[gedit] view: remove deprecated usage of gtk_widget_override_font

[Sébastien Lafargue <slafargue src gnome org>]

commit 100b91ee49feeaf848ff1486e952d27394fcbf74
Author: Sebastien Lafargue <slafargue gnome org>
Date:   Wed Nov 28 12:16:09 2018 +0100

    view: remove deprecated usage of gtk_widget_override_font
    
    We now use a css provider to change the font description.

 gedit/Makefile.am   |   2 +
 gedit/gedit-pango.c | 206 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 gedit/gedit-pango.h |  32 ++++++++
 gedit/gedit-view.c  |  52 ++++++++++---
 4 files changed, 280 insertions(+), 12 deletions(-)
---
diff --git a/gedit/Makefile.am b/gedit/Makefile.am
index fa2f92dd6..65ae371c8 100644
--- a/gedit/Makefile.am
+++ b/gedit/Makefile.am
@@ -120,6 +120,7 @@ gedit_NOINST_H_FILES =                                      \
        gedit/gedit-open-document-selector.h            \
        gedit/gedit-open-document-selector-helper.h     \
        gedit/gedit-open-document-selector-store.h      \
+       gedit/gedit-pango.h                             \
        gedit/gedit-plugins-engine.h                    \
        gedit/gedit-preferences-dialog.h                \
        gedit/gedit-print-job.h                         \
@@ -192,6 +193,7 @@ gedit_libgedit_c_files =                            \
        gedit/gedit-open-document-selector.c            \
        gedit/gedit-open-document-selector-helper.c     \
        gedit/gedit-open-document-selector-store.c      \
+       gedit/gedit-pango.c                             \
        gedit/gedit-plugins-engine.c                    \
        gedit/gedit-preferences-dialog.c                \
        gedit/gedit-print-job.c                         \
diff --git a/gedit/gedit-pango.c b/gedit/gedit-pango.c
new file mode 100644
index 000000000..10c548868
--- /dev/null
+++ b/gedit/gedit-pango.c
@@ -0,0 +1,206 @@
+/* gedit-pango.c
+ *
+ * This file is a copy of libdazzle dzl-pango.c
+ *
+ * Copyright (C) 2014-2017 Christian Hergert <christian hergert me>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define G_LOG_DOMAIN "gedit-pango"
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <gdk/gdk.h>
+#include <glib/gstdio.h>
+#include <math.h>
+
+#include "gedit-pango.h"
+
+#define FONT_FAMILY  "font-family"
+#define FONT_VARIANT "font-variant"
+#define FONT_STRETCH "font-stretch"
+#define FONT_WEIGHT  "font-weight"
+#define FONT_SIZE    "font-size"
+
+/**
+ * gedit_pango_font_description_to_css:
+ *
+ * This function will generate CSS suitable for Gtk's CSS engine
+ * based on the properties of the #PangoFontDescription.
+ *
+ * Returns: (transfer full): A newly allocated string containing the
+ *    CSS describing the font description.
+ */
+gchar *
+gedit_pango_font_description_to_css (const PangoFontDescription *font_desc)
+{
+  PangoFontMask mask;
+  GString *str;
+
+#define ADD_KEYVAL(key,fmt) \
+  g_string_append(str,key":"fmt";")
+#define ADD_KEYVAL_PRINTF(key,fmt,...) \
+  g_string_append_printf(str,key":"fmt";", __VA_ARGS__)
+
+  g_return_val_if_fail (font_desc, NULL);
+
+  str = g_string_new (NULL);
+
+  mask = pango_font_description_get_set_fields (font_desc);
+
+  if ((mask & PANGO_FONT_MASK_FAMILY) != 0)
+    {
+      const gchar *family;
+
+      family = pango_font_description_get_family (font_desc);
+      ADD_KEYVAL_PRINTF (FONT_FAMILY, "\"%s\"", family);
+    }
+
+  if ((mask & PANGO_FONT_MASK_STYLE) != 0)
+    {
+      PangoVariant variant;
+
+      variant = pango_font_description_get_variant (font_desc);
+
+      switch (variant)
+        {
+        case PANGO_VARIANT_NORMAL:
+          ADD_KEYVAL (FONT_VARIANT, "normal");
+          break;
+
+        case PANGO_VARIANT_SMALL_CAPS:
+          ADD_KEYVAL (FONT_VARIANT, "small-caps");
+          break;
+
+        default:
+          break;
+        }
+    }
+
+  if ((mask & PANGO_FONT_MASK_WEIGHT))
+    {
+      gint weight;
+
+      weight = pango_font_description_get_weight (font_desc);
+
+      /*
