same KeyEvent from within hotkey.bind

[agzam]

I need to bind a key and based on certain logic from within hs.hotkey.bind need to emulate the same sequence.

Let's say, for example I have a global bind: Control-C. Imagine in browser it would do something, but in Emacs it should do nothing, but also it should not shadow Emacs's default keybinding. So it needs to "throw the keys back" - replay Control-C sequence.

I've been trying to get this right using eventtap.event.newKeyEvent, hs.timer.doAfter - nothing works. Can someone help me to get this right? Thanks a lot!

[latenitefilms]

I'm not entirely sure I understand your question, but I think what you're after is better achieved with hs.eventtap as opposed to hs.hotkey.

For example:

hs.eventtap.new({hs.eventtap.event.types.keyUp}, function(event)
    local flags = event:getFlags()
    local keyCode = event:getKeyCode()
    if flags:containExactly({"ctrl"}) and keyCode == hs.keycodes.map["c"] then
        print("CTRL+C has been pressed.")
        -- INSERT LOGIC HERE.
        local shouldTheEventBeDeleted = true --  true if the event should be deleted, false if it should propagate to any other applications watching for that event
        local tableOfEventsToPost = {} -- a table of events to post        
        return shouldTheEventBeDeleted, tableOfEventsToPost
    end
end):start()

[asmagill]

If you're wanting the key combo to do something for most applications, but not for a few specific ones, you're better off using a window filter or application watcher and enabling/disabling the hotkey(s) when the active application changes.

Hotkey's as defined with hs.hotkey, when enabled, are always caught and can not be "passed through"... any attempt to create a synthetic version of the hot key combination with hs.eventtap.event will in turn be caught by hs.hotkey, thus creating an infinite loop... search the issues -- this has come up before.

Watching for a hotkey with hs.eventtap seems like it should be more flexible, but if your Mac gets busy, you may notice dropped keystrokes (and not just the ones you're trying to match on)... we've attempted rewriting hs.hotkey to use the eventtap infrastructure in the past and it just isn't fast enough to be enabled all of the time for key and flag events -- you have to catch them all then determine if its one you care about.

Search the issues and you should find some examples of watchers that should point you in the right direction... I'll try and post an example later but I'm not at my computer at the moment.

[latenitefilms]

As usual, @asmagill makes a really good point.

Here's an example of how to use hs.window.filter:

#2029 (comment)

There's an example of using hs.application.watcher in the Getting Started guide:

http://www.hammerspoon.org/go/#appevents

[agzam]

Thank you everyone for you help. Closing this, since not a real issue

[overvale]

I was able to get this working by adapting some code from some dot files

local function keyCode(modifiers, key)
  return function() hs.eventtap.keyStroke(modifiers, key, 0) end
end

-- Create a modal hotkey object with an absurd triggering hotkey,
-- since it will never be triggered from the keyboard
hotkeys = hs.hotkey.modal.new({"cmd", "shift", "alt"}, "F19")
-- Bind all your normal hotkeys to the modal state object
hotkeys:bind({'ctrl'}, ',', keyCode({'alt'}, 'left'))
hotkeys:bind({'ctrl'}, '.', keyCode({'alt'}, 'down'))
hotkeys:bind({'ctrl'}, "'", keyCode({'alt'}, 'forwarddelete'))
hotkeys:bind({'ctrl'}, ';', keyCode({'alt'}, 'delete'))
hotkeys:bind({'ctrl'}, 'u', keyCode({'cmd'}, 'delete'))

-- Define a callback function to be called when application events happen
function applicationWatcherCallback(appName, eventType, appObject)
  if (appName == "Emacs") then
    if (eventType == hs.application.watcher.activated) then
      -- Emacs just got focus, disable our hotkeys
      hotkeys:exit()
    elseif (eventType == hs.application.watcher.deactivated) then
      -- Emacs just lost focus, enable our hotkeys
      hotkeys:enter()
    end
  end
end

-- Create and start the application event watcher
watcher = hs.application.watcher.new(applicationWatcherCallback)
watcher:start()

-- Activate the modal state
hotkeys:enter()

I have no idea if this is a smart way to do it, but it was the only way I could get it to work.