deepin.deepin-wm: fix paths related to plugins and desktop files

[romildo]

Motivation for this change

• deepin.deepin-wm: set plugins dir from environment variable
• deepin.deepin-wm: use absolute path in desktop file

About packaging deepin for NixOS: #59023

See also #59244 (comment)

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nix-review --run "nix-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Assured whether relevant documentation is up to date
• Fits CONTRIBUTING.md.

[worldofpeace]

Are there any deepin-wm plugins distributed or used internally in other DDE components?
This will also need a wrapper used when there's plugins provided.

[romildo]

Are there any deepin-wm plugins distributed or used internally in other DDE components?

I did not find any.

Edited: I have looked at Arch Linux, and Deepin Linux.

[romildo]

Considering that there is no other DDE component that installs any plugins for deepin-wm, it may be more convenient now to not patch the source code to set plugins dir from environment variable. Also the wrapper is not needed currently.

@worldofpeace Do you agree?

[worldofpeace]

Yeah, I think there's a comment somewhere from me about patching only when there's a plugin ecosystem that's useful. For example in pantheon gala isn't patched because almost all development work for plugins eventually get upstreamed. And from the looks of it this is a fork of gala.

[worldofpeace]

Though I wouldn't toss the code away, it could change in the future who knows

[romildo]

I am removing the deepin-wm.plugins-dir.patch from this PR, and keeping its contents in this comment, case it is needed later on.

From 028f9214a251741df89b56836fa4e8efd16c8cb2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Romildo=20Malaquias?= <[email protected]>
Date: Fri, 19 Apr 2019 23:56:33 -0300
Subject: [PATCH] deepin.deepin-wm: set plugin dir from environment variable

---
 src/PluginManager.vala | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/PluginManager.vala b/src/PluginManager.vala
index 9ff8856..f9ac214 100644
--- a/src/PluginManager.vala
+++ b/src/PluginManager.vala
@@ -58,7 +58,11 @@ namespace Gala
 				return;
 			}
 
-			plugin_dir = File.new_for_path (Config.PLUGINDIR);
+                        string? plugin_dir_name = GLib.Environment.get_variable ("DEEPIN_WM_PLUGINS_DIR");
+                        if (plugin_dir_name == null || plugin_dir_name == "")
+                        	plugin_dir_name = Config.PLUGINDIR;
+			debug ("Plugin dir: %s", plugin_dir_name);
+			plugin_dir = File.new_for_path (plugin_dir_name);
 			if (!plugin_dir.query_exists ())
 				return;
 
-- 
2.21.0