[gtk/css-line-height: 2/4] label: Use line-height from css

[Matthias Clasen <matthiasc src gnome org>]

commit 630bbf8d9b8a22081a7d2115631bf78f6fa9f646
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Aug 6 14:20:10 2021 -0400

    label: Use line-height from css

 gtk/gtklabel.c | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)
---
diff --git a/gtk/gtklabel.c b/gtk/gtklabel.c
index d4e414d882..921d3703ff 100644
--- a/gtk/gtklabel.c
+++ b/gtk/gtklabel.c
@@ -53,6 +53,8 @@
 #include "gtkdragicon.h"
 #include "gtkcsscolorvalueprivate.h"
 #include "gtkjoinedmenuprivate.h"
+#include "gtkcssstylepropertyprivate.h"
+#include "gtkcssnumbervalueprivate.h"
 
 #include <math.h>
 #include <string.h>
@@ -841,6 +843,27 @@ gtk_label_update_layout_attributes (GtkLabel      *self,
   pango_attr_list_unref (attrs);
 }
 
+static void
+gtk_label_update_layout_line_spacing (GtkLabel *self)
+{
+  GtkCssStyle *style;
+  GtkCssStyleProperty *prop;
+  float line_spacing;
+
+  if (self->layout == NULL)
+    return;
+
+  style = gtk_css_node_get_style (gtk_widget_get_css_node (GTK_WIDGET (self)));
+  prop = _gtk_css_style_property_lookup_by_id (GTK_CSS_PROPERTY_LINE_HEIGHT);
+
+  if (style->font->line_height == _gtk_css_style_property_get_initial_value (prop))
+    line_spacing = 0.0;
+  else
+    line_spacing = _gtk_css_number_value_get (style->font->line_height, 1.0);
+
+  pango_layout_set_line_spacing (self->layout, line_spacing);
+}
+
 static void
 gtk_label_css_changed (GtkWidget         *widget,
                        GtkCssStyleChange *change)
@@ -851,6 +874,11 @@ gtk_label_css_changed (GtkWidget         *widget,
 
   GTK_WIDGET_CLASS (gtk_label_parent_class)->css_changed (widget, change);
 
+  if (gtk_css_style_change_affects (change, GTK_CSS_AFFECTS_TEXT_SIZE))
+    {
+      gtk_label_update_layout_line_spacing (self);
+    }
+
   if (gtk_css_style_change_affects (change, GTK_CSS_AFFECTS_TEXT_ATTRS))
     {
       new_attrs = gtk_css_style_get_pango_attributes (gtk_css_style_change_get_new_style (change));
@@ -860,7 +888,7 @@ gtk_label_css_changed (GtkWidget         *widget,
   else
     attrs_affected = FALSE;
 
-  if (change == NULL || attrs_affected  || (self->select_info && self->select_info->links))
+  if (change == NULL || attrs_affected || (self->select_info && self->select_info->links))
     {
       gtk_label_update_layout_attributes (self, new_attrs);
 
@@ -3982,6 +4010,7 @@ gtk_label_ensure_layout (GtkLabel *self)
   self->layout = gtk_widget_create_pango_layout (GTK_WIDGET (self), self->text);
 
   gtk_label_update_layout_attributes (self, NULL);
+  gtk_label_update_layout_line_spacing (self);
 
   switch (self->jtype)
     {