1364 lines
46 KiB
JavaScript
1364 lines
46 KiB
JavaScript
/* Copyright (c) 2006-2012 by OpenLayers Contributors (see authors.txt for
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* full list of contributors). Published under the 2-clause BSD license.
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* See license.txt in the OpenLayers distribution or repository for the
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* full text of the license. */
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/**
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* @requires OpenLayers/Layer/HTTPRequest.js
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* @requires OpenLayers/Tile/Image.js
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*/
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/**
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* Class: OpenLayers.Layer.Grid
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* Base class for layers that use a lattice of tiles. Create a new grid
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* layer with the <OpenLayers.Layer.Grid> constructor.
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*
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* Inherits from:
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* - <OpenLayers.Layer.HTTPRequest>
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*/
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OpenLayers.Layer.Grid = OpenLayers.Class(OpenLayers.Layer.HTTPRequest, {
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/**
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* APIProperty: tileSize
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* {<OpenLayers.Size>}
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*/
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tileSize: null,
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/**
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* Property: tileOriginCorner
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* {String} If the <tileOrigin> property is not provided, the tile origin
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* will be derived from the layer's <maxExtent>. The corner of the
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* <maxExtent> used is determined by this property. Acceptable values
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* are "tl" (top left), "tr" (top right), "bl" (bottom left), and "br"
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* (bottom right). Default is "bl".
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*/
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tileOriginCorner: "bl",
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/**
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* APIProperty: tileOrigin
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* {<OpenLayers.LonLat>} Optional origin for aligning the grid of tiles.
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* If provided, requests for tiles at all resolutions will be aligned
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* with this location (no tiles shall overlap this location). If
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* not provided, the grid of tiles will be aligned with the layer's
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* <maxExtent>. Default is ``null``.
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*/
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tileOrigin: null,
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/** APIProperty: tileOptions
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* {Object} optional configuration options for <OpenLayers.Tile> instances
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* created by this Layer, if supported by the tile class.
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*/
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tileOptions: null,
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/**
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* APIProperty: tileClass
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* {<OpenLayers.Tile>} The tile class to use for this layer.
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* Defaults is OpenLayers.Tile.Image.
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*/
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tileClass: OpenLayers.Tile.Image,
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/**
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* Property: grid
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* {Array(Array(<OpenLayers.Tile>))} This is an array of rows, each row is
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* an array of tiles.
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*/
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grid: null,
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/**
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* APIProperty: singleTile
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* {Boolean} Moves the layer into single-tile mode, meaning that one tile
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* will be loaded. The tile's size will be determined by the 'ratio'
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* property. When the tile is dragged such that it does not cover the
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* entire viewport, it is reloaded.
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*/
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singleTile: false,
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/** APIProperty: ratio
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* {Float} Used only when in single-tile mode, this specifies the
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* ratio of the size of the single tile to the size of the map.
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*/
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ratio: 1.5,
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/**
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* APIProperty: buffer
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* {Integer} Used only when in gridded mode, this specifies the number of
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* extra rows and colums of tiles on each side which will
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* surround the minimum grid tiles to cover the map.
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* For very slow loading layers, a larger value may increase
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* performance somewhat when dragging, but will increase bandwidth
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* use significantly.
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*/
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buffer: 0,
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/**
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* APIProperty: transitionEffect
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* {String} The transition effect to use when the map is zoomed.
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* Two posible values:
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*
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* null - No transition effect (the default).
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* "resize" - Existing tiles are resized on zoom to provide a visual
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* effect of the zoom having taken place immediately. As the
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* new tiles become available, they are drawn over top of the
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* resized tiles.
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*
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* Using "resize" on non-opaque layers can cause undesired visual
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* effects. This is therefore discouraged.
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*/
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transitionEffect: null,
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/**
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* APIProperty: numLoadingTiles
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* {Integer} How many tiles are still loading?
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*/
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numLoadingTiles: 0,
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/**
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* APIProperty: tileLoadingDelay
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* {Integer} Number of milliseconds before we shift and load
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* tiles when panning. Ignored if <OpenLayers.Animation.isNative> is
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* true. Default is 85.
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*/
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tileLoadingDelay: 85,
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/**
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* Property: serverResolutions
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* {Array(Number}} This property is documented in subclasses as
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* an API property.
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*/
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serverResolutions: null,
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/**
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* Property: moveTimerId
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* {Number} The id of the <deferMoveGriddedTiles> timer.
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*/
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moveTimerId: null,
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/**
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* Property: deferMoveGriddedTiles
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* {Function} A function that defers execution of <moveGriddedTiles> by
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* <tileLoadingDelay>. If <OpenLayers.Animation.isNative> is true, this
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* is null and unused.
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*/
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deferMoveGriddedTiles: null,
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/**
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* Property: tileQueueId
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* {Number} The id of the <drawTileFromQueue> animation.
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*/
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tileQueueId: null,
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/**
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* Property: tileQueue
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* {Array(<OpenLayers.Tile>)} Tiles queued for drawing.
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*/
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tileQueue: null,
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/**
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* Property: loading
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* {Boolean} Indicates if tiles are being loaded.
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*/
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loading: false,
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/**
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* Property: backBuffer
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* {DOMElement} The back buffer.
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*/
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backBuffer: null,
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/**
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* Property: gridResolution
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* {Number} The resolution of the current grid. Used for backbuffering.
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* This property is updated each the grid is initialized.
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*/
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gridResolution: null,
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/**
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* Property: backBufferResolution
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* {Number} The resolution of the current back buffer. This property is
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* updated each time a back buffer is created.
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*/
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backBufferResolution: null,
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/**
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* Property: backBufferLonLat
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* {Object} The top-left corner of the current back buffer. Includes lon
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* and lat properties. This object is updated each time a back buffer
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* is created.
