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ruby-****@sourc*****
2004年 6月 7日 (月) 23:17:41 JST
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URL = http://ruby-gnome2.sourceforge.jp//?How+to+Implement+Ruby-GNOME2
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= How to implement Ruby-GNOME2
This document explains how to implement an extension for Ruby-GNOME2.
== Signals and Properties
Accessors methods (((*set*))/((*get*))) for properties are automatically generated. Signals are also directly handled by GLib::Instantiatable#signal_connect. So, you do not need to manually implement them anymore.
== Deprecated/Obsolete classes/methods
Don't implement them.
== Macros
You need to know that there are some macros which can help you to easily implement a new class/method.
Almost of those macros are in the header files glib/src/rbgobject.h, rbglib.h and gtk/src/rbgtk.h.
=== Define class/interface
These macros are used in Init_*() functions:
--- G_DEF_CLASS(gtype, name, module)
--- G_DEF_CLASS2(gtype, name, module, mark, free)
Define a class. If you want to define mark and free functions by yourself, use G_DEF_CLASS2.
This returns a new ruby class value.
--- G_DEF_CLASS3(gtype_name, name, module)
Define a class dynamicaly. This is for private gtype classes such as GdkScreenX11, GdkWindowImplWin32.
This returns nothing. These classes can't define the methods/constants by themselves. And these classes appear since a method which creates the private gtype has been called by ruby script.
--- G_DEF_INTERFACE(gtype, name, module)
--- G_DEF_INTERFACE2(gtype, name, module, mark, free)
Define a module. If you want to define mark and free functions by yourself, use G_DEF_INTERFACE2.
--- void rbgobj_boxed_not_copy_obj(GType gtype)
Use this method if the GBoxed object shouldn't be copied during its RVALUE conversion (for example in GBOXED2RVAL or G_INITIALIZE).
=== Initialize object
These macros are used in class constructors (methods ((*initialize*))):
--- G_INITIALIZE(obj, cobj)
--- RBGTK_INITIALIZE(obj,gtkobj)
--- RBGST_INITIALIZE(obj,gstobj)
Initialize an object. If the class is a descendant of GtkObject, use RBGTK_INITIALIZE. If the class in a descendant of GstObject, use RBGST_INITIALIZE.
=== Convert Ruby <-> GLib/GTK
--- RVAL2GOBJ(obj)
--- GOBJ2RVAL(gobj)
VALUE(GLib::Object) <-> GObject
--- RVAL2BOXED(obj)
--- BOXED2RVAL(cobj, gtype)
VALUE(GLib::Boxed) <-> GBoxed
--- RVAL2GENUM(obj, gtype)
--- GENUM2RVAL(gobj, gtype)
VALUE(GLib::Enum) <-> GEnum
--- RVAL2GFLAGS(obj, gtype)
--- GFLAGS2RVAL(gobj, gtype)
VALUE(GLib::Flags) <-> GFlags
--- RVAL2CSTR(v)
--- CSTR2RVAL(s)
VALUE(String) <-> gchar*
--- CSTR2RVAL2(s)
Convert gchar* s to VALUE(String) and then call g_free(s).
--- RVAL2CBOOL(v)
--- CBOOL2RVAL(b)
VALUE(true or false) <-> gboolean
--- GVAL2RVAL(v)
GValue(GLib::Value) -> RValue.
RVAL2GVAL(v) is not yet prepared. If you want to convert RValue to GValue, then use rbgobj_rvalue_to_gvalue():
GValue gval = {0,};
g_value_init(&gval, RVAL2GTYPE(value));
rbgobj_rvalue_to_gvalue(value, &gval);
/* then use gval... */
--- GEV2RVAL(ev)
--- RVAL2GEV(ev)
- VALUE(Gtk::Event) <-> GtkEvent
+ VALUE(Gdk::Event) <-> GdkEvent
--- GLIST2ARY(list)
--- GSLIT2ARY(list)
GList/GSList of GObject -> Array
--- GLIST2ARY2(list)
--- GSLIT2ARY2(list)
GList/GSList of GBoxed -> Array
=== Convert RGObjClassInfo <-> GType,Ruby class/instance
--- CLASS2CINFO(klass)
Class -> RGObjClassInfo
--- GTYPE2CINFO(gtype)
GType -> RGObjClassInfo
--- RVAL2CINFO(obj)
VALUE -> RGObjClassInfo
=== Convert GType <->Ruby class/instance
--- GTYPE2CLASS(gtype)
GType -> Class
--- CLASS2GTYPE(klass)
Class -> GType
--- RVAL2GTYPE(obj)
VALUE -> GType
=== Relatives
This saves an object from the GC. Usually obj is self and rel is child widget/object or proc object.
--- G_RELATIVE(obj, rel)
Make a relation.
--- G_RELATIVE2(obj, rel, id, hash_key)
Make a removable relation.
--- G_REMOVE_RELATIVE(obj, id, hash_key)
Remove a relation.
