Files
openlayers/lib/OpenLayers/Layer/Grid.js
crschmidt 499c8db92a the mergeNewParams function does not reinitialize the tiles for layers
other than WMS. It should do this for any Grid layer. Ticket #496 includes
a patch for this: it adds a mergeNewParams call at the Layer.Grid level,
(subclassing Layer.HTTPRequest) which reinits the tile grid. This commit
also includes tests for this functionality. Since testing directly
on the Grid layer doesn't work (it's meant to be subclassed), we need to 
instead pick a second layer to test -- in this case, ka-Map. Thanks to
Bill Woodall for the patch.


git-svn-id: http://svn.openlayers.org/trunk/openlayers@2237 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf
2007-02-17 15:00:05 +00:00

454 lines
15 KiB
JavaScript

/* Copyright (c) 2006 MetaCarta, Inc., published under a modified BSD license.
* See http://svn.openlayers.org/trunk/openlayers/repository-license.txt
* for the full text of the license. */
/**
* @class
*
* @requires OpenLayers/Layer/HTTPRequest.js
*/
OpenLayers.Layer.Grid = OpenLayers.Class.create();
OpenLayers.Layer.Grid.prototype =
OpenLayers.Class.inherit( OpenLayers.Layer.HTTPRequest, {
/** @type OpenLayers.Size */
tileSize: null,
/** this is an array of rows, each row is an array of tiles
*
* @type Array(Array) */
grid: null,
/** @type Integer */
buffer: 2,
/**
* @constructor
*
* @param {String} name
* @param {String} url
* @param {Object} params
* @param {Object} options Hashtable of extra options to tag onto the layer
*/
initialize: function(name, url, params, options) {
OpenLayers.Layer.HTTPRequest.prototype.initialize.apply(this,
arguments);
this.grid = new Array();
},
/** on destroy, clear the grid.
*
*/
destroy: function() {
this.clearGrid();
this.grid = null;
this.tileSize = null;
OpenLayers.Layer.HTTPRequest.prototype.destroy.apply(this, arguments);
},
/**
* @param {Object} obj
*
* @returns An exact clone of this OpenLayers.Layer.Grid
* @type OpenLayers.Layer.Grid
*/
clone: function (obj) {
if (obj == null) {
obj = new OpenLayers.Layer.Grid(this.name,
this.url,
this.params,
this.options);
}
//get all additions from superclasses
obj = OpenLayers.Layer.HTTPRequest.prototype.clone.apply(this, [obj]);
// copy/set any non-init, non-simple values here
if (this.tileSize != null) {
obj.tileSize = this.tileSize.clone();
}
// we do not want to copy reference to grid, so we make a new array
obj.grid = new Array();
return obj;
},
/** When the layer is added to a map, then we can ask the map for
* its default tile size
*
* @param {OpenLayers.Map} map
*/
setMap: function(map) {
OpenLayers.Layer.HTTPRequest.prototype.setMap.apply(this, arguments);
if (this.tileSize == null) {
this.tileSize = this.map.getTileSize();
}
},
/** This function is called whenever the map is moved. All the moving
* of actual 'tiles' is done by the map, but moveTo's role is to accept
* a bounds and make sure the data that that bounds requires is pre-loaded.
