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Commit scale-based methods back into trunk. Layers or Maps now support setting

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a list of scales or resolutions in the options to the constructor, from which
resolutions are calculated. Map now has a 'setScale' function which will allow
you to zoom to as close to a given scale as possible.


git-svn-id: http://svn.openlayers.org/trunk/openlayers@1171 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf
This commit is contained in:
crschmidt
2006-08-09 19:14:16 +00:00
parent e3df606001
commit 6efaf328e5
5 changed files with 120 additions and 30 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
lib/OpenLayers/Layer.js
View File

@@ -54,7 +54,15 @@ OpenLayers.Layer.prototype = {
/** @type int */
maxZoomLevel: null,
/** @type float */
minScale: null,
/** @type float */
maxScale: null,
/** @type String */
units: null,
/**
* @constructor
@@ -162,6 +170,20 @@ OpenLayers.Layer.prototype = {
*/
setMap: function(map) {
this.map = map;
var properties = new Array(
'projection', 'minExtent', 'maxExtent',
'minScale', 'maxScale',
'maxResolution', 'minResolution',
'minZoomLevel', 'maxZoomLevel', 'units',
'scales', 'resolutions'
);
for(var i=0; i < properties.length; i++) {
if (this[properties[i]] == null) {
this[properties[i]] = this.map[properties[i]];
}
}
},
/**

11
lib/OpenLayers/Layer/Grid.js
View File

@@ -288,17 +288,6 @@ OpenLayers.Layer.Grid.prototype =
/* */
/********************************************************/
/**
* @returns Degrees per Pixel
* @type float
*/
getResolution: function() {
var maxRes = this.map.getMaxResolution();
var zoom = this.map.getZoom();
return maxRes / Math.pow(2, zoom);
},
/** Calculates based on resolution, center, and mapsize
*
* @returns A Bounds object which represents the lon/lat bounds of the

35
lib/OpenLayers/Layer/HTTPRequest.js
View File

@@ -36,6 +36,10 @@ OpenLayers.Layer.HTTPRequest.prototype =
this.params = Object.extend( new Object(), params);
},
setMap: function(map) {
OpenLayers.Layer.prototype.setMap.apply(this, arguments);
this.initResolutions();
},
/**
*
*/
@@ -137,6 +141,37 @@ OpenLayers.Layer.HTTPRequest.prototype =
}
return requestString;
},
initResolutions: function() {
if (this.scales != null) {
this.resolutions = new Array();
for(var i = 0; i < this.scales.length; i++)
this.resolutions[i] = OpenLayers.Util.getResolutionFromScale(this.scales[i], this.units);
this.maxZoomLevel = this.resolutions.length;
} else if (this.resolutions != null) {
this.maxZoomLevel = this.resolutions.length;
} else {
this.resolutions = new Array();
if (this.minScale)
this.maxResolution = OpenLayers.Util.getResolutionFromScale(this.minScale, this.units);
var maxRes = this.getMaxResolution();
if (this.maxScale) {
/* This will cause this.map.getMaxZoomLevel() to be set the next time
* it is called, which means that the next portion here will succeed. */
var minRes = OpenLayers.Util.getResolutionFromScale(this.maxScale);
this.maxZoomLevel = Math.floor(Math.log(maxRes/minRes) / Math.log(2));
}
for (var i=this.getMinZoomLevel(); i <= this.getMaxZoomLevel(); i++) {
this.resolutions.push(maxRes / Math.pow(2, i));
}
}
},
getResolution: function() {
var zoom = this.map.getZoom();
return this.resolutions[zoom];
},
/** @final @type String */
CLASS_NAME: "OpenLayers.Layer.HTTPRequest"

28
lib/OpenLayers/Map.js
View File

@@ -87,7 +87,7 @@ OpenLayers.Map.prototype = {
* zoom level 0 on gmaps
*
* @type float */
maxResolution: 1.40625,
maxResolution: null,
/** @type int */
minZoomLevel: 0,
@@ -210,14 +210,13 @@ OpenLayers.Map.prototype = {
// if maxResolution is specified as "auto", calculate it
// based on the maxExtent and the viewSize
//
if (this.maxResolution == null && this.minScale) {
this.maxResolution = OpenLayers.Util.getResolutionFromScale(this.minScale, this.units);
} else if (this.maxResolution == "auto" || this.maxResolution == null) {
if (this.maxResolution == "auto") {
var maxExtent = this.getMaxExtent();
var viewSize = this.getSize();
this.maxResolution = Math.max(maxExtent.getWidth() / viewSize.w,
maxExtent.getHeight() / viewSize.h );
} else {
this.maxResolution = 1.40625;
}
},
@@ -826,6 +825,25 @@ OpenLayers.Map.prototype = {
/* */
/********************************************************/
/** zoom to a specified scale
*
* @param {float} scale
*/
setScale: function(scale) {
var res = OpenLayers.Util.getResolutionFromScale(scale, this.baseLayer.units);
var size = this.getSize();
var w_deg = size.w * res;
var h_deg = size.h * res;
var center = this.getCenter();
var extent = new OpenLayers.Bounds(center.lon - w_deg / 2,
center.lat - h_deg / 2,
center.lon + w_deg / 2,
center.lat + h_deg / 2);
this.zoomToExtent(extent);
},
/** Zoom to a specific zoom level
*
* @param {int} zoom

54
lib/OpenLayers/Util.js
View File

@@ -1113,32 +1113,58 @@ OpenLayers.Util.createUniqueID = function(prefix) {
return prefix + Math.round(Math.random() * 10000);
};
/** constant inches per unit */
OpenLayers.INCHES_PER_UNIT = { // borrowed from MapServer mapscale.c
/** Constant inches per unit
* -- borrowed from MapServer mapscale.c
*
* @type Object */
OpenLayers.INCHES_PER_UNIT = {
'inches': 1.0,
'in': 1.0,
'ft': 12.0,
'mi': 63360.0,
'm': 39.3701,
'km': 39370.1,
'dd': 4374754,
'degrees': 4374754
};
OpenLayers.INCHES_PER_UNIT["in"]= OpenLayers.INCHES_PER_UNIT.inches;
OpenLayers.INCHES_PER_UNIT["degrees"] = OpenLayers.INCHES_PER_UNIT.dd;
/** sensible default */
/** A sensible default
* @type int */
OpenLayers.DOTS_PER_INCH = 72;
/**
* @param {float} scale
*
* @returns A normalized scale value, in 1 / X format.
* This means that if a value less than one ( already 1/x) is passed
* in, it just returns scale directly. Otherwise, it returns
* 1 / scale
* @type float
*/
OpenLayers.Util.normalizeScale = function (scale) {
if (scale > 1.0)
return 1.0 / scale;
else
return scale;
var normScale = (scale > 1.0) ? (1.0 / scale)
: scale;
return normScale;
};
/**
* @param {float} scale
* @param {String} units Index into OpenLayers.INCHES_PER_UNIT hashtable.
* Default is degrees
*
* @returns The corresponding resolution given passed-in scale and unit
* parameters.
* @type float
*/
OpenLayers.Util.getResolutionFromScale = function (scale, units) {
if (!units) units = "degrees";
scale = OpenLayers.Util.normalizeScale(scale);
return 1 / (scale * OpenLayers.INCHES_PER_UNIT[units]
* OpenLayers.DOTS_PER_INCH);
};
if (units == null) {
units = "degrees";
}
normScale = OpenLayers.Util.normalizeScale(scale);
var resolution = 1 / (normScale * OpenLayers.INCHES_PER_UNIT[units]
* OpenLayers.DOTS_PER_INCH);
return resolution;
};