1392 lines
47 KiB
JavaScript
1392 lines
47 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 backbuffer and
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* client zoom. This property is updated every time the grid is
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* 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 loaded tile
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* available to the listener, and an 'aborted' property, which will be
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* true when loading was aborted and no tile data is available.
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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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* Property: gridLayout
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* {Object} Object containing properties tilelon, tilelat, startcol,
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* startrow
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*/
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gridLayout: null,
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/**
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* Property: rowSign
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* {Number} 1 for grids starting at the top, -1 for grids starting at the
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* bottom. This is used for several grid index and offset calculations.
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*/
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rowSign: null,
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/**
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* Property: transitionendEvents
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* {Array} Event names for transitionend
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*/
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transitionendEvents: [
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'transitionend', 'webkitTransitionEnd', 'otransitionend',
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'oTransitionEnd'
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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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this._removeBackBuffer = OpenLayers.Function.bind(this.removeBackBuffer, this);
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this.initProperties();
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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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this.rowSign = this.tileOriginCorner.substr(0, 1) === "t" ? 1 : -1;
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},
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/**
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* Method: initProperties
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* Set any properties that depend on the value of singleTile.
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* Currently sets removeBackBufferDelay and className
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*/
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initProperties: function() {
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if (this.options.removeBackBufferDelay === undefined) {
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this.removeBackBufferDelay = this.singleTile ? 0 : 2500;
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}
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if (this.options.className === undefined) {
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this.className = this.singleTile ? 'olLayerGridSingleTile' :
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'olLayerGrid';
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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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this.gridLayout = null;
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}
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},
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/**
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* APIMethod: addOptions
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*
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* Parameters:
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* newOptions - {Object}
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* reinitialize - {Boolean} If set to true, and if resolution options of the
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* current baseLayer were changed, the map will be recentered to make
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* sure that it is displayed with a valid resolution, and a
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* changebaselayer event will be triggered.
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*/
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addOptions: function (newOptions, reinitialize) {
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var singleTileChanged = newOptions.singleTile !== undefined &&
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newOptions.singleTile !== this.singleTile;
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OpenLayers.Layer.HTTPRequest.prototype.addOptions.apply(this, arguments);
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if (this.map && singleTileChanged) {
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this.initProperties();
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this.clearGrid();
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this.tileSize = this.options.tileSize;
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this.setTileSize();
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this.moveTo(null, true);
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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(resolution);
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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(forceReTile) {
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if(zoomChanged && this.transitionEffect === 'resize') {
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this.applyBackBuffer(resolution);
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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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}
|
|
},
|
|
|
|
/**
|
|
* Method: getTileData
|
|
* Given a map location, retrieve a tile and the pixel offset within that
|
|
* tile corresponding to the location. If there is not an existing
|
|
* tile in the grid that covers the given location, null will be
|
|
* returned.
|
|
*
|
|
* Parameters:
|
|
* loc - {<OpenLayers.LonLat>} map location
|
|
*
|
|
* Returns:
|
|
* {Object} Object with the following properties: tile ({<OpenLayers.Tile>}),
|
|
* i ({Number} x-pixel offset from top left), and j ({Integer} y-pixel
|
|
* offset from top left).
|
|
*/
|
|
getTileData: function(loc) {
|
|
var data = null,
|
|
x = loc.lon,
|
|
y = loc.lat,
|
|
numRows = this.grid.length;
|
|
|
|
if (this.map && numRows) {
|
|
var res = this.map.getResolution(),
|
|
tileWidth = this.tileSize.w,
|
|
tileHeight = this.tileSize.h,
|
|
bounds = this.grid[0][0].bounds,
|
|
left = bounds.left,
|
|
top = bounds.top;
|
|
|
|
if (x < left) {
|
|
// deal with multiple worlds
|
|
if (this.map.baseLayer.wrapDateLine) {
|
|
var worldWidth = this.map.getMaxExtent().getWidth();
|
|
var worldsAway = Math.ceil((left - x) / worldWidth);
|
|
x += worldWidth * worldsAway;
|
|
}
|
|
}
|
|
// tile distance to location (fractional number of tiles);
|
|
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 server-supported resolution.
|
|
*
|
|
* Parameters:
|
|
* resolution - {Number} The base resolution. If undefined the
|
|
* map resolution is used.
