Thread: Exiting GTK+, allowing CLI to continue

My GUI currently never programmatically exits even though I push the X and the window disappears, so I have to exit the terminal thereby losing Valgrind's help (unless the program crashes). In the following code fragment which I thought would do this, w is the window.

Code:

    g_signal_connect(G_OBJECT(w), "delete_event", G_CALLBACK(delete_event), NULL);
    
    g_signal_connect(G_OBJECT(w), "destroy", G_CALLBACK(destroy), NULL);

And I define those callbacks thusly:

Code:

void destroy(GtkWidget *widget, gpointer data){
    gtk_main_quit();
}

gint delete_event(GtkWidget *widget, GdkEvent *event, gpointer data){
    return FALSE;
}

I thought that should work?

Thanks!

I looked thru a couple threads returned by Google; while you're right about Valgrind, they don't seem to have the issue of the hanging terminal (because they can actually see Valgind's report). I'd like to get around it whether Valgrind will still be useful or not; currently I must Ctrl+Shift+T, close the old gnome-terminal tab, then resume my debugging. I'd like it to be a seamless transition from one GTK+ session to the next, like a CLI program allows.

Or has the GTK+ development team purposely blocked Valgrind's output to avoid any more such bug reports?

Would it be unwise to call gtk_main_quit() and then exit(EXIT_SUCCESS) from the callback?

It actually worked. So apparently some function within gtk_main is never returning, surely because I did something wrong. This is my first GTK project, as you probably guessed, and I don't have a clue where to look for the bug. So if you or anyone else could give a hint, that would be fantastic. Here's my prime suspect - the source with all the GTK logic, which also happens to be the least stable. (I've cut out the irrelevant CLI logic, along with all the other functions the GUI code doesn't yet call.) Note that much of the start code is from the tutorial I used; I left it there because, for all I know, it may contain the problem.

Code:

#ifdef	__cplusplus
extern "C" {
#endif

#include "../Jesdisciple/toolkit.h"
#include "interface.h"
#include "outline.h"
#include <math.h>
#include <stdio.h>
#include <string.h>

#ifndef INTERFACE
	#define INTERFACE TEXTUAL
#endif

static struct outline *o = (struct outline *)NULL;

#if INTERFACE == GRAPHICAL

#include <gtk/gtk.h>

static GtkWidget *w = (GtkWidget *)NULL;

enum{
   TITLE_COLUMN,
   AUTHOR_COLUMN,
   CHECKED_COLUMN,
   N_COLUMNS
};
void prompt(struct outline_interface *this, char *message, size_t length, void (*receive)(char *, void **), void **args){
	GtkWidget *dialog = gtk_dialog_new_with_buttons("Outliner", (GtkWindow *)w, GTK_DIALOG_MODAL | GTK_DIALOG_DESTROY_WITH_PARENT, GTK_STOCK_CANCEL, GTK_STOCK_OK, NULL);
	GtkVBox *content = (GtkVBox *)gtk_dialog_get_content_area((GtkDialog *)dialog);
	GtkEntry *entry = (GtkEntry *)gtk_entry_new_with_max_length((gint)length);
	gtk_container_add((GtkContainer *)content, (GtkWidget *)entry);
	gtk_widget_show_all(dialog);
	g_signal_connect(G_OBJECT(dialog), "response", G_CALLBACK(receive), NULL);
	gtk_dialog_run((GtkDialog *)dialog);
}

void set_title(char *title, void **args){
	gtk_window_set_title((GtkWindow *)w, title);
}

void destroy(GtkWidget *widget, gpointer data){
	gtk_main_quit();
	exit(EXIT_SUCCESS);
}

gint delete_event(GtkWidget *widget, GdkEvent *event, gpointer data){
	return FALSE;
}

void start(struct outline_interface *this){
	GtkTreeStore *store;
	GtkWidget *tree;
	GtkTreeViewColumn *column;
	GtkCellRenderer *renderer;
	
	w = gtk_window_new(GTK_WINDOW_TOPLEVEL);
	
	g_signal_connect(G_OBJECT(w), "delete_event", G_CALLBACK(delete_event), NULL);
	
	g_signal_connect(G_OBJECT(w), "destroy", G_CALLBACK(destroy), NULL);
	
	gtk_container_set_border_width(GTK_CONTAINER(w), 10);

	/* Create a model.  We are using the store model for now, though we
	* could use any other GtkTreeModel */
	store = gtk_tree_store_new(N_COLUMNS, G_TYPE_STRING, G_TYPE_STRING, G_TYPE_BOOLEAN);

	void *args[1] = {NULL};
	this->prompt(this, "Enter a title for this outline.", 26, set_title, args);
	
	/* Create a view */
	tree = gtk_tree_view_new_with_model(GTK_TREE_MODEL (store));

	/* The view now holds a reference.  We can get rid of our own
	* reference */
	g_object_unref(G_OBJECT(store));

	/* Create a cell render and arbitrarily make it red for demonstration
	* purposes */
	renderer = gtk_cell_renderer_text_new();
	g_object_set(G_OBJECT(renderer), "foreground", "red", NULL);

	/* Create a column, associating the "text" attribute of the
	* cell_renderer to the first column of the model */
	column = gtk_tree_view_column_new_with_attributes ("Author", renderer, "text", AUTHOR_COLUMN, NULL);

	/* Add the column to the view. */
	gtk_tree_view_append_column(GTK_TREE_VIEW(tree), column);

	/* Second column.. title of the book. */
	renderer = gtk_cell_renderer_text_new();
	column = gtk_tree_view_column_new_with_attributes("Title", renderer, "text", TITLE_COLUMN, NULL);
	gtk_tree_view_append_column(GTK_TREE_VIEW(tree), column);

	/* Last column.. whether a book is checked out. */
	renderer = gtk_cell_renderer_toggle_new();
	column = gtk_tree_view_column_new_with_attributes("Checked out", renderer, "active", CHECKED_COLUMN, NULL);
	gtk_tree_view_append_column(GTK_TREE_VIEW(tree), column);
	
	/* This packs the tree into the window (a gtk container). */
	gtk_container_add(GTK_CONTAINER(w), tree);
	
	gtk_widget_show_all(w);
	
	gtk_main();
	
	if(o != (struct outline *)NULL)
		o->free(o);
}
#endif

#ifdef __cplusplus
}
#endif

*backs up* Wait a sec... I just tried it with GDB and it has problems after gtk_main, on the line just before return 0; - then it hung just like Valgrind. On that line, I free a global but GDB complained that it couldn't access 0x33. I tried printing the address of the variable and it just gives the same complaint for the printf call. Then I tried simply running the program without a debugger and didn't have any problems.

I ran it through GDB again and the only strange thing was this:

Code:

0xb77a6685 in __libc_start_main () from /lib/tls/i686/cmov/libc.so.6
(gdb) 
Single stepping until exit from function __libc_start_main, 
which has no line number information.

Program exited normally.

Then I tried Valgrind again; no problems. And the original strange behavior of GDB only happens when I set a breakpoint on a function other than main, but it still exits normally. Should I submit a bug report for GCC...?