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*/
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backBufferLonLat: null,
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/**
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* Property: backBufferTimerId
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* {Number} The id of the back buffer timer. This timer is used to
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* delay the removal of the back buffer, thereby preventing
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* flash effects caused by tile animation.
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*/
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backBufferTimerId: null,
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/**
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* APIProperty: removeBackBufferDelay
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* {Number} Delay for removing the backbuffer when all tiles have finished
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* loading. Can be set to 0 when no css opacity transitions for the
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* olTileImage class are used. Default is 0 for <singleTile> layers,
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* 2500 for tiled layers. See <className> for more information on
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* tile animation.
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*/
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removeBackBufferDelay: null,
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/**
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* APIProperty: className
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* {String} Name of the class added to the layer div. If not set in the
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* options passed to the constructor then className defaults to
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* "olLayerGridSingleTile" for single tile layers (see <singleTile>),
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* and "olLayerGrid" for non single tile layers.
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*
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* Note:
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*
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* The displaying of tiles is not animated by default for single tile
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* layers - OpenLayers' default theme (style.css) includes this:
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* (code)
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* .olLayerGrid .olTileImage {
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* -webkit-transition: opacity 0.2s linear;
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* -moz-transition: opacity 0.2s linear;
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* -o-transition: opacity 0.2s linear;
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* transition: opacity 0.2s linear;
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* }
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* (end)
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* To animate tile displaying for any grid layer the following
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* CSS rule can be used:
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* (code)
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* .olTileImage {
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* -webkit-transition: opacity 0.2s linear;
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* -moz-transition: opacity 0.2s linear;
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* -o-transition: opacity 0.2s linear;
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* transition: opacity 0.2s linear;
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* }
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* (end)
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* In that case, to avoid flash effects, <removeBackBufferDelay>
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* should not be zero.
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*/
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className: null,
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/**
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* Register a listener for a particular event with the following syntax:
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* (code)
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* layer.events.register(type, obj, listener);
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* (end)
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*
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* Listeners will be called with a reference to an event object. The
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* properties of this event depends on exactly what happened.
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*
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* All event objects have at least the following properties:
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* object - {Object} A reference to layer.events.object.
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* element - {DOMElement} A reference to layer.events.element.
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*
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* Supported event types:
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* tileloadstart - Triggered when a tile starts loading. Listeners receive
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* an object as first argument, which has a tile property that
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* references the tile that starts loading.
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* tileloaded - Triggered when each new tile is
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* loaded, as a means of progress update to listeners.
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* listeners can access 'numLoadingTiles' if they wish to keep
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* track of the loading progress. Listeners are called with an object
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* with a tile property as first argument, making the loded tile
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* available to the listener.
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* tileerror - Triggered before the tileloaded event (i.e. when the tile is
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* still hidden) if a tile failed to load. Listeners receive an object
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* as first argument, which has a tile property that references the
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* tile that could not be loaded.
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*/
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/**
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* Constructor: OpenLayers.Layer.Grid
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* Create a new grid layer
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*
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* Parameters:
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* name - {String}
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* url - {String}
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* params - {Object}
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* options - {Object} Hashtable of extra options to tag onto the layer
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*/
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initialize: function(name, url, params, options) {
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OpenLayers.Layer.HTTPRequest.prototype.initialize.apply(this,
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arguments);
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this.grid = [];
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this.tileQueue = [];
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if (this.removeBackBufferDelay === null) {
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this.removeBackBufferDelay = this.singleTile ? 0 : 2500;
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}
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if (this.className === null) {
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this.className = this.singleTile ? 'olLayerGridSingleTile' :
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'olLayerGrid';
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}
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if (!OpenLayers.Animation.isNative) {
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this.deferMoveGriddedTiles = OpenLayers.Function.bind(function() {
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this.moveGriddedTiles(true);
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this.moveTimerId = null;
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}, this);
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}
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},
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/**
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* Method: setMap
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*
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* Parameters:
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* map - {<OpenLayers.Map>} The map.
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*/
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setMap: function(map) {
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OpenLayers.Layer.HTTPRequest.prototype.setMap.call(this, map);
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OpenLayers.Element.addClass(this.div, this.className);
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},
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/**
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* Method: removeMap
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* Called when the layer is removed from the map.
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*
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* Parameters:
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* map - {<OpenLayers.Map>} The map.
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*/
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removeMap: function(map) {
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if (this.moveTimerId !== null) {
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window.clearTimeout(this.moveTimerId);
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this.moveTimerId = null;
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}
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this.clearTileQueue();
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if(this.backBufferTimerId !== null) {
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window.clearTimeout(this.backBufferTimerId);
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this.backBufferTimerId = null;
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}
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},
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/**
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* APIMethod: destroy
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* Deconstruct the layer and clear the grid.
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*/
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destroy: function() {
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this.removeBackBuffer();
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this.clearGrid();
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this.grid = null;
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this.tileSize = null;
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OpenLayers.Layer.HTTPRequest.prototype.destroy.apply(this, arguments);
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},
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/**
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* Method: clearGrid
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* Go through and remove all tiles from the grid, calling
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* destroy() on each of them to kill circular references
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*/
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clearGrid:function() {
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this.clearTileQueue();
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if (this.grid) {
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for(var iRow=0, len=this.grid.length; iRow<len; iRow++) {
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var row = this.grid[iRow];
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for(var iCol=0, clen=row.length; iCol<clen; iCol++) {
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var tile = row[iCol];
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this.destroyTile(tile);
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}
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}
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this.grid = [];
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this.gridResolution = null;
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}
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},
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/**
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* APIMethod: clone
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* Create a clone of this layer
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*
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* Parameters:
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* obj - {Object} Is this ever used?
