[console/zbrown/quick-ci-check: 4/5] settings: introduce KgxSettings

[Zander Brown <zbrown src gnome org>]

commit 1a67369c71527104c38f9b952abbb2449c800f9c
Author: Zander Brown <zbrown gnome org>
Date:   Tue Aug 16 23:30:17 2022 +0100

    settings: introduce KgxSettings
    
    Similar to KgxWatcher this will let us slim down KgxApplication
    
    Further it raises the possibility of different KgxWindows (or possibly
    even KgxTabs…) being hooked to different instances — which may prove
    handy for term-intent stuff
    
    Note this commit simply defines the type, it isn't yet used

 src/kgx-settings.c | 374 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/kgx-settings.h |  42 ++++++
 src/meson.build    |   2 +
 3 files changed, 418 insertions(+)
---
diff --git a/src/kgx-settings.c b/src/kgx-settings.c
new file mode 100644
index 0000000..2337cb3
--- /dev/null
+++ b/src/kgx-settings.c
@@ -0,0 +1,374 @@
+/* kgx-settings.c
+ *
+ * Copyright 2022 Zander Brown
+ *
+ * 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/>.
+ */
+
+/**
+ * SECTION:kgx-proxy-info
+ * @short_description: An object with proxy details
+ * @title: KgxProxyInfo
+ *
+ * #KgxProxyInfo maps org.gnome.system.proxy to environmental variables
+ * when launching new sessions
+ *
+ * Note that whilst changes to system settings are tracked, they _cannot_ be
+ * applied existing terminals
+ *
+ * Only manual proxies are supported
+ */
+
+#include "kgx-config.h"
+
+#include <gio/gio.h>
+
+#include "kgx-settings.h"
+#include "kgx-terminal.h"
+
+
+/**
+ * DESKTOP_INTERFACE_SETTINGS_SCHEMA:
+ * The schema that defines the system fonts
+ */
+#define DESKTOP_INTERFACE_SETTINGS_SCHEMA "org.gnome.desktop.interface"
+
+/**
+ * MONOSPACE_FONT_KEY_NAME:
+ * The name of the key in %DESKTOP_INTERFACE_SETTINGS_SCHEMA for the monospace
+ * font
+ */
+#define MONOSPACE_FONT_KEY_NAME "monospace-font-name"
+
+
+struct _KgxSettings {
+  GObject      parent_instance;
+
+  KgxTheme     theme;
+  double       scale;
+  int64_t      scrollback_lines;
+
+  GSettings   *settings;
+  GSettings   *desktop_interface;
+};
+
+
+G_DEFINE_TYPE (KgxSettings, kgx_settings, G_TYPE_OBJECT)
+
+
+enum {
+  PROP_0,
+  PROP_THEME,
+  PROP_FONT,
+  PROP_FONT_SCALE,
+  PROP_SCALE_CAN_INCREASE,
+  PROP_SCALE_CAN_DECREASE,
+  PROP_SCROLLBACK_LINES,
+  LAST_PROP
+};
+
+static GParamSpec *pspecs[LAST_PROP] = { NULL, };
+
+
+static void
+kgx_settings_dispose (GObject *object)
+{
+  KgxSettings *self = KGX_SETTINGS (object);
+
+  g_clear_object (&self->settings);
+  g_clear_object (&self->desktop_interface);
+
+  G_OBJECT_CLASS (kgx_settings_parent_class)->dispose (object);
+}
+
+
+static void
+update_scale (KgxSettings *self, double value)
+{
+  double clamped = CLAMP (value, KGX_FONT_SCALE_MIN, KGX_FONT_SCALE_MAX);
+
+  if (self->scale == clamped) {
+    return;
+  }
+
+  self->scale = clamped;
+
+  g_object_notify_by_pspec (G_OBJECT (self), pspecs[PROP_FONT_SCALE]);
+  g_object_notify_by_pspec (G_OBJECT (self), pspecs[PROP_SCALE_CAN_INCREASE]);
+  g_object_notify_by_pspec (G_OBJECT (self), pspecs[PROP_SCALE_CAN_DECREASE]);
+}
+
+
+static void
+kgx_settings_set_property (GObject      *object,
+                           guint         property_id,
+                           const GValue *value,
+                           GParamSpec   *pspec)
+{
+  KgxSettings *self = KGX_SETTINGS (object);
+
+  switch (property_id) {
+    case PROP_THEME:
+      self->theme = g_value_get_enum (value);
+      break;
+    case PROP_FONT_SCALE:
+      update_scale (self, g_value_get_double (value));
+      break;
+    case PROP_SCROLLBACK_LINES:
+      kgx_settings_set_scrollback (self, g_value_get_int64 (value));
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+  }
+}
+
+
+static void
+kgx_settings_get_property (GObject    *object,
+                           guint       property_id,
+                           GValue     *value,
+                           GParamSpec *pspec)
+{
+  KgxSettings *self = KGX_SETTINGS (object);
+
