[metacity] libmetacity: add meta_theme_impl_get_scale

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 81135bc5487346ed8eaefa5307a0e217c4b2576e
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Mon Nov 28 19:16:57 2016 +0200

    libmetacity: add meta_theme_impl_get_scale

 libmetacity/meta-theme-gtk.c          |    6 ++--
 libmetacity/meta-theme-impl-private.h |    6 ++--
 libmetacity/meta-theme-impl.c         |   39 +++++++++++++++++++-------------
 libmetacity/meta-theme-metacity.c     |    6 ++--
 libmetacity/meta-theme.c              |   10 ++++----
 5 files changed, 37 insertions(+), 30 deletions(-)
---
diff --git a/libmetacity/meta-theme-gtk.c b/libmetacity/meta-theme-gtk.c
index 22a8f67..f80c553 100644
--- a/libmetacity/meta-theme-gtk.c
+++ b/libmetacity/meta-theme-gtk.c
@@ -235,7 +235,7 @@ meta_theme_gtk_get_frame_borders (MetaThemeImpl    *impl,
     text_height = 0;
 
   /* Scale geometry for HiDPI, see comment in meta_theme_gtk_draw_frame () */
-  scale = get_window_scaling_factor ();
+  scale = meta_theme_impl_get_scale (impl);
 
   title_height = layout->gtk.title_margin.top +
                  text_height / scale +
@@ -327,7 +327,7 @@ meta_theme_gtk_calc_geometry (MetaThemeImpl     *impl,
   fgeom->height = height;
 
   /* Scale geometry for HiDPI, see comment in meta_theme_gtk_draw_frame () */
-  scale = get_window_scaling_factor ();
+  scale = meta_theme_impl_get_scale (impl);
 
   content_width = width -
                   borders.invisible.left - layout->gtk.frame_border.left * scale -
@@ -655,7 +655,7 @@ meta_theme_gtk_draw_frame (MetaThemeImpl           *impl,
    *    radii, ...) at the correct scale - as a result, we have to "unscale"
    *    the geometry again to not apply the scaling twice
    */
-  scale = get_window_scaling_factor ();
+  scale = meta_theme_impl_get_scale (impl);
   cairo_scale (cr, scale, scale);
 
   borders = &fgeom->borders;
diff --git a/libmetacity/meta-theme-impl-private.h b/libmetacity/meta-theme-impl-private.h
index 1112fc3..9227618 100644
--- a/libmetacity/meta-theme-impl-private.h
+++ b/libmetacity/meta-theme-impl-private.h
@@ -80,6 +80,9 @@ G_GNUC_INTERNAL
 gboolean           meta_theme_impl_get_composited (MetaThemeImpl           *impl);
 
 G_GNUC_INTERNAL
+gint               meta_theme_impl_get_scale      (MetaThemeImpl           *impl);
+
+G_GNUC_INTERNAL
 void               meta_theme_impl_add_style_set  (MetaThemeImpl           *impl,
                                                    MetaFrameType            type,
                                                    MetaFrameStyleSet       *style_set);
@@ -93,9 +96,6 @@ void               scale_border                   (GtkBorder               *bord
                                                    double                   factor);
 
 G_GNUC_INTERNAL
-int                get_window_scaling_factor      (void);
-
-G_GNUC_INTERNAL
 gboolean           is_button_visible              (MetaButton              *button,
                                                    MetaFrameFlags           flags);
 
diff --git a/libmetacity/meta-theme-impl.c b/libmetacity/meta-theme-impl.c
index 1a1da9e..e523ffb 100644
--- a/libmetacity/meta-theme-impl.c
+++ b/libmetacity/meta-theme-impl.c
@@ -25,6 +25,7 @@
 typedef struct
 {
   gboolean           composited;
+  gint               scale;
 
   MetaFrameStyleSet *style_sets_by_type[META_FRAME_TYPE_LAST];
 } MetaThemeImplPrivate;
@@ -105,6 +106,28 @@ meta_theme_impl_get_composited (MetaThemeImpl *impl)
   return priv->composited;
 }
 
