Fix a problem determining zoom levels. Updated some docs.

lib/OpenLayers/Control/UTFGrid.js

@@ -169,14 +169,13 @@ OpenLayers.Control.UTFGrid = OpenLayers.Class(OpenLayers.Control, {
             this.lastXy = evt.xy;
         }
         
-        var newHtml = this.formatOutput(lonLat);
-
         var layers = this.findLayers();
         if (layers.length > 0) {
             var layer;
             for (var i=0, len=layers.length; i<len; i++) {
                 layer = layers[i];
                 var info = layer.getTileInfo( lonLat );
+                //MP TODO make function
                 if (this.debugElement) {
                     var debug = "<ul>";
                     debug += "<li>i :" + info.i + "</li>";
@@ -192,7 +191,7 @@ OpenLayers.Control.UTFGrid = OpenLayers.Class(OpenLayers.Control, {
                 }
                 var tile = info.tile;
                 /*
-                TODO Sanity checks
+                MP TODO Sanity checks
                 if ((Math.floor(info.i) >= tileSize) ||
                     (Math.floor(info.j) >= tileSize)) alert("TOO BIG");
                 */
@@ -217,6 +216,7 @@ OpenLayers.Control.UTFGrid = OpenLayers.Class(OpenLayers.Control, {
 
     /**
      * Method: callback
+     * MP TODO
      * Takes the attrs and does somethings with them
      * this is a default (intended to be overridden)
      */
@@ -259,28 +259,11 @@ OpenLayers.Control.UTFGrid = OpenLayers.Class(OpenLayers.Control, {
         }
     },
 
-    /**
-     * Method: formatOutput
-     * Override to provide custom display output
-     *
-     * Parameters:
-     * lonLat - {<OpenLayers.LonLat>} Location to display
-     */
-    formatOutput: function(lonLat) {
-        var digits = parseInt(this.numDigits);
-        var newHtml =
-            this.prefix +
-            lonLat.lon.toFixed(digits) +
-            this.separator + 
-            lonLat.lat.toFixed(digits) +
-            this.suffix;
-        return newHtml;
-    },
-
     /**
      * Method: findLayers
      * Internal method to get the layers, independent of whether we are
      *     inspecting the map or using a client-provided array
+     *     MP TODO respect list of user-supplied candidates
      */
     findLayers: function() {
         var candidates = this.layers || this.map.layers;

lib/OpenLayers/Layer/UTFGrid.js

@@ -9,7 +9,7 @@
 
 /** 
  * Class: OpenLayers.Layer.UTFGrid
- * TODO
+ * MP TODO
  * 
  * Inherits from:
  *  - <OpenLayers.Layer.Grid>
@@ -26,7 +26,8 @@ OpenLayers.Layer.UTFGrid = OpenLayers.Class(OpenLayers.Layer.Grid, {
      * APIProperty: sphericalMecator
      * Whether the tile extents should be set to the defaults for 
      *    spherical mercator. Useful for things like OpenStreetMap.
-     *    Default is false, except for the OSM subclass.
+     *    Default is true as most (all?) utfgrid implementations assume
+     *    sperical mercator.
      */
     sphericalMercator: false,
 
@@ -143,7 +144,9 @@ OpenLayers.Layer.UTFGrid = OpenLayers.Class(OpenLayers.Layer.Grid, {
      * loc - {<OpenLayers.LonLat} A location in map coordinates.
      *
      * Returns:
-     * {Object} An object with "col", "row", "i", and "j" properties.  The col
+     * {Object} An object with 
+     *     MP TODO 
+     *     "col", "row", "i", and "j" properties.  The col
      *     and row values are zero based tile indexes from the top left.  The
      *     i and j values are the number of pixels to the left and top 
      *     (respectively) of the given location within the target tile.
@@ -159,7 +162,7 @@ OpenLayers.Layer.UTFGrid = OpenLayers.Class(OpenLayers.Layer.Grid, {
 
         // Get the current grid offset
         var gridOrigin = this.grid[0][0].bounds;
-        // TODO rounding errors can cause intermittent problems (4.9999 should be 5)
+        // MP TODO rounding errors can cause intermittent problems (4.9999 should be 5)
         // flooring will cause big problems (4.999 becomes 4)... do round or toFixed later?
         var gridColOffset = 
                 (gridOrigin.left - this.tileOrigin.lon) / (res * this.tileSize.w);
@@ -177,7 +180,6 @@ OpenLayers.Layer.UTFGrid = OpenLayers.Class(OpenLayers.Layer.Grid, {
         
         var tile = this.grid[gridRow][gridCol];
 