+  switch (property_id) {
+    case PROP_THEME:
+      g_value_set_enum (value, self->theme);
+      break;
+    case PROP_FONT:
+      g_value_take_boxed (value, kgx_settings_get_font (self));
+      break;
+    case PROP_FONT_SCALE:
+      g_value_set_double (value, self->scale);
+      break;
+    case PROP_SCALE_CAN_INCREASE:
+      g_value_set_boolean (value, self->scale < KGX_FONT_SCALE_MAX);
+      break;
+    case PROP_SCALE_CAN_DECREASE:
+      g_value_set_boolean (value, self->scale > KGX_FONT_SCALE_MIN);
+      break;
+    case PROP_SCROLLBACK_LINES:
+      g_value_set_int64 (value, self->scrollback_lines);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+  }
+}
+
+
+static void
+kgx_settings_class_init (KgxSettingsClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = kgx_settings_dispose;
+  object_class->set_property = kgx_settings_set_property;
+  object_class->get_property = kgx_settings_get_property;
+
+  /**
+   * KgxSettings:theme:
+   *
+   * The palette to use, one of the values of #KgxTheme
+   *
+   * Officially only "night" exists, "hacker" is just a little fun
+   *
+   * Bound to ‘theme’ GSetting so changes persist
+   */
+  pspecs[PROP_THEME] =
+    g_param_spec_enum ("theme", "Theme", "Terminal theme",
+                       KGX_TYPE_THEME, KGX_THEME_NIGHT,
+                       G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
+
+  pspecs[PROP_FONT] =
+    g_param_spec_boxed ("font", "Font", "Monospace font",
+                         PANGO_TYPE_FONT_DESCRIPTION,
+                         G_PARAM_READABLE | G_PARAM_STATIC_STRINGS | G_PARAM_EXPLICIT_NOTIFY);
+
+  pspecs[PROP_FONT_SCALE] =
+    g_param_spec_double ("font-scale", "Font scale", "Font scaling",
+                         KGX_FONT_SCALE_MIN,
+                         KGX_FONT_SCALE_MAX,
+                         KGX_FONT_SCALE_DEFAULT,
+                         G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS | G_PARAM_EXPLICIT_NOTIFY);
+
+  pspecs[PROP_SCALE_CAN_INCREASE] =
+    g_param_spec_boolean ("scale-can-increase", NULL, NULL,
+                          TRUE,
+                          G_PARAM_READABLE | G_PARAM_STATIC_STRINGS | G_PARAM_EXPLICIT_NOTIFY);
+
+  pspecs[PROP_SCALE_CAN_DECREASE] =
+    g_param_spec_boolean ("scale-can-decrease", NULL, NULL,
+                          TRUE,
+                          G_PARAM_READABLE | G_PARAM_STATIC_STRINGS | G_PARAM_EXPLICIT_NOTIFY);
+
+  /**
+   * KgxSettings:scrollback-lines:
+   *
+   * How many lines of scrollback #KgxTerminal should keep
+   *
+   * Bound to ‘scrollback-lines’ GSetting so changes persist
+   */
+  pspecs[PROP_SCROLLBACK_LINES] =
+    g_param_spec_int64 ("scrollback-lines", "Scrollback Lines", "Size of the scrollback",
+                        G_MININT64, G_MAXINT64, 512,
+                        G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS | G_PARAM_EXPLICIT_NOTIFY);
+
+  g_object_class_install_properties (object_class, LAST_PROP, pspecs);
+}
+
+
+static void
+font_changed (GSettings    *settings,
+              const char   *key,
+              KgxSettings  *self)
+{
+  g_object_notify_by_pspec (G_OBJECT (self), pspecs[PROP_FONT]);
+}
+
+
+static void
+kgx_settings_init (KgxSettings *self)
+{
+  self->settings = g_settings_new (KGX_APPLICATION_ID);
+  g_settings_bind (self->settings, "theme",
+                   self, "theme",
+                   G_SETTINGS_BIND_DEFAULT);
+  g_settings_bind (self->settings, "font-scale",
+                   self, "font-scale",
+                   G_SETTINGS_BIND_DEFAULT);
+  g_settings_bind (self->settings, "scrollback-lines",
+                   self, "scrollback-lines",
+                   G_SETTINGS_BIND_DEFAULT);
+
+  self->desktop_interface = g_settings_new (DESKTOP_INTERFACE_SETTINGS_SCHEMA);
+  g_signal_connect (self->desktop_interface,
+                    "changed::" MONOSPACE_FONT_KEY_NAME,
+                    G_CALLBACK (font_changed),
+                    self);
+}
+
+
+/**
+ * kgx_settings_get_font:
+ * @self: the #KgxSettings