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*
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* Returns:
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* {<OpenLayers.Layer.Grid>} An exact clone of this OpenLayers.Layer.Grid
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*/
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clone: function (obj) {
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if (obj == null) {
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obj = new OpenLayers.Layer.Grid(this.name,
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this.url,
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this.params,
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this.getOptions());
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}
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//get all additions from superclasses
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obj = OpenLayers.Layer.HTTPRequest.prototype.clone.apply(this, [obj]);
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// copy/set any non-init, non-simple values here
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if (this.tileSize != null) {
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obj.tileSize = this.tileSize.clone();
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}
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// we do not want to copy reference to grid, so we make a new array
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obj.grid = [];
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obj.gridResolution = null;
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// same for backbuffer and tile queue
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obj.backBuffer = null;
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obj.backBufferTimerId = null;
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obj.tileQueue = [];
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obj.tileQueueId = null;
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obj.loading = false;
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obj.moveTimerId = null;
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return obj;
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},
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/**
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* Method: moveTo
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* This function is called whenever the map is moved. All the moving
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* of actual 'tiles' is done by the map, but moveTo's role is to accept
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* a bounds and make sure the data that that bounds requires is pre-loaded.
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*
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* Parameters:
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* bounds - {<OpenLayers.Bounds>}
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* zoomChanged - {Boolean}
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* dragging - {Boolean}
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*/
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moveTo:function(bounds, zoomChanged, dragging) {
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OpenLayers.Layer.HTTPRequest.prototype.moveTo.apply(this, arguments);
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bounds = bounds || this.map.getExtent();
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if (bounds != null) {
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// if grid is empty or zoom has changed, we *must* re-tile
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var forceReTile = !this.grid.length || zoomChanged;
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// total bounds of the tiles
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var tilesBounds = this.getTilesBounds();
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// the new map resolution
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var resolution = this.map.getResolution();
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// the server-supported resolution for the new map resolution
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var serverResolution = this.getServerResolution(resolution);
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if (this.singleTile) {
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// We want to redraw whenever even the slightest part of the
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// current bounds is not contained by our tile.
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// (thus, we do not specify partial -- its default is false)
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if ( forceReTile ||
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(!dragging && !tilesBounds.containsBounds(bounds))) {
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// In single tile mode with no transition effect, we insert
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// a non-scaled backbuffer when the layer is moved. But if
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// a zoom occurs right after a move, i.e. before the new
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// image is received, we need to remove the backbuffer, or
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// an ill-positioned image will be visible during the zoom
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// transition.
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if(zoomChanged && this.transitionEffect !== 'resize') {
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this.removeBackBuffer();
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}
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if(!zoomChanged || this.transitionEffect === 'resize') {
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this.applyBackBuffer(serverResolution);
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}
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this.initSingleTile(bounds);
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}
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} else {
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// if the bounds have changed such that they are not even
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// *partially* contained by our tiles (e.g. when user has
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// programmatically panned to the other side of the earth on
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// zoom level 18), then moveGriddedTiles could potentially have
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// to run through thousands of cycles, so we want to reTile
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// instead (thus, partial true).
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forceReTile = forceReTile ||
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!tilesBounds.intersectsBounds(bounds, {
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worldBounds: this.map.baseLayer.wrapDateLine &&
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this.map.getMaxExtent()
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});
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if(resolution !== serverResolution) {
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bounds = this.map.calculateBounds(null, serverResolution);
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if(forceReTile) {
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// stretch the layer div
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var scale = serverResolution / resolution;
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this.transformDiv(scale);
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}
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} else {
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// reset the layer width, height, left, top, to deal with
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// the case where the layer was previously transformed
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this.div.style.width = '100%';
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this.div.style.height = '100%';
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this.div.style.left = '0%';
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this.div.style.top = '0%';
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}
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if(forceReTile) {
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if(zoomChanged && this.transitionEffect === 'resize') {
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this.applyBackBuffer(serverResolution);
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}
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this.initGriddedTiles(bounds);
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} else {
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this.moveGriddedTiles();
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}
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}
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}
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},
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/**
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* Method: getTileData
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* Given a map location, retrieve a tile and the pixel offset within that
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* tile corresponding to the location. If there is not an existing
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* tile in the grid that covers the given location, null will be
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* returned.
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*
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* Parameters:
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* loc - {<OpenLayers.LonLat>} map location
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*
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* Returns:
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* {Object} Object with the following properties: tile ({<OpenLayers.Tile>}),
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* i ({Number} x-pixel offset from top left), and j ({Integer} y-pixel
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* offset from top left).
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*/
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getTileData: function(loc) {
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var data = null,
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x = loc.lon,
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y = loc.lat,
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numRows = this.grid.length;
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if (this.map && numRows) {
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var res = this.map.getResolution(),
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tileWidth = this.tileSize.w,
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tileHeight = this.tileSize.h,
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bounds = this.grid[0][0].bounds,
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left = bounds.left,
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top = bounds.top;
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if (x < left) {
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// deal with multiple worlds
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if (this.map.baseLayer.wrapDateLine) {
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var worldWidth = this.map.getMaxExtent().getWidth();
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var worldsAway = Math.ceil((left - x) / worldWidth);
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x += worldWidth * worldsAway;
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}
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}
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// tile distance to location (fractional number of tiles);
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var dtx = (x - left) / (res * tileWidth);
|
|
var dty = (top - y) / (res * tileHeight);
|
|
// index of tile in grid
|
|
var col = Math.floor(dtx);
|
|
var row = Math.floor(dty);
|
|
if (row >= 0 && row < numRows) {
|
|
var tile = this.grid[row][col];
|
|
if (tile) {
|
|
data = {
|
|
tile: tile,
|
|
// pixel index within tile
|
|
i: Math.floor((dtx - col) * tileWidth),
|
|
j: Math.floor((dty - row) * tileHeight)
|
|
};
|
|
}
|
|
}
|
|
}
|
|
return data;
|
|
},
|
|
|
|
/**
|
|
* Method: queueTileDraw
|
|
* Adds a tile to the animation queue that will draw it.
