Tile.Image improvements and partial rewrite. Thanks erilem for the excellent collaboration during the review phase. p=me,erilem r=erilem (closes #3419)
git-svn-id: http://svn.openlayers.org/trunk/openlayers@12241 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf
This commit is contained in:
ahocevar
201
lib/OpenLayers/Tile/BackBufferable.js
Normal file
201
lib/OpenLayers/Tile/BackBufferable.js
Normal file
@@ -0,0 +1,201 @@
|
||||
/* Copyright (c) 2006-2011 by OpenLayers Contributors (see authors.txt for
|
||||
* full list of contributors). Published under the Clear BSD license.
|
||||
* See http://svn.openlayers.org/trunk/openlayers/license.txt for the
|
||||
* full text of the license. */
|
||||
|
||||
|
||||
/*
|
||||
* @requires OpenLayers/Tile.js
|
||||
* @requires OpenLayers/Util.js
|
||||
*/
|
||||
|
||||
/*
|
||||
* Class: OpenLayers.Tile.BackBufferable
|
||||
* Base class for tiles that can have backbuffers during transitions. Do not
|
||||
* create instances of this class.
|
||||
*/
|
||||
OpenLayers.Tile.BackBufferable = OpenLayers.Class(OpenLayers.Tile, {
|
||||
|
||||
/**
|
||||
* Property: backBufferMode
|
||||
* {Integer} Bitmap: 0 for no backbuffering at all, 1 for singleTile
|
||||
* layers, 2 for transition effect set, 3 for both.
|
||||
*/
|
||||
backBufferMode: null,
|
||||
|
||||
/**
|
||||
* Property: backBufferData
|
||||
* {Object} Object including the necessary data for the back
|
||||
* buffer.
|
||||
*
|
||||
* The object includes three properties:
|
||||
* tile - {DOMElement} The DOM element for the back buffer.
|
||||
* bounds - {<OpenLayers.Bounds>} The bounds of the tile to back.
|
||||
* resolution - {Number} The resolution of the tile to back.
|
||||
*/
|
||||
backBufferData: null,
|
||||
|
||||
/**
|
||||
* Method: initialize
|
||||
* Determines the backBuffer mode and registers events
|
||||
*/
|
||||
initialize: function() {
|
||||
OpenLayers.Tile.prototype.initialize.apply(this, arguments);
|
||||
|
||||
var transitionSupported = OpenLayers.Util.indexOf(
|
||||
this.layer.SUPPORTED_TRANSITIONS,
|
||||
this.layer.transitionEffect) != -1;
|
||||
this.backBufferMode = (this.layer.singleTile && 1) |
|
||||
(transitionSupported && 2);
|
||||
|
||||
this.backBufferData = {};
|
||||
if (!this.size) {
|
||||
this.size = new OpenLayers.Size(256, 256);
|
||||
}
|
||||
},
|
||||
|
||||
/**
|
||||
* Method: draw
|
||||
* Check that a tile should be drawn, and draw it.
|
||||
*
|
||||
* Returns:
|
||||
* {Boolean} Was a tile drawn?
|
||||
*/
|
||||
draw: function() {
|
||||
var draw = OpenLayers.Tile.prototype.shouldDraw.apply(this, arguments),
|
||||
backBufferMode = this.backBufferMode;
|
||||
if (draw) {
|
||||
this.updateBackBuffer();
|
||||
}
|
||||
this.clear();
|
||||
if (!draw) {
|
||||
this.resetBackBuffer();
|
||||
};
|
||||
return draw;
|
||||
},
|
||||
|
||||
/**
|
||||
* Method: getTile
|
||||
* Get the tile's markup. To be implemented by subclasses.
|
||||
*
|
||||
* Returns:
|
||||
* {DOMElement} The tile's markup
|
||||
*/
|
||||
|
||||
/**
|
||||
* Method: createBackBuffer
|
||||
* Create a copy of this tile's markup for the back buffer. To be
|
||||
* implemented by subclasses.
|
||||
*
|
||||
* Returns:
|
||||
* {DOMElement} A copy of the tile's markup.
|
||||
*/
|
||||
|
||||
/**
|
||||
* Method: setBackBufferData
|
||||
* Stores the current bounds and resolution, for offset and ratio
|
||||
* calculations
|
||||
*/
|
||||
setBackBufferData: function() {
|
||||
this.backBufferData = OpenLayers.Util.extend(this.backBufferData, {
|
||||
bounds: this.bounds,
|
||||
resolution: this.layer.map.getResolution()
|
||||
});
|
||||
},
|
||||
|
||||
/**
|
||||
* Method: updateBackBuffer
|
||||
* Update the <backBufferData>, and return a new or reposition the
|
||||
* backBuffer. When a backbuffer is returned, the tile's markup is not
|
||||
* available any more.
