[gnome-shell/wip/nielsdg/g-object-notify: 3/4] st-button: Use g_object_notify_by_pspec()

[Niels De Graef <nielsdg src gnome org>]

commit 2dc2faa5a2747e1081b427f6d89f7eae9398191f
Author: Niels De Graef <nielsdegraef gmail com>
Date:   Wed Jul 31 07:32:21 2019 +0200

    st-button: Use g_object_notify_by_pspec()
    
    `g_object_notify()` actually takes a global lock to look up the property
    by its name, which means there is a performance hit (albeit tiny) every
    time this function is called. For this reason, always try to use
    `g_object_notify_by_pspec()` instead.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/652

 src/st/st-button.c | 87 +++++++++++++++++++++++++++++-------------------------
 1 file changed, 46 insertions(+), 41 deletions(-)
---
diff --git a/src/st/st-button.c b/src/st/st-button.c
index 3af1811f7..681205e81 100644
--- a/src/st/st-button.c
+++ b/src/st/st-button.c
@@ -54,9 +54,13 @@ enum
   PROP_BUTTON_MASK,
   PROP_TOGGLE_MODE,
   PROP_CHECKED,
-  PROP_PRESSED
+  PROP_PRESSED,
+
+  N_PROPS
 };
 
+static GParamSpec *props[N_PROPS] = { NULL, };
+
 enum
 {
   CLICKED,
@@ -476,41 +480,42 @@ st_button_class_init (StButtonClass *klass)
   widget_class->style_changed = st_button_style_changed;
   widget_class->get_accessible_type = st_button_accessible_get_type;
 
-  pspec = g_param_spec_string ("label",
-                               "Label",
-                               "Label of the button",
-                               NULL,
-                               ST_PARAM_READWRITE);
-  g_object_class_install_property (gobject_class, PROP_LABEL, pspec);
-
-  pspec = g_param_spec_flags ("button-mask",
-                              "Button mask",
-                              "Which buttons trigger the 'clicked' signal",
-                              ST_TYPE_BUTTON_MASK, ST_BUTTON_ONE,
-                              ST_PARAM_READWRITE);
-  g_object_class_install_property (gobject_class, PROP_BUTTON_MASK, pspec);
-
-  pspec = g_param_spec_boolean ("toggle-mode",
-                                "Toggle Mode",
-                                "Enable or disable toggling",
-                                FALSE,
-                                ST_PARAM_READWRITE);
-  g_object_class_install_property (gobject_class, PROP_TOGGLE_MODE, pspec);
-
-  pspec = g_param_spec_boolean ("checked",
-                                "Checked",
-                                "Indicates if a toggle button is \"on\""
-                                " or \"off\"",
-                                FALSE,
-                                ST_PARAM_READWRITE);
-  g_object_class_install_property (gobject_class, PROP_CHECKED, pspec);
-
-  pspec = g_param_spec_boolean ("pressed",
-                                "Pressed",
-                                "Indicates if the button is pressed in",
-                                FALSE,
-                                ST_PARAM_READABLE);
-  g_object_class_install_property (gobject_class, PROP_PRESSED, pspec);
+  props[PROP_LABEL] =
+      g_param_spec_string ("label",
+                           "Label",
+                           "Label of the button",
+                           NULL,
+                           ST_PARAM_READWRITE);
+
+  props[PROP_BUTTON_MASK] =
+      g_param_spec_flags ("button-mask",
+                          "Button mask",
+                          "Which buttons trigger the 'clicked' signal",
+                          ST_TYPE_BUTTON_MASK, ST_BUTTON_ONE,
+                          ST_PARAM_READWRITE);
+
+  props[PROP_TOGGLE_MODE] =
+      g_param_spec_boolean ("toggle-mode",
+                            "Toggle Mode",
+                            "Enable or disable toggling",
+                            FALSE,
+                            ST_PARAM_READWRITE);
+
+  props[PROP_CHECKED] =
+      g_param_spec_boolean ("checked",
+                            "Checked",
+                            "Indicates if a toggle button is \"on\" or \"off\"",
+                            FALSE,
+                            ST_PARAM_READWRITE);
+
+  props[PROP_PRESSED] =
+      g_param_spec_boolean ("pressed",
+                            "Pressed",
+                            "Indicates if the button is pressed in",
+                            FALSE,
+                            ST_PARAM_READABLE);
+
+  g_object_class_install_properties (gobject_class, N_PROPS, props);
 
 
   /**
@@ -631,7 +636,7 @@ st_button_set_label (StButton    *button,
   /* Fake a style change so that we reset the style properties on the label */
   st_widget_style_changed (ST_WIDGET (button));
 
-  g_object_notify (G_OBJECT (button), "label");
+  g_object_notify_by_pspec (G_OBJECT (button), props[PROP_LABEL]);
 }
 
 /**
@@ -670,7 +675,7 @@ st_button_set_button_mask (StButton     *button,
   priv = st_button_get_instance_private (button);
   priv->button_mask = mask;
 
-  g_object_notify (G_OBJECT (button), "button-mask");
+  g_object_notify_by_pspec (G_OBJECT (button), props[PROP_BUTTON_MASK]);
 }
 
 /**
@@ -708,7 +713,7 @@ st_button_set_toggle_mode (StButton *button,
   priv = st_button_get_instance_private (button);
   priv->is_toggle = toggle;
 
-  g_object_notify (G_OBJECT (button), "toggle-mode");
+  g_object_notify_by_pspec (G_OBJECT (button), props[PROP_TOGGLE_MODE]);
 }
 
 /**
@@ -754,7 +759,7 @@ st_button_set_checked (StButton *button,
         st_widget_remove_style_pseudo_class (ST_WIDGET (button), "checked");
     }
 
-  g_object_notify (G_OBJECT (button), "checked");
+  g_object_notify_by_pspec (G_OBJECT (button), props[PROP_CHECKED]);
 }
 
 /**
@@ -877,7 +882,7 @@ st_button_accessible_notify_label_cb (StButton   *button,
                                       GParamSpec *psec,
                                       AtkObject  *accessible)
 {
-  g_object_notify (G_OBJECT (accessible), "accessible-name");
+  g_object_notify_by_pspec (G_OBJECT (accessible), props[PROP_ACCESSIBLE_NAME]);
 }
 
 static void