chromoting/DesktopCanvas.java

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chromoting;
 
 import android.graphics.Matrix;
 import android.graphics.PointF;
 import android.graphics.Rect;
 import android.graphics.RectF;
 
 /**
  * This class is responsible for transforming the desktop image matrix.
  */
 public class DesktopCanvas {
     /**
      * Maximum allowed zoom level - see {@link #repositionImageWithZoom()}.
      */
     private static final float MAX_ZOOM_FACTOR = 100.0f;
 
-    private final DesktopView mViewer;
+    private final RenderStub mRenderStub;
     private final RenderData mRenderData;
 
     /**
      * Represents the desired center of the viewport.  This value may not represent the actual
      * center of the viewport as adjustments are made to ensure as much of the desktop is visible as
      * possible.  This value needs to be a pair of floats so the desktop image can be positioned
      * with sub-pixel accuracy for smoother panning animations at high zoom levels.
      */
     private PointF mViewportPosition = new PointF();
 
     /**
      * Represents the amount of space, in pixels, used by system UI.
      */
     private Rect mSystemUiOffsetPixels = new Rect();
 
-    public DesktopCanvas(DesktopView viewer, RenderData renderData) {
-        mViewer = viewer;
+    public DesktopCanvas(RenderStub renderStub, RenderData renderData) {
+        mRenderStub = renderStub;
         mRenderData = renderData;
     }
 
     /**
      * Shifts the viewport by the passed in deltas (in image coordinates).
      *
      * @param useScreenCenter Determines whether to use the desired viewport position or the actual
      *                        center of the screen for positioning.
      * @param deltaX The distance (in image coordinates) to move the viewport along the x-axis.
      * @param deltaY The distance (in image coordinates) to move the viewport along the y-axis.
@@ skipping 152 matching lines @@
         if (rectScreen.bottom - rectScreen.top < viewportSize.y) {
             yAdjust = -(bottomDelta + topDelta) / 2;
         } else if (topDelta > 0 && bottomDelta > 0) {
             yAdjust = -Math.min(topDelta, bottomDelta);
         } else if (topDelta < 0 && bottomDelta < 0) {
             yAdjust = Math.min(-topDelta, -bottomDelta);
         }
 
         mRenderData.transform.postTranslate(xAdjust, yAdjust);
 
-        mViewer.transformationChanged(mRenderData.transform);
+        mRenderStub.setTransformation(mRenderData.transform);
     }
 
     /**
      * Repositions the image by translating and zooming it, to keep the zoom level within sensible
      * limits. The minimum zoom level is chosen to avoid black space around all 4 sides. The
      * maximum zoom level is set arbitrarily, so that the user can zoom out again in a reasonable
      * time, and to prevent arithmetic overflow problems from displaying the image.
      *
      * @param centerViewport Determines whether the viewport will be translated to the desired
      *                       center position before being adjusted to fit the screen boundaries.
@@ skipping 18 matching lines @@
             // Displayed image is too small in both directions, so apply the minimum zoom
             // level needed to fit either the width or height.
             float scale = Math.min((float) mRenderData.screenWidth / mRenderData.imageWidth,
                                    (float) mRenderData.screenHeight / mRenderData.imageHeight);
             mRenderData.transform.setScale(scale, scale);
         }
 
         repositionImage(centerViewport);
     }
 }