window swallowing

init.lua

@@ -5,6 +5,7 @@
 
 
 return {
-    layout = require("bling.layout")
+    layout = require("bling.layout"),
+    module = require("bling.module"),
 }
 

module/init.lua

@@ -0,0 +1,3 @@
+return {
+    window_swallowing = require("bling.module.window_swallowing")
+}

module/window_swallowing.lua

@@ -0,0 +1,95 @@
+local awful = require("awful")
+local gears = require("gears")
+local beautiful = require("beautiful")
+
+-- It might actually swallow too much, that's why there is a filter option by classname
+-- without the don't-swallow-list it would also swallow for example 
+-- file pickers or new firefox windows spawned by an already existing one
+
+local window_swallowing_activated = false
+
+-- you might want to add or remove applications here
+local dont_swallow_classname_list = beautiful.dont_swallow_classname_list or {"firefox", "Gimp"} 
+local activate_dont_swallow_filter = beautiful.dont_swallow_filter_activated or true
+
+-- makes c the same size and position as parent_client
+local function copy_size(c, parent_client)
+    if not c or not parent_client then
+        return
+    end
+    if not c.valid or not parent_client.valid then
+        return
+    end
+    c.floating = parent_client.floating
+    c.x = parent_client.x;
+    c.y = parent_client.y;
+    c.width = parent_client.width;
+    c.height = parent_client.height;
+    -- TODO that function should also support "copying" the 
+    -- index of the parent_client to the new c 
+end
+
+-- checks if client classname matches with any entry of the dont-swallow-list
+local function check_if_swallow(c) 
+    if not activate_dont_swallow_filter then 
+        return true 
+    end 
+    for _, classname in ipairs(dont_swallow_classname_list) do 
+        if classname == c.class then 
+            return false
+        end 
+    end 
+    return true
+end 
+
+-- the function that will be connected to / disconnected from the spawn client signal
+local function manage_clientspawn(c)
+    -- get the last focused window to check if it is a parent window
+    local parent_client=awful.client.focus.history.get(c.screen, 1)
+    if not parent_client then return end 
+    
+    -- io.popen is normally discouraged. Should probably be changed 
+    local handle = io.popen([[pstree -T -p -a -s ]] .. tostring(c.pid) ..  [[ | sed '2q;d' | grep -o '[0-9]*$' | tr -d '\n']])
+    local parent_pid = handle:read("*a")
+    handle:close()
+
+    if (tostring(parent_pid) == tostring(parent_client.pid)) and check_if_swallow(c) then 
+
+        c:connect_signal("unmanage", function()
+            parent_client.minimized = false 
+            copy_size(parent_client, c)
+        end)
+
+        copy_size(c, parent_client)
+        parent_client.minimized = true
+
+    end
+end
+
+-- without the following functions that module would be autoloaded by require("bling") 
+-- a toggle window swallowing hotkey is also possible that way
+
+local function start()
+    client.connect_signal("manage", manage_clientspawn)
+    window_swallowing_activated = true
+end 
+
+local function stop()
+    client.disconnect_signal("manage", manage_clientspawn)
+    window_swallowing_activated = false
+end 
+
+local function toggle()
+    if window_swallowing_activated then 
+        stop()
+    else 
+        start()
+    end 
+end 
+
+return {
+    start = start,
+    stop = stop,
+    toggle = toggle
+}
+