[metacity] libmetacity: add MetaCssProvider

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 68e0b2e84e9834a807c250a419846549cc5cee8f
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Thu Jun 2 20:23:57 2016 +0300

    libmetacity: add MetaCssProvider
    
    Add MetaCssProvider that has same theme loading code as
    GtkCssProvider. This is needed to create GTK+ theme reload
    functionality in metacity-theme-viewer without restarting
    application.

 configure.ac                            |    7 +
 libmetacity/Makefile.am                 |    2 +
 libmetacity/meta-css-provider-private.h |   35 ++++
 libmetacity/meta-css-provider.c         |  311 +++++++++++++++++++++++++++++++
 4 files changed, 355 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 16a4ad7..a8140ce 100644
--- a/configure.ac
+++ b/configure.ac
@@ -97,6 +97,13 @@ PKG_CHECK_MODULES([METACITY_THEME_VIEWER], [
 ])
 
 dnl **************************************************************************
+dnl Get GTK+ data prefix, needed by libmetacity
+dnl **************************************************************************
+
+GTK_DATA_PREFIX=`$PKG_CONFIG --variable=prefix gtk+-3.0`
+AC_DEFINE_UNQUOTED([GTK_DATA_PREFIX], ["$GTK_DATA_PREFIX"], [GTK+ data prefix])
+
+dnl **************************************************************************
 
