Add ol.View2D#centerOn

src/ol/view2d.exports

@@ -4,6 +4,7 @@
 @exportProperty ol.View2D.prototype.constrainRotation
 @exportProperty ol.View2D.prototype.fitExtent
 @exportProperty ol.View2D.prototype.fitGeometry
+@exportProperty ol.View2D.prototype.centerOn
 @exportProperty ol.View2D.prototype.getView2D
 @exportProperty ol.View2D.prototype.getZoom
 @exportProperty ol.View2D.prototype.setZoom

src/ol/view2d.js

@@ -497,6 +497,34 @@ ol.View2D.prototype.fitGeometry = function(geometry, size, opt_options) {
 };
 
 
+/**
+ * Center on coordinate and view position.
+ * Take care on the map angle.
+ * @param {ol.Coordinate} coordinate Coordinate.
+ * @param {ol.Size} size Box pixel size.
+ * @param {ol.Pixel} position Position on the view to center on.
+ * @todo stability experimental
+ */
+ol.View2D.prototype.centerOn = function(coordinate, size, position) {
+  // calculate rotated position
+  var rotation = this.getRotation();
+  var cosAngle = Math.cos(-rotation);
+  var sinAngle = Math.sin(-rotation);
+  var rotX = coordinate[0] * cosAngle - coordinate[1] * sinAngle;
+  var rotY = coordinate[1] * cosAngle + coordinate[0] * sinAngle;
+  var resolution = this.getResolution();
+  rotX += (size[0] / 2 - position[0]) * resolution;
+  rotY += (position[1] - size[1] / 2) * resolution;
+
+  // go back to original angle
+  sinAngle = -sinAngle; // go back to original rotation
+  var centerX = rotX * cosAngle - rotY * sinAngle;
+  var centerY = rotY * cosAngle + rotX * sinAngle;
+
+  this.setCenter([centerX, centerY]);
+};
+
+
 /**
  * @return {boolean} Is defined.
  */

test/spec/ol/view2d.test.js

@@ -172,6 +172,34 @@ describe('ol.View2D', function() {
       expect(view.getCenter()[1]).to.be(46300);
     });
   });
+
+  describe('centerOn', function() {
+    var view;
+    beforeEach(function() {
+      view = new ol.View2D({
+        resolutions: [200, 100, 50, 20, 10, 5, 2, 1]
+      });
+    });
+    it('fit correctly to the coordinates', function() {
+      view.setResolution(10);
+      view.centerOn(
+          [6000, 46000],
+          [400, 400],
+          [300, 300]
+      );
+      expect(view.getCenter()[0]).to.be(5000);
+      expect(view.getCenter()[1]).to.be(47000);
+
+      view.setRotation(Math.PI / 4);
+      view.centerOn(
+          [6000, 46000],
+          [400, 400],
+          [300, 300]
+      );
+      expect(view.getCenter()[0]).to.be(4585.78643762691);
+      expect(view.getCenter()[1]).to.be(46000);
+    });
+  });
 });
 
 goog.require('ol.View2D');