+ *
+ * Creates a #PangoFontDescription for the system monospace font.
+ *
+ * Returns: (transfer full): a new #PangoFontDescription
+ */
+PangoFontDescription *
+kgx_settings_get_font (KgxSettings *self)
+{
+  /* Adapted from gnome-terminal */
+  g_autofree char *font = NULL;
+
+  g_return_val_if_fail (KGX_IS_SETTINGS (self), NULL);
+
+  font = g_settings_get_string (self->desktop_interface,
+                                MONOSPACE_FONT_KEY_NAME);
+
+  return pango_font_description_from_string (font);
+}
+
+
+void
+kgx_settings_increase_scale (KgxSettings *self)
+{
+  g_return_if_fail (KGX_IS_SETTINGS (self));
+
+  update_scale (self, self->scale + 0.1);
+}
+
+
+void
+kgx_settings_decrease_scale (KgxSettings *self)
+{
+  g_return_if_fail (KGX_IS_SETTINGS (self));
+
+  update_scale (self, self->scale - 0.1);
+}
+
+
+void
+kgx_settings_reset_scale (KgxSettings *self)
+{
+  g_return_if_fail (KGX_IS_SETTINGS (self));
+
+  update_scale (self, KGX_FONT_SCALE_DEFAULT);
+}
+
+
+/**
+ * Return: (transfer full):
+ */
+GStrv
+kgx_settings_get_shell (KgxSettings *self)
+{
+  g_autofree char *user_shell = NULL;
+  g_auto (GStrv) shell = NULL;
+  g_auto (GStrv) custom_shell = NULL;
+
+  g_return_val_if_fail (KGX_IS_SETTINGS (self), NULL);
+
+  custom_shell = g_settings_get_strv (self->settings, "shell");
+
+  if (g_strv_length (custom_shell) > 0) {
+    return g_steal_pointer (&custom_shell);
+  }
+
+  user_shell = vte_get_user_shell ();
+
+  if (G_LIKELY (user_shell)) {
+    shell = g_new0 (char *, 2);
+    shell[0] = g_steal_pointer (&user_shell);
+    shell[1] = NULL;
+
+    return g_steal_pointer (&shell);
+  }
+
+  /* We could probably do something other than /bin/sh */
+  shell = g_new0 (char *, 2);
+  shell[0] = g_strdup ("/bin/sh");
+  shell[1] = NULL;
+  g_warning ("No Shell! Defaulting to “%s”", shell[0]);
+
+  return g_steal_pointer (&shell);
+}
+
+
+void
+kgx_settings_set_custom_shell (KgxSettings *self, const char *const *shell)
+{
+  g_return_if_fail (KGX_IS_SETTINGS (self));
+
+  g_settings_set_strv (self->settings, "shell", shell);
+}
+
+
+void
+kgx_settings_set_scrollback (KgxSettings *self,
+                             int64_t      value)
+{
+  g_return_if_fail (KGX_IS_SETTINGS (self));
+
+  if (self->scrollback_lines == value) {
+    return;
+  }
+
+  self->scrollback_lines = value;
+
+  g_object_notify_by_pspec (G_OBJECT (self), pspecs[PROP_SCROLLBACK_LINES]);
+}
diff --git a/src/kgx-settings.h b/src/kgx-settings.h
new file mode 100644
index 0000000..2881071
--- /dev/null
+++ b/src/kgx-settings.h
@@ -0,0 +1,42 @@
+/* kgx-settings.h
+ *
+ * Copyright 2022 Zander Brown
+ *
+ * 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/>.
+ */
+
+#pragma once
+
+#include <glib-object.h>
+#include <pango/pango.h>
+
+#include "kgx-terminal.h"
+
+G_BEGIN_DECLS
+
+#define KGX_TYPE_SETTINGS kgx_settings_get_type ()
+
+G_DECLARE_FINAL_TYPE (KgxSettings, kgx_settings, KGX, SETTINGS, GObject)
+
+PangoFontDescription *kgx_settings_get_font          (KgxSettings       *self);
+void                  kgx_settings_increase_scale    (KgxSettings       *self);
+void                  kgx_settings_decrease_scale    (KgxSettings       *self);
+void                  kgx_settings_reset_scale       (KgxSettings       *self);
+GStrv                 kgx_settings_get_shell         (KgxSettings       *self);
+void                  kgx_settings_set_custom_shell  (KgxSettings       *self,
+                                                      const char *const *shell);
+void                  kgx_settings_set_scrollback    (KgxSettings       *self,
+                                                      int64_t            value);
+
+G_END_DECLS
diff --git a/src/meson.build b/src/meson.build
index e5dfc84..ac27d3d 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -11,6 +11,8 @@ kgx_sources = [
   'kgx-process.h',
   'kgx-proxy-info.c',
   'kgx-proxy-info.h',
+  'kgx-settings.c',
+  'kgx-settings.h',
   'kgx-simple-tab.c',
   'kgx-simple-tab.h',
   'kgx-tab-button.c',