dojo.provide("dojox.html.metrics");
(function(){
var dhm = dojox.html.metrics;
// derived from Morris John's emResized measurer
dhm.getFontMeasurements = function(){
// summary
// Returns an object that has pixel equivilents of standard font size values.
var heights = {
'1em':0, '1ex':0, '100%':0, '12pt':0, '16px':0, 'xx-small':0, 'x-small':0,
'small':0, 'medium':0, 'large':0, 'x-large':0, 'xx-large':0
};
if(dojo.isIE){
// we do a font-size fix if and only if one isn't applied already.
// NOTE: If someone set the fontSize on the HTML Element, this will kill it.
dojo.doc.documentElement.style.fontSize="100%";
}
// set up the measuring node.
var div=dojo.doc.createElement("div");
var ds = div.style;
ds.position="absolute";
ds.left="-100px";
ds.top="0";
ds.width="30px";
ds.height="1000em";
ds.border="0";
ds.margin="0";
ds.padding="0";
ds.outline="0";
ds.lineHeight="1";
ds.overflow="hidden";
dojo.body().appendChild(div);
// do the measurements.
for(var p in heights){
ds.fontSize = p;
heights[p] = Math.round(div.offsetHeight * 12/16) * 16/12 / 1000;
}
dojo.body().removeChild(div);
div = null;
return heights; // object
};
var fontMeasurements = null;
dhm.getCachedFontMeasurements = function(recalculate){
if(recalculate || !fontMeasurements){
fontMeasurements = dhm.getFontMeasurements();
}
return fontMeasurements;
};
var measuringNode = null, empty = {};
dhm.getTextBox = function(/* String */ text, /* Object */ style, /* String? */ className){
var m;
if(!measuringNode){
m = measuringNode = dojo.doc.createElement("div");
m.style.position = "absolute";
m.style.left = "-10000px";
m.style.top = "0";
dojo.body().appendChild(m);
}else{
m = measuringNode;
}
// reset styles
m.className = "";
m.style.border = "0";
m.style.margin = "0";
m.style.padding = "0";
m.style.outline = "0";
// set new style
if(arguments.length > 1 && style){
for(var i in style){
if(i in empty){ continue; }
m.style[i] = style[i];
}
}
// set classes
if(arguments.length > 2 && className){
m.className = className;
}
// take a measure
m.innerHTML = text;
return dojo.marginBox(m);
};
// determine the scrollbar sizes on load.
var scroll={ w:16, h:16 };
dhm.getScrollbar=function(){ return { w:scroll.w, h:scroll.h }; };
dhm._fontResizeNode = null;
dhm.initOnFontResize = function(interval){
var f = dhm._fontResizeNode = dojo.doc.createElement("iframe");
var fs = f.style;
fs.position = "absolute";
fs.width = "5em";
fs.height = "10em";
fs.top = "-10000px";
if(dojo.isIE){
f.onreadystatechange = function(){
if(f.contentWindow.document.readyState == "complete"){
f.onresize = f.contentWindow.parent[dojox._scopeName].html.metrics._fontresize;
}
};
}else{
f.onload = function(){
f.contentWindow.onresize = f.contentWindow.parent[dojox._scopeName].html.metrics._fontresize;
};
}
//The script tag is to work around a known firebug race condition. See comments in bug #9046
f.setAttribute("src", "javascript:''");
dojo.body().appendChild(f);
dhm.initOnFontResize = function(){};
};
dhm.onFontResize = function(){};
dhm._fontresize = function(){
dhm.onFontResize();
}
dojo.addOnUnload(function(){
// destroy our font resize iframe if we have one
var f = dhm._fontResizeNode;
if(f){
if(dojo.isIE && f.onresize){
f.onresize = null;
}else if(f.contentWindow && f.contentWindow.onresize){
f.contentWindow.onresize = null;
}
dhm._fontResizeNode = null;
}
});
dojo.addOnLoad(function(){
// getScrollbar metrics node
try{
var n=dojo.doc.createElement("div");
n.style.cssText = "top:0;left:0;width:100px;height:100px;overflow:scroll;position:absolute;visibility:hidden;";
dojo.body().appendChild(n);
scroll.w = n.offsetWidth - n.clientWidth;
scroll.h = n.offsetHeight - n.clientHeight;
dojo.body().removeChild(n);
//console.log("Scroll bar dimensions: ", scroll);
delete n;
}catch(e){}
// text size poll setup
if("fontSizeWatch" in dojo.config && !!dojo.config.fontSizeWatch){
dhm.initOnFontResize();
}
});
})();