From 9af6ab55db161f395a4f8c9a79b1d5b7e5b4936c Mon Sep 17 00:00:00 2001 From: Mathieu Lacage Date: Wed, 9 Jun 2004 20:22:04 +0000 Subject: [PATCH] commit first patches from stefan, work on the chaining up section --- docs/reference/gobject/tut_gobject.xml | 34 +++++++++++++-------- docs/reference/gobject/tut_howto.xml | 55 +++++++++++++++++++++------------- 2 files changed, 56 insertions(+), 33 deletions(-) diff --git a/docs/reference/gobject/tut_gobject.xml b/docs/reference/gobject/tut_gobject.xml index 1ee22d4..0d3fd3a 100644 --- a/docs/reference/gobject/tut_gobject.xml +++ b/docs/reference/gobject/tut_gobject.xml @@ -17,7 +17,7 @@ Generic per-object properties with set/get function pairs Easy use of signals - All the GTK objects and all of the objects in Gnome libraries which use the glib type + All the GTK+ objects and all of the objects in Gnome libraries which use the glib type system inherit from GObject which is why it is important to understand the details of how it works. @@ -53,12 +53,12 @@ The example below shows how MamanBar overrides the parent's constructor: -#define MAMAN_BAR_TYPE (maman_bar_get_type ()) -#define MAMAN_BAR(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), MAMAN_BAR_TYPE, MamanBar)) -#define MAMAN_BAR_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), MAMAN_BAR_TYPE, MamanBarClass)) -#define MAMAN_IS_BAR(obj) (G_TYPE_CHECK_TYPE ((obj), MAMAN_BAR_TYPE)) -#define MAMAN_IS_BAR_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), MAMAN_BAR_TYPE)) -#define MAMAN_BAR_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), MAMAN_BAR_TYPE, MamanBarClass)) +#define MAMAN_TYPE_BAR (maman_bar_get_type ()) +#define MAMAN_BAR(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), MAMAN_TYPE_BAR, MamanBar)) +#define MAMAN_BAR_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), MAMAN_TYPE_BAR, MamanBarClass)) +#define MAMAN_IS_BAR(obj) (G_TYPE_CHECK_TYPE ((obj), MAMAN_TYPE_BAR)) +#define MAMAN_IS_BAR_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), MAMAN_TYPE_BAR)) +#define MAMAN_BAR_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), MAMAN_TYPE_BAR, MamanBarClass)) typedef struct _MamanBar MamanBar; typedef struct _MamanBarClass MamanBarClass; @@ -74,7 +74,7 @@ struct _MamanBarClass { /* class members */ }; -/* used by MAMAN_BAR_TYPE */ +/* used by MAMAN_TYPE_BAR */ GType maman_bar_get_type (void); static GObject * @@ -88,7 +88,7 @@ maman_bar_constructor (GType type, /* Invoke parent constructor. */ MamanBarClass *klass; GObjectClass *parent_class; - klass = MAMAN_BAR_CLASS (g_type_class_peek (MAMAN_BAR_TYPE)); + klass = MAMAN_BAR_CLASS (g_type_class_peek (MAMAN_TYPE_BAR)); parent_class = G_OBJECT_CLASS (g_type_class_peek_parent (klass)); obj = parent_class->constructor (type, n_construct_properties, @@ -142,7 +142,7 @@ GType maman_bar_get_type (void) If the user instantiates an object MamanBar with: -MamanBar *bar = g_object_new (MAMAN_BAR_TYPE, NULL); +MamanBar *bar = g_object_new (MAMAN_TYPE_BAR, NULL); If this is the first instantiation of such an object, the maman_b_class_init function will be invoked after any maman_b_base_class_init function. @@ -504,7 +504,8 @@ void g_object_run_dispose (GObject *object); Object properties - One of GObject's nice features is its generic get/set mechanism. When an object + One of GObject's nice features is its generic get/set mechanism for object + properties. When an object is instanciated, the object's class_init handler should be used to register the object's properties with g_object_class_install_property (implemented in gobject.c). @@ -620,7 +621,7 @@ maman_bar_class_init (gpointer g_class, GObject *bar; GValue val = {0,}; -bar = g_object_new (MAMAN_SUBBAR_TYPE, NULL); +bar = g_object_new (MAMAN_TYPE_SUBBAR, NULL); g_value_init (&val, G_TYPE_CHAR); g_value_set_char (&val, 11); g_object_set_property (G_OBJECT (bar), "papa-number", &val); @@ -699,6 +700,10 @@ g_object_set_property (G_OBJECT (bar), "papa-number", &val); can only be delayed by the notification freezing mechanism. + + Accessing multiple properties at once + + It is interesting to note that the g_object_set and g_object_set_valist (vararg version) functions can be used to set @@ -728,6 +733,11 @@ g_object_set (G_OBJECT (foo), Of course, the "notify" signal will be emitted for each property set. + + + + + diff --git a/docs/reference/gobject/tut_howto.xml b/docs/reference/gobject/tut_howto.xml index 3c465ca..87290d9 100644 --- a/docs/reference/gobject/tut_howto.xml +++ b/docs/reference/gobject/tut_howto.xml @@ -291,7 +291,7 @@ maman_bar_init (GTypeInstance *instance, Now, if you need special construction properties, install the properties in the class_init function, override the set and get methods and implement the get and set methods as described in . Make sure that these properties use a construct only - pspec by setting the param spec's flag field to G_PARAM_CONSTRUCT_ONLY: this helps + GParamSpec by setting the param spec's flag field to G_PARAM_CONSTRUCT_ONLY: this helps GType ensure that these properties are not set again later by malicious user code. static void @@ -439,7 +439,7 @@ if (self->private->dispose_has_run) { - non-virtual public methods + Non-virtual public methods These are the simplest: you want to provide a simple method which can act on your object. All you need @@ -460,7 +460,7 @@ void maman_bar_do_action (MamanBar *self, /* parameters */) - Virtual Public methods + Virtual public methods This is the preferred way to create polymorphic GObjects. All you need to do is to @@ -536,7 +536,7 @@ void maman_bar_do_action_two (MamanBar *self, /* parameters */) - Virtual Private Methods + Virtual private Methods These are very similar to Virtual Public methods. They just don't have a public function to call the @@ -628,6 +628,19 @@ maman_bar_subtype_class_init (MamanBarSubTypeClass *klass) + + Chaining up + +

Chaining up is commonly used to implement the Chain Of Responsability pattern in C++: each class in a + given inheritance hierarchy is expected to override the same method and then call from within each method + the overriden method of the parent. Personally, I am not sure this is a very smart idea (a detailed explanation + of why I think it is a bad idea would take too much space for this document) but I can show you how to do it and + here is an example. +

+ +

To invoke the parent method XXX

