[gnome-builder] vim: Check for open buffer in :bnext and :bprev commands

[Matthew Leeds <mwleeds src gnome org>]

commit bd41b3fa1641e13067c78670a371576e31ebaf4d
Author: Matthew Leeds <mleeds redhat com>
Date:   Mon Jul 4 00:25:23 2016 -0400

    vim: Check for open buffer in :bnext and :bprev commands
    
    The vim commands :bnext and :bprev let the user switch to another
    buffer. If those commands are executed without any buffers open,
    ide_widget_action() fails and emits a warning. This commit checks if any
    buffers are open, and if not the command gracefully gives up. This
    matches vim's behavior.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=768356

 plugins/command-bar/gb-vim.c |   28 ++++++++++++++++++++++++----
 1 files changed, 24 insertions(+), 4 deletions(-)
---
diff --git a/plugins/command-bar/gb-vim.c b/plugins/command-bar/gb-vim.c
index 48701f1..c2bcade 100644
--- a/plugins/command-bar/gb-vim.c
+++ b/plugins/command-bar/gb-vim.c
@@ -749,10 +749,20 @@ gb_vim_command_bnext (GtkWidget      *active_widget,
                       const gchar    *options,
                       GError        **error)
 {
+  IdeWorkbench *workbench;
+  IdeContext *context;
+  IdeBufferManager *bufmgr;
+  guint n_buffers;
+
   g_assert (GTK_IS_WIDGET (active_widget));
 
-  // TODO: check for an open buffer ?
-  ide_widget_action (GTK_WIDGET (active_widget), "view-stack", "next-view", NULL);
+  workbench = ide_widget_get_workbench (GTK_WIDGET (active_widget));
+  context = ide_workbench_get_context (workbench);
+  bufmgr = ide_context_get_buffer_manager (context);
+  n_buffers = ide_buffer_manager_get_n_buffers (bufmgr);
+
+  if (n_buffers > 0)
+    ide_widget_action (GTK_WIDGET (active_widget), "view-stack", "next-view", NULL);
 
   return TRUE;
 }
@@ -763,10 +773,20 @@ gb_vim_command_bprevious (GtkWidget      *active_widget,
                           const gchar    *options,
                           GError        **error)
 {
+  IdeWorkbench *workbench;
+  IdeContext *context;
+  IdeBufferManager *bufmgr;
+  guint n_buffers;
+
   g_assert (GTK_IS_WIDGET (active_widget));
 
-  // TODO: check for an open buffer ?
-  ide_widget_action (GTK_WIDGET (active_widget), "view-stack", "previous-view", NULL);
+  workbench = ide_widget_get_workbench (GTK_WIDGET (active_widget));
+  context = ide_workbench_get_context (workbench);
+  bufmgr = ide_context_get_buffer_manager (context);
+  n_buffers = ide_buffer_manager_get_n_buffers (bufmgr);
+
+  if (n_buffers > 0)
+    ide_widget_action (GTK_WIDGET (active_widget), "view-stack", "previous-view", NULL);
 
   return TRUE;
 }