Merge pull request #1075 from fredj/center-constraint

Add ol.CenterConstraint

examples/wms-custom-proj.js

@@ -62,6 +62,7 @@ var map = new ol.Map({
   view: new ol.View2D({
     projection: projection,
     center: [660000, 190000],
+    extent: extent,
     zoom: 2
   })
 });

examples/wms-image-custom-proj.js

@@ -54,6 +54,7 @@ var map = new ol.Map({
   view: new ol.View2D({
     projection: projection,
     center: [660000, 190000],
+    extent: extent,
     zoom: 2
   })
 });

src/objectliterals.jsdoc

@@ -101,6 +101,7 @@
  * @property {ol.Coordinate|undefined} center The initial center for the view.
  *     The coordinate system for the center is specified with the `projection`
  *     option.
+ * @property {ol.Extent|undefined} extent The extent to constraint the center to.
  * @property {number|undefined} maxResolution The maximum resolution used to
  *     determine the resolution constraint. It is used together with `maxZoom`
  *     and `zoomFactor`. If unspecified it is calculated in such a way that the

src/ol/centerconstraint.js

@@ -0,0 +1,42 @@
+goog.provide('ol.CenterConstraint');
+goog.provide('ol.CenterConstraintType');
+
+goog.require('goog.math');
+
+
+/**
+ * @typedef {function((ol.Coordinate|undefined)): (ol.Coordinate|undefined)}
+ */
+ol.CenterConstraintType;
+
+
+/**
+ * @param {ol.Extent} extent Extent.
+ * @return {ol.CenterConstraintType}
+ */
+ol.CenterConstraint.createExtent = function(extent) {
+  return (
+      /**
+       * @param {ol.Coordinate|undefined} center Center.
+       * @return {ol.Coordinate|undefined} Center.
+       */
+      function(center) {
+        if (goog.isDef(center)) {
+          return [
+            goog.math.clamp(center[0], extent[0], extent[2]),
+            goog.math.clamp(center[1], extent[1], extent[3])
+          ];
+        } else {
+          return undefined;
+        }
+      });
+};
+
+
+/**
+ * @param {ol.Coordinate|undefined} center Center.
+ * @return {ol.Coordinate|undefined} Center.
+ */
+ol.CenterConstraint.none = function(center) {
+  return center;
+};

src/ol/constraints.js

@@ -1,5 +1,6 @@
 goog.provide('ol.Constraints');
 
+goog.require('ol.CenterConstraintType');
 goog.require('ol.ResolutionConstraintType');
 goog.require('ol.RotationConstraintType');
 
@@ -7,12 +8,19 @@ goog.require('ol.RotationConstraintType');
 
 /**
  * @constructor
+ * @param {ol.CenterConstraintType} centerConstraint Center constraint.
  * @param {ol.ResolutionConstraintType} resolutionConstraint
  *     Resolution constraint.
  * @param {ol.RotationConstraintType} rotationConstraint
  *     Rotation constraint.
  */
-ol.Constraints = function(resolutionConstraint, rotationConstraint) {
+ol.Constraints =
+    function(centerConstraint, resolutionConstraint, rotationConstraint) {
+
+  /**
+   * @type {ol.CenterConstraintType}
+   */
+  this.center = centerConstraint;
 
   /**
    * @type {ol.ResolutionConstraintType}

src/ol/interaction/dragpaninteraction.js

@@ -68,6 +68,7 @@ ol.interaction.DragPan.prototype.handleDrag = function(mapBrowserEvent) {
   ];
   ol.coordinate.rotate(newCenter, view2DState.rotation);
   ol.coordinate.add(newCenter, this.startCenter);
+  newCenter = view.constrainCenter(newCenter);
   map.requestRenderFrame();
   view.setCenter(newCenter);
 };
@@ -95,6 +96,7 @@ ol.interaction.DragPan.prototype.handleDragEnd = function(mapBrowserEvent) {
       centerpx[0] - distance * Math.cos(angle),
       centerpx[1] - distance * Math.sin(angle)
     ]);
+    dest = view.constrainCenter(dest);
     view.setCenter(dest);
   }
   map.requestRenderFrame();

src/ol/interaction/interaction.js

@@ -42,7 +42,9 @@ ol.interaction.Interaction.pan = function(
         easing: ol.easing.linear
       }));
     }
-    view.setCenter([currentCenter[0] + delta[0], currentCenter[1] + delta[1]]);
+    var center = view.constrainCenter(
+        [currentCenter[0] + delta[0], currentCenter[1] + delta[1]]);
+    view.setCenter(center);
   }
 };
 

src/ol/interaction/touchpaninteraction.js

@@ -69,6 +69,7 @@ ol.interaction.TouchPan.prototype.handleTouchMove = function(mapBrowserEvent) {
     ol.coordinate.scale(center, view2DState.resolution);
     ol.coordinate.rotate(center, view2DState.rotation);
     ol.coordinate.add(center, view2DState.center);
+    center = view.constrainCenter(center);
     map.requestRenderFrame();
     view.setCenter(center);
   }
@@ -95,6 +96,7 @@ ol.interaction.TouchPan.prototype.handleTouchEnd =
         centerpx[0] - distance * Math.cos(angle),
         centerpx[1] - distance * Math.sin(angle)
       ]);
+      dest = view.constrainCenter(dest);
       view.setCenter(dest);
     }
     map.requestRenderFrame();

src/ol/view2d.js

@@ -4,6 +4,7 @@ goog.provide('ol.View2D');
 goog.provide('ol.View2DProperty');
 
 goog.require('goog.asserts');
+goog.require('ol.CenterConstraint');
 goog.require('ol.Constraints');
 goog.require('ol.IView2D');
 goog.require('ol.IView3D');
@@ -112,6 +113,7 @@ ol.View2D = function(opt_options) {
    */
   this.minResolution_ = resolutionConstraintInfo.minResolution;
 
+  var centerConstraint = ol.View2D.createCenterConstraint_(options);
   var resolutionConstraint = resolutionConstraintInfo.constraint;
   var rotationConstraint = ol.View2D.createRotationConstraint_(options);
 
@@ -119,8 +121,8 @@ ol.View2D = function(opt_options) {
    * @private
    * @type {ol.Constraints}
    */
-  this.constraints_ = new ol.Constraints(resolutionConstraint,
-      rotationConstraint);
+  this.constraints_ = new ol.Constraints(
+      centerConstraint, resolutionConstraint, rotationConstraint);
 
   if (goog.isDef(options.resolution)) {
     values[ol.View2DProperty.RESOLUTION] = options.resolution;
@@ -172,6 +174,15 @@ ol.View2D.prototype.calculateCenterZoom = function(resolution, anchor) {
 };
 
 
+/**
+ * @param {ol.Coordinate|undefined} center Center.
+ * @return {ol.Coordinate|undefined} Constrained center.
+ */
+ol.View2D.prototype.constrainCenter = function(center) {
+  return this.constraints_.center(center);
+};
+
+
 /**
  * Get the constrained the resolution of this view.
  * @param {number|undefined} resolution Resolution.
@@ -472,6 +483,20 @@ ol.View2D.prototype.setZoom = function(zoom) {
 };
 
 
+/**
+ * @param {ol.View2DOptions} options View2D options.
+ * @private
+ * @return {ol.CenterConstraintType}
+ */
+ol.View2D.createCenterConstraint_ = function(options) {
+  if (goog.isDef(options.extent)) {
+    return ol.CenterConstraint.createExtent(options.extent);
+  } else {
+    return ol.CenterConstraint.none;
+  }
+};
+
+
 /**
  * @private
  * @param {ol.View2DOptions} options View2D options.