+       * WORKAROUND:
+       *
+       * font-weight with numbers does not appear to be working as expected
+       * right now. So for the common (bold/normal), let's just use the string
+       * and let gtk warn for the other values, which shouldn't really be
+       * used for this.
+       */
+
+      switch (weight)
+        {
+        case PANGO_WEIGHT_SEMILIGHT:
+          /*
+           * 350 is not actually a valid css font-weight, so we will just round
+           * up to 400.
+           */
+        case PANGO_WEIGHT_NORMAL:
+          ADD_KEYVAL (FONT_WEIGHT, "normal");
+          break;
+
+        case PANGO_WEIGHT_BOLD:
+          ADD_KEYVAL (FONT_WEIGHT, "bold");
+          break;
+
+        case PANGO_WEIGHT_THIN:
+        case PANGO_WEIGHT_ULTRALIGHT:
+        case PANGO_WEIGHT_LIGHT:
+        case PANGO_WEIGHT_BOOK:
+        case PANGO_WEIGHT_MEDIUM:
+        case PANGO_WEIGHT_SEMIBOLD:
+        case PANGO_WEIGHT_ULTRABOLD:
+        case PANGO_WEIGHT_HEAVY:
+        case PANGO_WEIGHT_ULTRAHEAVY:
+        default:
+          /* round to nearest hundred */
+          weight = round (weight / 100.0) * 100;
+          ADD_KEYVAL_PRINTF ("font-weight", "%d", weight);
+          break;
+        }
+    }
+
+#ifndef GDK_WINDOWING_QUARTZ
+  /*
+   * We seem to get "Condensed" for fonts on the Quartz backend,
+   * which is rather annoying as it results in us always hitting
+   * fallback (stretch) paths. So let's cheat and just disable
+   * stretch support for now on Quartz.
+   */
+  if ((mask & PANGO_FONT_MASK_STRETCH))
+    {
+      switch (pango_font_description_get_stretch (font_desc))
+        {
+        case PANGO_STRETCH_ULTRA_CONDENSED:
+          ADD_KEYVAL (FONT_STRETCH, "untra-condensed");
+          break;
+
+        case PANGO_STRETCH_EXTRA_CONDENSED:
+          ADD_KEYVAL (FONT_STRETCH, "extra-condensed");
+          break;
+
+        case PANGO_STRETCH_CONDENSED:
+          ADD_KEYVAL (FONT_STRETCH, "condensed");
+          break;
+
+        case PANGO_STRETCH_SEMI_CONDENSED:
+          ADD_KEYVAL (FONT_STRETCH, "semi-condensed");
+          break;
+
+        case PANGO_STRETCH_NORMAL:
+          ADD_KEYVAL (FONT_STRETCH, "normal");
+          break;
+
+        case PANGO_STRETCH_SEMI_EXPANDED:
+          ADD_KEYVAL (FONT_STRETCH, "semi-expanded");
+          break;
+
+        case PANGO_STRETCH_EXPANDED:
+          ADD_KEYVAL (FONT_STRETCH, "expanded");
+          break;
+
+        case PANGO_STRETCH_EXTRA_EXPANDED:
+          ADD_KEYVAL (FONT_STRETCH, "extra-expanded");
+          break;
+
+        case PANGO_STRETCH_ULTRA_EXPANDED:
+          ADD_KEYVAL (FONT_STRETCH, "untra-expanded");
+          break;
+
+        default:
+          break;
+        }
+    }
+#endif
+
+  if ((mask & PANGO_FONT_MASK_SIZE))
+    {
+      gint font_size;
+
+      font_size = pango_font_description_get_size (font_desc) / PANGO_SCALE;
+      ADD_KEYVAL_PRINTF ("font-size", "%dpt", font_size);
+    }
+
+  return g_string_free (str, FALSE);
+
+#undef ADD_KEYVAL
+#undef ADD_KEYVAL_PRINTF
+}
diff --git a/gedit/gedit-pango.h b/gedit/gedit-pango.h
new file mode 100644
index 000000000..022edc571
--- /dev/null
+++ b/gedit/gedit-pango.h
@@ -0,0 +1,32 @@
+/* gedit-pango.h
+ *
+ * This file is a copy of libdazzle dzl-pango.h
+ *
+ * Copyright (C) 2014 Christian Hergert <christian hergert me>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GEDIT_PANGO_H
+#define GEDIT_PANGO_H
+
+#include <pango/pango.h>
+
+G_BEGIN_DECLS
+
+gchar *gedit_pango_font_description_to_css (const PangoFontDescription *font_desc);
+
+G_END_DECLS
+
+#endif /* GEDIT_PANGO_H */
diff --git a/gedit/gedit-view.c b/gedit/gedit-view.c
index 441d29306..9ff201164 100644
--- a/gedit/gedit-view.c
+++ b/gedit/gedit-view.c
@@ -28,6 +28,7 @@
 #include "gedit-view-activatable.h"
 #include "gedit-plugins-engine.h"
 #include "gedit-debug.h"
+#include "gedit-pango.h"
 #include "gedit-utils.h"
 #include "gedit-settings.h"
 #include "gedit-app.h"
@@ -43,10 +44,13 @@ enum
 
