Implement getAbsoluteBoundingBox and getAbsoluteMatrix

uxebu · Oct 30, 2012 · c0e67b6 · c0e67b6
1 parent 1093cb2
commit c0e67b6
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Showing 3 changed files with 67 additions and 2 deletions.
diff --git a/CHANGELOG b/CHANGELOG
@@ -1,6 +1,7 @@
 v0.4.2
 -------------------
-
+ * Added support for getAbsoluteBoundingBox and getAbsoluteMatrix on
+   DisplayObject
 
 v0.4.1 / 2012-10-26
 -------------------

diff --git a/src/runner/display_object.js b/src/runner/display_object.js
@@ -577,12 +577,37 @@ define([
       return this;
     },
 
+    /** 
+     * Gets the matrix of the DisplayObject combined with all ancestor matrices
+     *
+     * @returns {Matrix} The resulting matrix
+     */
+    getAbsoluteMatrix: function() {
+      var matrix = this.attr('matrix').clone();
+      var parent = this;
+      while ((parent = parent.parent) && parent.id !== 0) {
+        matrix.concat(parent.attr('matrix'));
+      }
+      return matrix;
+    },
+
+    /** 
+     * Computed the absolute bounding box relative to the top-most ancestor
+     *
+     * @returns {Object} an object with all box properties
+     *  (left, top, right, bottom, width, height)
+     */
+    getAbsoluteBoundingBox: function() {
+      return this.getBoundingBox( this.getAbsoluteMatrix() );
+    },
+
     /**
      * Computes bounding boxes and single data points of a display object.
      *
      * @param {Matrix} [transform=null] A transform to apply to all points
      *    before computation.
      * @returns {Object} an object with all box properties
+     *  (left, top, right, bottom, width, height)
      */
     getBoundingBox: function(transform) {
       var x = 0, y = 0;

diff --git a/test/display_object-spec.js b/test/display_object-spec.js
@@ -1,11 +1,12 @@
 define([
   'bonsai/runner/display_object',
+  'bonsai/runner/group',
   'bonsai/event_emitter',
   'bonsai/runner/matrix',
   'bonsai/tools',
   'common/mock',
   'common/displayobject-lifecycle'
-], function(DisplayObject, EventEmitter, Matrix, tools, mock, testLifeCycle) {
+], function(DisplayObject, Group, EventEmitter, Matrix, tools, mock, testLifeCycle) {
   describe('DisplayObject', function() {
     testLifeCycle(function() {
       return new DisplayObject();
@@ -209,6 +210,44 @@ define([
         });
       });
 
+      describe('getAbsoluteBoundingBox', function() {
+        it('Gets absolute bbox relative to top-most ancestor', function() {
+          var a = new Group().attr('scaleX', 2);
+          var b = new Group().attr('scaleY', 1.5).attr('scaleX', 2).attr('x', 20);
+          var obj = new DisplayObject();
+          b.addTo(a);
+          obj.addTo(b);
+          obj.attr({
+            x: 100,
+            y: 100
+          });
+          expect(obj.getAbsoluteBoundingBox()).toEqual({
+            top: 150,
+            left: 440,
+            bottom: 150,
+            right: 440,
+            width: 0,
+            height: 0
+          });
+        });
+      });
+
+      describe('getAbsoluteMatrix', function() {
+        it('Gets the matrix of the DisplayObject concat\'d with all ancestors\' matrices', function() {
+          var a = new Group().attr('scaleX', 2);
+          var b = new Group().attr('scaleY', 1.5).attr('scaleX', 2).attr('x', 20);
+          var obj = new DisplayObject();
+          b.addTo(a);
+          obj.addTo(b);
+          obj.attr({
+            x: 100,
+            y: 100
+          });
+          var m = obj.getAbsoluteMatrix();
+          expect(m).toEqual(new Matrix(4, 0, 0, 1.5, 440, 150));
+        });
+      });
+
       describe('with transform parameter', function() {
         var outerTransform = new Matrix(0.313, 1.527, -0.429, 0.240, 145.25, 234.75);
         var zeroTransformed = outerTransform.transformPoint({x: 0, y: 0});