Merge pull request #524 from ahocevar/panzoombar

Zoom level restriction improvements. r=@bartvde

lib/OpenLayers/Control/PanZoomBar.js

@@ -99,6 +99,7 @@ OpenLayers.Control.PanZoomBar = OpenLayers.Class(OpenLayers.Control.PanZoom, {
 
         this.map.events.un({
             "changebaselayer": this.redraw,
+            "updatesize": this.redraw,
             scope: this
         });
 
@@ -116,7 +117,11 @@ OpenLayers.Control.PanZoomBar = OpenLayers.Class(OpenLayers.Control.PanZoom, {
      */
     setMap: function(map) {
         OpenLayers.Control.PanZoom.prototype.setMap.apply(this, arguments);
-        this.map.events.register("changebaselayer", this, this.redraw);
+        this.map.events.on({
+            "changebaselayer": this.redraw,
+            "updatesize": this.redraw,
+            scope: this
+        });
     },
 
     /** 
@@ -189,6 +194,7 @@ OpenLayers.Control.PanZoomBar = OpenLayers.Class(OpenLayers.Control.PanZoom, {
     _addZoomBar:function(centered) {
         var imgLocation = OpenLayers.Util.getImageLocation("slider.png");
         var id = this.id + "_" + this.map.id;
+        var minZoom = this.map.getMinZoom();
         var zoomsToEnd = this.map.getNumZoomLevels() - 1 - this.map.getZoom();
         var slider = OpenLayers.Util.createAlphaImageDiv(id,
                        centered.add(-1, zoomsToEnd * this.zoomStopHeight), 
@@ -211,7 +217,7 @@ OpenLayers.Control.PanZoomBar = OpenLayers.Class(OpenLayers.Control.PanZoom, {
         
         var sz = {
             w: this.zoomStopWidth,
-            h: this.zoomStopHeight * this.map.getNumZoomLevels()
+            h: this.zoomStopHeight * (this.map.getNumZoomLevels() - minZoom)
         };
         var imgLocation = OpenLayers.Util.getImageLocation("zoombar.png");
         var div = null;
@@ -242,7 +248,7 @@ OpenLayers.Control.PanZoomBar = OpenLayers.Class(OpenLayers.Control.PanZoom, {
         this.map.events.register("zoomend", this, this.moveZoomBar);
 
         centered = centered.add(0, 
-            this.zoomStopHeight * this.map.getNumZoomLevels());
+            this.zoomStopHeight * (this.map.getNumZoomLevels() - minZoom));
         return centered; 
     },
     

lib/OpenLayers/Map.js

@@ -83,6 +83,7 @@ OpenLayers.Map = OpenLayers.Class({
      * mouseout - triggered after mouseout the map
      * mousemove - triggered after mousemove the map
      * changebaselayer - triggered after the base layer changes
+     * updatesize - triggered after the <updateSize> method was executed
      */
 