|
|
*
|
|
* Parameters:
|
|
* evt - {Object} Listener argument of the tile's beforedraw event
|
|
*/
|
|
queueTileDraw: function(evt) {
|
|
var tile = evt.object;
|
|
if (!~OpenLayers.Util.indexOf(this.tileQueue, tile)) {
|
|
// queue only if not in queue already
|
|
this.tileQueue.push(tile);
|
|
}
|
|
if (!this.tileQueueId) {
|
|
this.tileQueueId = OpenLayers.Animation.start(
|
|
OpenLayers.Function.bind(this.drawTileFromQueue, this),
|
|
null, this.div
|
|
);
|
|
}
|
|
return false;
|
|
},
|
|
|
|
/**
|
|
* Method: drawTileFromQueue
|
|
* Draws the first tile from the tileQueue, and unqueues that tile
|
|
*/
|
|
drawTileFromQueue: function() {
|
|
if (this.tileQueue.length === 0) {
|
|
this.clearTileQueue();
|
|
} else {
|
|
this.tileQueue.shift().draw(true);
|
|
}
|
|
},
|
|
|
|
/**
|
|
* Method: clearTileQueue
|
|
* Clears the animation queue
|
|
*/
|
|
clearTileQueue: function() {
|
|
OpenLayers.Animation.stop(this.tileQueueId);
|
|
this.tileQueueId = null;
|
|
this.tileQueue = [];
|
|
},
|
|
|
|
/**
|
|
* Method: destroyTile
|
|
*
|
|
* Parameters:
|
|
* tile - {<OpenLayers.Tile>}
|
|
*/
|
|
destroyTile: function(tile) {
|
|
this.removeTileMonitoringHooks(tile);
|
|
tile.destroy();
|
|
},
|
|
|
|
/**
|
|
* Method: getServerResolution
|
|
* Return the closest highest server-supported resolution. Throw an
|
|
* exception if none is found in the serverResolutions array.
|
|
*
|
|
* Parameters:
|
|
* resolution - {Number} The base resolution. If undefined the
|
|
* map resolution is used.
|
|
*
|
|
* Returns:
|
|
* {Number} The closest highest server resolution value.
|
|
*/
|
|
getServerResolution: function(resolution) {
|
|
resolution = resolution || this.map.getResolution();
|
|
if(this.serverResolutions &&
|
|
OpenLayers.Util.indexOf(this.serverResolutions, resolution) === -1) {
|
|
var i, serverResolution;
|
|
for(i=this.serverResolutions.length-1; i>= 0; i--) {
|
|
serverResolution = this.serverResolutions[i];
|
|
if(serverResolution > resolution) {
|
|
resolution = serverResolution;
|
|
break;
|
|
}
|
|
}
|
|
if(i === -1) {
|
|
throw 'no appropriate resolution in serverResolutions';
|
|
}
|
|
}
|
|
return resolution;
|
|
},
|
|
|
|
/**
|
|
* Method: getServerZoom
|
|
* Return the zoom value corresponding to the best zoom supported by the server
|
|
* resolution.
|
|
*
|
|
* Returns:
|
|
* {Number} The closest server supported zoom.
|
|
*/
|
|
getServerZoom: function() {
|
|
return this.map.getZoomForResolution(this.getServerResolution());
|
|
},
|
|
|
|
/**
|
|
* Method: transformDiv
|
|
* Transform the layer div.
|
|
*
|
|
* Parameters:
|
|
* scale - {Number} The value by which the layer div is to
|
|
* be scaled.
|
|
*/
|
|
transformDiv: function(scale) {
|
|
|
|
// scale the layer div
|
|
|
|
this.div.style.width = 100 * scale + '%';
|
|
this.div.style.height = 100 * scale + '%';
|
|
|
|
// and translate the layer div as necessary
|
|
|
|
var size = this.map.getSize();
|
|
var lcX = parseInt(this.map.layerContainerDiv.style.left, 10);
|
|
var lcY = parseInt(this.map.layerContainerDiv.style.top, 10);
|
|
var x = (lcX - (size.w / 2.0)) * (scale - 1);
|
|
var y = (lcY - (size.h / 2.0)) * (scale - 1);
|
|
|
|
this.div.style.left = x + '%';
|
|
this.div.style.top = y + '%';
|
|
},
|
|
|
|
/**
|
|
* Method: getResolutionScale
|
|
* Return the value by which the layer is currently scaled.
|
|
*
|
|
* Returns:
|
|
* {Number} The resolution scale.
|
|
*/
|
|
getResolutionScale: function() {
|
|
return parseInt(this.div.style.width, 10) / 100;
|
|
},
|
|
|
|
/**
|
|
* Method: applyBackBuffer
|
|
* Create, insert, scale and position a back buffer for the layer.
|
|
*
|
|
* Parameters:
|
|
* resolution - {Number} The resolution to transition to.