*
* @param {OpenLayers.Bounds} bounds
* @param {Boolean} zoomChanged
* @param {Boolean} dragging
*/
moveTo:function(bounds, zoomChanged, dragging) {
OpenLayers.Layer.HTTPRequest.prototype.moveTo.apply(this, arguments);
if (bounds == null) {
bounds = this.map.getExtent();
}
if (bounds != null) {
if (!this.grid.length || zoomChanged
|| !this.getGridBounds().containsBounds(bounds, true)) {
this._initTiles();
} else {
var buffer = (this.buffer) ? this.buffer*1.5 : 1;
while (true) {
var tlLayer = this.grid[0][0].position;
var tlViewPort =
this.map.getViewPortPxFromLayerPx(tlLayer);
if (tlViewPort.x > -this.tileSize.w * (buffer - 1)) {
this.shiftColumn(true);
} else if (tlViewPort.x < -this.tileSize.w * buffer) {
this.shiftColumn(false);
} else if (tlViewPort.y > -this.tileSize.h * (buffer - 1)) {
this.shiftRow(true);
} else if (tlViewPort.y < -this.tileSize.h * buffer) {
this.shiftRow(false);
} else {
break;
}
};
if (this.buffer == 0) {
for (var r=0, rl=this.grid.length; r<rl; r++) {
var row = this.grid[r];
for (var c=0, cl=row.length; c<cl; c++) {
var tile = row[c];
if (!tile.drawn && tile.bounds.intersectsBounds(bounds, false)) {
tile.draw();
}
}
}
}
}
}
},
/**
* @private
*
* @returns A Bounds object representing the bounds of all the currently
* loaded tiles (including those partially or not at all seen
* onscreen)
* @type OpenLayers.Bounds
*/
getGridBounds:function() {
var bottom = this.grid.length - 1;
var bottomLeftTile = this.grid[bottom][0];
var right = this.grid[0].length - 1;
var topRightTile = this.grid[0][right];
return new OpenLayers.Bounds(bottomLeftTile.bounds.left,
bottomLeftTile.bounds.bottom,
topRightTile.bounds.right,
topRightTile.bounds.top);
},
/**
* @private
*/
_initTiles:function() {
// work out mininum number of rows and columns; this is the number of
// tiles required to cover the viewport plus one for panning
var viewSize = this.map.getSize();
var minRows = Math.ceil(viewSize.h/this.tileSize.h) + 1;
var minCols = Math.ceil(viewSize.w/this.tileSize.w) + 1;
var bounds = this.map.getExtent();
var extent = this.map.getMaxExtent();
var resolution = this.map.getResolution();
var tilelon = resolution * this.tileSize.w;
var tilelat = resolution * this.tileSize.h;
var offsetlon = bounds.left - extent.left;
var tilecol = Math.floor(offsetlon/tilelon) - this.buffer;
var tilecolremain = offsetlon/tilelon - tilecol;
var tileoffsetx = -tilecolremain * this.tileSize.w;
var tileoffsetlon = extent.left + tilecol * tilelon;
var offsetlat = bounds.top - (extent.bottom + tilelat);
var tilerow = Math.ceil(offsetlat/tilelat) + this.buffer;
var tilerowremain = tilerow - offsetlat/tilelat;
var tileoffsety = -tilerowremain * this.tileSize.h;
var tileoffsetlat = extent.bottom + tilerow * tilelat;
tileoffsetx = Math.round(tileoffsetx); // heaven help us
tileoffsety = Math.round(tileoffsety);
this.origin = new OpenLayers.Pixel(tileoffsetx, tileoffsety);
var startX = tileoffsetx;
var startLon = tileoffsetlon;
var rowidx = 0;
do {
var row = this.grid[rowidx++];
if (!row) {
row = new Array();
this.grid.push(row);
}
tileoffsetlon = startLon;
tileoffsetx = startX;
var colidx = 0;
do {
var tileBounds = new OpenLayers.Bounds(tileoffsetlon,
tileoffsetlat,
tileoffsetlon + tilelon,
tileoffsetlat + tilelat);
var x = tileoffsetx;
x -= parseInt(this.map.layerContainerDiv.style.left);
var y = tileoffsety;
y -= parseInt(this.map.layerContainerDiv.style.top);
var px = new OpenLayers.Pixel(x, y);
var tile = row[colidx++];
if (!tile) {
tile = this.addTile(tileBounds, px);
row.push(tile);
} else {
tile.moveTo(tileBounds, px, false);
}
tileoffsetlon += tilelon;
tileoffsetx += this.tileSize.w;
} while ((tileoffsetlon <= bounds.right + tilelon * this.buffer)
|| colidx < minCols)
tileoffsetlat -= tilelat;
tileoffsety += this.tileSize.h;
} while((tileoffsetlat >= bounds.bottom - tilelat * this.buffer)
|| rowidx < minRows)
// remove extra rows
while (this.grid.length > rowidx) {
var row = this.grid.pop();
for (var i=0, l=row.length; i<l; i++) {
row[i].destroy();
}
}
// remove extra columns
while (this.grid[0].length > colidx) {
for (var i=0, l=this.grid.length; i<l; i++) {
var row = this.grid[i];
var tile = row.pop();
tile.destroy();
}
}
//now actually draw the tiles
this.spiralTileLoad();
},
/**
* @private
*
* Starts at the top right corner of the grid and proceeds in a spiral
* towards the center, adding tiles one at a time to the beginning of a
* queue.
*
* Once all the grid's tiles have been added to the queue, we go back
* and iterate through the queue (thus reversing the spiral order from
* outside-in to inside-out), calling draw() on each tile.
