gtkbin seems to not get event from my gtkwindow toplevel widget - gtk

Question

I have some questions, in this moment I try to make a custom widget in gtk with gtkbin so I want to know if it is possible to subclass gtkbin and how to do that...
Thanks for your help.

Answer 1

I have finally managed to implement this myself. Here's how for people who want to derive gtkbin widget.
1) It is important to understand the hierarchy of widgets.
>Hierarchy of widgets:
GtkWidget <- GtkContainer <- GtkBin
If Gtkcontainer and GtkBin don't rewrite a contumize function for GtkWidgetClass->draw, for example, the custom widget class which derives directly from GtkBin will use the default draw function of the GtkWidgetClass.
2) Info about gtkbin:
Download the source code of gtk and open gtkwidget.c, gtkcontainer.c, gtkwindow.c and look at the class_init function in all this files.
In the GtkWidgetClass:
1) We have to see that, widget class doesn't implement the "draw" function:
GtkWidgetClass->draw
2) We have to see that, the implementation of GtkWidgetClass->get_preferred_width and GtkWidgetClass_preferred_width_height always returns "0" which is not correct.
We also see that GtkWidgetClass->size_allocate only allocates size for the widget you want to derive, it doesn't take in count the children of the customize widget.
You have to rewrite these four functions to everything to work properly.
Since GtkWindow is a widget which derives directly from GtkBin, we can implement our functions by viewing the corresponding implementation in GtkWindow.c file and make some changes.
Here is my implementation:
widget_class->get_preferred_width = item_list_get_preferred_width;
widget_class->get_preferred_height = item_list_get_preferred_height;
widget_class->draw = dsn_itemlist_draw;
widget_class->size_allocate = item_list_size_allocate;
void item_list_size_allocate (GtkWidget *widget,
GtkAllocation *allocation)
{
GtkAllocation child_allocation;
GtkWidget *child;
guint border_width;
gtk_widget_set_allocation (widget, allocation);
child = gtk_bin_get_child (GTK_BIN(widget));
if (child && gtk_widget_get_visible (child))
{
border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
child_allocation.x = border_width;
child_allocation.y = border_width;
child_allocation.width = MAX (1, allocation->width - border_width * 2);
child_allocation.height = MAX (1, allocation->height - border_width * 2);
gtk_widget_size_allocate (child, &child_allocation);
}
}
gboolean dsn_itemlist_draw( GtkWidget *widget, cairo_t *cr)
{
GtkWidget *child;
GtkBin *bin = GTK_BIN(widget);
GtkContainer *container = GTK_CONTAINER(widget);
child = gtk_bin_get_child(bin);
gtk_container_propagate_draw(container, child, cr);
printf("bonnnnnnn\n");
return TRUE;
}
void item_list_get_preferred_width(GtkWidget *widget,
gint *minimum_size,
gint *natural_size)
{
//GtkWindow *window;
GtkWidget *child;
guint border_width;
//window = GTK_WINDOW (widget);
child = gtk_bin_get_child (GTK_BIN (widget)/*(window)*/);
border_width = 0;//gtk_container_get_border_width (GTK_CONTAINER (window));
*minimum_size = border_width * 2;
*natural_size = border_width * 2;
if (child && gtk_widget_get_visible (child))
{
gint child_min, child_nat;
gtk_widget_get_preferred_width (child, &child_min, &child_nat);
*minimum_size += child_min;
*natural_size += child_nat;
}
}
void item_list_get_preferred_height(GtkWidget *widget,
gint *minimum_size,
gint *natural_size)
{
//GtkWindow *window;
GtkWidget *child;
guint border_width;
//window = GTK_WINDOW (widget);
child = gtk_bin_get_child (GTK_BIN (widget)/*(window)*/);
border_width = 0;//gtk_container_get_border_width (GTK_CONTAINER (window));
*minimum_size = border_width * 2;
*natural_size = border_width * 2;
if (child && gtk_widget_get_visible (child))
{
gint child_min, child_nat;
gtk_widget_get_preferred_height (child, &child_min, &child_nat);
*minimum_size += child_min;
*natural_size += child_nat;
}
}
Note: In the init function, we have to tell gtk that our widget doesn't own a window (gdkwindow) but that it inherits one from its parent widget by calling
gtk_widget_set_has_window (GTK_WIDGET (this_instance), FALSE);
That concludes...