|
|
*/
|
|
applyBackBuffer: function(resolution) {
|
|
if(this.backBufferTimerId !== null) {
|
|
this.removeBackBuffer();
|
|
}
|
|
var backBuffer = this.backBuffer;
|
|
if(!backBuffer) {
|
|
backBuffer = this.createBackBuffer();
|
|
if(!backBuffer) {
|
|
return;
|
|
}
|
|
this.div.insertBefore(backBuffer, this.div.firstChild);
|
|
this.backBuffer = backBuffer;
|
|
|
|
// set some information in the instance for subsequent
|
|
// calls to applyBackBuffer where the same back buffer
|
|
// is reused
|
|
var topLeftTileBounds = this.grid[0][0].bounds;
|
|
this.backBufferLonLat = {
|
|
lon: topLeftTileBounds.left,
|
|
lat: topLeftTileBounds.top
|
|
};
|
|
this.backBufferResolution = this.gridResolution;
|
|
}
|
|
|
|
var style = backBuffer.style;
|
|
|
|
// scale the back buffer
|
|
var ratio = this.backBufferResolution / resolution;
|
|
style.width = 100 * ratio + '%';
|
|
style.height = 100 * ratio + '%';
|
|
|
|
// and position it (based on the grid's top-left corner)
|
|
var position = this.getViewPortPxFromLonLat(
|
|
this.backBufferLonLat, resolution);
|
|
var leftOffset = parseInt(this.map.layerContainerDiv.style.left, 10);
|
|
var topOffset = parseInt(this.map.layerContainerDiv.style.top, 10);
|
|
backBuffer.style.left = Math.round(position.x - leftOffset) + '%';
|
|
backBuffer.style.top = Math.round(position.y - topOffset) + '%';
|
|
},
|
|
|
|
/**
|
|
* Method: createBackBuffer
|
|
* Create a back buffer.
|
|
*
|
|
* Returns:
|
|
* {DOMElement} The DOM element for the back buffer, undefined if the
|
|
* grid isn't initialized yet.
|
|
*/
|
|
createBackBuffer: function() {
|
|
var backBuffer;
|
|
if(this.grid.length > 0) {
|
|
backBuffer = document.createElement('div');
|
|
backBuffer.id = this.div.id + '_bb';
|
|
backBuffer.className = 'olBackBuffer';
|
|
backBuffer.style.position = 'absolute';
|
|
backBuffer.style.width = '100%';
|
|
backBuffer.style.height = '100%';
|
|
for(var i=0, lenI=this.grid.length; i<lenI; i++) {
|
|
for(var j=0, lenJ=this.grid[i].length; j<lenJ; j++) {
|
|
var tile = this.grid[i][j].createBackBuffer();
|
|
if(!tile) {
|
|
continue;
|
|
}
|
|
// to be able to correctly position the back buffer we
|
|
// place the tiles grid at (0, 0) in the back buffer
|
|
tile.style.top = (i * this.tileSize.h) + '%';
|
|
tile.style.left = (j * this.tileSize.w) + '%';
|
|
backBuffer.appendChild(tile);
|
|
}
|
|
}
|
|
}
|
|
return backBuffer;
|
|
},
|
|
|
|
/**
|
|
* Method: removeBackBuffer
|
|
* Remove back buffer from DOM.
|
|
*/
|
|
removeBackBuffer: function() {
|
|
if(this.backBuffer) {
|
|
this.div.removeChild(this.backBuffer);
|
|
this.backBuffer = null;
|
|
this.backBufferResolution = null;
|
|
if(this.backBufferTimerId !== null) {
|
|
window.clearTimeout(this.backBufferTimerId);
|
|
this.backBufferTimerId = null;
|
|
}
|
|
}
|
|
},
|
|
|
|
/**
|
|
* Method: moveByPx
|
|
* Move the layer based on pixel vector.
|
|
*
|
|
* Parameters:
|
|
* dx - {Number}
|
|
* dy - {Number}
|
|
*/
|
|
moveByPx: function(dx, dy) {
|
|
if (!this.singleTile) {
|
|
this.moveGriddedTiles();
|
|
}
|
|
},
|
|
|
|
/**
|
|
* APIMethod: setTileSize
|
|
* Check if we are in singleTile mode and if so, set the size as a ratio
|
|
* of the map size (as specified by the layer's 'ratio' property).
|
|
*
|
|
* Parameters:
|
|
* size - {<OpenLayers.Size>}
|
|
*/
|
|
setTileSize: function(size) {
|
|
if (this.singleTile) {
|
|
size = this.map.getSize();
|
|
size.h = parseInt(size.h * this.ratio);
|
|
size.w = parseInt(size.w * this.ratio);
|
|
}
|
|
OpenLayers.Layer.HTTPRequest.prototype.setTileSize.apply(this, [size]);
|
|
},
|
|
|
|
/**
|
|
* APIMethod: getTilesBounds
|
|
* Return the bounds of the tile grid.
|
|
*
|
|
* Returns:
|
|
* {<OpenLayers.Bounds>} A Bounds object representing the bounds of all the
|
|
* currently loaded tiles (including those partially or not at all seen
|
|
* onscreen).
