[gnome-builder] greeter: re-open previous project if we detect one

[Christian Hergert <chergert src gnome org>]

commit afbbbb14327931442b2385efafb1d132b0e3204c
Author: Christian Hergert <chergert redhat com>
Date:   Fri Jan 12 21:18:17 2018 -0800

    greeter: re-open previous project if we detect one
    
    The prefix checks are sort of shaky, but we don't really support that
    level of complexity in projects anyway. And we need to ensure we don't
    open projects with different build systems at the same time.

 src/libide/greeter/ide-greeter-perspective.c | 37 ++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)
---
diff --git a/src/libide/greeter/ide-greeter-perspective.c b/src/libide/greeter/ide-greeter-perspective.c
index 6ae59156c..052d7db41 100644
--- a/src/libide/greeter/ide-greeter-perspective.c
+++ b/src/libide/greeter/ide-greeter-perspective.c
@@ -907,12 +907,49 @@ ide_greeter_perspective_project_activated (IdeGreeterPerspective *self,
                                            IdeProjectInfo        *project_info,
                                            IdeGreeterSection     *section)
 {
+  const GList *windows;
+  GFile *info_file;
+
   IDE_ENTRY;
 
   g_assert (IDE_IS_GREETER_PERSPECTIVE (self));
   g_assert (IDE_IS_PROJECT_INFO (project_info));
   g_assert (IDE_IS_GREETER_SECTION (section));
 
+  if (!(info_file = ide_project_info_get_file (project_info)))
+    goto load_project;
+
+  /* Look to see if we can find an already open project matching info */
+  windows = gtk_application_get_windows (GTK_APPLICATION (IDE_APPLICATION_DEFAULT));
+
+  for (const GList *iter = windows; iter != NULL; iter = iter->next)
+    {
+      GtkWindow *window = iter->data;
+      IdeContext *context;
+      GFile *project_file;
+
+      if (!IDE_IS_WORKBENCH (window))
+        continue;
+
+      if (!(context = ide_workbench_get_context (IDE_WORKBENCH (window))))
+        continue;
+
+      project_file = ide_context_get_project_file (context);
+
+      if (g_file_equal (project_file, info_file) ||
+          g_file_has_prefix (project_file, info_file) ||
+          g_file_has_prefix (info_file, project_file))
+        {
+          GtkWidget *toplevel = gtk_widget_get_toplevel (GTK_WIDGET (self));
+
+          gtk_window_present (window);
+          gtk_window_close (GTK_WINDOW (toplevel));
+
+          IDE_EXIT;
+        }
+    }
+
+load_project:
   ide_greeter_perspective_load_project (self, project_info);
 
   IDE_EXIT;