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/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
* full list of contributors). Published under the 2-clause BSD license.
* See license.txt in the OpenLayers distribution or repository for the
* full text of the license. */
/**
* @requires OpenLayers/Control.js
* @requires OpenLayers/Handler/Box.js
*/
/**
* Class: OpenLayers.Control.ZoomBox
* The ZoomBox control enables zooming directly to a given extent, by drawing
* a box on the map. The box is drawn by holding down shift, whilst dragging
* the mouse.
*
* Inherits from:
* - <OpenLayers.Control>
*/
OpenLayers.Control.ZoomBox = OpenLayers.Class(OpenLayers.Control, {
/**
* Property: type
* {OpenLayers.Control.TYPE}
*/
type: OpenLayers.Control.TYPE_TOOL,
/**
* Property: out
* {Boolean} Should the control be used for zooming out?
*/
out: false,
/**
* APIProperty: keyMask
* {Integer} Zoom only occurs if the keyMask matches the combination of
* keys down. Use bitwise operators and one or more of the
* <OpenLayers.Handler> constants to construct a keyMask. Leave null if
* not used mask. Default is null.
*/
keyMask: null,
/**
* APIProperty: alwaysZoom
* {Boolean} Always zoom in/out when box drawn, even if the zoom level does
* not change.
*/
alwaysZoom: false,
/**
* APIProperty: zoomOnClick
* {Boolean} Should we zoom when no box was dragged, i.e. the user only
* clicked? Default is true.
*/
zoomOnClick: true,
/**
* Method: draw
*/
draw: function() {
this.handler = new OpenLayers.Handler.Box( this,
{done: this.zoomBox}, {keyMask: this.keyMask} );
},
/**
* Method: zoomBox
*
* Parameters:
* position - {<OpenLayers.Bounds>} or {<OpenLayers.Pixel>}
*/
zoomBox: function (position) {
if (position instanceof OpenLayers.Bounds) {
var bounds,
targetCenterPx = position.getCenterPixel();
if (!this.out) {
var minXY = this.map.getLonLatFromPixel({
x: position.left,
y: position.bottom
});
var maxXY = this.map.getLonLatFromPixel({
x: position.right,
y: position.top
});
bounds = new OpenLayers.Bounds(minXY.lon, minXY.lat,
maxXY.lon, maxXY.lat);
} else {
var pixWidth = position.right - position.left;
var pixHeight = position.bottom - position.top;
var zoomFactor = Math.min((this.map.size.h / pixHeight),
(this.map.size.w / pixWidth));
var extent = this.map.getExtent();
var center = this.map.getLonLatFromPixel(targetCenterPx);
var xmin = center.lon - (extent.getWidth()/2)*zoomFactor;
var xmax = center.lon + (extent.getWidth()/2)*zoomFactor;
var ymin = center.lat - (extent.getHeight()/2)*zoomFactor;
var ymax = center.lat + (extent.getHeight()/2)*zoomFactor;
bounds = new OpenLayers.Bounds(xmin, ymin, xmax, ymax);
}
// always zoom in/out
var lastZoom = this.map.getZoom(),
size = this.map.getSize(),
centerPx = {x: size.w / 2, y: size.h / 2},
zoom = this.map.getZoomForExtent(bounds),
oldRes = this.map.getResolution(),
newRes = this.map.getResolutionForZoom(zoom);
if (oldRes == newRes) {
this.map.setCenter(this.map.getLonLatFromPixel(targetCenterPx));
} else {
var zoomOriginPx = {
x: (oldRes * targetCenterPx.x - newRes * centerPx.x) /
(oldRes - newRes),
y: (oldRes * targetCenterPx.y - newRes * centerPx.y) /
(oldRes - newRes)
};
this.map.zoomTo(zoom, zoomOriginPx);
}
if (lastZoom == this.map.getZoom() && this.alwaysZoom == true){
this.map.zoomTo(lastZoom + (this.out ? -1 : 1));
}
} else if (this.zoomOnClick) { // it's a pixel
if (!this.out) {
this.map.zoomTo(this.map.getZoom() + 1, position);
} else {
this.map.zoomTo(this.map.getZoom() - 1, position);
}
}
},
CLASS_NAME: "OpenLayers.Control.ZoomBox"
});
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