Remove code duplication in Viewport.applyConstraints.

src/viewport.js

@@ -555,40 +555,27 @@ $.Viewport.prototype = {
     },
 
     /**
+     * Enforces the minZoom, maxZoom and visibilityRatio constraints by
+     * zooming and panning to the closest acceptable zoom and location.
      * @function
+     * @param {Boolean} [immediately=false]
      * @return {OpenSeadragon.Viewport} Chainable.
      * @fires OpenSeadragon.Viewer.event:constrain
      */
-    applyConstraints: function( immediately ) {
+    applyConstraints: function(immediately) {
-        var actualZoom = this.getZoom(),
+        this.fitBoundsWithConstraints(this.getBounds(), immediately);
-            constrainedZoom = Math.max(
-                Math.min( actualZoom, this.getMaxZoom() ),
-                this.getMinZoom()
-            ),
-            bounds,
-            constrainedBounds;
-
-        if ( actualZoom != constrainedZoom ) {
-            this.zoomTo( constrainedZoom, this.zoomPoint, immediately );
-        }
-
-        bounds = this.getBoundsNoRotate();
-
-        constrainedBounds = this._applyBoundaryConstraints( bounds, immediately );
-
-        if ( bounds.x !== constrainedBounds.x || bounds.y !== constrainedBounds.y || immediately ){
-            this.fitBounds( constrainedBounds, immediately );
-        }
-
         return this;
     },
 
     /**
+     * Equivalent to {@link OpenSeadragon.Viewport#applyConstraints}
      * @function
-     * @param {Boolean} immediately
+     * @param {Boolean} [immediately=false]
+     * @return {OpenSeadragon.Viewport} Chainable.
+     * @fires OpenSeadragon.Viewer.event:constrain
      */
-    ensureVisible: function( immediately ) {
+    ensureVisible: function(immediately) {
-        return this.applyConstraints( immediately );
+        return this.applyConstraints(immediately);
     },
 
     /**
@@ -670,29 +657,41 @@ $.Viewport.prototype = {
     },
 
     /**
+     * Makes the viewport zoom and pan so that the specified bounds take
+     * as much space as possible in the viewport.
+     * Note: this method ignores the constraints (minZoom, maxZoom and
+     * visibilityRatio).
+     * Use {@link OpenSeadragon.Viewport#fitBoundsWithConstraints} to enforce
+     * them.
      * @function
      * @param {OpenSeadragon.Rect} bounds
-     * @param {Boolean} immediately
+     * @param {Boolean} [immediately=false]
      * @return {OpenSeadragon.Viewport} Chainable.
      */
-    fitBounds: function( bounds, immediately ) {
+    fitBounds: function(bounds, immediately) {
-        return this._fitBounds( bounds, {
+        return this._fitBounds(bounds, {
             immediately: immediately,
             constraints: false
-        } );
+        });
     },
 
     /**
+     * Makes the viewport zoom and pan so that the specified bounds take
+     * as much space as possible in the viewport while enforcing the constraints
+     * (minZoom, maxZoom and visibilityRatio).
+     * Note: because this method enforces the constraints, part of the
+     * provided bounds may end up outside of the viewport.
+     * Use {@link OpenSeadragon.Viewport#fitBounds} to ignore them.
      * @function
      * @param {OpenSeadragon.Rect} bounds
-     * @param {Boolean} immediately
+     * @param {Boolean} [immediately=false]
      * @return {OpenSeadragon.Viewport} Chainable.
      */
-    fitBoundsWithConstraints: function( bounds, immediately ) {
+    fitBoundsWithConstraints: function(bounds, immediately) {
-        return this._fitBounds( bounds, {
+        return this._fitBounds(bounds, {
             immediately: immediately,
             constraints: true
-        } );
+        });
     },
 
     /**

test/modules/events.js

@@ -678,45 +678,20 @@
     } );
 
     // ----------
-    asyncTest( 'Viewer: preventDefaultAction', function () {
+    asyncTest('Viewer: preventDefaultAction', function() {
-        var $canvas = $( viewer.element ).find( '.openseadragon-canvas' ).not( '.navigator .openseadragon-canvas' ),
+        var $canvas = $(viewer.element).find('.openseadragon-canvas')
-            tracker = viewer.innerTracker,
+            .not('.navigator .openseadragon-canvas');
-            origClickHandler,
+        var tracker = viewer.innerTracker;
-            origDragHandler,
+        var epsilon = 0.0000001;
-            dragCount = 10,
-            originalZoom = 0,
-            originalBounds = null;
-
-        var onOpen = function ( event ) {
-            viewer.removeHandler( 'open', onOpen );
-
-            // Hook viewer events to set preventDefaultAction
-            origClickHandler = tracker.clickHandler;
-            tracker.clickHandler = function ( event ) {
-                event.preventDefaultAction = true;
-                return origClickHandler( event );
-            };
-            origDragHandler = tracker.dragHandler;
-            tracker.dragHandler = function ( event ) {
-                event.preventDefaultAction = true;
-                return origDragHandler( event );
-            };
-
-            originalZoom = viewer.viewport.getZoom();
-            originalBounds = viewer.viewport.getBounds();
-
-            var event = {
-                clientX:1,
-                clientY:1
-            };
 