*/
spiralTileLoad: function() {
var tileQueue = new Array();
var directions = ["right", "down", "left", "up"];
var iRow = 0;
var iCell = -1;
var direction = OpenLayers.Util.indexOf(directions, "right");
var directionsTried = 0;
while( directionsTried < directions.length) {
var testRow = iRow;
var testCell = iCell;
switch (directions[direction]) {
case "right":
testCell++;
break;
case "down":
testRow++;
break;
case "left":
testCell--;
break;
case "up":
testRow--;
break;
}
// if the test grid coordinates are within the bounds of the
// grid, get a reference to the tile.
var tile = null;
if ((testRow < this.grid.length) && (testRow >= 0) &&
(testCell < this.grid[0].length) && (testCell >= 0)) {
tile = this.grid[testRow][testCell];
}
if ((tile != null) && (!tile.queued)) {
//add tile to beginning of queue, mark it as queued.
tileQueue.unshift(tile);
tile.queued = true;
//restart the directions counter and take on the new coords
directionsTried = 0;
iRow = testRow;
iCell = testCell;
} else {
//need to try to load a tile in a different direction
direction = (direction + 1) % 4;
directionsTried++;
}
}
// now we go through and draw the tiles in forward order
for(var i=0; i < tileQueue.length; i++) {
var tile = tileQueue[i]
tile.draw();
//mark tile as unqueued for the next time (since tiles are reused)
tile.queued = false;
}
},
/**
* addTile gives subclasses of Grid the opportunity to create an
* OpenLayer.Tile of their choosing. The implementer should initialize
* the new tile and take whatever steps necessary to display it.
*
* @param {OpenLayers.Bounds} bounds
*
* @returns The added OpenLayers.Tile
* @type OpenLayers.Tile
*/
addTile:function(bounds, position) {
// Should be implemented by subclasses
},
/**
* Once params have been changed, we will need to re-init our tiles
*
* @param {Object} newParams Hashtable of new params to use
*/
mergeNewParams:function(newArguments) {
OpenLayers.Layer.HTTPRequest.prototype.mergeNewParams.apply(this,
[newArguments]);
if (this.map != null) {
this._initTiles();
}
},
/** go through and remove all tiles from the grid, calling
* destroy() on each of them to kill circular references
*
* @private
*/
clearGrid:function() {
if (this.grid) {
for(var iRow=0; iRow < this.grid.length; iRow++) {
var row = this.grid[iRow];
for(var iCol=0; iCol < row.length; iCol++) {
row[iCol].destroy();
}
this.grid = [];
}
}
},
/**
* @private
*
* @param {Boolean} prepend if true, prepend to beginning.
* if false, then append to end
*/
shiftRow:function(prepend) {
var modelRowIndex = (prepend) ? 0 : (this.grid.length - 1);
var modelRow = this.grid[modelRowIndex];
var resolution = this.map.getResolution();
var deltaY = (prepend) ? -this.tileSize.h : this.tileSize.h;
var deltaLat = resolution * -deltaY;
var row = (prepend) ? this.grid.pop() : this.grid.shift();
for (var i=0; i < modelRow.length; i++) {
var modelTile = modelRow[i];
var bounds = modelTile.bounds.clone();
var position = modelTile.position.clone();
bounds.bottom = bounds.bottom + deltaLat;
bounds.top = bounds.top + deltaLat;
position.y = position.y + deltaY;
row[i].moveTo(bounds, position);
}
if (prepend) {
this.grid.unshift(row);
} else {
this.grid.push(row);
}
},
/**
* @private
*
* @param {Boolean} prepend if true, prepend to beginning.
* if false, then append to end
*/
shiftColumn: function(prepend) {
var deltaX = (prepend) ? -this.tileSize.w : this.tileSize.w;
var resolution = this.map.getResolution();
var deltaLon = resolution * deltaX;
for (var i=0; i<this.grid.length; i++) {
var row = this.grid[i];
var modelTileIndex = (prepend) ? 0 : (row.length - 1);
var modelTile = row[modelTileIndex];
var bounds = modelTile.bounds.clone();
var position = modelTile.position.clone();
bounds.left = bounds.left + deltaLon;
bounds.right = bounds.right + deltaLon;
position.x = position.x + deltaX;
var tile = prepend ? this.grid[i].pop() : this.grid[i].shift()
tile.moveTo(bounds, position);
if (prepend) {
this.grid[i].unshift(tile);
} else {
this.grid[i].push(tile);
}
}
},
/** @final @type String */
CLASS_NAME: "OpenLayers.Layer.Grid"
});