Warning: unable to set property `editable' of type `gboolean' from value of type `gchararray'

做GTK编程的时候，使用TreeView控件时出现这个警告，也就是无法使单元格变为“editable”，原因出在这里：

column = gtk.TreeViewColumn(columName[columnNum], renderer, editable=True)

原理解TreeViewColumn的构造函数接受的参数里面可以接受设置Cellrenderer的属性，就直接给editable设True，于是就得到以上警告。

换用add_attribute、set_attributes，均是如此。

Google上搜到同样错误警告，但是他的原因是设错值类型，我明明设了True啊……

自己观察pygtk-demo的代码和手册，突然发现在构造函数里面给出的属性设置值不应该是直接的值，而是对应Model里面的相应column的值！看手册的描述：

Zero or more attribute=column pairs may be added to specify from which tree model column to retrieve the attribute value.

呃，果然是看手册时候大意了，这么多年来还是让英语介词搞的晕头转向。如果在构造函数里面设True这个值，就会被解析为1，去对应Model里面第二栏的类型，是字符串的gchararray，当然对不上了。

解决办法是renderer.set_property("editable", True)，调用继承自GObject的set_property方法来设置对象属性。

1 ICON "icon.ico"

3. run : (windres was include in Mingw)

windres logo.rc logo.o

4. link the "logo.o" file together with other object files to the final exe file.

The solution was written in a tutorial, http://scentric.net/tutorial/sec-editable-cells.html

there seems quite several GTK tutorials, but most of their contents were duplicated, though I always learn the tricks from them... ^_^

Note:

renderer = gtk_cell_renderer_text_new();
...
g_object_set_data(G_OBJECT(renderer), "my_column_num", GUINT_TO_POINTER(COLUMN_NAME));

...

renderer = gtk_cell_renderer_text_new();
...
g_object_set_data(G_OBJECT(renderer), "my_column_num", GUINT_TO_POINTER(COLUMN_YEAR_OF_BIRTH));

...

the "renderer" must be create several times in this trick, for a object couldn't carry the same property in different value twice, itn's it?

首先找来找去没有见到有right-click的signal，Google了一下，从Maillist里面的解答找到头绪，由GtkWidget的button_press_event来实现。GTK+ Reference Manual里面一点都没提到这个信号，原来这个button指鼠标的button，键盘的键叫做key……

http://mail.gnome.org/archives/gtk-list/2002-August/msg00119.html

button_press_event emits when any mouse button pressed, when handling with this signal, use a callback prototype in this way:

gboolean callback (GtkWidget *widget,
GdkEventButton *event,
gpointer data);

and you can determine which button was press with event->button (values 1,2,3...3 stands for the right button, 1 for left and 2 for middle), and if you want give this signal back to the widget, just return FALSE.

另外一个问题是popup menu, 在glade3里面添加了一个popup menu, 照搬老方法，初始化程序的时候

tree->menu = GTK_WIDGET ( gtk_builder_get_object (builder, "menu1") );

弹出窗口：

gtk_menu_popup (GTK_MENU(user_data->menu), NULL, NULL, NULL, NULL, event->button, event->time);

郁闷的事情来了，程序运行的时候提示：

(tree:28254): GLib-GObject-WARNING **: invalid unclassed pointer in cast to `GtkMenu'

(tree:28254): Gtk-CRITICAL **: gtk_menu_popup: assertion `GTK_IS_MENU (menu)' failed

在Reference里面看了半天，注意到GtkBuilder Description的一段话：

A GtkBuilder holds a reference to all objects that it has constructed and drops these references when it is finalized. This finalization can cause the destruction of non-widget objects or widgets which are not contained in a toplevel window. For toplevel windows constructed by a builder, it is the responsibility of the user to call gtk_widget_destroy() to get rid of them and all the widgets they contain.

在Glade3里面看到，popup menu不属于toplevel的window，看来小menu在g_object_unref (G_OBJECT (builder));的时候被收回去了……可是怎么解决呢？总不能不收了builder吧，builder占的内存可不小的，很容易造成内存泄漏……

It's obvious that the menu allocation was released after initialing the application, I have to solve this problem.

In the Reference Manual, I found a function.

g_object_ref ()

gpointer g_object_ref (gpointer object);

Increases the reference count of object.

The reference count really mean something, worth to read about it carefully. I just add one more statement after getting the menu widget:

这个reference count大有来头。在gtk_builder_get_object (builder, "menu1")后，加了一句:

g_object_ref ((gpointer)tree->menu);

Yes，the whole world goes the right way now!!!!