How to add multiple presets to responsive design view without having to resize the screen each time

Question

I want to be able to add multiple screen size presets to the responsive design view capability but don't want to have to resize the screen and add each one individually via the custom preset function.
Have seen that some posts on the internet (http://g-liu.com/blog/2013/08/firefox-rdm-presets/) that say this can be done but cannot find where the config is held in ver 26.0?

Answer 1

You can also do the opposite and create custom settings in the responsive design mode window.
You can hold down the Shift key and drag the borders via the (right border, bottom border, bottom right corner) resize icons to get specific dimensions and give the current custom setting a name to add them as a preset.
This will add the preset to the devtools.responsiveUI.presets pref.
See also my post here for a bookmarklet.
*[[/questions/957590]]
You can paste the current value of the pref in the prompt to see a list of currently defined presets.<br />
You can add a new preset by entering the width,height,name values in the prompt.<br />
Copy the new preset list to the pref.
<pre><nowiki>javascript:(function(){
function rdObj(w,h,n){with(this){key=w+"x"+h;if(n)name=n;width=w;height=h;}}
rdObj.prototype={key:"",name:"",width:"",height:""};
var n={},p='<width>x<height> <name> OR width,height,name',rd=[];
while(p!=null){
p=prompt(p,JSON.stringify(rd));
if(/^(\d{3,4})[,x](\d{3,4})([, ](.+))?$/.test(p)){
n=new rdObj(RegExp.$1,RegExp.$2,RegExp.$4);rd.push(n);
}else{try{rd=JSON.parse(p);}catch(e){}}
}})()</nowiki></pre>