|
|
*/
|
|
getTilesBounds: function() {
|
|
var bounds = null;
|
|
|
|
var length = this.grid.length;
|
|
if (length) {
|
|
var bottomLeftTileBounds = this.grid[length - 1][0].bounds,
|
|
width = this.grid[0].length * bottomLeftTileBounds.getWidth(),
|
|
height = this.grid.length * bottomLeftTileBounds.getHeight();
|
|
|
|
bounds = new OpenLayers.Bounds(bottomLeftTileBounds.left,
|
|
bottomLeftTileBounds.bottom,
|
|
bottomLeftTileBounds.left + width,
|
|
bottomLeftTileBounds.bottom + height);
|
|
}
|
|
return bounds;
|
|
},
|
|
|
|
/**
|
|
* Method: initSingleTile
|
|
*
|
|
* Parameters:
|
|
* bounds - {<OpenLayers.Bounds>}
|
|
*/
|
|
initSingleTile: function(bounds) {
|
|
this.clearTileQueue();
|
|
|
|
//determine new tile bounds
|
|
var center = bounds.getCenterLonLat();
|
|
var tileWidth = bounds.getWidth() * this.ratio;
|
|
var tileHeight = bounds.getHeight() * this.ratio;
|
|
|
|
var tileBounds =
|
|
new OpenLayers.Bounds(center.lon - (tileWidth/2),
|
|
center.lat - (tileHeight/2),
|
|
center.lon + (tileWidth/2),
|
|
center.lat + (tileHeight/2));
|
|
|
|
var px = this.map.getLayerPxFromLonLat({
|
|
lon: tileBounds.left,
|
|
lat: tileBounds.top
|
|
});
|
|
|
|
if (!this.grid.length) {
|
|
this.grid[0] = [];
|
|
}
|
|
|
|
var tile = this.grid[0][0];
|
|
if (!tile) {
|
|
tile = this.addTile(tileBounds, px);
|
|
|
|
this.addTileMonitoringHooks(tile);
|
|
tile.draw();
|
|
this.grid[0][0] = tile;
|
|
} else {
|
|
tile.moveTo(tileBounds, px);
|
|
}
|
|
|
|
//remove all but our single tile
|
|
this.removeExcessTiles(1,1);
|
|
|
|
// store the resolution of the grid
|
|
this.gridResolution = this.getServerResolution();
|
|
},
|
|
|
|
/**
|
|
* Method: calculateGridLayout
|
|
* Generate parameters for the grid layout.
|
|
*
|
|
* Parameters:
|
|
* bounds - {<OpenLayers.Bound>|Object} OpenLayers.Bounds or an
|
|
* object with a 'left' and 'top' properties.
|
|
* origin - {<OpenLayers.LonLat>|Object} OpenLayers.LonLat or an
|
|
* object with a 'lon' and 'lat' properties.
|
|
* resolution - {Number}
|
|
*
|
|
* Returns:
|
|
* {Object} containing properties tilelon, tilelat, tileoffsetlat,
|
|
* tileoffsetlat, tileoffsetx, tileoffsety
|
|
*/
|
|
calculateGridLayout: function(bounds, origin, resolution) {
|
|
var tilelon = resolution * this.tileSize.w;
|
|
var tilelat = resolution * this.tileSize.h;
|
|
|
|
var offsetlon = bounds.left - origin.lon;
|
|
var tilecol = Math.floor(offsetlon/tilelon) - this.buffer;
|
|
var tilecolremain = offsetlon/tilelon - tilecol;
|
|
var tileoffsetx = -tilecolremain * this.tileSize.w;
|
|
var tileoffsetlon = origin.lon + tilecol * tilelon;
|
|
|
|
var offsetlat = bounds.top - (origin.lat + tilelat);
|
|
var tilerow = Math.ceil(offsetlat/tilelat) + this.buffer;
|
|
var tilerowremain = tilerow - offsetlat/tilelat;
|
|
var tileoffsety = -tilerowremain * this.tileSize.h;
|
|
var tileoffsetlat = origin.lat + tilerow * tilelat;
|
|
|
|
return {
|
|
tilelon: tilelon, tilelat: tilelat,
|
|
tileoffsetlon: tileoffsetlon, tileoffsetlat: tileoffsetlat,
|
|
tileoffsetx: tileoffsetx, tileoffsety: tileoffsety
|
|
};
|
|
|
|
},
|
|
|
|
/**
|
|
* Method: getTileOrigin
|
|
* Determine the origin for aligning the grid of tiles. If a <tileOrigin>
|
|
* property is supplied, that will be returned. Otherwise, the origin
|
|
* will be derived from the layer's <maxExtent> property. In this case,
|
|
* the tile origin will be the corner of the <maxExtent> given by the
|
|
* <tileOriginCorner> property.
|
|
*
|
|
* Returns:
|
|
* {<OpenLayers.LonLat>} The tile origin.
|
|
*/
|
|
getTileOrigin: function() {
|
|
var origin = this.tileOrigin;
|
|
if (!origin) {
|
|
var extent = this.getMaxExtent();
|
|
var edges = ({
|
|
"tl": ["left", "top"],
|
|
"tr": ["right", "top"],
|
|
"bl": ["left", "bottom"],
|
|
"br": ["right", "bottom"]
|
|
})[this.tileOriginCorner];
|
|
origin = new OpenLayers.LonLat(extent[edges[0]], extent[edges[1]]);
|
|
}
|
|
return origin;
|
|
},
|
|
|
|
/**
|
|
* Method: initGriddedTiles
|
|
*
|
|
* Parameters:
|
|
* bounds - {<OpenLayers.Bounds>}
|
|
*/
|
|
initGriddedTiles:function(bounds) {
|
|
this.clearTileQueue();
|
|
|
|
// work out mininum number of rows and columns; this is the number of
|
|
// tiles required to cover the viewport plus at least one for panning
|
|
|
|
var viewSize = this.map.getSize();
|
|
var minRows = Math.ceil(viewSize.h/this.tileSize.h) +
|
|
Math.max(1, 2 * this.buffer);
|
|
var minCols = Math.ceil(viewSize.w/this.tileSize.w) +
|
|
Math.max(1, 2 * this.buffer);
|
|
|
|
var origin = this.getTileOrigin();
|
|
var resolution = this.getServerResolution();
|
|
|
|
var tileLayout = this.calculateGridLayout(bounds, origin, resolution);
|
|
|
|
var tileoffsetx = Math.round(tileLayout.tileoffsetx); // heaven help us