+ + @@ -661,12 +674,12 @@ maman_bar_subtype_class_init (MamanBarSubTypeClass *klass) #include <glib-object.h> -#define MAMAN_IBAZ_TYPE (maman_ibaz_get_type ()) -#define MAMAN_IBAZ(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), MAMAN_IBAZ_TYPE, MamanIbaz)) -#define MAMAN_IBAZ_CLASS(vtable) (G_TYPE_CHECK_CLASS_CAST ((vtable), MAMAN_IBAZ_TYPE, MamanIbazClass)) -#define MAMAN_IS_IBAZ(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), MAMAN_IBAZ_TYPE)) -#define MAMAN_IS_IBAZ_CLASS(vtable) (G_TYPE_CHECK_CLASS_TYPE ((vtable), MAMAN_IBAZ_TYPE)) -#define MAMAN_IBAZ_GET_CLASS(inst) (G_TYPE_INSTANCE_GET_INTERFACE ((inst), MAMAN_IBAZ_TYPE, MamanIbazClass)) +#define MAMAN_TYPE_IBAZ (maman_ibaz_get_type ()) +#define MAMAN_IBAZ(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), MAMAN_TYPE_IBAZ, MamanIbaz)) +#define MAMAN_IBAZ_CLASS(vtable) (G_TYPE_CHECK_CLASS_CAST ((vtable), MAMAN_TYPE_IBAZ, MamanIbazClass)) +#define MAMAN_IS_IBAZ(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), MAMAN_TYPE_IBAZ)) +#define MAMAN_IS_IBAZ_CLASS(vtable) (G_TYPE_CHECK_CLASS_TYPE ((vtable), MAMAN_TYPE_IBAZ)) +#define MAMAN_IBAZ_GET_CLASS(inst) (G_TYPE_INSTANCE_GET_INTERFACE ((inst), MAMAN_TYPE_IBAZ, MamanIbazClass)) typedef struct _MamanIbaz MamanIbaz; /* dummy object */ @@ -774,12 +787,12 @@ void maman_ibaz_do_action (MamanIbaz *self) #include <glib-object.h> -#define MAMAN_BAZ_TYPE (maman_baz_get_type ()) -#define MAMAN_BAZ(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), MAMAN_BAZ_TYPE, Mamanbaz)) -#define MAMAN_BAZ_CLASS(vtable) (G_TYPE_CHECK_CLASS_CAST ((vtable), MAMAN_BAZ_TYPE, MamanbazClass)) -#define MAMAN_IS_BAZ(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), MAMAN_BAZ_TYPE)) -#define MAMAN_IS_BAZ_CLASS(vtable) (G_TYPE_CHECK_CLASS_TYPE ((vtable), MAMAN_BAZ_TYPE)) -#define MAMAN_BAZ_GET_CLASS(inst) (G_TYPE_INSTANCE_GET_CLASS ((inst), MAMAN_BAZ_TYPE, MamanbazClass)) +#define MAMAN_TYPE_BAZ (maman_baz_get_type ()) +#define MAMAN_BAZ(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), MAMAN_TYPE_BAZ, Mamanbaz)) +#define MAMAN_BAZ_CLASS(vtable) (G_TYPE_CHECK_CLASS_CAST ((vtable), MAMAN_TYPE_BAZ, MamanbazClass)) +#define MAMAN_IS_BAZ(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), MAMAN_TYPE_BAZ)) +#define MAMAN_IS_BAZ_CLASS(vtable) (G_TYPE_CHECK_CLASS_TYPE ((vtable), MAMAN_TYPE_BAZ)) +#define MAMAN_BAZ_GET_CLASS(inst) (G_TYPE_INSTANCE_GET_CLASS ((inst), MAMAN_TYPE_BAZ, MamanbazClass)) typedef struct _MamanBaz MamanBaz; @@ -831,7 +844,7 @@ maman_baz_get_type (void) "MamanBazType", &info, 0); g_type_add_interface_static (type, - MAMAN_IBAZ_TYPE, + MAMAN_TYPE_IBAZ, &ibaz_info); } return type; @@ -840,7 +853,7 @@ maman_baz_get_type (void) This function is very much like all the similar functions we looked at previously. The only interface-specific code present here is the call to g_type_add_interface_static which is used to inform the type system that this just-registered GType also implements the interface - MAMAN_IBAZ_TYPE. + MAMAN_TYPE_IBAZ. @@ -889,7 +902,7 @@ baz_instance_init (GTypeInstance *instance, type = g_type_register_static (G_TYPE_INTERFACE, "MamanIbar", &info, 0); /* Make the MamanIbar interface require MamanIbaz interface. */ - g_type_interface_add_prerequisite (type, MAMAN_IBAZ_TYPE); + g_type_interface_add_prerequisite (type, MAMAN_TYPE_IBAZ); The code shown above adds the MamanIbaz interface to the list of prerequisites of MamanIbar while the code below shows how an implementation can implement both interfaces and register their implementations: @@ -961,10 +974,10 @@ maman_bar_get_type (void) "MamanBarType", &info, 0); g_type_add_interface_static (type, - MAMAN_IBAZ_TYPE, + MAMAN_TYPE_IBAZ, &ibaz_info); g_type_add_interface_static (type, - MAMAN_IBAR_TYPE, + MAMAN_TYPE_IBAR, &ibar_info); } return type; -- 2.7.4