|
|
*
|
|
* Returns:
|
|
* {Number} The closest server resolution value.
|
|
*/
|
|
getServerResolution: function(resolution) {
|
|
var distance = Number.POSITIVE_INFINITY;
|
|
resolution = resolution || this.map.getResolution();
|
|
if(this.serverResolutions &&
|
|
OpenLayers.Util.indexOf(this.serverResolutions, resolution) === -1) {
|
|
var i, newDistance, newResolution, serverResolution;
|
|
for(i=this.serverResolutions.length-1; i>= 0; i--) {
|
|
newResolution = this.serverResolutions[i];
|
|
newDistance = Math.abs(newResolution - resolution);
|
|
if (newDistance > distance) {
|
|
break;
|
|
}
|
|
distance = newDistance;
|
|
serverResolution = newResolution;
|
|
}
|
|
resolution = serverResolution;
|
|
}
|
|
return resolution;
|
|
},
|
|
|
|
/**
|
|
* Method: getServerZoom
|
|
* Return the zoom value corresponding to the best matching server
|
|
* resolution, taking into account <serverResolutions> and <zoomOffset>.
|
|
*
|
|
* Returns:
|
|
* {Number} The closest server supported zoom. This is not the map zoom
|
|
* level, but an index of the server's resolutions array.
|
|
*/
|
|
getServerZoom: function() {
|
|
var resolution = this.getServerResolution();
|
|
return this.serverResolutions ?
|
|
OpenLayers.Util.indexOf(this.serverResolutions, resolution) :
|
|
this.map.getZoomForResolution(resolution) + (this.zoomOffset || 0);
|
|
},
|
|
|
|
/**
|
|
* 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 ratio = this.backBufferResolution / resolution;
|
|
|
|
// scale the tiles inside the back buffer
|
|
var tiles = backBuffer.childNodes, tile;
|
|
for (var i=tiles.length-1; i>=0; --i) {
|
|
tile = tiles[i];
|
|
tile.style.top = ((ratio * tile._i * tile._h) | 0) + 'px';
|
|
tile.style.left = ((ratio * tile._j * tile._w) | 0) + 'px';
|
|
tile.style.width = Math.round(ratio * tile._w) + 'px';
|
|
tile.style.height = Math.round(ratio * tile._h) + 'px';
|
|
}
|
|
|
|
// and position it (based on the grid's top-left corner)
|
|
var position = this.getViewPortPxFromLonLat(
|
|
this.backBufferLonLat, resolution);
|
|
var leftOffset = this.map.layerContainerOriginPx.x;
|
|
var topOffset = this.map.layerContainerOriginPx.y;
|
|
backBuffer.style.left = Math.round(position.x - leftOffset) + 'px';
|
|
backBuffer.style.top = Math.round(position.y - topOffset) + 'px';
|
|
},
|
|
|
|
/**
|
|
* 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';
|
|
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],
|
|
markup = this.grid[i][j].createBackBuffer();
|
|
if (markup) {
|
|
markup._i = i;
|
|
markup._j = j;
|
|
markup._w = tile.size.w;
|
|
markup._h = tile.size.h;
|
|
backBuffer.appendChild(markup);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return backBuffer;
|
|
},
|
|
|
|
/**
|
|
* Method: removeBackBuffer
|
|
* Remove back buffer from DOM.
