[mutter] theme: Support margins on titlebar title/buttons

[Florian Müllner <fmuellner src gnome org>]

commit e0ffef06dd810ff5acb54605f05f95133541151b
Author: Florian Müllner <fmuellner gnome org>
Date:   Thu Jan 14 17:32:46 2016 +0100

    theme: Support margins on titlebar title/buttons
    
    GTK+ improved its CSS support, and the default theme started to make
    use of it, so we must update our theming code accordingly. Add support
    for margins where they make sense.

 src/ui/theme-private.h |    5 +++++
 src/ui/theme.c         |   32 +++++++++++++++++++++++++++++---
 2 files changed, 34 insertions(+), 3 deletions(-)
---
diff --git a/src/ui/theme-private.h b/src/ui/theme-private.h
index ea3c532..c27c3f9 100644
--- a/src/ui/theme-private.h
+++ b/src/ui/theme-private.h
@@ -60,6 +60,11 @@ struct _MetaFrameLayout
   /** Border/padding of titlebar buttons */
   GtkBorder button_border;
 
+  /** Margin of title */
+  GtkBorder title_margin;
+  /** Margin of titlebar buttons */
+  GtkBorder button_margin;
+
   /** Min size of titlebar region */
   GtkRequisition titlebar_min_size;
   /** Min size of titlebar buttons */
diff --git a/src/ui/theme.c b/src/ui/theme.c
index 7d7cef0..c33d086 100644
--- a/src/ui/theme.c
+++ b/src/ui/theme.c
@@ -79,9 +79,12 @@ meta_frame_layout_get_borders (const MetaFrameLayout *layout,
 
   if (!layout->has_title)
     text_height = 0;
+  else
+    text_height = layout->title_margin.top + text_height + layout->title_margin.bottom;
 
   buttons_height = MAX ((int)layout->icon_size, layout->button_min_size.height) +
-    layout->button_border.top + layout->button_border.bottom;
+    layout->button_margin.top + layout->button_border.top +
+    layout->button_margin.bottom + layout->button_border.bottom;
   content_height = MAX (buttons_height, text_height);
   content_height = MAX (content_height, layout->titlebar_min_size.height) +
                    layout->titlebar_border.top + layout->titlebar_border.bottom;
@@ -297,10 +300,18 @@ meta_frame_layout_sync_with_style (MetaFrameLayout *layout,
   get_padding_and_border (style, &layout->titlebar_border);
   scale_border (&layout->titlebar_border, layout->title_scale);
 
+  style = style_info->styles[META_STYLE_ELEMENT_TITLE];
+  gtk_style_context_get_margin (style, gtk_style_context_get_state (style),
+                                &layout->title_margin);
+  scale_border (&layout->title_margin, layout->title_scale);
+
   style = style_info->styles[META_STYLE_ELEMENT_BUTTON];
   get_min_size (style, &layout->button_min_size);
   get_padding_and_border (style, &layout->button_border);
   scale_border (&layout->button_border, layout->title_scale);
+  gtk_style_context_get_margin (style, gtk_style_context_get_state (style),
+                                &layout->button_margin);
+  scale_border (&layout->button_margin, layout->title_scale);
 
   style = style_info->styles[META_STYLE_ELEMENT_IMAGE];
   get_min_size (style, &requisition);
@@ -312,6 +323,13 @@ meta_frame_layout_sync_with_style (MetaFrameLayout *layout,
   layout->button_border.top += border.top;
   layout->button_border.bottom += border.bottom;
 
+  gtk_style_context_get_margin (style, gtk_style_context_get_state (style),
+                                &border);
+  layout->button_border.left += border.left;
+  layout->button_border.right += border.right;
+  layout->button_border.top += border.top;
+  layout->button_border.bottom += border.bottom;
+
   layout->button_min_size.width = MAX(layout->button_min_size.width,
                                       requisition.width);
   layout->button_min_size.height = MAX(layout->button_min_size.height,
@@ -442,11 +460,15 @@ meta_frame_layout_calc_geometry (MetaFrameLayout        *layout,
 
       space_used_by_buttons = 0;
 
+      space_used_by_buttons += layout->button_margin.left * scale * n_left;
       space_used_by_buttons += button_width * n_left;
+      space_used_by_buttons += layout->button_margin.right * scale * n_left;
       space_used_by_buttons += (button_width * 0.75) * n_left_spacers;
       space_used_by_buttons += layout->titlebar_spacing * scale * MAX (n_left - 1, 0);
 
+      space_used_by_buttons += layout->button_margin.left * scale * n_right;
       space_used_by_buttons += button_width * n_right;
+      space_used_by_buttons += layout->button_margin.right * scale * n_right;
       space_used_by_buttons += (button_width * 0.75) * n_right_spacers;
       space_used_by_buttons += layout->titlebar_spacing * scale * MAX (n_right - 1, 0);
 
@@ -516,6 +538,8 @@ meta_frame_layout_calc_geometry (MetaFrameLayout        *layout,
       if (x < 0) /* if we go negative, leave the buttons we don't get to as 0-width */
         break;
 
+      x -= layout->button_margin.right * scale;
+
       rect = right_func_rects[i];
       rect->visible.x = x - button_width;
       if (right_buttons_has_spacer[i])
@@ -541,7 +565,7 @@ meta_frame_layout_calc_geometry (MetaFrameLayout        *layout,
       else
         g_memmove (&(rect->clickable), &(rect->visible), sizeof(rect->clickable));
 
-      x = rect->visible.x;
+      x = rect->visible.x - layout->button_margin.left * scale;
 
       if (i > 0)
         x -= layout->titlebar_spacing;
@@ -560,6 +584,8 @@ meta_frame_layout_calc_geometry (MetaFrameLayout        *layout,
     {
       MetaButtonSpace *rect;
 
+      x += layout->button_margin.left * scale;
+
       rect = left_func_rects[i];
 
       rect->visible.x = x;
@@ -586,7 +612,7 @@ meta_frame_layout_calc_geometry (MetaFrameLayout        *layout,
       else
         g_memmove (&(rect->clickable), &(rect->visible), sizeof(rect->clickable));
 
-      x = rect->visible.x + rect->visible.width;
+      x = rect->visible.x + rect->visible.width + layout->button_margin.right * scale;
       if (i < n_left - 1)
         x += layout->titlebar_spacing * scale;
       if (left_buttons_has_spacer[i])