Files
openlayers/src/ol/dom/tilelayerrenderer.js
2012-07-18 14:49:30 +02:00

137 lines
3.8 KiB
JavaScript

goog.provide('ol.dom.TileLayerRenderer');
goog.require('ol.dom.LayerRenderer');
/**
* @constructor
* @extends {ol.dom.LayerRenderer}
* @param {ol.dom.Map} map Map.
* @param {ol.TileLayer} tileLayer Tile layer.
* @param {!Element} target Target.
*/
ol.dom.TileLayerRenderer = function(map, tileLayer, target) {
goog.base(this, map, tileLayer, target);
/**
* @type {Object}
* @private
*/
this.renderedTiles_ = {};
};
goog.inherits(ol.dom.TileLayerRenderer, ol.dom.LayerRenderer);
/**
* @inheritDoc
*/
ol.dom.TileLayerRenderer.prototype.redraw = function() {
var map = this.getMap();
var extent = map.getExtent();
var resolution = map.getResolution();
if (!goog.isDef(extent) || !goog.isDef(resolution)) {
return;
}
var tileLayer = /** @type {ol.TileLayer} */ (this.getLayer());
var tileStore = tileLayer.getStore();
var tileGrid = tileStore.getTileGrid();
var z = tileGrid.getZForResolution(resolution);
var tileBounds = tileGrid.getExtentTileBounds(z, extent);
var tileSize = tileGrid.getTileSize();
var offset = this.getTilesMapOffset_(extent, tileBounds, resolution);
var fragment = document.createDocumentFragment();
var key, tile, x, y, img, newTiles = false;
tileBounds.forEachTileCoord(z, function(tileCoord) {
key = tileCoord.toString();
tile = this.renderedTiles_[key];
if (!goog.isDef(tile)) {
tile = tileStore.getTile(tileCoord);
if (goog.isNull(tile)) {
} else {
if (!tile.isLoaded()) {
tile.load();
}
this.renderedTiles_[key] = tile;
x = tileSize.width * (tileCoord.x - tileBounds.minX);
y = tileSize.height * (tileBounds.maxY - tileCoord.y);
img = tile.getImage();
img.style.position = 'absolute';
img.style.top = (y - offset.y) + 'px';
img.style.left = (x - offset.x) + 'px';
img.style.width = tileSize.width + 'px';
img.style.height = tileSize.height + 'px';
goog.dom.appendChild(fragment, img);
newTiles = true;
}
}
return false;
}, this);
if (newTiles) {
this.target.appendChild(fragment);
}
this.removeInvisibleTiles_(tileBounds, z);
};
/**
* Get the pixel offset between top-left corner of tiles and top-left
* corner of map. Return positive values.
*
* @private
* @param {ol.Extent} extent Map extent.
* @param {ol.TileBounds} tileBounds Tile bounds.
* @param {number} resolution Resolution.
* @return {goog.math.Coordinate} Offset.
*/
ol.dom.TileLayerRenderer.prototype.getTilesMapOffset_ = function(
extent, tileBounds, resolution) {
var tileLayer = /** @type {ol.TileLayer} */ (this.getLayer());
var tileStore = tileLayer.getStore();
var tileGrid = tileStore.getTileGrid();
var z = tileGrid.getZForResolution(resolution);
var tileCoord = new ol.TileCoord(z, tileBounds.minX, tileBounds.maxY);
var tileCoordExtent = tileGrid.getTileCoordExtent(tileCoord);
var offset = new goog.math.Coordinate(
Math.round((this.origin.x - tileCoordExtent.minX) / resolution),
Math.round((tileCoordExtent.maxY - this.origin.y) / resolution));
return offset;
};
/**
* Get rid of tiles outside the rendered extent.
* @private
* @param {ol.TileBounds} tileBounds Tile bounds.
* @param {number} z Z.
*/
ol.dom.TileLayerRenderer.prototype.removeInvisibleTiles_ = function(
tileBounds, z) {
var key, tileCoord, prune, tile;
for (key in this.renderedTiles_) {
tileCoord = ol.TileCoord.fromString(key);
prune = z !== tileCoord.z ||
tileCoord.x < tileBounds.minX ||
tileCoord.x > tileBounds.maxX ||
tileCoord.y < tileBounds.minY ||
tileCoord.y > tileBounds.maxY;
if (prune) {
tile = this.renderedTiles_[key];
delete this.renderedTiles_[key];
this.target.removeChild(tile.getImage());
}
}
};