 struct _GeditViewPrivate
 {
-       GSettings        *editor_settings;
-       GtkTextBuffer    *current_buffer;
-       PeasExtensionSet *extensions;
-       gchar            *direct_save_uri;
+       GSettings            *editor_settings;
+       GtkTextBuffer        *current_buffer;
+       PeasExtensionSet     *extensions;
+       gchar                *direct_save_uri;
+
+       GtkCssProvider       *css_provider;
+       PangoFontDescription *font_desc;
 };
 
 G_DEFINE_TYPE_WITH_PRIVATE (GeditView, gedit_view, GTK_SOURCE_TYPE_VIEW)
@@ -154,8 +158,14 @@ gedit_view_init (GeditView *view)
                          G_CALLBACK (on_notify_buffer_cb),
                          NULL);
 
+
+       view->priv->css_provider = gtk_css_provider_new ();
        context = gtk_widget_get_style_context (GTK_WIDGET (view));
        gtk_style_context_add_class (context, "gedit-view");
+
+       gtk_style_context_add_provider (context,
+                                       GTK_STYLE_PROVIDER (view->priv->css_provider),
+                                       GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
 }
 
 static void
@@ -176,6 +186,9 @@ gedit_view_dispose (GObject *object)
         */
        g_signal_handlers_disconnect_by_func (view, on_notify_buffer_cb, NULL);
 
+       g_clear_object (&view->priv->css_provider);
+       g_clear_pointer (&view->priv->font_desc, pango_font_description_free);
+
        G_OBJECT_CLASS (gedit_view_parent_class)->dispose (object);
 }
 
@@ -951,6 +964,23 @@ gedit_view_scroll_to_cursor (GeditView *view)
                                      0.0);
 }
 
+static void
+update_css_provider (GeditView *view)
+{
+       gchar *str;
+       gchar *css;
+
+       g_assert (GEDIT_IS_VIEW (view));
+       g_assert (view->priv->font_desc != NULL);
+
+       str = gedit_pango_font_description_to_css (view->priv->font_desc);
+       css = g_strdup_printf ("textview { %s }", str ? str : "");
+       gtk_css_provider_load_from_data (view->priv->css_provider, css, -1, NULL);
+
+       g_free (css);
+       g_free (str);
+}
+
 /**
  * gedit_view_set_font:
  * @view: a #GeditView
@@ -965,12 +995,12 @@ gedit_view_set_font (GeditView   *view,
                     gboolean     default_font,
                     const gchar *font_name)
 {
-       PangoFontDescription *font_desc;
-
        gedit_debug (DEBUG_VIEW);
 
        g_return_if_fail (GEDIT_IS_VIEW (view));
 
+       g_clear_pointer (&view->priv->font_desc, pango_font_description_free);
+
        if (default_font)
        {
                GeditSettings *settings;
@@ -979,21 +1009,19 @@ gedit_view_set_font (GeditView   *view,
                settings = _gedit_app_get_settings (GEDIT_APP (g_application_get_default ()));
                font = gedit_settings_get_system_font (settings);
 
-               font_desc = pango_font_description_from_string (font);
+               view->priv->font_desc = pango_font_description_from_string (font);
                g_free (font);
        }
        else
        {
                g_return_if_fail (font_name != NULL);
 
-               font_desc = pango_font_description_from_string (font_name);
+               view->priv->font_desc = pango_font_description_from_string (font_name);
        }
 
-       g_return_if_fail (font_desc != NULL);
-
-       gtk_widget_override_font (GTK_WIDGET (view), font_desc);
+       g_return_if_fail (view->priv->font_desc != NULL);
 
-       pango_font_description_free (font_desc);
+       update_css_provider (view);
 }
 
 /* ex:set ts=8 noet: */