+        function simulateClickAndDrag() {
             $canvas.simulate( 'focus', event );
             // Drag to pan
             Util.simulateViewerClickWithDrag( {
                 viewer: viewer,
                 widthFactor: 0.25,
                 heightFactor: 0.25,
-                dragCount: dragCount,
+                dragCount: 10,
                 dragDx: 1,
                 dragDy: 1
             } );
@@ -730,20 +705,57 @@
                 dragDy: 0
             } );
             $canvas.simulate( 'blur', event );
+        }
 
-            var zoom = viewer.viewport.getZoom(),
+        var onOpen = function() {
-                bounds = viewer.viewport.getBounds();
+            viewer.removeHandler('open', onOpen);
 
-            equal( zoom, originalZoom, "Zoom prevented" );
+            // Hook viewer events to set preventDefaultAction
-            ok( bounds.x == originalBounds.x && bounds.y == originalBounds.y, 'Pan prevented' );
+            var origClickHandler = tracker.clickHandler;
+            tracker.clickHandler = function(event) {
+                event.preventDefaultAction = true;
+                return origClickHandler(event);
+            };
+            var origDragHandler = tracker.dragHandler;
+            tracker.dragHandler = function(event) {
+                event.preventDefaultAction = true;
+                return origDragHandler(event);
+            };
+
+            var originalZoom = viewer.viewport.getZoom();
+            var originalBounds = viewer.viewport.getBounds();
+
+            simulateClickAndDrag();
+
+            var zoom = viewer.viewport.getZoom();
+            var bounds = viewer.viewport.getBounds();
+            Util.assessNumericValue(zoom, originalZoom, epsilon,
+                "Zoom should be prevented");
+            Util.assertRectangleEquals(bounds, originalBounds, epsilon,
+                'Pan should be prevented');
+
+            tracker.clickHandler = origClickHandler;
+            tracker.dragHandler = origDragHandler;
+
+            simulateClickAndDrag();
+
+            var zoom = viewer.viewport.getZoom();
+            var bounds = viewer.viewport.getBounds();
+            Util.assessNumericValue(zoom, 0.002, epsilon,
+                "Zoom should not be prevented");
+            Util.assertRectangleEquals(
+                bounds,
+                new OpenSeadragon.Rect(-250, -0.25, 500, 0.5),
+                epsilon,
+                'Pan should not be prevented');
 
             viewer.close();
             start();
         };
 
-        viewer.addHandler( 'open', onOpen );
+        viewer.addHandler('open', onOpen);
-        viewer.open( '/test/data/testpattern.dzi' );
+        viewer.open('/test/data/testpattern.dzi');
-    } );
+    });
 
     // ----------
     asyncTest( 'EventSource/MouseTracker/Viewer: event.originalEvent event.userData canvas-drag canvas-drag-end canvas-release canvas-click', function () {

test/modules/viewport.js

@@ -409,7 +409,7 @@
         viewer.open(DZI_PATH);
     });
 
-    asyncTest('ensureVisible', function(){
+    asyncTest('ensureVisible', function() {
         var openHandler = function(event) {
             viewer.removeHandler('open', openHandler);
             var viewport = viewer.viewport;
@@ -427,6 +427,45 @@
         viewer.open(DZI_PATH);
     });
 
+    asyncTest('applyConstraints', function() {
+        var openHandler = function() {
+            viewer.removeHandler('open', openHandler);
+            var viewport = viewer.viewport;
+
+            viewport.fitBounds(new OpenSeadragon.Rect(1, 1, 1, 1), true);
+            viewport.visibilityRatio = 0.3;
+            viewport.applyConstraints(true);
+            var bounds = viewport.getBounds();
+            Util.assertRectangleEquals(
+                bounds,
+                new OpenSeadragon.Rect(0.7, 0.7, 1, 1),
+                EPSILON,
+                "Viewport.applyConstraints should move viewport.");
+            start();
+        };
+        viewer.addHandler('open', openHandler);
+        viewer.open(DZI_PATH);
+    });
+
+    asyncTest('applyConstraints with rotation', function() {
+        var openHandler = function() {
+            viewer.removeHandler('open', openHandler);
+            var viewport = viewer.viewport;
+            viewport.setRotation(45);
+            viewport.fitBounds(new OpenSeadragon.Rect(1, 1, 1, 1), true);
+            viewport.applyConstraints(true);
+            var bounds = viewport.getBounds();
+            Util.assertRectangleEquals(
+                bounds,
+                new OpenSeadragon.Rect(1, 0, Math.sqrt(2), Math.sqrt(2), 45),
+                EPSILON,
+                "Viewport.applyConstraints with rotation should move viewport.");
+            start();
+        };
+        viewer.addHandler('open', openHandler);
+        viewer.open(DZI_PATH);
+    });
+
     // Fit bounds tests
     var testRectsFitBounds = [
         new OpenSeadragon.Rect(0, -0.75, 0.5, 1),