From 94dede75113b934d7f49cf8b880e61dfdb170e58 Mon Sep 17 00:00:00 2001
From: Uli Schlachter <psychon@znc.in>
Date: Sat, 26 Mar 2016 18:33:45 +0100
Subject: [PATCH] Add functions for calling something for every screen

This adds gears.screen which contains a wrapper around
screen.connect_signal("added", func) that also calls the callback function for
each screen that already exists. This is added in gears.screen so that it can
also be used from e.g. wibox, if needed. Feel free to move this elsewhere if
that's a bad idea (I'm not really convinced of it).

Signed-off-by: Uli Schlachter <psychon@znc.in>
---
 lib/gears/init.lua   |  1 +
 lib/gears/screen.lua | 29 +++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+)
 create mode 100644 lib/gears/screen.lua

diff --git a/lib/gears/init.lua b/lib/gears/init.lua
index 4f5e83f6e..3fe46b448 100644
--- a/lib/gears/init.lua
+++ b/lib/gears/init.lua
@@ -18,6 +18,7 @@ return
     matrix = require("gears.matrix");
     shape = require("gears.shape");
     protected_call = require("gears.protected_call");
+    screen = require("gears.screen");
 }
 
 -- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80
diff --git a/lib/gears/screen.lua b/lib/gears/screen.lua
new file mode 100644
index 000000000..fea8fd1ed
--- /dev/null
+++ b/lib/gears/screen.lua
@@ -0,0 +1,29 @@
+---------------------------------------------------------------------------
+-- @author Uli Schlachter
+-- @copyright 2016 Uli Schlachter
+-- @release @AWESOME_VERSION@
+-- @classmod gears.screen
+---------------------------------------------------------------------------
+
+local screen = screen
+
+local module = {}
+
+--- Call a function for each existing and created-in-the-future screen.
+-- @tparam function func The function to call.
+function module.connect_for_each_screen(func)
+    for s in screen do
+        func(s)
+    end
+    screen.connect_signal("added", func)
+end
+
+--- Undo the effect of connect_for_each_screen.
+-- @tparam function func The function that should no longer be called.
+function module.disconnect_for_each_screen(func)
+    screen.disconnect_signal("added", func)
+end
+
+return module
+
+-- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80