[gtksourceview] assistant: let caller know if position changed

[Christian Hergert <chergert src gnome org>]

commit 428c7148b7ab02aa0f167f32c97532130ec86b74
Author: Christian Hergert <chergert redhat com>
Date:   Fri Sep 2 14:42:14 2022 -0700

    assistant: let caller know if position changed
    
    The hope for this originally is that we could use the result of this
    function to determine what level of widget invalidation we needed on
    the GtkSourceView to ensure we had an allocation for the next snapshot.
    
    In practice, it didn't matter because either way we need to do a full
    gtk_widget_queue_resize(). However, it does attempt to avoid invalidating
    some state in the popover so it's useful enough to keep it around so we
    know explicitely when we've changed things.

 gtksourceview/gtksourceassistant.c | 45 ++++++++++++++++++++++++++------------
 1 file changed, 31 insertions(+), 14 deletions(-)
---
diff --git a/gtksourceview/gtksourceassistant.c b/gtksourceview/gtksourceassistant.c
index 6ad96109..a431756a 100644
--- a/gtksourceview/gtksourceassistant.c
+++ b/gtksourceview/gtksourceassistant.c
@@ -117,15 +117,12 @@ get_gutter_width (GtkSourceView *view)
        return 0;
 }
 
-static void
+static gboolean
 _gtk_source_assistant_update_position (GtkSourceAssistant *assistant)
 {
        GtkSourceAssistantPrivate *priv = _gtk_source_assistant_get_instance_private (assistant);
-       const GList *children = NULL;
        GtkWidget *parent;
-       GdkRectangle rect;
-       int x = 0;
-       int y = 0;
+       gboolean changed = FALSE;
 
        g_assert (GTK_SOURCE_IS_ASSISTANT (assistant));
 
@@ -134,6 +131,10 @@ _gtk_source_assistant_update_position (GtkSourceAssistant *assistant)
        if (GTK_SOURCE_IS_VIEW (parent))
        {
                GdkRectangle visible_rect;
+               GdkRectangle old_rect;
+               GdkRectangle rect;
+               int old_x, old_y;
+               int x, y;
 
                gtk_text_view_get_visible_rect (GTK_TEXT_VIEW (parent), &visible_rect);
 
@@ -144,22 +145,38 @@ _gtk_source_assistant_update_position (GtkSourceAssistant *assistant)
                rect.y -= visible_rect.y;
                rect.x += get_gutter_width (GTK_SOURCE_VIEW (parent));
 
-               gtk_popover_set_offset (GTK_POPOVER (assistant), x, y);
-               gtk_popover_set_pointing_to (GTK_POPOVER (assistant), &rect);
+               gtk_popover_get_offset (GTK_POPOVER (assistant), &old_x, &old_y);
+
+               if (old_x != x || old_y != y)
+               {
+                       gtk_popover_set_offset (GTK_POPOVER (assistant), x, y);
+                       changed = TRUE;
+               }
+
+               if (!gtk_popover_get_pointing_to (GTK_POPOVER (assistant), &old_rect) ||
+                   !gdk_rectangle_equal (&old_rect, &rect))
+               {
+                       gtk_popover_set_pointing_to (GTK_POPOVER (assistant), &rect);
+                       changed = TRUE;
+               }
        }
 
        if (priv->child != NULL)
        {
-               children = _gtk_source_assistant_child_get_attached (priv->child);
-       }
+               const GList *children = _gtk_source_assistant_child_get_attached (priv->child);
 
-       for (const GList *iter = children; iter; iter = iter->next)
-       {
-               GtkSourceAssistant *child = iter->data;
+               for (const GList *iter = children; iter; iter = iter->next)
+               {
+                       GtkSourceAssistant *child = iter->data;
+                       int x, y;
 
-               _gtk_source_assistant_get_offset (child, &x, &y);
-               gtk_popover_set_offset (GTK_POPOVER (child), x, y);
+                       _gtk_source_assistant_get_offset (child, &x, &y);
+                       gtk_popover_set_offset (GTK_POPOVER (child), x, y);
+               }
        }
+
+
+       return changed;
 }
 
 static gboolean