[gnome-shell/gbsneto/fix-switching-scale: 1/4] st/theme-node: Consider scale factor when comparing

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 084ee518ee5100f66ea92433a0a44b8f22031c12
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Fri Apr 3 17:44:54 2020 -0300

    st/theme-node: Consider scale factor when comparing
    
    The CSS engine of St is scale-aware, which means every length
    and size it produces is multiplied by the current scale factor.
    
    However, the individual nodes aren't aware of the scale factor
    when they compare to each other.
    
    Store and compare the scale factors in the nodes themselves.
    
    Fixes https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/1635
    
    https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1176

 src/st/st-theme-node-private.h | 2 ++
 src/st/st-theme-node.c         | 6 ++++++
 2 files changed, 8 insertions(+)
---
diff --git a/src/st/st-theme-node-private.h b/src/st/st-theme-node-private.h
index 57f3bd6d8f..50e6b50b7e 100644
--- a/src/st/st-theme-node-private.h
+++ b/src/st/st-theme-node-private.h
@@ -117,6 +117,8 @@ struct _StThemeNode {
   CoglPipeline *color_pipeline;
 
   StThemeNodePaintState cached_state;
+
+  int scale_factor;
 };
 
 void _st_theme_node_ensure_background (StThemeNode *node);
diff --git a/src/st/st-theme-node.c b/src/st/st-theme-node.c
index 31057b0129..bd55235176 100644
--- a/src/st/st-theme-node.c
+++ b/src/st/st-theme-node.c
@@ -219,6 +219,8 @@ st_theme_node_new (StThemeContext    *context,
   if (theme == NULL && parent_node != NULL)
     theme = parent_node->theme;
 
+  g_object_get (context, "scale-factor", &node->scale_factor, NULL);
+
   g_set_object (&node->theme, theme);
   node->element_type = element_type;
   node->element_id = g_strdup (element_id);
@@ -345,6 +347,7 @@ st_theme_node_equal (StThemeNode *node_a, StThemeNode *node_b)
       node_a->context != node_b->context ||
       node_a->theme != node_b->theme ||
       node_a->element_type != node_b->element_type ||
+      node_a->scale_factor != node_b->scale_factor ||
       g_strcmp0 (node_a->element_id, node_b->element_id) ||
       g_strcmp0 (node_a->inline_style, node_b->inline_style))
     return FALSE;
@@ -3967,6 +3970,9 @@ st_theme_node_geometry_equal (StThemeNode *node,
 
   g_return_val_if_fail (ST_IS_THEME_NODE (other), FALSE);
 
+  if (node->scale_factor != other->scale_factor)
+    return FALSE;
+
   _st_theme_node_ensure_geometry (node);
   _st_theme_node_ensure_geometry (other);