|
|
var tileoffsety = Math.round(tileLayout.tileoffsety);
|
|
|
|
var tileoffsetlon = tileLayout.tileoffsetlon;
|
|
var tileoffsetlat = tileLayout.tileoffsetlat;
|
|
|
|
var tilelon = tileLayout.tilelon;
|
|
var tilelat = tileLayout.tilelat;
|
|
|
|
var startX = tileoffsetx;
|
|
var startLon = tileoffsetlon;
|
|
|
|
var rowidx = 0;
|
|
|
|
var layerContainerDivLeft = parseInt(this.map.layerContainerDiv.style.left);
|
|
var layerContainerDivTop = parseInt(this.map.layerContainerDiv.style.top);
|
|
|
|
var tileData = [], center = this.map.getCenter();
|
|
do {
|
|
var row = this.grid[rowidx++];
|
|
if (!row) {
|
|
row = [];
|
|
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 -= layerContainerDivLeft;
|
|
|
|
var y = tileoffsety;
|
|
y -= layerContainerDivTop;
|
|
|
|
var px = new OpenLayers.Pixel(x, y);
|
|
var tile = row[colidx++];
|
|
if (!tile) {
|
|
tile = this.addTile(tileBounds, px);
|
|
this.addTileMonitoringHooks(tile);
|
|
row.push(tile);
|
|
} else {
|
|
tile.moveTo(tileBounds, px, false);
|
|
}
|
|
var tileCenter = tileBounds.getCenterLonLat();
|
|
tileData.push({
|
|
tile: tile,
|
|
distance: Math.pow(tileCenter.lon - center.lon, 2) +
|
|
Math.pow(tileCenter.lat - center.lat, 2)
|
|
});
|
|
|
|
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);
|
|
|
|
//shave off exceess rows and colums
|
|
this.removeExcessTiles(rowidx, colidx);
|
|
|
|
// store the resolution of the grid
|
|
this.gridResolution = this.getServerResolution();
|
|
|
|
//now actually draw the tiles
|
|
tileData.sort(function(a, b) {
|
|
return a.distance - b.distance;
|
|
});
|
|
for (var i=0, ii=tileData.length; i<ii; ++i) {
|
|
tileData[i].tile.draw();
|
|
}
|
|
},
|
|
|
|
/**
|
|
* Method: getMaxExtent
|
|
* Get this layer's maximum extent. (Implemented as a getter for
|
|
* potential specific implementations in sub-classes.)
|
|
*
|
|
* Returns:
|
|
* {<OpenLayers.Bounds>}
|
|
*/
|
|
getMaxExtent: function() {
|
|
return this.maxExtent;
|
|
},
|
|
|
|
/**
|
|
* APIMethod: addTile
|
|
* Create a tile, initialize it, and add it to the layer div.
|
|
*
|
|
* Parameters
|
|
* bounds - {<OpenLayers.Bounds>}
|
|
* position - {<OpenLayers.Pixel>}
|
|
*
|
|
* Returns:
|
|
* {<OpenLayers.Tile>} The added OpenLayers.Tile
|
|
*/
|
|
addTile: function(bounds, position) {
|
|
var tile = new this.tileClass(
|
|
this, position, bounds, null, this.tileSize, this.tileOptions
|
|
);
|
|
tile.events.register("beforedraw", this, this.queueTileDraw);
|
|
return tile;
|
|
},
|
|
|
|
/**
|
|
* Method: addTileMonitoringHooks
|
|
* This function takes a tile as input and adds the appropriate hooks to
|
|
* the tile so that the layer can keep track of the loading tiles.
|
|
*
|
|
* Parameters:
|
|
* tile - {<OpenLayers.Tile>}
|
|
*/
|
|
addTileMonitoringHooks: function(tile) {
|
|
|
|
tile.onLoadStart = function() {
|
|
//if that was first tile then trigger a 'loadstart' on the layer
|
|
if (this.loading === false) {
|
|
this.loading = true;
|
|
this.events.triggerEvent("loadstart");
|
|
}
|
|
this.events.triggerEvent("tileloadstart", {tile: tile});
|
|
this.numLoadingTiles++;
|
|
};
|
|
|
|
tile.onLoadEnd = function() {
|
|
this.numLoadingTiles--;
|
|
this.events.triggerEvent("tileloaded", {tile: tile});
|
|
//if that was the last tile, then trigger a 'loadend' on the layer
|
|
if (this.tileQueue.length === 0 && this.numLoadingTiles === 0) {
|
|
this.loading = false;
|
|
this.events.triggerEvent("loadend");
|
|
if(this.backBuffer) {
|
|
// the removal of the back buffer is delayed to prevent flash
|
|
// effects due to the animation of tile displaying
|
|
this.backBufferTimerId = window.setTimeout(
|
|
OpenLayers.Function.bind(this.removeBackBuffer, this),
|
|
this.removeBackBufferDelay
|
|
);
|
|
}
|
|
}
|
|
};
|
|
|
|
tile.onLoadError = function() {
|
|
this.events.triggerEvent("tileerror", {tile: tile});
|
|
};
|
|
|
|
tile.events.on({
|
|
"loadstart": tile.onLoadStart,
|
|
"loadend": tile.onLoadEnd,
|
|
"unload": tile.onLoadEnd,
|
|
"loaderror": tile.onLoadError,
|
|
scope: this
|
|
});
|
|
},
|
|
|
|
/**
|
|
* Method: removeTileMonitoringHooks
|
|
* This function takes a tile as input and removes the tile hooks
|
|
* that were added in addTileMonitoringHooks()
|
|
*
|
|
* Parameters:
|
|
* tile - {<OpenLayers.Tile>}
|
|
*/
|
|
removeTileMonitoringHooks: function(tile) {
|
|
tile.unload();
|
|
tile.events.un({
|
|
"loadstart": tile.onLoadStart,
|
|
"loadend": tile.onLoadEnd,
|
|
"unload": tile.onLoadEnd,
|
|
"loaderror": tile.onLoadError,
|
|
scope: this
|
|
});
|
|
},
|
|
|
|
/**
|
|
* Method: moveGriddedTiles
|
|
*
|
|
* Parameter:
|
|
* deferred - {Boolean} true if this is a deferred call that should not
|
|
* be delayed.