     /**
@@ -1490,6 +1491,7 @@ OpenLayers.Map = OpenLayers.Class({
     
             }
         }
+        this.events.triggerEvent("updatesize");
     },
     
     /**
@@ -1784,18 +1786,42 @@ OpenLayers.Map = OpenLayers.Class({
      * <baseLayer>'s maxExtent.
      */
     adjustZoom: function(zoom) {
-        var resolution, resolutions = this.baseLayer.resolutions,
-            maxResolution = this.getMaxExtent().getWidth() / this.size.w;
-        if (this.getResolutionForZoom(zoom) > maxResolution) {
-            for (var i=zoom|0, ii=resolutions.length; i<ii; ++i) {
-                if (resolutions[i] <= maxResolution) {
-                    zoom = i;
-                    break;
-                }
+        if (this.baseLayer && this.baseLayer.wrapDateLine) {
+            var resolution, resolutions = this.baseLayer.resolutions,
+                maxResolution = this.getMaxExtent().getWidth() / this.size.w;
+            if (this.getResolutionForZoom(zoom) > maxResolution) {
+                if (this.fractionalZoom) {
+                    zoom = this.getZoomForResolution(maxResolution);
+                } else {
+                    for (var i=zoom|0, ii=resolutions.length; i<ii; ++i) {
+                        if (resolutions[i] <= maxResolution) {
+                            zoom = i;
+                            break;
+                        }
+                    }
+                } 
             }
         }
         return zoom;
     },
+    
+    /**
+     * APIMethod: getMinZoom
+     * Returns the minimum zoom level for the current map view. If the base
+     * layer is configured with <wrapDateLine> set to true, this will be the
+     * first zoom level that shows no more than one world width in the current
+     * map viewport. Components that rely on this value (e.g. zoom sliders)
+     * should also listen to the map's "updatesize" event and call this method
+     * in the "updatesize" listener.
+     *
+     * Returns:
+     * {Number} Minimum zoom level that shows a map not wider than its
+     * <baseLayer>'s maxExtent. This is an Integer value, unless the map is
+     * configured with <fractionalZoom> set to true.
+     */
+    getMinZoom: function() {
+        return this.adjustZoom(0);
+    },
 
     /**
      * Method: moveTo
@@ -1818,13 +1844,11 @@ OpenLayers.Map = OpenLayers.Class({
                 zoom = Math.round(zoom);
             }
         }
-        if (this.baseLayer.wrapDateLine) {
-            var requestedZoom = zoom;
-            zoom = this.adjustZoom(zoom);
-            if (zoom !== requestedZoom) {
-                // zoom was adjusted, so keep old lonlat to avoid panning
-                lonlat = this.getCenter();
-            }
+        var requestedZoom = zoom;
+        zoom = this.adjustZoom(zoom);
+        if (zoom !== requestedZoom) {
+            // zoom was adjusted, so keep old lonlat to avoid panning
+            lonlat = this.getCenter();
         }
         // dragging is false by default
         var dragging = options.dragging || this.dragging;

tests/Control/PanZoomBar.html

@@ -33,6 +33,31 @@
         map.addControl(control2, new OpenLayers.Pixel(100,100));
         t.eq( control2.div.style.top, "100px", "2nd control div is located correctly");
     }
+    
+    function test_draw(t) {
+        t.plan(3);
+        map = new OpenLayers.Map('map', {controls:[]});
+        var layer = new OpenLayers.Layer.WMS("Test Layer",
+            "http://octo.metacarta.com/cgi-bin/mapserv?",
+            {map: "/mapdata/vmap_wms.map", layers: "basic"});
+        map.addLayer(layer);
+        map.zoomToMaxExtent();
+        control = new OpenLayers.Control.PanZoomBar();
+        map.addControl(control);
+        t.eq(control.zoombarDiv.style.height, '176px', "Bar's height is correct.");
+
+        map.baseLayer.wrapDateLine = true;
+
+        control.redraw();
+        t.eq(control.zoombarDiv.style.height, '154px', "Bar's height is correct after minZoom restriction.");
+
+        map.div.style.width = "512px";
+        map.updateSize();
+        t.eq(control.zoombarDiv.style.height, '165px', "Bar's height is correct after resize and minZoom restriction.");
+
+        map.div.style.width = "1024px";
+        map.destroy();
+    }
 
     function test_Control_PanZoomBar_clearDiv(t) {
         t.plan(2);

tests/Map.html

@@ -2047,7 +2047,7 @@
     }
 
     function test_adjustZoom(t) {
-        t.plan(4);
+        t.plan(5);
         var map = new OpenLayers.Map({
             div: 'map',
             layers: [
@@ -2062,6 +2062,9 @@
         
         t.eq(map.adjustZoom(9), 9, "valid zoom maintained");
         t.eq(map.adjustZoom(1), 2, "zoom adjusted to not exceed world width");
+        
+        map.fractionalZoom = true;
+        t.eq(map.adjustZoom(1).toPrecision(3), "1.29", "zoom adjusted to match world width");
 
         map.moveTo([16, 48], 0);
         t.eq(map.getCenter().toShortString(), "0, 0", "no panning when moveTo is called with invalid zoom");