[gnome-software] snap: update logic to pick which app from the snap to launch.

[Robert Ancell <rancell src gnome org>]

commit c3ffc1b1056a7668c719709c001aee422875bfea
Author: James Henstridge <james jamesh id au>
Date:   Fri Jun 30 16:17:47 2017 +0800

    snap: update logic to pick which app from the snap to launch.
    
    Previously, the first app reported by snapd would be launched.  We now
    favour apps with desktop files, and will favour an app whose name
    matches the snap name (i.e. the "main" app) over others.

 plugins/snap/gs-plugin-snap.c |   84 +++++++++++++++++++++++++++++++---------
 1 files changed, 65 insertions(+), 19 deletions(-)
---
diff --git a/plugins/snap/gs-plugin-snap.c b/plugins/snap/gs-plugin-snap.c
index 930a0ec..7424343 100644
--- a/plugins/snap/gs-plugin-snap.c
+++ b/plugins/snap/gs-plugin-snap.c
@@ -21,6 +21,7 @@
 
 #include <config.h>
 
+#include <gio/gdesktopappinfo.h>
 #include <snapd-glib/snapd-glib.h>
 #include <gnome-software.h>
 
@@ -423,6 +424,51 @@ get_store_snap (GsPlugin *plugin, const gchar *name, GCancellable *cancellable,
        return g_object_ref (g_ptr_array_index (snaps, 0));
 }
 
+static void
+find_launch_app (GsApp *app, SnapdSnap *local_snap)
+{
+       const char *snap_name;
+       GPtrArray *apps;
+       guint i;
+       const char *launch_name = NULL;
+       const char *launch_desktop = NULL;
+
+       snap_name = snapd_snap_get_name (local_snap);
+       apps = snapd_snap_get_apps (local_snap);
+
+       /* Pick the "main" app from the snap.  In order of
+        * preference, we want to pick:
+        *
+        *   1. the main app, provided it has a desktop file
+        *   2. the first app with a desktop file
+        *   3. the main app
+        *   4. the first app
+        *
+        * The "main app" is one whose name matches the snap name.
+        */
+       for (i = 0; i < apps->len; i++) {
+               SnapdApp *snap_app = apps->pdata[i];
+               const char *app_name = snapd_app_get_name (snap_app);
+               const char *app_desktop = snapd_app_get_desktop_file (snap_app);
+               gboolean is_main_app = !g_strcmp0(snap_name, app_name);
+
+               if (launch_name == NULL || is_main_app) {
+                       launch_name = app_name;
+               }
+               if (launch_desktop == NULL || is_main_app) {
+                       if (app_desktop != NULL) {
+                               launch_desktop = app_desktop;
+                       }
+               }
+       }
+
+       gs_app_set_metadata (app, "snap::launch-name", launch_name);
+       gs_app_set_metadata (app, "snap::launch-desktop", launch_desktop);
+
+       if (!launch_name)
+               gs_app_add_quirk (app, AS_APP_QUIRK_NOT_LAUNCHABLE);
+}
+
 gboolean
 gs_plugin_refine_app (GsPlugin *plugin,
                      GsApp *app,
@@ -449,9 +495,7 @@ gs_plugin_refine_app (GsPlugin *plugin,
        /* get information from installed snaps */
        local_snap = snapd_client_list_one_sync (client, id, cancellable, NULL);
        if (local_snap != NULL) {
-               GPtrArray *apps;
-               const gchar *name, *launch_name = NULL;
-
+               const gchar *name;
                if (gs_app_get_state (app) == AS_APP_STATE_UNKNOWN)
                        gs_app_set_state (app, AS_APP_STATE_INSTALLED);
                name = snapd_snap_get_title (local_snap);
@@ -468,13 +512,7 @@ gs_plugin_refine_app (GsPlugin *plugin,
                if (g_strcmp0 (icon_url, "") == 0)
                        icon_url = NULL;
 
-               apps = snapd_snap_get_apps (local_snap);
-               if (apps->len > 0)
-                       launch_name = snapd_app_get_name (apps->pdata[0]);
-               if (launch_name != NULL)
-                       gs_app_set_metadata (app, "snap::launch-name", launch_name);
-               else
-                       gs_app_add_quirk (app, AS_APP_QUIRK_NOT_LAUNCHABLE);
+               find_launch_app (app, local_snap);
        }
 
        /* get information from snap store */
@@ -643,8 +681,7 @@ gs_plugin_launch (GsPlugin *plugin,
                  GError **error)
 {
        const gchar *launch_name;
-       g_autofree gchar *binary_name = NULL;
-       GAppInfoCreateFlags flags = G_APP_INFO_CREATE_NONE;
+       const gchar *launch_desktop;
        g_autoptr(GAppInfo) info = NULL;
 
        /* We can only launch apps we know of */
@@ -652,17 +689,26 @@ gs_plugin_launch (GsPlugin *plugin,
                return TRUE;
 
        launch_name = gs_app_get_metadata_item (app, "snap::launch-name");
+       launch_desktop = gs_app_get_metadata_item (app, "snap::launch-desktop");
        if (!launch_name)
                return TRUE;
 
-       if (g_strcmp0 (launch_name, gs_app_get_id (app)) == 0)
-               binary_name = g_strdup_printf ("/snap/bin/%s", launch_name);
-       else
-               binary_name = g_strdup_printf ("/snap/bin/%s.%s", gs_app_get_id (app), launch_name);
+       if (launch_desktop) {
+               info = (GAppInfo *)g_desktop_app_info_new_from_filename (launch_desktop);
+       } else {
+               g_autofree gchar *binary_name = NULL;
+               GAppInfoCreateFlags flags = G_APP_INFO_CREATE_NONE;
+
+               if (g_strcmp0 (launch_name, gs_app_get_id (app)) == 0)
+                       binary_name = g_strdup_printf ("/snap/bin/%s", launch_name);
+               else
+                       binary_name = g_strdup_printf ("/snap/bin/%s.%s", gs_app_get_id (app), launch_name);
+
+               if (!is_graphical (plugin, app, cancellable))
+                       flags |= G_APP_INFO_CREATE_NEEDS_TERMINAL;
+               info = g_app_info_create_from_commandline (binary_name, NULL, flags, error);
+       }
 
-       if (!is_graphical (plugin, app, cancellable))
-               flags |= G_APP_INFO_CREATE_NEEDS_TERMINAL;
-       info = g_app_info_create_from_commandline (binary_name, NULL, flags, error);
        if (info == NULL)
                return FALSE;