SemanticScuttle/includes/js/dojox/image/MagnifierLite.js

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if(!dojo._hasResource["dojox.image.MagnifierLite"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
dojo._hasResource["dojox.image.MagnifierLite"] = true;
dojo.provide("dojox.image.MagnifierLite");
dojo.experimental("dojox.image.MagnifierLite");
dojo.require("dijit._Widget");
dojo.declare("dojox.image.MagnifierLite",
[dijit._Widget],{
// summary: Adds magnification on a portion of an image element
//
// description: An unobtrusive way to add an unstyled overlay
// above the srcNode image element. The overlay/glass is a
// scaled version of the src image (so larger images sized down
// are clearer).
//
// The logic behind requiring the src image to be large is
// "it's going to be downloaded, anyway" so this method avoids
// having to make thumbnails and 2 http requests among other things.
//
// glassSize: Int
// the width and height of the bounding box
glassSize: 125,
// scale: Decimal
// the multiplier of the Mangification.
scale: 6,
postCreate: function(){
this.inherited(arguments);
// images are hard to make into workable templates, so just add outer overlay
// and skip using dijit._Templated
this._adjustScale();
this._createGlass();
this.connect(this.domNode,"onmouseenter","_showGlass");
this.connect(this.glassNode,"onmousemove","_placeGlass");
this.connect(this.img,"onmouseout","_hideGlass");
// when position of domNode changes, _adjustScale needs to run.
// window.resize isn't it always, FIXME:
this.connect(window,"onresize","_adjustScale");
},
_createGlass: function(){
// summary: make img and glassNode elements as children of the body
this.glassNode = dojo.doc.createElement('div');
this.surfaceNode = this.glassNode.appendChild(dojo.doc.createElement('div'));
dojo.addClass(this.glassNode,"glassNode");
dojo.body().appendChild(this.glassNode);
with(this.glassNode.style){
height = this.glassSize + "px";
width = this.glassSize + "px";
}
this.img = dojo.doc.createElement('img');
this.glassNode.appendChild(this.img);
this.img.src = this.domNode.src;
// float the image around inside the .glassNode
with(this.img.style){
position = "relative";
top = 0; left = 0;
width = this._zoomSize.w+"px";
height = this._zoomSize.h+"px";
}
},
_adjustScale: function(){
// summary: update the calculations should this.scale change
this.offset = dojo.coords(this.domNode,true);
this._imageSize = { w: this.offset.w, h:this.offset.h };
this._zoomSize = {
w: this._imageSize.w * this.scale,
h: this._imageSize.h * this.scale
};
},
_showGlass: function(e){
// summary: show the overlay
this._placeGlass(e);
with(this.glassNode.style){
visibility = "visible";
display = "";
}
},
_hideGlass: function(e){
// summary: hide the overlay
this.glassNode.style.visibility = "hidden";
this.glassNode.style.display = "none";
},
_placeGlass: function(e){
// summary: position the overlay centered under the cursor
this._setImage(e);
var t = Math.floor(e.pageY - (this.glassSize/2));
var l = Math.floor(e.pageX - (this.glassSize/2));
dojo.style(this.glassNode,"top",t);
dojo.style(this.glassNode,"left",l);
},
_setImage: function(e){
// summary: set the image's offset in the clipping window relative to the mouse position
var xOff = (e.pageX - this.offset.l) / this.offset.w;
var yOff = (e.pageY - this.offset.t) / this.offset.h;
var x = (this._zoomSize.w * xOff * -1)+(this.glassSize*xOff);
var y = (this._zoomSize.h * yOff * -1)+(this.glassSize*yOff);
with(this.img.style){
top = y+"px";
left = x+"px";
}
}
});
}