Changeset 4229

Timestamp:

09/12/07 00:00:31 (11 months ago)

Author:

euzuro

Message:

making the layerswitcher a little smarter. Instead of fancy 'noEvent' parameters, we just keep track of the state at each redraw. When asked to redraw, we then check first to see if anything has changed before going ahead with the redraw. Also in this patch, we add a 'visibilitychanged' event to the layer's events object -- upon request by users. (Closes #878)

Files:

• trunk/openlayers/lib/OpenLayers/Control/LayerSwitcher.js (modified) (7 diffs)
• trunk/openlayers/lib/OpenLayers/Layer.js (modified) (2 diffs)
• trunk/openlayers/lib/OpenLayers/Map.js (modified) (3 diffs)
• trunk/openlayers/tests/Control/test_LayerSwitcher.html (modified) (2 diffs)
• trunk/openlayers/tests/test_Layer.html (modified) (2 diffs)

trunk/openlayers/lib/OpenLayers/Control/LayerSwitcher.js

@@ -20 +20 @@
-    activeColor: "darkblue",
-    
+    /**  
+     * Property: layerStates 
+     * {Array(Object)} Basically a copy of the "state" of the map's layers 
+     *     the last time the control was drawn. We have this in order to avoid
+     *     unnecessarily redrawing the control.
+     */
+    layerStates: null,
+    
-
-  // DOM Elements
@@ -87 +95 @@
-    initialize: function(options) {
-        OpenLayers.Control.prototype.initialize.apply(this, arguments);
+        this.layerStates = [];
-    },
-
@@ -172 +181 @@
-
-
+    /**
+     * Method: checkRedraw
+     * Checks if the layer state has changed since the last redraw() call.
+     * 
+     * Returns:
+     * {Boolean} The layer state changed since the last redraw() call. 
+     */
+    checkRedraw: function() {
+        var redraw = false;
+        if ( !this.layerStates.length ||
+             (this.map.layers.length != this.layerStates.length) ) {
+            redraw = true;
+        } else {
+            for (var i=0; i < this.layerStates.length; i++) {
+                var layerState = this.layerStates[i];
+                var layer = this.map.layers[i];
+                if ( (layerState.name != layer.name) || 
+                     (layerState.visibility != layer.visibility) ) {
+                    redraw = true;
+                    break;
+                }    
+            }
+        }    
+        return redraw;
+    },
+    
-    /** 
-     * Method: redraw
@@ -182 +217 @@
-     */  
-    redraw: function() {
+        //if the state hasn't changed since last redraw, no need 
+        // to do anything. Just return the existing div.
+        if (!this.checkRedraw()) { 
+            return this.div; 
+        } 
-
-        //clear out previous layers 
@@ -190 +230 @@
-        var containsBaseLayers = false;
-        
+        // Save state -- for checking layer if the map state changed.
+        // We save this before redrawing, because in the process of redrawing
+        // we will trigger more visibility changes, and we want to not redraw
+        // and enter an infinite loop.
+        this.layerStates = new Array(this.map.layers.length);
+        for (var i = 0; i < this.map.layers.length; i++) {
+            var layer = this.map.layers[i];
+            this.layerStates[i] = {
+                'name': layer.name, 
+                'visibility': layer.visibility
+            };
+        }    
+
-        var layers = this.map.layers.slice();
-        if (!this.ascending) { layers.reverse(); }
@@ -287 +340 @@
-            if (this.inputElem.type == "radio") {
-                this.inputElem.checked = true;
-
-
+
-            } else {
-                this.inputElem.checked = !this.inputElem.checked;
@@ -330 +382 @@
-        for(var i=0; i < this.dataLayers.length; i++) {
-            var layerEntry = this.dataLayers[i];   
-, true
+
-        }
-

trunk/openlayers/lib/OpenLayers/Layer.js

@@ -33 +33 @@
-     * {Array(String)} Supported application event types
-     */
-
+, "visibilitychanged"
-        
-    /**
@@ -498 +498 @@
-     * Parameters:
-     * visible - {Boolean} Whether or not to display the layer (if in range)
-
-
-
+
+
-        if (visibility != this.visibility) {
-            this.visibility = visibility;
-            this.display(visibility);
-            this.redraw();
-
-
+
-                this.map.events.triggerEvent("changelayer");
-            }
+            this.events.triggerEvent("visibilitychanged");
-        }
-    },

trunk/openlayers/lib/OpenLayers/Map.js

@@ -661 +661 @@
-     * Parameters:
-     * newBaseLayer - {<OpenLayers.Layer>}
-
-
-
+
+
-        var oldExtent = null;
-        if(this.baseLayer) {
@@ -676 +675 @@
-                // make the old base layer invisible 
-                if (this.baseLayer != null) {
-, noEvent
+
-                }
-
@@ -702 +701 @@
-                }
-
-
-
-
+
-            }        
-        }

trunk/openlayers/tests/Control/test_LayerSwitcher.html

@@ -66 +66 @@
-    function test_04_Control_LayerSwitcher_redraw (t) {
-
-8
+12
-
-        map = new OpenLayers.Map('map');
@@ -92 +92 @@
-        t.eq(markersInput.name, markers.name, "wms correctly named");
-        t.eq(markersInput.value, markers.name, "wms correctly valued");
+
+        t.eq(false, control.checkRedraw(), "check redraw is false");
+        
+        control = new OpenLayers.Control.LayerSwitcher();
+        control.redraw = function() { 
+            t.ok(true, "redraw called when setting vis");
+        }
+        map.addControl(control); 
+        markers.setVisibility(false); 
+        t.eq(control.checkRedraw(), true, "check redraw is true after changing layer and not letting redraw happen.");
-
-    }

trunk/openlayers/tests/test_Layer.html

@@ -119 +119 @@
-    function test_05_Layer_visibility(t) {
-
-5)
+7);
-
-        var layer = new OpenLayers.Layer('Test Layer');
@@ -140 +140 @@
-        layermoved = false; 
-        layer.moveTo = function() { layermoved = true; }
+        
+        layer.events.register('visibilitychanged', t, function() {
+            this.ok(true, "Visibility changed calls layer event.");
+        });    
-        
-        layer.setVisibility(false);