[almanah] UI: Using system document font

[Álvaro Peña <alvaropg src gnome org>]

commit be98cf82af2b03bcc7347d8003299647d832e359
Author: Álvaro Peña <alvaropg gmail com>
Date:   Mon Oct 12 19:16:25 2015 +0200

    UI: Using system document font
    
    The GtkTextView now uses the configured system document font updating
    the font if the user changes the setting.
    
    The width of the GtkTextView is calculated with a random 15 words
    sentences which can be translated in to adjust the size for different
    languages.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=754842

 src/main-window.c |   92 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/ui/almanah.ui |    3 ++
 2 files changed, 95 insertions(+), 0 deletions(-)
---
diff --git a/src/main-window.c b/src/main-window.c
index 579f929..64e07e4 100644
--- a/src/main-window.c
+++ b/src/main-window.c
@@ -45,6 +45,10 @@
 /* Interval for automatically saving the current entry. Currently an arbitrary 10 minutes. */
 #define SAVE_ENTRY_INTERVAL 10 * 60 /* seconds */
 
+#define ALMANAH_MAIN_WINDOW_DESKTOP_INTERFACE_SETTINGS_SCHEMA "org.gnome.desktop.interface"
+#define ALMANAH_MAIN_WINDOW_DOCUMENT_FONT_KEY_NAME "document-font-name"
+#define ALMANAH_MAIN_WINDOW_FIXED_MARGIN_FONT 20
+
 static void almanah_main_window_dispose (GObject *object);
 #ifdef ENABLE_SPELL_CHECKING
 static void spell_checking_enabled_changed_cb (GSettings *settings, gchar *key, AlmanahMainWindow *self);
@@ -64,6 +68,9 @@ static void mw_events_updated_cb (AlmanahEventManager *event_manager, AlmanahEve
 static gboolean save_entry_timeout_cb (AlmanahMainWindow *self);
 static void mw_setup_headerbar (AlmanahMainWindow *main_window, AlmanahApplication *application);
 
+static void mw_setup_size_text_view (AlmanahMainWindow *self);
+static int mw_get_font_width (GtkWidget *widget, const gchar *font_name);
+
 /* GActions callbacks */
 void mw_cut_activate_cb           (GSimpleAction *action, GVariant *parameter, gpointer user_data);
 void mw_copy_activate_cb          (GSimpleAction *action, GVariant *parameter, gpointer user_data);
@@ -83,6 +90,7 @@ void mw_events_tree_view_row_activated_cb (GtkTreeView *tree_view, GtkTreePath *
 /* Other callbacks */
 void mw_calendar_day_selected_cb (AlmanahCalendarButton *calendar, AlmanahMainWindow *main_window);
 void mw_calendar_select_date_clicked_cb (AlmanahCalendarButton *calendar, AlmanahMainWindow *main_window);
+void mw_desktop_interface_settings_changed (GSettings *settings, gchar *key, gpointer user_data);
 
 struct _AlmanahMainWindowPrivate {
        GtkWidget *header_bar;
@@ -94,6 +102,7 @@ struct _AlmanahMainWindowPrivate {
        GtkWidget *events_expander;
        GtkLabel *events_count_label;
        GtkTreeSelection *events_selection;
+       GtkWidget *entry_scrolled;
 
        gboolean updating_formatting;
        gboolean pending_bold_active;
@@ -104,6 +113,8 @@ struct _AlmanahMainWindowPrivate {
        gulong current_entry_notify_id; /* signal handler for current_entry::notify */
        guint save_entry_timeout_id; /* source ID for timer to save current entry periodically */
 
+       GSettings *desktop_interface_settings;
+
 #ifdef ENABLE_SPELL_CHECKING
        GSettings *settings;
        gulong spell_checking_enabled_changed_id; /* signal handler for 
application->settings::changed::spell-checking-enabled */
@@ -152,6 +163,8 @@ almanah_main_window_init (AlmanahMainWindow *self)
        self->priv->header_bar = gtk_header_bar_new ();
        gtk_window_set_titlebar (GTK_WINDOW (self), self->priv->header_bar);
        gtk_header_bar_set_show_close_button (GTK_HEADER_BAR (self->priv->header_bar), TRUE);
+
+       self->priv->desktop_interface_settings;
 }
 
 static void
@@ -166,6 +179,8 @@ almanah_main_window_dispose (GObject *object)
 
        set_current_entry (ALMANAH_MAIN_WINDOW (object), NULL);
 
+       g_clear_object (&priv->desktop_interface_settings);
+
 #ifdef ENABLE_SPELL_CHECKING
        if (priv->settings != NULL) {
                if (priv->spell_checking_enabled_changed_id != 0) {
@@ -233,6 +248,7 @@ almanah_main_window_new (AlmanahApplication *application)
        priv = ALMANAH_MAIN_WINDOW (main_window)->priv;
 
        /* Grab our child widgets */
+       priv->entry_scrolled = GTK_WIDGET (gtk_builder_get_object (builder, 
"almanah_mw_main_content_scrolled_window"));
        priv->entry_view = GTK_TEXT_VIEW (gtk_builder_get_object (builder, "almanah_mw_entry_view"));
        priv->entry_buffer = gtk_text_view_get_buffer (priv->entry_view);
        priv->entry_tags_area = ALMANAH_ENTRY_TAGS_AREA (gtk_builder_get_object (builder, 
"almanah_mw_entry_tags_area"));
@@ -284,6 +300,9 @@ almanah_main_window_new (AlmanahApplication *application)
        /* Set up the main toolbar */
        mw_setup_headerbar (main_window, application);
 