|
|
*/
|
|
removeBackBuffer: function() {
|
|
if (this._transitionElement) {
|
|
for (var i=this.transitionendEvents.length-1; i>=0; --i) {
|
|
OpenLayers.Event.stopObserving(this._transitionElement,
|
|
this.transitionendEvents[i], this._removeBackBuffer);
|
|
}
|
|
delete this._transitionElement;
|
|
}
|
|
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, 10);
|
|
size.w = parseInt(size.w * this.ratio, 10);
|
|
}
|
|
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} Object containing properties tilelon, tilelat, startcol,
|
|
* startrow
|
|
*/
|
|
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 rowSign = this.rowSign;
|
|
|
|
var offsetlat = rowSign * (origin.lat - bounds.top + tilelat);
|
|
var tilerow = Math[~rowSign ? 'floor' : 'ceil'](offsetlat/tilelat) - this.buffer * rowSign;
|
|
|
|
return {
|
|
tilelon: tilelon, tilelat: tilelat,
|
|
startcol: tilecol, startrow: tilerow
|
|
};
|
|
|
|
},
|
|
|
|
/**
|
|
* 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: getTileBoundsForGridIndex
|
|
*
|
|
* Parameters:
|
|
* row - {Number} The row of the grid
|
|
* col - {Number} The column of the grid
|
|
*
|
|
* Returns:
|
|
* {<OpenLayers.Bounds>} The bounds for the tile at (row, col)
|
|
*/
|
|
getTileBoundsForGridIndex: function(row, col) {
|
|
var origin = this.getTileOrigin();
|
|
var tileLayout = this.gridLayout;
|
|
var tilelon = tileLayout.tilelon;
|
|
var tilelat = tileLayout.tilelat;
|
|
var startcol = tileLayout.startcol;
|
|
var startrow = tileLayout.startrow;
|
|
var rowSign = this.rowSign;
|
|
return new OpenLayers.Bounds(
|
|
origin.lon + (startcol + col) * tilelon,
|
|
origin.lat - (startrow + row * rowSign) * tilelat * rowSign,
|
|
origin.lon + (startcol + col + 1) * tilelon,
|
|
origin.lat - (startrow + (row - 1) * rowSign) * tilelat * rowSign
|
|
);
|
|
},
|
|
|
|
/**
|
|
* 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 origin = this.getTileOrigin();
|
|
var resolution = this.map.getResolution(),
|
|
serverResolution = this.getServerResolution(),
|
|
ratio = resolution / serverResolution,
|
|
tileSize = {
|
|
w: this.tileSize.w / ratio,
|
|
h: this.tileSize.h / ratio
|
|
};
|
|
|
|
var minRows = Math.ceil(viewSize.h/tileSize.h) +
|
|
2 * this.buffer + 1;
|
|
var minCols = Math.ceil(viewSize.w/tileSize.w) +
|
|
2 * this.buffer + 1;
|
|
|
|
var tileLayout = this.calculateGridLayout(bounds, origin, serverResolution);
|
|
this.gridLayout = tileLayout;
|
|
|
|
var tilelon = tileLayout.tilelon;
|
|
var tilelat = tileLayout.tilelat;
|
|
|
|
var layerContainerDivLeft = this.map.layerContainerOriginPx.x;
|
|
var layerContainerDivTop = this.map.layerContainerOriginPx.y;
|
|
|
|
var tileBounds = this.getTileBoundsForGridIndex(0, 0);
|
|
var startPx = this.map.getViewPortPxFromLonLat(
|
|
new OpenLayers.LonLat(tileBounds.left, tileBounds.top)
|
|
);
|
|
startPx.x = Math.round(startPx.x) - layerContainerDivLeft;
|
|
startPx.y = Math.round(startPx.y) - layerContainerDivTop;
|
|
|
|
var tileData = [], center = this.map.getCenter();
|
|
|
|
var rowidx = 0;
|
|
do {
|
|
var row = this.grid[rowidx];
|
|
if (!row) {
|
|
row = [];
|
|
this.grid.push(row);
|
|
}
|
|
|
|
var colidx = 0;
|
|
do {
|
|
tileBounds = this.getTileBoundsForGridIndex(rowidx, colidx);
|
|
var px = startPx.clone();
|
|
px.x = px.x + colidx * Math.round(tileSize.w);
|
|
px.y = px.y + rowidx * Math.round(tileSize.h);
|
|
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)
|
|
});
|
|
|
|
colidx += 1;
|
|
} while ((tileBounds.right <= bounds.right + tilelon * this.buffer)
|
|
|| colidx < minCols);
|
|
|
|
rowidx += 1;
|
|
} while((tileBounds.bottom >= bounds.bottom - tilelat * this.buffer)
|
|
|| rowidx < minRows);
|
|
|
|
//shave off exceess rows and colums
|
|
this.removeExcessTiles(rowidx, colidx);
|
|
|
|
var resolution = this.getServerResolution(),
|
|