-
         return {
             globalCol: globalCol, 
             globalRow: globalRow, 
@@ -195,7 +197,7 @@ OpenLayers.Layer.UTFGrid = OpenLayers.Class(OpenLayers.Layer.Grid, {
     /**
      * APIProperty: tileClass
      * {<OpenLayers.Tile>} The tile class to use for this layer.
-     *     Defaults is OpenLayers.Tile (not Tile.Image)
+     *     Defaults is OpenLayers.Tile.UTFGrid (not Tile.Image)
      */
     tileClass: OpenLayers.Tile.UTFGrid,
 
@@ -216,9 +218,10 @@ OpenLayers.Layer.UTFGrid = OpenLayers.Class(OpenLayers.Layer.Grid, {
         var y = Math.round((this.maxExtent.top - bounds.top) /
             (res * this.tileSize.h));
         var resolutions = this.serverResolutions || this.resolutions;
-        var z = this.zoomOffset == 0 ?
+        var z = this.getServerZoom();
-            OpenLayers.Util.indexOf(resolutions, res) :
+        if (this.zoomOffset > 0) {
-            this.getServerZoom() + this.zoomOffset;
+            z += this.zoomOffset;
+        }
 
         var limit = Math.pow(2, z);
         if (this.wrapDateLine)

lib/OpenLayers/Tile/UTFGrid.js

@@ -11,7 +11,9 @@
 /**
  * Class: OpenLayers.Tile.UTFGrid
  * Instances of OpenLayers.Tile.UTFGrid are used to manage the image tiles
- * TODO
+ * MP TODO
+ * IMPORTANT - remove all traces of IMAGES
+ *
  * <OpenLayers.Tile.UTFGrid> constructor.
  *
  * Inherits from:
@@ -69,6 +71,7 @@ OpenLayers.Tile.UTFGrid = OpenLayers.Class(OpenLayers.Tile, {
     /** 
      * APIMethod: destroy
      * nullify references to prevent circular references and memory leaks
+     * MP TODO what do we need to clear for the utfgrid implementation?
      */
     destroy: function() {
         if (this.imgDiv)  {
@@ -90,6 +93,7 @@ OpenLayers.Tile.UTFGrid = OpenLayers.Class(OpenLayers.Tile, {
      */
     draw: function() {
         var drawn = OpenLayers.Tile.prototype.draw.apply(this, arguments);
+        console.log(drawn);
         if (drawn) {
             if (this.isLoading) {
                 //if we're already loading, send 'reload' instead of 'loadstart'.
@@ -108,7 +112,7 @@ OpenLayers.Tile.UTFGrid = OpenLayers.Class(OpenLayers.Tile, {
             });
 
             /*
-             * TODO Investigate JSONP method to avoid xbrowser polucy
+             * MP TODO Investigate JSONP method to avoid xbrowser polucy
              *
             grid = function(e) { 
                 console.log(e);
@@ -122,9 +126,7 @@ OpenLayers.Tile.UTFGrid = OpenLayers.Class(OpenLayers.Tile, {
             var res = ols.read();
             console.log(res.priv);
             */
-
             this.positionTile();
-            //this.renderTile();
         } else {
             this.unload();
         }
@@ -145,31 +147,6 @@ OpenLayers.Tile.UTFGrid = OpenLayers.Class(OpenLayers.Tile, {
         } 
     },
     
-    /**
-     * Method: renderTile
-     * Internal function to actually initialize the image tile,
-     *     position it correctly, and set its url.
-     */
-    renderTile: function() {
-        this.layer.div.appendChild(this.getTile());
-        if (this.layer.async) {
-            // Asynchronous image requests call the asynchronous getURL method
-            // on the layer to fetch an image that covers 'this.bounds', in the scope of
-            // 'this', setting the 'url' property of the layer itself, and running
-            // the callback 'initImage' when the image request returns.
-            var myId = this.asyncRequestId = (this.asyncRequestId || 0) + 1;
-            this.layer.getURLasync(this.bounds, this, "url", function() {
-                if (myId == this.asyncRequestId) {
-                    this.initImage();
-                }
-            });
-        } else {
-            // synchronous image requests get the url immediately.
-            this.url = this.layer.getURL(this.bounds);
-            this.initImage();
-        }
-    },
-
     /**
      * Method: positionTile
      * Using the properties currenty set on the layer, position the tile correctly.
@@ -186,6 +163,7 @@ OpenLayers.Tile.UTFGrid = OpenLayers.Class(OpenLayers.Tile, {
 
     /** 
      * Method: clear
+     * MP TODO remove the json from the DOM!
      * Remove the tile from the DOM, clear it of any image related data so that
      * it can be reused in a new location.
      */