Shallow Thoughts : tags : crikey

Pasting the Primary X Selection into Firefox

Sometimes I need to take a URL from some text app -- like a shell window, or an IRC comment -- and open it in Firefox.

If it's a standard http://, that's trivial: I highlight the URL with my house (often a doubleclick will do it), go to my Firefox window and middleclick somewhere in the content area, anywhere that's not a link, and Firefox goes to the URL.

That works because selecting anything, in X, copies the selection to the Primary selection buffer. The Primary selection is different from the Clipboard selection that's used with Windows and Mac style Ctrl-X/Ctrl-C/Ctrl-V copy and paste; it's faster and doesn't require switching between keyboard and mouse. Since your hand is already on the mouse (from selecting the text), you don't have to move to the keyboard to type Ctrl-C, then back to the mouse to go to the Firefox window, then back to the keyboard to type Ctrl-V.

But it fails in some cases. Like when someone says in IRC, "There's a great example of that at coolhacks.org/greatexample". You can highlight coolhacks.org/greatexample and middleclick in Firefox all you want, but Firefox doesn't recognize it as a URL and won't go there. Or if I want to highlight a couple of search terms and pass them into a Google search.

(Rant: middlemouse used to work for these cases, but it was disabled -- without even an option for getting it back -- due to a lot of whining in bugzilla by people coming from Windows backgrounds who didn't like middleclick paste because they found it unexpected, yet who weren't willing to turn it off with the middlemouse.contentLoadURL pref).

So in those cases, what I've been doing is:

• Highlight the URL or search terms
• Switch to the Firefox window
• Ctrl-L -- this focuses and highlights the URL bar without changing the X selection
• Backspace (or Ctrl-U, Ctrl-K, any key that clears the URLbar)
• Move the mouse to the URL bar (a small target) and middleclick
• Hit Enter

It works, but it's a lot more steps, and entails several switches between keyboard and mouse. Frustrating!

It would be a little less frustrating if I had a key binding in Firefox that said "Paste the current X primary selection." A web search shows that quite a few other people have been bothered by this problem -- for instance, discussions here and here, and plenty of bugs, like 228011, 1070518, and 1461168 -- but without any solutions, even though one of those bugs has a patch attached. Apparently in most apps, Ctrl-Insert inserts the Primary X selection -- but in Firefox and a few others, it inserts the Clipboard instead, just like Ctrl-C.

I could write my own fix, by unzipping Firefox's omni.ja file and editing various .xul and .js files inside it. (Update a decade later: probably not any more, as Mozilla has steadily reduced the number of things you can change in omni.ja and moved them into C++ code.) But if I were doing that, I could just as easily revert Firefox's original behavior of going to the link. Neither of these is difficult; the problem is that every time I Firefox updates (which is about twice a week these days), things break until I manually go in and unzip the jar and make my changes again. I used to do that, but I got tired of needing to do it so often. And I tried to do it via a Firefox extension, until Mozilla changed the Firefox extension API so that extensions couldn't modify key bindings any more.

Since Firefox changes so often, it's nicer to have a solution that's entirely outside of Firefox. And a comment in one of those discussion threads gave me an idea: make a key binding in my window manager that uses xset to copy the primary selection to the clipboard, then use my crikey program to insert a fake Ctrl-V that Firefox will see.

Here's a command to do that:

xsel -o -p | xsel -i -b; crikey -s 1 "^V"

xsel -o prints a current X selection, and -p specifies the Primary. xsel -i sets an X selection to whatever it gets on standard input (which in this case will be whatever was in the Primary selection), and -b tells it to set the Clipboard selection.

Then crikey -s 1 "^V" waits one second (I'll probably reduce this after more testing) and then generates an X event for a Ctrl-V.

I bound that command to Ctrl-Insert in my window manager, Openbox, like this:

<keybind key="C-Insert">
  <action name="Execute">
    <execute>/bin/sh -c 'xsel -o -p | xsel -i -b; crikey -s 1 "^V"'</execute>
  </action>
</keybind>

Now, whenever I type Ctrl-Insert, whatever program I'm in will do a Ctrl-V but insert the Primary selection rather than the Clipboard. It should work in other recalcitrant programs, like LibreOffice, as well. In Firefox, now, I just have to type Ctrl-L Ctrl-Insert Return.

Of course, it's easy enough to make a binding specific to Firefox that does the Ctrl-L and the Return automatically. I've bound that to Alt-Insert, and its execute line looks like this:

    <execute>/bin/sh -c 'xsel -o -p | xsel -i -b; crikey -s 1 "^L^V\\n"'</execute>

Fun with Linux! Now the only hard part will be remembering to use the bindings instead of doing things the hard way.

Wed, 19 Aug 2009

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Sun, 25 May 2008