|
||||
*
|
||||
* Returns:
|
||||
* {HTMLDivElement} the tile's markup in a cloned element, or undefined if
|
||||
* no backbuffer is currently available or needed
|
||||
*/
|
||||
updateBackBuffer: function() {
|
||||
var layer = this.layer, map = layer.map,
|
||||
backBufferMode = this.backBufferMode,
|
||||
data = this.backBufferData,
|
||||
tile = this.getTile(),
|
||||
backBuffer = data.tile,
|
||||
resolution = data.resolution,
|
||||
ratio = resolution ? resolution / map.getResolution() : 1,
|
||||
|
||||
// Cases where we don't position and return a back buffer, but only
|
||||
// update backBufferData and return undefined:
|
||||
// (1) current ratio and backBufferMode dont't require a backbuffer
|
||||
notNeeded = !(ratio == 1 ? backBufferMode & 1 : backBufferMode & 2),
|
||||
// (2) the tile is not appended to the layer's div
|
||||
noParent = tile && tile.parentNode !== layer.div,
|
||||
// (3) we don't have a tile available that we could use as buffer
|
||||
noTile = !(tile && tile.childNodes.length > 0),
|
||||
// (4) no backbuffer is displayed for a tile that's still loading
|
||||
noBackBuffer = data.tile && !this.isLoading;
|
||||
if (notNeeded || noParent || noTile || noBackBuffer) {
|
||||
this.setBackBufferData();
|
||||
return;
|
||||
}
|
||||
|
||||
// Create a back buffer tile and add it to the DOM
|
||||
if (!backBuffer) {
|
||||
backBuffer = this.createBackBuffer();
|
||||
// some browsers fire the onload event before the image is
|
||||
// displayed, so we keep the buffer until the whole layer finished
|
||||
// loading to avoid visual glitches
|
||||
layer.events.register("loadend", this, this.resetBackBuffer);
|
||||
data.tile = backBuffer;
|
||||
layer.div.insertBefore(backBuffer, tile);
|
||||
}
|
||||
|
||||
// Position the back buffer now that we have one
|
||||
var lonLat = {lon: data.bounds.left, lat: data.bounds.top},
|
||||
position = map.getPixelFromLonLat(lonLat),
|
||||
containerStyle = map.layerContainerDiv.style,
|
||||
leftOffset = parseInt(containerStyle.left, 10),
|
||||
topOffset = parseInt(containerStyle.top, 10),
|
||||
style = backBuffer.style;
|
||||
style.left = (position.x - leftOffset) + "px";
|
||||
style.top = (position.y - topOffset) + "px";
|
||||
style.width = (this.size.w * ratio) + "px";
|
||||
style.height = (this.size.h * ratio) + "px";
|
||||
|
||||
return backBuffer;
|
||||
},
|
||||
|
||||
/**
|
||||
* Method: resetBackBuffer
|
||||
* Handler for the layer's loadend event.
|
||||
*/
|
||||
resetBackBuffer: function() {
|
||||
this.layer.events.unregister("loadend", this, this.resetBackBuffer);
|
||||
this.removeBackBuffer();
|
||||
this.setBackBufferData();
|
||||
},
|
||||
|
||||
/**
|
||||
* Method: removeBackBuffer
|
||||
* Removes the backBuffer for this tile.
|
||||
*/
|
||||
removeBackBuffer: function() {
|
||||
var backBufferData = this.backBufferData;
|
||||
var backBuffer = backBufferData.tile;
|
||||
delete backBufferData.tile;
|
||||
var parent = backBuffer && backBuffer.parentNode;
|
||||
if (backBuffer) {
|
||||
parent.removeChild(backBuffer);
|
||||
}
|
||||
},
|
||||
|
||||
/**
|
||||
* APIMethod: destroy
|
||||
* nullify references to prevent circular references and memory leaks
|
||||
*/
|
||||
destroy: function() {
|
||||
this.removeBackBuffer();
|
||||
this.layer.events.unregister("loadend", this, this.resetBackBuffer);
|
||||
this.backBufferData = null;
|
||||
OpenLayers.Tile.prototype.destroy.apply(this, arguments);
|
||||
}
|
||||
|
||||
});
|
||||
Reference in New Issue
Block a user