+       /* Setting up the diary entry text view */
+       mw_setup_size_text_view (main_window);
+
        /* Select the current day and month */
        almanah_calendar_button_select_today(main_window->priv->calendar_button);
 
@@ -1339,6 +1358,79 @@ mw_setup_headerbar (AlmanahMainWindow *main_window, AlmanahApplication *applicat
        gtk_header_bar_pack_end (GTK_HEADER_BAR (main_window->priv->header_bar), button);
 }
 
+
+static void
+mw_setup_size_text_view (AlmanahMainWindow *self)
+{
+       gchar *font_name = NULL;
+       gchar *css_font = NULL;
+       GtkStyleContext *style_context;
+       GtkCssProvider *css_provider;
+       int fixed_width;
+
+       g_return_if_fail (ALMANAH_IS_MAIN_WINDOW (self));
+
+       /* Read the document font name & size, calculate the size of a randome sentence
+          with 15 words and change the minimum size for the text view. */
+
+       if (self->priv->desktop_interface_settings == NULL) {
+               self->priv->desktop_interface_settings = g_settings_new 
(ALMANAH_MAIN_WINDOW_DESKTOP_INTERFACE_SETTINGS_SCHEMA);
+               g_signal_connect (self->priv->desktop_interface_settings, "changed", G_CALLBACK 
(mw_desktop_interface_settings_changed), self);
+       }
+       font_name = g_settings_get_string (self->priv->desktop_interface_settings, 
ALMANAH_MAIN_WINDOW_DOCUMENT_FONT_KEY_NAME);
+       css_font = g_strdup_printf (".almanah-mw-entry-view { font: %s; }", font_name);
+       css_provider = gtk_css_provider_get_default ();
+       gtk_css_provider_load_from_data (css_provider, css_font, strlen(css_font), NULL);
+       style_context = gtk_widget_get_style_context (GTK_WIDGET (self->priv->entry_view));
+       gtk_style_context_add_provider (style_context, GTK_STYLE_PROVIDER (css_provider), 
GTK_STYLE_PROVIDER_PRIORITY_USER);
+
+       /* Setting up entry GtkTextView size based on font size plus a margin */
+       fixed_width = mw_get_font_width (GTK_WIDGET (self->priv->entry_view), font_name) + 
ALMANAH_MAIN_WINDOW_FIXED_MARGIN_FONT;
+       /* The ScrolledWindow (parent container for the text view) must be at
+          least the new width plus the text view margin */
+       gtk_widget_set_size_request(GTK_WIDGET (self->priv->entry_scrolled),
+                                   fixed_width + gtk_widget_get_margin_start (GTK_WIDGET 
(self->priv->entry_view)) + gtk_widget_get_margin_end (GTK_WIDGET (self->priv->entry_view)),
+                                   -1);
+       gtk_widget_set_size_request(GTK_WIDGET (self->priv->entry_view), fixed_width, -1);
+
+       g_free (font_name);
+       g_free (css_font);
+}
+
+
+int
+mw_get_font_width (GtkWidget *widget, const gchar *font_name)
+{
+       int width, height;
+       PangoFontDescription *desc;
+       PangoLayout *layout;
+
+       desc = pango_font_description_from_string (font_name);
+       layout = pango_layout_new (gtk_widget_get_pango_context (widget));
+       pango_layout_set_font_description (layout, desc);
+       /* Translators: this sentence is just used in startup to estimate the width
+          of a 15 words sentence. Translate with some randome sentences with just 15 words.
+          See: https://bugzilla.gnome.org/show_bug.cgi?id=754841 */
+       pango_layout_set_text (layout, _("This is just a fifteen words sentence to calculate the diary entry 
text view size"), -1);
+
+       pango_layout_get_pixel_size (layout, &width, &height);
+
+       g_object_unref (layout);
+
+       return width;
+}
+
+
+void
+mw_desktop_interface_settings_changed (__attribute__ ((unused)) GSettings *settings, gchar *key, gpointer 
user_data)
+{
+       if (g_ascii_strcasecmp (ALMANAH_MAIN_WINDOW_DOCUMENT_FONT_KEY_NAME, key) != 0)
+               return;
+
+       mw_setup_size_text_view (ALMANAH_MAIN_WINDOW (user_data));
+}
+
+
 #ifdef ENABLE_SPELL_CHECKING
 static void
 spell_checking_enabled_changed_cb (GSettings *settings, __attribute__ ((unused)) gchar *key, 
AlmanahMainWindow *self)
diff --git a/src/ui/almanah.ui b/src/ui/almanah.ui
index 5357e64..668f74e 100644
--- a/src/ui/almanah.ui
+++ b/src/ui/almanah.ui
@@ -126,6 +126,9 @@
                                                                                <property 
name="vexpand">True</property>
                                                                                <property 
name="margin-start">20</property>
                                                                                <property 
name="margin-end">20</property>
+                                                                               <style>
+                                                                                       <class 
name="almanah-mw-entry-view"/>
+                                                                               </style>
                                                                                <child 
internal-child="accessible">
                                                                                        <object 
class="AtkObject" id="a11y-almanah_mw_entry_view">
                                                                                                <property 
name="AtkObject::accessible-name" translatable="yes">Entry editing area</property>