街景地图源码

版本2.10 /*2010-11-21 huanggp 修改2处对象为空错误保护 lib\OpenLayers\Tile\Image.js 281行 renderTile: function() { if (this.imgDiv == null) { this.initImgDiv(); } try{ this.imgDiv.viewRequestID = this.layer.map.viewRequestID; }catch(e){ } if (this.layer.async) { // Asyncronous 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 'positionFrame' when the image request returns. this.layer.getURLasync(this.bounds, this, "url", this.positionImage); } else { // syncronous image requests get the url and position the frame immediately, // and don't wait for an image request to come back. // needed for changing to a different server for onload error if (this.layer.url instanceof Array) { this.imgDiv.urls = this.layer.url.slice(); } this.url = this.layer.getURL(this.bounds); // position the frame immediately this.positionImage(); } return true; }, lib\OpenLayers\Layer.js 917行 getResolution: function() { try{ var zoom = this.map.getZoom(); return this.getResolutionForZoom(zoom); }catch(e){ } }, */ /*2011-01-10 huanggp 修改1处对象为空错误保护 lib\OpenLayers\Layer\Grid.js 624行 shiftRow:function(prepend) { var modelRowIndex = (prepend) ? 0 : (this.grid.length - 1); var grid = this.grid; var modelRow = grid[modelRowIndex]; var resolution = this.map.getResolution(); var deltaY = (prepend) ? -this.tileSize.h : this.tileSize.h; var deltaLat = resolution * -deltaY; var row = (prepend) ? grid.pop() : grid.shift(); for (var i=0, len=modelRow.length; i<len; 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; try{ row[i].moveTo(bounds, position); }catch(e){ } } if (prepend) { grid.unshift(row); } else { grid.push(row); } }, */ /*2011-01-19 yangkun 恢复1处对象为空错误保护 lib\OpenLayers\Layer\Grid.js 624行 shiftRow:function(prepend) { var modelRowIndex = (prepend) ? 0 : (this.grid.length - 1); var grid = this.grid; var modelRow = grid[modelRowIndex]; var resolution = this.map.getResolution(); var deltaY = (prepend) ? -this.tileSize.h : this.tileSize.h; var deltaLat = resolution * -deltaY; var row = (prepend) ? grid.pop() : grid.shift(); for (var i=0, len=modelRow.length; i<len; 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) { grid.unshift(row); } else { grid.push(row); } }, */ /*2011-05-21 huanggp 修改显示过度效果 OpenLayers/lib/OpenLayers/Tile/Image.js /** * Method: startTransition 开始显示过度效果 * This method is invoked on tiles that are backBuffers for tiles in the * grid. The grid tile is about to be cleared and a new tile source * loaded. This is where the transition effect needs to be started * to provide visual continuity. */ startTransition: function() { // backBufferTile has to be valid and ready to use if (!this.backBufferTile || !this.backBufferTile.imgDiv) { return; } // calculate the ratio of change between the current resolution of the // backBufferTile and the layer. If several animations happen in a // row, then the backBufferTile will scale itself appropriately for // each request. var ratio = 1; if (this.backBufferTile.resolution) { ratio = this.backBufferTile.resolution / this.layer.getResolution(); } // if the ratio is not the same as it was last time (i.e. we are // zooming), then we need to adjust the backBuffer tile //A //OpenLayers //if (ratio != this.lastRatio) { //update by huanggp if (this.backBufferTile.resolution != this.layer.getResolution()) { if (this.layer.transitionEffect == 'resize') { // In this case, we can just immediately resize the // backBufferTile. var upperLeft = new OpenLayers.LonLat( this.backBufferTile.bounds.left, this.backBufferTile.bounds.top ); var size = new OpenLayers.Size( this.backBufferTile.size.w * ratio, this.backBufferTile.size.h * ratio ); var px = this.layer.map.getLayerPxFromLonLat(upperLeft); OpenLayers.Util.modifyDOMElement(this.backBufferTile.frame, null, px, size); var imageSize = this.backBufferTile.imageSize; imageSize = new OpenLayers.Size(imageSize.w * ratio, imageSize.h * ratio); var imageOffset = this.backBufferTile.imageOffset; if(imageOffset) { imageOffset = new OpenLayers.Pixel( imageOffset.x * ratio, imageOffset.y * ratio ); } OpenLayers.Util.modifyDOMElement( this.backBufferTile.imgDiv, null, imageOffset, imageSize ) ; this.backBufferTile.show(); } } else { // default effect is just to leave the existing tile // until the new one loads if this is a singleTile and // there was no change in resolution. Otherwise we // don't bother to show the backBufferTile at all if (this.layer.singleTile) { this.backBufferTile.show(); } else { this.backBufferTile.hide(); } } this.lastRatio = ratio; }, OpenLayers/lib/OpenLayers/Layer.js /** * APIMethod: getResolutionForZoom 根据地图显示级别获取图层当前分辨率 * * Parameter: * zoom - {Float} * * Returns: * {Float} A suitable resolution for the specified zoom. */ getResolutionForZoom: function(zoom) { //B //OpenLayers //zoom = Math.max(0, Math.min(zoom, this.resolutions.length - 1)); //update by huanggp if(this.options.topLevel){ zoom = Math.max(0, Math.min(zoom - this.options.topLevel, this.resolutions.length - 1)); }else{ zoom = Math.max(0, Math.min(zoom, this.resolutions.length - 1)); } var resolution; if(this.map.fractionalZoom) { var low = Math.floor(zoom); var high = Math.ceil(zoom); resolution = this.resolutions[low] -