[gtksourceview] completion: tab in snippet takes precidence over completion

[Christian Hergert <chergert src gnome org>]

commit e8ac375aa5e378627edf3c82790bc5a56f35bf19
Author: Christian Hergert <chergert redhat com>
Date:   Fri Sep 2 14:12:24 2022 -0700

    completion: tab in snippet takes precidence over completion
    
    If you have an active snippet (especially from a previous copmletion), then
    tabbing should move you through the snippet positions, not activate the
    completion you might be typing through. You can always still use enter to
    activate any completion in the current position.

 gtksourceview/gtksourcecompletionlistbox.c | 30 +++++++++++++++++++++++++++++-
 gtksourceview/gtksourceview-private.h      |  1 +
 gtksourceview/gtksourceview.c              | 10 ++++++++++
 3 files changed, 40 insertions(+), 1 deletion(-)
---
diff --git a/gtksourceview/gtksourcecompletionlistbox.c b/gtksourceview/gtksourcecompletionlistbox.c
index 47db89c3..4c002b0d 100644
--- a/gtksourceview/gtksourcecompletionlistbox.c
+++ b/gtksourceview/gtksourcecompletionlistbox.c
@@ -27,6 +27,7 @@
 #include "gtksourcecompletionlistboxrow-private.h"
 #include "gtksourcecompletionproposal.h"
 #include "gtksourcecompletionprovider.h"
+#include "gtksourceview-private.h"
 
 struct _GtkSourceCompletionListBox
 {
@@ -482,6 +483,33 @@ activate_nth_cb (GtkWidget *widget,
        return TRUE;
 }
 
+static gboolean
+activate_nth_tab_cb (GtkWidget *widget,
+                     GVariant  *param,
+                     gpointer   user_data)
+{
+       GtkSourceCompletionListBox *self = (GtkSourceCompletionListBox *)widget;
+       GtkSourceView *view;
+
+       g_assert (GTK_SOURCE_IS_COMPLETION_LIST_BOX (self));
+
+       if (self->context == NULL)
+       {
+               return FALSE;
+       }
+
+       /* If Tab was pressed by we have a snippet active, that takes precidence
+        * and we should ignore this completion request.
+        */
+       view = gtk_source_completion_context_get_view (self->context);
+       if (!view || _gtk_source_view_has_snippet (view))
+       {
+               return FALSE;
+       }
+
+       return activate_nth_cb (widget, param, user_data);
+}
+
 static gboolean
 _gtk_source_completion_list_box_key_pressed_cb (GtkSourceCompletionListBox *self,
                                                 guint                       keyval,
@@ -756,7 +784,7 @@ gtk_source_completion_list_box_class_init (GtkSourceCompletionListBoxClass *klas
        gtk_widget_class_add_binding (widget_class, GDK_KEY_9, GDK_ALT_MASK, activate_nth_cb, "(i)", 9);
        gtk_widget_class_add_binding (widget_class, GDK_KEY_Return, 0, activate_nth_cb, "(i)", 0);
        gtk_widget_class_add_binding (widget_class, GDK_KEY_KP_Enter, 0, activate_nth_cb, "(i)", 0);
-       gtk_widget_class_add_binding (widget_class, GDK_KEY_Tab, 0, activate_nth_cb, "(i)", 0);
+       gtk_widget_class_add_binding (widget_class, GDK_KEY_Tab, 0, activate_nth_tab_cb, "(i)", 0);
        gtk_widget_class_add_binding (widget_class, GDK_KEY_Right, 0, move_next_alternate, NULL);
        gtk_widget_class_add_binding (widget_class, GDK_KEY_Left, 0, move_previous_alternate, NULL);
        gtk_widget_class_add_binding_action (widget_class, GDK_KEY_Escape, 0, "assistant.hide", NULL);
diff --git a/gtksourceview/gtksourceview-private.h b/gtksourceview/gtksourceview-private.h
index 46460a6d..72d0ba14 100644
--- a/gtksourceview/gtksourceview-private.h
+++ b/gtksourceview/gtksourceview-private.h
@@ -49,6 +49,7 @@ typedef struct _GtkSourceViewSnippets
        gulong                buffer_cursor_moved_handler;
 } GtkSourceViewSnippets;
 
+gboolean _gtk_source_view_has_snippet              (GtkSourceView           *view);
 void     _gtk_source_view_add_assistant            (GtkSourceView           *view,
                                                     GtkSourceAssistant      *assistant);
 void     _gtk_source_view_remove_assistant         (GtkSourceView           *view,
diff --git a/gtksourceview/gtksourceview.c b/gtksourceview/gtksourceview.c
index d0dc90b0..592235e6 100644
--- a/gtksourceview/gtksourceview.c
+++ b/gtksourceview/gtksourceview.c
@@ -5541,3 +5541,13 @@ _gtk_source_view_get_current_line_number_bold (GtkSourceView *view)
 
        return priv->current_line_number_bold;
 }
+
+gboolean
+_gtk_source_view_has_snippet (GtkSourceView *view)
+{
+       GtkSourceViewPrivate *priv = gtk_source_view_get_instance_private (view);
+
+       g_return_val_if_fail (GTK_SOURCE_IS_VIEW (view), FALSE);
+
+       return priv->snippets.queue.length > 0;
+}