Add center constraint to ol.View2D

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/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/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.