Add ol.interaction.TouchRotateAndZoom

src/ol/interaction/touchrotateandzoominteraction.js

@@ -0,0 +1,146 @@
+// FIXME works for View2D only
+
+goog.provide('ol.interaction.TouchRotateAndZoom');
+
+goog.require('goog.asserts');
+goog.require('ol.View');
+goog.require('ol.ViewHint');
+goog.require('ol.interaction.Touch');
+
+
+
+/**
+ * @constructor
+ * @extends {ol.interaction.Touch}
+ */
+ol.interaction.TouchRotateAndZoom = function() {
+
+  goog.base(this);
+
+  /**
+   * @private
+   * @type {number|undefined}
+   */
+  this.lastAngle_;
+
+  /**
+   * @private
+   * @type {number|undefined}
+   */
+  this.lastDistance_;
+
+  /**
+   * @private
+   * @type {boolean}
+   */
+  this.rotating_ = false;
+
+  /**
+   * @private
+   * @type {number}
+   */
+  this.rotationDelta_ = 0.0;
+
+  /**
+   * @private
+   * @type {number}
+   */
+  this.rotationThreshold_ = 0.3;
+
+};
+goog.inherits(ol.interaction.TouchRotateAndZoom, ol.interaction.Touch);
+
+
+/**
+ * @inheritDoc
+ */
+ol.interaction.TouchRotateAndZoom.prototype.handleTouchMove =
+    function(mapBrowserEvent) {
+  goog.asserts.assert(this.targetTouches.length >= 2);
+  var scaleDelta = 1.0;
+  var rotationDelta = 0.0;
+
+  var centroid = ol.interaction.Touch.centroid(this.targetTouches);
+
+  var touch0 = this.targetTouches[0];
+  var touch1 = this.targetTouches[1];
+  var dx = touch0.clientX - touch1.clientX;
+  var dy = touch0.clientY - touch1.clientY;
+
+  // angle between touches
+  var angle = Math.atan2(
+      touch1.clientY - touch0.clientY,
+      touch1.clientX - touch0.clientX);
+
+  // distance between touches
+  var distance = Math.sqrt(dx * dx + dy * dy);
+
+  if (goog.isDef(this.lastDistance_)) {
+    scaleDelta = this.lastDistance_ / distance;
+  }
+  this.lastDistance_ = distance;
+
+  if (goog.isDef(this.lastAngle_)) {
+    var delta = angle - this.lastAngle_;
+    this.rotationDelta_ += delta;
+    if (!this.rotating_ &&
+        Math.abs(this.rotationDelta_) > this.rotationThreshold_) {
+      this.rotating_ = true;
+    }
+    rotationDelta = delta;
+  }
+  this.lastAngle_ = angle;
+
+  var map = mapBrowserEvent.map;
+  var view = map.getView();
+
+  // rotate / scale anchor point.
+  // FIXME: should be the intersection point between the lines:
+  //     touch0,touch1 and previousTouch0,previousTouch1
+  var viewportPosition = goog.style.getClientPosition(map.getViewport());
+  centroid.x -= viewportPosition.x;
+  centroid.y -= viewportPosition.y;
+  var anchor = map.getCoordinateFromPixel(centroid);
+
+  // scale
+  view.zoom_(map, view.getResolution() * scaleDelta, anchor);
+
+  // rotate
+  if (this.rotating_) {
+    view.rotate(map, view.getRotation() + rotationDelta, anchor);
+  }
+};
+
+
+/**
+ * @inheritDoc
+ */
+ol.interaction.TouchRotateAndZoom.prototype.handleTouchEnd =
+    function(mapBrowserEvent) {
+  if (this.targetTouches.length < 2) {
+    var view = mapBrowserEvent.map.getView();
+    view.setHint(ol.ViewHint.PANNING, -1);
+    return false;
+  } else {
+    return true;
+  }
+};
+
+
+/**
+ * @inheritDoc
+ */
+ol.interaction.TouchRotateAndZoom.prototype.handleTouchStart =
+    function(mapBrowserEvent) {
+  if (this.targetTouches.length >= 2) {
+    var view = mapBrowserEvent.map.getView();
+    this.lastDistance_ = undefined;
+    this.lastAngle_ = undefined;
+    this.rotating_ = false;
+    this.rotationDelta_ = 0.0;
+    view.setHint(ol.ViewHint.PANNING, 1);
+    return true;
+  } else {
+    return false;
+  }
+};

src/ol/map.js

@@ -55,6 +55,7 @@ goog.require('ol.interaction.KeyboardPan');
 goog.require('ol.interaction.KeyboardZoom');
 goog.require('ol.interaction.MouseWheelZoom');
 goog.require('ol.interaction.TouchPan');
+goog.require('ol.interaction.TouchRotateAndZoom');
 goog.require('ol.interaction.condition');
 goog.require('ol.layer.Layer');
 goog.require('ol.renderer.Map');
@@ -966,6 +967,12 @@ ol.Map.createInteractions_ = function(mapOptions) {
     interactions.push(new ol.interaction.TouchPan());
   }
 
+  var touchRotateZoom = goog.isDef(mapOptions.touchRotateZoom) ?
+      mapOptions.touchRotateZoom : true;
+  if (touchRotateZoom) {
+    interactions.push(new ol.interaction.TouchRotateAndZoom());
+  }
+
   var dragPan = goog.isDef(mapOptions.dragPan) ?
       mapOptions.dragPan : true;
   if (dragPan) {