naughty: resize naughtifications to the minimum needed space

This commits adds support for :extents() to naughty. It changes the
behaviour of naughty.config.presets.*.width so that if it's set to nil,
the notification gets resized automagically. Else the value of width is
used for the notification's width.
The meaning of naughty.config.presets.*.height changed similarly, now,
if set, it means the literal height of the notifications. If unset, the
notification gets resized automagically as well.

Signed-off-by: Gregor Best <farhaven@googlemail.com>
Signed-off-by: Julien Danjou <julien@danjou.info>

lib/naughty.lua.in

@@ -91,8 +91,8 @@ config.presets = {
         hover_timeout = nil,
         position = "top_right",
         screen = 1,
-        width = 300,
+        width = nil,
-        height = 16,
+        height = nil,
         icon = nil,
         icon_size = nil
     },
@@ -273,6 +273,7 @@ function notify(args)
     local screen = args.screen or (args.preset and args.preset.screen) or config.presets.normal.screen
     local ontop = args.ontop or config.ontop
     local width = args.width or (args.preset and args.preset.width) or config.presets.normal.width
+    local height = args.preset and args.preset.height or config.presets.normal.height
     local hover_timeout = args.hover_timeout or (args.preset and args.preset.hover_timeout) or config.presets.normal.hover_timeout
     local opacity = args.opacity or (args.preset and args.preset.opacity) or config.presets.normal.opacity
 
@@ -370,13 +371,31 @@ function notify(args)
                                border_width = config.border_width })
 
     -- position the wibox
-    local lines = 1; for i in string.gmatch(title..text, "\n") do lines = lines + 1 end
+    if height then
-    local height = args.preset and args.preset.height or config.presets.normal.height
+        if iconbox and iconbox.image.height > height then
-    if iconbox and iconbox.image.height > lines * height then
             notification.height = iconbox.image.height
         else
-        notification.height = lines * height end
+            notification.height = height
+        end
+    else
+        if iconbox and iconbox:extents().height > textbox:extents().height then
+            notification.height = iconbox:extents().height
+        else
+            notification.height = textbox:extents().height
+        end
+    end
+    if width then
         notification.width = width
+    else
+        notification.width = textbox:extents().width + (iconbox and iconbox:extents().width or 0) + (2 * (config.border_width or 0))
+    end
+    if notification.width > capi.screen[screen].workarea.width - 2 * (config.border_width or 0) then
+        notification.width = capi.screen[screen].workarea.width - 2 * (config.border_width or 0)
+    end
+    if notification.height > capi.screen[screen].workarea.height - 2 * (config.border_width or 0) - 2 * (config.padding or 0) then
+        notification.height = capi.screen[screen].workarea.height - 2 * (config.border_width or 0) - 2 * (config.padding or 0)
+    end
+
     local offset = get_offset(screen, notification.position, nil, notification.width, notification.height)
     notification.box:geometry({ width = notification.width,
                                 height = notification.height,