+gint
+meta_theme_impl_get_scale (MetaThemeImpl *impl)
+{
+  GValue value = G_VALUE_INIT;
+  MetaThemeImplPrivate *priv;
+  GdkScreen *screen;
+
+  priv = meta_theme_impl_get_instance_private (impl);
+
+  if (priv->scale != 0)
+    return priv->scale;
+
+  screen = gdk_screen_get_default ();
+
+  g_value_init (&value, G_TYPE_INT);
+
+  if (gdk_screen_get_setting (screen, "gdk-window-scaling-factor", &value))
+    return g_value_get_int (&value);
+  else
+    return 1;
+}
+
 void
 meta_theme_impl_add_style_set (MetaThemeImpl     *impl,
                                MetaFrameType      type,
@@ -141,22 +164,6 @@ scale_border (GtkBorder *border,
   border->bottom *= factor;
 }
 
-int
-get_window_scaling_factor (void)
-{
-  GdkScreen *screen;
-  GValue value = G_VALUE_INIT;
-
-  screen = gdk_screen_get_default ();
-
-  g_value_init (&value, G_TYPE_INT);
-
-  if (gdk_screen_get_setting (screen, "gdk-window-scaling-factor", &value))
-    return g_value_get_int (&value);
-  else
-    return 1;
-}
-
 gboolean
 is_button_visible (MetaButton     *button,
                    MetaFrameFlags  flags)
diff --git a/libmetacity/meta-theme-metacity.c b/libmetacity/meta-theme-metacity.c
index 702d092..35989e1 100644
--- a/libmetacity/meta-theme-metacity.c
+++ b/libmetacity/meta-theme-metacity.c
@@ -4645,7 +4645,7 @@ meta_theme_metacity_get_frame_borders (MetaThemeImpl    *impl,
     text_height = 0;
 
   /* Scale geometry for HiDPI, see comment in meta_theme_metacity_draw_frame () */
-  scale = get_window_scaling_factor ();
+  scale = meta_theme_impl_get_scale (impl);
 
   buttons_height = layout->metacity.button_height +
                    layout->button_border.top +
@@ -4799,7 +4799,7 @@ meta_theme_metacity_calc_geometry (MetaThemeImpl     *impl,
   button_height = -1;
 
   /* Scale geometry for HiDPI, see comment in meta_theme_metacity_draw_frame () */
-  scale = get_window_scaling_factor ();
+  scale = meta_theme_impl_get_scale (impl);
 
   switch (layout->metacity.button_sizing)
     {
@@ -5303,7 +5303,7 @@ meta_theme_metacity_draw_frame (MetaThemeImpl           *impl,
    *    radii, ...) at the correct scale - as a result, we have to "unscale"
    *    the geometry again to not apply the scaling twice
    */
-  scale = get_window_scaling_factor ();
+  scale = meta_theme_impl_get_scale (impl);
   cairo_scale (cr, scale, scale);
 
   borders = &fgeom->borders;
diff --git a/libmetacity/meta-theme.c b/libmetacity/meta-theme.c
index ccbd110..5a6fded 100644
--- a/libmetacity/meta-theme.c
+++ b/libmetacity/meta-theme.c
@@ -79,11 +79,11 @@ get_style_info (MetaTheme   *theme,
 
   if (style_info == NULL)
     {
-      gint window_scale;
+      gint scale;
 
-      window_scale = get_window_scaling_factor ();
+      scale = meta_theme_impl_get_scale (theme->impl);
       style_info = meta_style_info_new (theme->gtk_theme_name, variant,
-                                        theme->composited, window_scale);
+                                        theme->composited, scale);
 
       g_hash_table_insert (theme->variants, g_strdup (key), style_info);
     }
@@ -195,7 +195,7 @@ font_desc_apply_scale (PangoFontDescription *font_desc,
 
   old_size = pango_font_description_get_size (font_desc);
   style = get_frame_style (theme, type, flags);
-  scale = get_window_scaling_factor ();
+  scale = meta_theme_impl_get_scale (theme->impl);
 
   new_size = MAX (old_size * (style->layout->title_scale / scale), 1);
 
@@ -308,7 +308,7 @@ get_title_height (MetaTheme      *theme,
       pango_font_metrics_unref (metrics);
 
       title_height = PANGO_PIXELS (ascent + descent);
-      scale = get_window_scaling_factor ();
+      scale = meta_theme_impl_get_scale (theme->impl);
 
       title_height *= scale;