=== Setter methods
--- G_DEF_SETTER(klass, name)
--- G_DEF_SETTERS(klass)
These macros can be used to implement automatically setters methods with operator ((*=*)).
You implement by yourself the method set_hoge(aValue), and then you call G_DEF_SETTER(klass, "hoge").
set_hoge(a) #return self (implemented by yourself)
hoge=(a) #return a (created automatically from set_hoge)
If you have several set methods in a single class, then you can call G_DEF_SETTERS which will do the magic for all of them.
=== Define constants
--- G_DEF_CONSTANTS(mod, type, strip_prefix)
Define constants of Module/Class from GType. G_DEF_CONSTANTS is used with G_DEF_CLASS.
Here is a practical example from Gtk::Window source code:
/* Define Gtk::Window::TOPLEVEL and Gtk::Window::POPUP. */
G_DEF_CLASS(GTK_TYPE_WINDOW_TYPE, "Type", gWindow);
G_DEF_CONSTANTS(gWindow, GTK_TYPE_WINDOW_TYPE, "GTK_WINDOW_");
--- G_RENAME_CONSTANT(orig, alt)
Rename constants which has been defined with G_DEF_CONSTANTS().
--- G_RENAME_NICK(orig, alt)
Rename nick of GEnum/GFlags which start numerical character.
Ruby/GLib define the methods of GFlags from nick automatically. If nick starts numerical character, it causes a syntax error.
=== Block
--- G_BLOCK_PROC()
This macro calls either rb_f_lambda() (Ruby <= 1.7.x) or rb_block_proc() (Ruby >= 1.8.x).
You shouldn't use rb_f_lambda() or rb_block_proc() directly, if you want to produce portable code.
=== Argument of properties as hash
--- G_SET_PROPERTIES(self, properties)
This macro will help you to implement set_hoge(a, {:foo => 0, :bar =>"hoge"}) for properties.
=== Symbol properties
--- G_SET_SYMBOL_PROPERTY(gtype, name)
Define this in Init_*() for properties which use Symbol instead of String (e.g. Gtk::Stock).
=== Implement class which does not conform to GType system (no G*_TYPE_* macros)
You can either use traditional method, or implement the class as a GBoxed object.
Here is an example for the class ((*Foo*)):
(1) Create the following function, which will return a GLib type for our class:
GType foo_get_type(void) {
static GType our_type = 0;
if (our_type == 0) {
our_type = g_boxed_type_register_static("Foo",
(GBoxedCopyFunc)foo_copy,
(GBoxedFreeFunc)g_free);
}
return our_type;
}
If Foo has foo_ref/foo_unref, then use them instead of foo_copy, g_free.
(2) Create the following function, which will return a copy of an objet from our class:
Foo* foo_copy(const Foo* foo) {
Foo* new_foo;
g_return_val_if_fail (foo != NULL, NULL);
new_foo = g_new(Foo, sizeof(Foo));
*new_foo = *foo;
return new_foo;
}
Rarely, there are some objects which shouldn't make copy and shouldn't free them, you may need to write it as follows:
Foo* foo_copy(const Foo* foo) {
return (Foo*)foo;
}
void foo_free(gpointer foo) {
/* do nothing */
}
GType foo_get_type(void) {
static GType our_type = 0;
if (our_type == 0) {
our_type = g_boxed_type_register_static("Foo",
(GBoxedCopyFunc)foo_copy,
(GBoxedFreeFunc)foo_free);
}
return our_type;
}
Furthermore, some objects may need to do g_free() there in this case.
(3) Define a G*_TYPE_* macro:
#define G_TYPE_FOO (foo_get_type())
(4) You can now call in your Init_*() function:
void Init_foo(void) {
VALUE cFoo = G_DEF_CLASS(G_TYPE_FOO, "Foo", aModule);
/* ... */
}
(5) And for conversions:
/* Ruby -> GLib */
RVAL2BOXED(objet, G_TYPE_FOO);
/* GLib -> Ruby */
BOXED2RVAL(objet, G_TYPE_FOO))
=== GError handling
--- RAISE_GERROR(GError* error)
This macro will throw a Ruby exception according to the error code.
=== GLib::Object#signal_connect's block variables set manually
--- G_DEF_SIGNAL_FUNC(klass, signal_name, signal_g2r_func);
--- signal_g2r_func(guint num, const GValue* values);
You can define with these macros block variables for signals by yourself.
These macros should be used only in special case (since signals are automatically handled).
=== Recommended editors
If you develop Ruby-GNOME2 with GNU Emacs, I recommend you to customize your ~/.emacs file as follows:
(c-add-style
"ruby"
'("bsd"
(c-basic-offset . 4)
(c-offsets-alist
(case-label . 2)
(label . 2)
(statement-case-open . 2)
(statement-case-intro . 2))))
(add-hook 'c-mode-common-hook
'(lambda () (setq indent-tabs-mode nil)))
- ((<Masao>))