Add ultra-sexy RotateAndZoom control

src/ol/control/shiftdragrotateandzoom.js

@@ -0,0 +1,73 @@
+goog.provide('ol.control.ShiftDragRotateAndZoom');
+
+goog.require('goog.math.Vec2');
+goog.require('ol.MapBrowserEvent');
+goog.require('ol.control.Drag');
+
+
+
+/**
+ * @constructor
+ * @extends {ol.control.Drag}
+ */
+ol.control.ShiftDragRotateAndZoom = function() {
+  goog.base(this);
+};
+goog.inherits(ol.control.ShiftDragRotateAndZoom, ol.control.Drag);
+
+
+/**
+ * @private
+ * @type {number}
+ */
+ol.control.ShiftDragRotateAndZoom.prototype.startRatio_;
+
+
+/**
+ * @private
+ * @type {number}
+ */
+ol.control.ShiftDragRotateAndZoom.prototype.startRotation_;
+
+
+/**
+ * @inheritDoc
+ */
+ol.control.ShiftDragRotateAndZoom.prototype.handleDrag =
+    function(mapBrowserEvent) {
+  var browserEvent = mapBrowserEvent.browserEvent;
+  var map = mapBrowserEvent.map;
+  var resolution = map.getResolution();
+  var size = map.getSize();
+  var delta = new goog.math.Vec2(
+      browserEvent.offsetX - size.width / 2,
+      size.height / 2 - browserEvent.offsetY);
+  var theta = Math.atan2(delta.y, delta.x);
+  // FIXME this should use map.withFrozenRendering but an assertion fails :-(
+  map.setRotation(this.startRotation_ - theta);
+  map.setResolution(this.startRatio_ * delta.magnitude());
+};
+
+
+/**
+ * @inheritDoc
+ */
+ol.control.ShiftDragRotateAndZoom.prototype.handleDragStart =
+    function(mapBrowserEvent) {
+  var browserEvent = mapBrowserEvent.browserEvent;
+  var map = mapBrowserEvent.map;
+  if (map.canRotate() && browserEvent.shiftKey) {
+    var resolution = map.getResolution();
+    var size = map.getSize();
+    var delta = new goog.math.Vec2(
+        browserEvent.offsetX - size.width / 2,
+        size.height / 2 - browserEvent.offsetY);
+    var theta = Math.atan2(delta.y, delta.x);
+    this.startRotation_ = (map.getRotation() || 0) + theta;
+    this.startRatio_ = resolution / delta.magnitude();
+    browserEvent.preventDefault();
+    return true;
+  } else {
+    return false;
+  }
+};