am f73bd14a: Merge "ADT/Layoutlib: implement Canvas.concat(Matrix)" into eclair

Merge commit 'f73bd14a8d5932b34a0e6e4d2de78b74705276b8' into eclair-plus-aosp

* commit 'f73bd14a8d5932b34a0e6e4d2de78b74705276b8':
  ADT/Layoutlib: implement Canvas.concat(Matrix)

tools/layoutlib/bridge/src/android/graphics/Canvas.java

@@ -236,10 +236,15 @@ public class Canvas extends _Original_Canvas {
      */
     @Override
     public int save() {
+        // get the current save count
+        int count = mGraphicsStack.size();
+
+        // create a new graphics and add it to the stack
         Graphics2D g = (Graphics2D)getGraphics2d().create();
         mGraphicsStack.push(g);
 
-        return mGraphicsStack.size() - 1;
+        // return the old save count
+        return count;
     }
 
     /* (non-Javadoc)
@@ -274,10 +279,9 @@ public class Canvas extends _Original_Canvas {
      */
     @Override
     public int getSaveCount() {
-        return mGraphicsStack.size() - 1;
+        return mGraphicsStack.size();
     }
 
-
     /* (non-Javadoc)
      * @see android.graphics.Canvas#clipRect(float, float, float, float, android.graphics.Region.Op)
      */
@@ -953,10 +957,6 @@ public class Canvas extends _Original_Canvas {
      */
     @Override
     public void setMatrix(Matrix matrix) {
-        // since SetMatrix *replaces* all the other transformation, we have to restore/save
-        restore();
-        save();
-
         // get the new current graphics
         Graphics2D g = getGraphics2d();
 
@@ -968,6 +968,27 @@ public class Canvas extends _Original_Canvas {
         }
     }
 
+    /* (non-Javadoc)
+     * @see android.graphics.Canvas#concat(android.graphics.Matrix)
+     */
+    @Override
+    public void concat(Matrix matrix) {
+        // get the current top graphics2D object.
+        Graphics2D g = getGraphics2d();
+
+        // get its current matrix
+        AffineTransform currentTx = g.getTransform();
+        // get the AffineTransform of the given matrix
+        AffineTransform matrixTx = matrix.getTransform();
+
+        // combine them so that the given matrix is applied after.
+        currentTx.preConcatenate(matrixTx);
+
+        // give it to the graphics2D as a new matrix replacing all previous transform
+        g.setTransform(currentTx);
+    }
+
+
     // --------------------
 
     /* (non-Javadoc)
@@ -1007,15 +1028,6 @@ public class Canvas extends _Original_Canvas {
         return super.clipRegion(region);
     }
 
-    /* (non-Javadoc)
-     * @see android.graphics.Canvas#concat(android.graphics.Matrix)
-     */
-    @Override
-    public void concat(Matrix matrix) {
-        // TODO Auto-generated method stub
-        super.concat(matrix);
-    }
-
     /* (non-Javadoc)
      * @see android.graphics.Canvas#drawArc(android.graphics.RectF, float, float, boolean, android.graphics.Paint)
      */

tools/layoutlib/bridge/src/android/graphics/Matrix.java

@@ -87,8 +87,12 @@ public class Matrix extends _Original_Matrix {
     }
 
     public AffineTransform getTransform() {
-        return new AffineTransform(mValues[0], mValues[1], mValues[2],
-                mValues[3], mValues[4], mValues[5]);
+        // the AffineTransform constructor takes the value in a different order
+        // for a matrix [ 0 1 2 ]
+        //              [ 3 4 5 ]
+        // the order is 0, 3, 1, 4, 2, 5...
+        return new AffineTransform(mValues[0], mValues[3], mValues[1],
+                mValues[4], mValues[2], mValues[5]);
     }
 
     public boolean hasPerspective() {