[gnome-panel] panel: Size the PanelSeparator by css styling

[Vincent Untz <vuntz src gnome org>]

commit f94190fe79d2e697ba216d8b6f84626a1b5470fc
Author: Peter Hurley <peter hurleysoftware com>
Date:   Sat Mar 3 17:19:47 2012 -0500

    panel: Size the PanelSeparator by css styling
    
    Instead of using a fixed value of 10 for the width/height of the
    PanelSeparator, compute the size dimensions based on the size of the css
    box dimensions and the enclosed GtkSeparator.
    
    This allows the theme to specify the dimensions to accomplish a
    particular look.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=671329

 gnome-panel/panel-separator.c |   96 ++++++++++++++++++++++++++++++++++++++---
 1 files changed, 89 insertions(+), 7 deletions(-)
---
diff --git a/gnome-panel/panel-separator.c b/gnome-panel/panel-separator.c
index 80d9f08..a13742d 100644
--- a/gnome-panel/panel-separator.c
+++ b/gnome-panel/panel-separator.c
@@ -29,8 +29,6 @@
 
 #include "panel-separator.h"
 
-#define SEPARATOR_SIZE 10
-
 #define PANEL_SEPARATOR_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), PANEL_TYPE_SEPARATOR, PanelSeparatorPrivate))
 
 struct _PanelSeparatorPrivate {
@@ -57,8 +55,34 @@ panel_separator_get_preferred_width (GtkWidget *widget,
 
 	if (separator->priv->orientation == GTK_ORIENTATION_VERTICAL)
 		*minimal_width = *natural_width = size;
-	else
-		*minimal_width = *natural_width = SEPARATOR_SIZE;
+	else {
+		/* set width based on css styling & width of GtkSeparator */
+		GtkStyleContext *context;
+		GtkStateFlags    state;
+		GtkWidget       *child;
+		GtkBorder        padding;
+		GtkBorder        border;
+		gint             width;
+
+		context = gtk_widget_get_style_context (widget);
+		state = gtk_widget_get_state_flags (widget);
+
+		child = gtk_bin_get_child (GTK_BIN (widget));
+
+		if (child && gtk_widget_get_visible (child))
+			gtk_widget_get_preferred_width (child,
+							minimal_width,
+							natural_width);
+		else
+			*minimal_width = *natural_width = 0;
+
+		gtk_style_context_get_border (context, state, &border);
+		gtk_style_context_get_padding (context, state, &padding);
+
+		width = border.left + border.right + padding.left + padding.right;
+		*minimal_width += width;
+		*natural_width += width;
+	}
 }
 
 static void
@@ -73,9 +97,34 @@ panel_separator_get_preferred_height (GtkWidget *widget,
 
 	size = panel_toplevel_get_size (separator->priv->panel->toplevel);
 
-	if (separator->priv->orientation == GTK_ORIENTATION_VERTICAL)
-		*minimal_height = *natural_height = SEPARATOR_SIZE;
-	else
+	if (separator->priv->orientation == GTK_ORIENTATION_VERTICAL) {
+		/* set height based on css styling & height of GtkSeparator */
+		GtkStyleContext *context;
+		GtkStateFlags    state;
+		GtkWidget       *child;
+		GtkBorder        padding;
+		GtkBorder        border;
+		gint             height;
+
+		context = gtk_widget_get_style_context (widget);
+		state = gtk_widget_get_state_flags (widget);
+
+		child = gtk_bin_get_child (GTK_BIN (widget));
+
+		if (child && gtk_widget_get_visible (child))
+			gtk_widget_get_preferred_height (child,
+							 minimal_height,
+							 natural_height);
+		else
+			*minimal_height = *natural_height = 0;
+
+		gtk_style_context_get_border (context, state, &border);
+		gtk_style_context_get_padding (context, state, &padding);
+
+		height = border.top + border.bottom + padding.top + padding.bottom;
+		*minimal_height += height;
+		*natural_height += height;
+	} else
 		*minimal_height = *natural_height = size;
 }
 
@@ -84,12 +133,45 @@ panel_separator_size_allocate (GtkWidget     *widget,
 			       GtkAllocation *allocation)
 {
 	GtkAllocation    old_allocation;
+	GtkStyleContext *context;
+	GtkStateFlags    state;
+	GtkBorder        padding;
+	GtkBorder        border;
+	GtkAllocation    new_allocation;
+	GtkWidget       *child;
 	PanelBackground *background;
 
 	gtk_widget_get_allocation (widget, &old_allocation);
 
 	GTK_WIDGET_CLASS (panel_separator_parent_class)->size_allocate (widget, allocation);
 
+	/* We cannot return early here if allocation == old_allocation because
+	 * the event_box base class just sized the child and we need to
+	 * recalculate and resize the child (the actual GtkSeparator).
+	 *
+	 * Preferably, the event_box base class would offer a method of moving
+	 * the private event window, in which case, calling its size_allocate
+	 * would not be necessary. But, alas, no. */
+
+	context = gtk_widget_get_style_context (widget);
+	state = gtk_widget_get_state_flags (widget);
+
+	gtk_style_context_get_border (context, state, &border);
+	gtk_style_context_get_padding (context, state, &padding);
+
+	new_allocation.x = border.left + padding.left;
+	new_allocation.y = border.top + padding.top;
+	new_allocation.width = allocation->width -
+		(border.left + border.right + padding.left + padding.right);
+	new_allocation.height = allocation->height -
+		(border.top + border.bottom + padding.top + padding.bottom);
+	new_allocation.width = MAX (1, new_allocation.width);
+	new_allocation.height = MAX (1, new_allocation.height);
+
+	child = gtk_bin_get_child (GTK_BIN (widget));
+	if (child && gtk_widget_get_visible (child))
+		gtk_widget_size_allocate (child, &new_allocation);
+
 	if (old_allocation.x      == allocation->x &&
 	    old_allocation.y      == allocation->y &&
 	    old_allocation.width  == allocation->width &&