immediately = resolution === this.gridResolution;
|
|
// store the resolution of the grid
|
|
this.gridResolution = resolution;
|
|
|
|
//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(immediately);
|
|
}
|
|
},
|
|
|
|
/**
|
|
* 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(evt) {
|
|
this.numLoadingTiles--;
|
|
this.events.triggerEvent("tileloaded", {
|
|
tile: tile,
|
|
aborted: evt.type === "unload"
|
|
});
|
|
//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) {
|
|
this._transitionElement = tile.imgDiv;
|
|
for (var i=this.transitionendEvents.length-1; i>=0; --i) {
|
|
OpenLayers.Event.observe(this._transitionElement,
|
|
this.transitionendEvents[i],
|
|
this._removeBackBuffer);
|
|
}
|
|
// the removal of the back buffer is delayed to prevent
|
|
// flash effects due to the animation of tile displaying
|
|
this.backBufferTimerId = window.setTimeout(
|
|
this._removeBackBuffer, 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;
|
|
while(true) {
|
|
var tlTile = this.grid[0][0];
|
|
var tlViewPort = {
|
|
x: tlTile.position.x +
|
|
this.map.layerContainerOriginPx.x,
|
|
y: tlTile.position.y +
|
|
this.map.layerContainerOriginPx.y
|
|
};
|
|
var ratio = this.getServerResolution() / this.map.getResolution();
|
|
var tileSize = {
|
|
w: Math.round(this.tileSize.w * ratio),
|
|
h: Math.round(this.tileSize.h * ratio)
|
|
};
|
|
if (tlViewPort.x > -tileSize.w * (buffer - 1)) {
|
|
this.shiftColumn(true, tileSize);
|
|
} else if (tlViewPort.x < -tileSize.w * buffer) {
|
|
this.shiftColumn(false, tileSize);
|
|
} else if (tlViewPort.y > -tileSize.h * (buffer - 1)) {
|
|
this.shiftRow(true, tileSize);
|
|
} else if (tlViewPort.y < -tileSize.h * buffer) {
|
|
this.shiftRow(false, tileSize);
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
},
|
|
|
|
/**
|
|
* Method: shiftRow
|
|
* Shifty grid work
|
|
*
|
|
* Parameters:
|
|
* prepend - {Boolean} if true, prepend to beginning.
|
|
* if false, then append to end
|
|
* tileSize - {Object} rendered tile size; object with w and h properties
|
|
*/
|
|
shiftRow: function(prepend, tileSize) {
|
|
var grid = this.grid;
|
|
var rowIndex = prepend ? 0 : (grid.length - 1);
|
|
var sign = prepend ? -1 : 1;
|
|
var rowSign = this.rowSign;
|
|
var tileLayout = this.gridLayout;
|
|
tileLayout.startrow += sign * rowSign;
|
|
|
|
var modelRow = grid[rowIndex];
|
|
var row = grid[prepend ? 'pop' : 'shift']();
|
|
for (var i=0, len=row.length; i<len; i++) {
|
|
var tile = row[i];
|
|
var position = modelRow[i].position.clone();
|
|
position.y += tileSize.h * sign;
|
|
tile.moveTo(this.getTileBoundsForGridIndex(rowIndex, i), position);
|
|
}
|
|
grid[prepend ? 'unshift' : '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
|
|
* tileSize - {Object} rendered tile size; object with w and h properties
|
|
*/
|
|
shiftColumn: function(prepend, tileSize) {
|
|
var grid = this.grid;
|
|
var colIndex = prepend ? 0 : (grid[0].length - 1);
|
|
var sign = prepend ? -1 : 1;
|
|
var tileLayout = this.gridLayout;
|
|
tileLayout.startcol += sign;
|
|
|
|
for (var i=0, len=grid.length; i<len; i++) {
|
|
var row = grid[i];
|
|
var position = row[colIndex].position.clone();
|
|
var tile = row[prepend ? 'pop' : 'shift']();
|
|
position.x += tileSize.w * sign;
|
|
tile.moveTo(this.getTileBoundsForGridIndex(i, colIndex), position);
|
|
row[prepend ? 'unshift' : '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) {
|
|
var i, l;
|
|
|
|
// remove extra rows
|
|
while (this.grid.length > rows) {
|
|
var row = this.grid.pop();
|
|
for (i=0, l=row.length; i<l; i++) {
|
|
var tile = row[i];
|
|
this.destroyTile(tile);
|
|
}
|
|
}
|
|
|
|
// remove extra columns
|
|
for (i=0, l=this.grid.length; i<l; i++) {
|
|
while (this.grid[i].length > columns) {
|
|
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"
|
|
});
|