From 6f5d566ec0397d0e75c4b2e0386917d2e94d0538 Mon Sep 17 00:00:00 2001
From: Stefano Mazzucco <stefano@curso.re>
Date: Wed, 8 May 2019 16:41:39 +0100
Subject: [PATCH] Use lgi to get icons directly from GTK

Rather than setting a path to the icons, use lgi to get the current GTK theme
and then look up the icons. Then set the image as a cairo surface by using the
GTK api directly.

With this change, one can modify their GTK icon theme (e.g. with lxappearance),
restart AwesomeWM and have the widget's icon automatically updated.
---
 README.md        | 18 +++++++-----------
 power_widget.lua | 40 ++++++++++++++++++++++------------------
 2 files changed, 29 insertions(+), 29 deletions(-)

diff --git a/README.md b/README.md
index f0ec6eb..745de93 100644
--- a/README.md
+++ b/README.md
@@ -53,20 +53,16 @@ documentation of your display manager of choice for more information.
 
 # Configuration
 
-The widget displays power icons that are searched in the folders defined
-in the table `beautiful.upower_icon_theme_dirs` with extensions defined
-in the table `beautiful.upower_icon_extensions`.
-The default is to look into `"/usr/share/icons/Adwaita/scalable/devices/"`
-and  `"/usr/share/icons/Adwaita/scalable/status/"`for
-icons whose extension is `"svg"`. Note that the directory paths *must* end
-with a slash and that the extensions *must not* contain a dot.
-The icons are searched using Awesome's
-[`awful.util.geticonpath` function](https://awesomewm.org/doc/api/modules/awful.util.html#geticonpath).
+The widget will display the battery icons defined in your GTK+ theme and it
+will resize them to fit in the available space. This means that you can switch
+your icon theme, for example using `lxappearance`, and update the widget by
+restarting AwesomeWM.
 
 You can specify a GUI client to be launched when the widget is right-clicked.
 This can be done by changing the `gui_client` field of the widget. The default
-is to have no client. For example, you could use the [XFCE4 Power Manager](http://goodies.xfce.org/projects/applications/xfce4-power-manager)
-or the [GNOME one](https://projects.gnome.org/gnome-power-manager/).
+is to have no client. For example, you could use the [XFCE4 Power
+Manager](http://goodies.xfce.org/projects/applications/xfce4-power-manager) or
+the [GNOME one](https://projects.gnome.org/gnome-power-manager/).
 
 You can set the critical battery percentage at which a warning will be
 displayed using the `critical_percentage` property (defaults to `5`).
diff --git a/power_widget.lua b/power_widget.lua
index 0a7fd6a..05dc9e5 100644
--- a/power_widget.lua
+++ b/power_widget.lua
@@ -1,5 +1,5 @@
 --[[
-  Copyright 2017 Stefano Mazzucco <stefano AT curso DOT re>
+  Copyright 2017-2019 Stefano Mazzucco <stefano AT curso DOT re>
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -15,37 +15,41 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ]]
 
-local beautiful = require("beautiful")
-
 local wibox = require("wibox")
 local awful = require("awful")
 local naughty = require("naughty")
 
+local lgi = require('lgi')
+local icon_theme = lgi.Gtk.IconTheme.get_default()
+local IconLookupFlags = lgi.Gtk.IconLookupFlags
+
 local power = require("upower_dbus")
 local WarningLevel = power.enums.BatteryWarningLevel
 
 local spawn_with_shell = awful.spawn.with_shell or awful.util.spawn_with_shell
-local icon_theme_dirs = { -- The trailing slash is mandatory!
-  "/usr/share/icons/Adwaita/scalable/status/",
-  "/usr/share/icons/Adwaita/scalable/devices/"}
-local icon_theme_extensions = {"svg"}
-icon_theme_dirs = beautiful.upower_icon_theme_dirs or icon_theme_dirs
-icon_theme_extensions = beautiful.upower_icon_theme_extension or icon_theme_extensions
 
-local widget = wibox.widget.imagebox()
+local icon_size = 64
+local icon_flags = {IconLookupFlags.GENERIC_FALLBACK}
+
+local widget = wibox.widget {
+  resize = true,
+  widget = wibox.widget.imagebox
+}
+
 widget.critical_percentage = 5
 
-local function build_icon_path(device)
-  if device.IconName then
-    return awful.util.geticonpath(device.IconName, icon_theme_extensions, icon_theme_dirs)
-  end
-  return ""
-end
-
 function widget:update()
   self.device:update_mappings()
 
-  self:set_image(build_icon_path(self.device))
+  local icon = icon_theme:lookup_icon(
+    self.device.IconName,
+    icon_size,
+    icon_flags
+  )
+
+  if icon then
+    self.image = icon:load_surface()
+  end
 
   if self.device.IsPresent then