 # Honor aclocal flags
 AC_SUBST(ACLOCAL_AMFLAGS, "\${ACLOCAL_FLAGS}")
diff --git a/libmetacity/Makefile.am b/libmetacity/Makefile.am
index 4fd809e..e378fd0 100644
--- a/libmetacity/Makefile.am
+++ b/libmetacity/Makefile.am
@@ -13,6 +13,8 @@ libmetacity_la_SOURCES = \
        meta-color-private.h \
        meta-color-spec.c \
        meta-color-spec-private.h \
+       meta-css-provider.c \
+       meta-css-provider-private.h \
        meta-draw-op.c \
        meta-draw-op-private.h \
        meta-draw-spec.c \
diff --git a/libmetacity/meta-css-provider-private.h b/libmetacity/meta-css-provider-private.h
new file mode 100644
index 0000000..4a20b34
--- /dev/null
+++ b/libmetacity/meta-css-provider-private.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2016 Alberts Muktupāvels
+ *
+ * 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 2 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 META_CSS_PROVIDER_PRIVATE_H
+#define META_CSS_PROVIDER_PRIVATE_H
+
+#include <gtk/gtk.h>
+
+G_BEGIN_DECLS
+
+#define META_TYPE_CSS_PROVIDER meta_css_provider_get_type ()
+G_DECLARE_FINAL_TYPE (MetaCssProvider, meta_css_provider,
+                      META, CSS_PROVIDER, GtkCssProvider)
+
+G_GNUC_INTERNAL
+GtkCssProvider *meta_css_provider_new (const gchar *name,
+                                       const gchar *variant);
+
+G_END_DECLS
+
+#endif
diff --git a/libmetacity/meta-css-provider.c b/libmetacity/meta-css-provider.c
new file mode 100644
index 0000000..544d934
--- /dev/null
+++ b/libmetacity/meta-css-provider.c
@@ -0,0 +1,311 @@
+/*
+ * Copyright (C) 2016 Alberts Muktupāvels
+ *
+ * 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 2 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/>.
+ */
+
+#include "config.h"
+#include "meta-css-provider-private.h"
+
+struct _MetaCssProvider
+{
+  GtkCssProvider  parent;
+
+  gchar          *name;
+  gchar          *variant;
+
+  GResource      *resource;
+};
+
+enum
+{
+  PROP_0,
+
+  PROP_NAME,
+  PROP_VARIANT,
+
+  LAST_PROP
+};
+
+static GParamSpec *properties[LAST_PROP] = { NULL };
+
+G_DEFINE_TYPE (MetaCssProvider, meta_css_provider, GTK_TYPE_CSS_PROVIDER)
+
+static gchar *
+get_theme_dir (void)
+{
+  const gchar *prefix;
+
+  prefix = g_getenv ("GTK_DATA_PREFIX");
+
+  if (prefix == NULL)
+    prefix = GTK_DATA_PREFIX;
+
+  return g_build_filename (prefix, "share", "themes", NULL);
+}
+
+static gint
+get_minor_version (void)
+{
+  if (GTK_MINOR_VERSION % 2)
+    return GTK_MINOR_VERSION + 1;
+
+  return GTK_MINOR_VERSION;
+}
+
+static gchar *
+find_theme_dir (const gchar *dir,
+                const gchar *subdir,
+                const gchar *name,
+                const gchar *variant)
+{
+  gchar *file;
+  gchar *base;
+  gchar *subsubdir;
+  gint i;
+  gchar *path;
+
+  if (variant)
+    file = g_strconcat ("gtk-", variant, ".css", NULL);
+  else
+    file = g_strdup ("gtk.css");
+
+  if (subdir)
+    base = g_build_filename (dir, subdir, name, NULL);
+  else
+    base = g_build_filename (dir, name, NULL);
+
+  for (i = get_minor_version (); i >= 0; i = i - 2)
+    {
+      if (i < 14)
+        i = 0;
+
+      subsubdir = g_strdup_printf ("gtk-3.%d", i);
+      path = g_build_filename (base, subsubdir, file, NULL);
+      g_free (subsubdir);
+
+      if (g_file_test (path, G_FILE_TEST_EXISTS))
+        break;
+
+      g_free (path);
+      path = NULL;
+    }
+
+  g_free (file);
+  g_free (base);
+
+  return path;
+}
+
+static gchar *
+find_theme (const gchar *name,
+            const gchar *variant)
+{
+  gchar *path;
+  const gchar *const *dirs;
+  gint i;
+  gchar *dir;
+
+  /* First look in the user's data directory */
+  path = find_theme_dir (g_get_user_data_dir (), "themes", name, variant);
+  if (path)
+    return path;
+
+  /* Next look in the user's home directory */
+  path = find_theme_dir (g_get_home_dir (), ".themes", name, variant);
+  if (path)
+    return path;
+
+  /* Look in system data directories */
+  dirs = g_get_system_data_dirs ();
+  for (i = 0; dirs[i]; i++)
+    {
+      path = find_theme_dir (dirs[i], "themes", name, variant);
+      if (path)
+        return path;
+    }
+
+  /* Finally, try in the default theme directory */
+  dir = get_theme_dir ();
+  path = find_theme_dir (dir, NULL, name, variant);
+  g_free (dir);
+
+  return path;
+}
+
+static gboolean
+load_builtin_theme (GtkCssProvider *provider,
+                    const gchar    *name,
+                    const gchar    *variant)
+{
+  gchar *path;
+
+  if (variant != NULL)
+    path = g_strdup_printf ("/org/gtk/libgtk/theme/%s/gtk-%s.css", name, variant);
+  else
+    path = g_strdup_printf ("/org/gtk/libgtk/theme/%s/gtk.css", name);
+
+  if (g_resources_get_info (path, 0, NULL, NULL, NULL))
+    {
+      gtk_css_provider_load_from_resource (provider, path);
+      g_free (path);
+
+      return TRUE;
+    }
+
+  g_free (path);
+
+  return FALSE;
+}
+
+static void
+provider_load_named (MetaCssProvider *provider,
+                     const gchar     *name,
+                     const gchar     *variant)
+{
+  GtkCssProvider *css_provider;
+  gchar *path;
+
+  if (name == NULL)
+    return;
+
+  css_provider = GTK_CSS_PROVIDER (provider);
+
+  if (load_builtin_theme (css_provider, name, variant))
+    return;
+
+  path = find_theme (name, variant);
+
+  if (path != NULL)
+    {
+      gchar *dir;
+      gchar *file;
+
+      dir = g_path_get_dirname (path);
+      file = g_build_filename (dir, "gtk.gresource", NULL);
+      g_free (dir);
+
+      provider->resource = g_resource_load (file, NULL);
+      g_free (file);
+
+      if (provider->resource != NULL)
+        g_resources_register (provider->resource);
+
+      gtk_css_provider_load_from_path (css_provider, path, NULL);
+      g_free (path);
+    }
+  else if (variant != NULL)
+    {
+      provider_load_named (provider, name, NULL);
+    }
+}
+
+static void
+meta_css_provider_constructed (GObject *object)
+{
+  MetaCssProvider *provider;
+
+  G_OBJECT_CLASS (meta_css_provider_parent_class)->constructed (object);
+
+  provider = META_CSS_PROVIDER (object);
+
+  provider_load_named (provider, provider->name, provider->variant);
+}
+
+static void
+meta_css_provider_finalize (GObject *object)
+{
+  MetaCssProvider *provider;
+
+  provider = META_CSS_PROVIDER (object);
+
+  if (provider->resource)
+    {
+      g_resources_unregister (provider->resource);
+      g_resource_unref (provider->resource);
+      provider->resource = NULL;
+    }
+
+  G_OBJECT_CLASS (meta_css_provider_parent_class)->finalize (object);
+}
+
+static void
+meta_css_provider_set_property (GObject      *object,
+                                guint         property_id,
+                                const GValue *value,
+                                GParamSpec   *pspec)
+{
+  MetaCssProvider *provider;
+
+  provider = META_CSS_PROVIDER (object);
+
+  switch (property_id)
+    {
+      case PROP_NAME:
+        provider->name = g_value_dup_string (value);
+        break;
+
+      case PROP_VARIANT:
+        provider->variant = g_value_dup_string (value);
+        break;
+
+      default:
+        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+        break;
+    }
+}
+
+static void
+meta_css_provider_class_init (MetaCssProviderClass *provider_class)
+{
+  GObjectClass *object_class;
+
+  object_class = G_OBJECT_CLASS (provider_class);
+
+  object_class->constructed = meta_css_provider_constructed;
+  object_class->finalize = meta_css_provider_finalize;
+  object_class->set_property = meta_css_provider_set_property;
+
+  properties[PROP_NAME] =
+    g_param_spec_string ("name",
+                         "GTK+ Theme Name",
+                         "GTK+ Theme Name",
+                         NULL,
+                         G_PARAM_CONSTRUCT_ONLY | G_PARAM_WRITABLE |
+                         G_PARAM_STATIC_STRINGS);
+
+  properties[PROP_VARIANT] =
+    g_param_spec_string ("variant",
+                         "GTK+ Theme Variant",
+                         "GTK+ Theme Variant",
+                         NULL,
+                         G_PARAM_CONSTRUCT_ONLY | G_PARAM_WRITABLE |
+                         G_PARAM_STATIC_STRINGS);
+
+  g_object_class_install_properties (object_class, LAST_PROP, properties);
+}
+
+static void
+meta_css_provider_init (MetaCssProvider *provider)
+{
+}
+
+GtkCssProvider *
+meta_css_provider_new (const gchar *name,
+                       const gchar *variant)
+{
+  return g_object_new (META_TYPE_CSS_PROVIDER,
+                       "name", name, "variant", variant,
+                       NULL);
+}