|
|
*/
|
|
moveGriddedTiles: function(deferred) {
|
|
if (!deferred && !OpenLayers.Animation.isNative) {
|
|
if (this.moveTimerId != null) {
|
|
window.clearTimeout(this.moveTimerId);
|
|
}
|
|
this.moveTimerId = window.setTimeout(
|
|
this.deferMoveGriddedTiles, this.tileLoadingDelay
|
|
);
|
|
return;
|
|
}
|
|
var buffer = this.buffer || 1;
|
|
var scale = this.getResolutionScale();
|
|
while(true) {
|
|
var tlViewPort = {
|
|
x: (this.grid[0][0].position.x * scale) +
|
|
parseInt(this.div.style.left, 10) +
|
|
parseInt(this.map.layerContainerDiv.style.left),
|
|
y: (this.grid[0][0].position.y * scale) +
|
|
parseInt(this.div.style.top, 10) +
|
|
parseInt(this.map.layerContainerDiv.style.top)
|
|
};
|
|
var tileSize = {
|
|
w: this.tileSize.w * scale,
|
|
h: this.tileSize.h * scale
|
|
};
|
|
if (tlViewPort.x > -tileSize.w * (buffer - 1)) {
|
|
this.shiftColumn(true);
|
|
} else if (tlViewPort.x < -tileSize.w * buffer) {
|
|
this.shiftColumn(false);
|
|
} else if (tlViewPort.y > -tileSize.h * (buffer - 1)) {
|
|
this.shiftRow(true);
|
|
} else if (tlViewPort.y < -tileSize.h * buffer) {
|
|
this.shiftRow(false);
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
},
|
|
|
|
/**
|
|
* Method: shiftRow
|
|
* Shifty grid work
|
|
*
|
|
* Parameters:
|
|
* prepend - {Boolean} if true, prepend to beginning.
|
|
* if false, then append to end
|
|
*/
|
|
shiftRow:function(prepend) {
|
|
var modelRowIndex = (prepend) ? 0 : (this.grid.length - 1);
|
|
var grid = this.grid;
|
|
var modelRow = grid[modelRowIndex];
|
|
|
|
var resolution = this.getServerResolution();
|
|
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);
|
|
}
|
|
},
|
|
|
|
/**
|
|
* Method: shiftColumn
|
|
* Shift grid work in the other dimension
|
|
*
|
|
* Parameters:
|
|
* prepend - {Boolean} 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.getServerResolution();
|
|
var deltaLon = resolution * deltaX;
|
|
|
|
for (var i=0, len=this.grid.length; i<len; 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) {
|
|
row.unshift(tile);
|
|
} else {
|
|
row.push(tile);
|
|
}
|
|
}
|
|
},
|
|
|
|
/**
|
|
* Method: removeExcessTiles
|
|
* When the size of the map or the buffer changes, we may need to
|
|
* remove some excess rows and columns.
|
|
*
|
|
* Parameters:
|
|
* rows - {Integer} Maximum number of rows we want our grid to have.
|
|
* columns - {Integer} Maximum number of columns we want our grid to have.
|
|
*/
|
|
removeExcessTiles: function(rows, columns) {
|
|
|
|
// remove extra rows
|
|
while (this.grid.length > rows) {
|
|
var row = this.grid.pop();
|
|
for (var i=0, l=row.length; i<l; i++) {
|
|
var tile = row[i];
|
|
this.destroyTile(tile);
|
|
}
|
|
}
|
|
|
|
// remove extra columns
|
|
while (this.grid[0].length > columns) {
|
|
for (var i=0, l=this.grid.length; i<l; i++) {
|
|
var row = this.grid[i];
|
|
var tile = row.pop();
|
|
this.destroyTile(tile);
|
|
}
|
|
}
|
|
},
|
|
|
|
/**
|
|
* Method: onMapResize
|
|
* For singleTile layers, this will set a new tile size according to the
|
|
* dimensions of the map pane.
|
|
*/
|
|
onMapResize: function() {
|
|
if (this.singleTile) {
|
|
this.clearGrid();
|
|
this.setTileSize();
|
|
}
|
|
},
|
|
|
|
/**
|
|
* APIMethod: getTileBounds
|
|
* Returns The tile bounds for a layer given a pixel location.
|
|
*
|
|
* Parameters:
|
|
* viewPortPx - {<OpenLayers.Pixel>} The location in the viewport.
|
|
*
|
|
* Returns:
|
|
* {<OpenLayers.Bounds>} Bounds of the tile at the given pixel location.
|
|
*/
|
|
getTileBounds: function(viewPortPx) {
|
|
var maxExtent = this.maxExtent;
|
|
var resolution = this.getResolution();
|
|
var tileMapWidth = resolution * this.tileSize.w;
|
|
var tileMapHeight = resolution * this.tileSize.h;
|
|
var mapPoint = this.getLonLatFromViewPortPx(viewPortPx);
|
|
var tileLeft = maxExtent.left + (tileMapWidth *
|
|
Math.floor((mapPoint.lon -
|
|
maxExtent.left) /
|
|
tileMapWidth));
|
|
var tileBottom = maxExtent.bottom + (tileMapHeight *
|
|
Math.floor((mapPoint.lat -
|
|
maxExtent.bottom) /
|
|
tileMapHeight));
|
|
return new OpenLayers.Bounds(tileLeft, tileBottom,
|
|
tileLeft + tileMapWidth,
|
|
tileBottom + tileMapHeight);
|
|
},
|
|
|
|
CLASS_NAME: "OpenLayers.Layer.Grid"
|
|
});
|