awesome/lib/awful/keygrabber.lua

98 lines
2.9 KiB
Lua

---------------------------------------------------------------------------
--- Keygrabber Stack
--
-- @author dodo
-- @copyright 2012 dodo
-- @release @AWESOME_VERSION@
-- @module awful.keygrabber
---------------------------------------------------------------------------
local ipairs = ipairs
local table = table
local capi = {
keygrabber = keygrabber }
local keygrabber = {}
-- Private data
local grabbers = {}
local keygrabbing = false
local function grabber(mod, key, event)
for i, g in ipairs(grabbers) do
-- continue if the grabber explicitly returns false
if g(mod, key, event) ~= false then
break
end
end
end
--- Stop grabbing the keyboard for the provided callback.
-- When no callback is given, the last grabber gets removed (last one added to
-- the stack).
-- @param g The key grabber that must be removed.
function keygrabber.stop(g)
for i, v in ipairs(grabbers) do
if v == g then
table.remove(grabbers, i)
break
end
end
-- Stop the global key grabber if the last grabber disappears from stack.
if #grabbers == 0 then
keygrabbing = false
capi.keygrabber.stop()
end
end
---
-- Grab keyboard input and read pressed keys, calling the least callback
-- function from the stack at each keypress, until the stack is empty.
--
-- Calling run with the same callback again will bring the callback
-- to the top of the stack.
--
-- The callback function receives three arguments:
--
-- * a table containing modifiers keys
-- * a string with the pressed key
-- * a string with either "press" or "release" to indicate the event type
--
-- A callback can return `false` to pass the events to the next
-- keygrabber in the stack.
-- @param g The key grabber callback that will get the key events until it will be deleted or a new grabber is added.
-- @return the given callback `g`.
-- @usage
-- -- The following function can be bound to a key, and be used to resize a
-- -- client using the keyboard.
--
-- function resize(c)
-- local grabber = awful.keygrabber.run(function(mod, key, event)
-- if event == "release" then return end
--
-- if key == 'Up' then awful.client.moveresize(0, 0, 0, 5, c)
-- elseif key == 'Down' then awful.client.moveresize(0, 0, 0, -5, c)
-- elseif key == 'Right' then awful.client.moveresize(0, 0, 5, 0, c)
-- elseif key == 'Left' then awful.client.moveresize(0, 0, -5, 0, c)
-- else awful.keygrabber.stop(grabber)
-- end
-- end)
-- end
function keygrabber.run(g)
-- Remove the grabber if it is in the stack.
keygrabber.stop(g)
-- Record the grabber that has been added most recently.
table.insert(grabbers, 1, g)
-- Start the keygrabber if it is not running already.
if not keygrabbing then
keygrabbing = true
capi.keygrabber.run(grabber)
end
return g
end
return keygrabber
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