GTK+ Forums

Turtel · Posted: Tue Mar 09, 2010 6:17 am Post subject: computation in a window

I want to take data1 and data2 (both are fraction numbers or integers not text) then do something and print the results in dialog or frame with text.

I am also getting following two errors on compilation and while running how to remove them:-

1.In function ‘enter_callback’:
ex.c:11: warning: assignment discards qualifiers from pointer target type
2.whie running i am getting error Gtk-CRITICAL **: gtk_box_pack: assertion `child->parent == NULL' failed
The code is given below compile it and see. Could anyone please correct me.................

Code: (C)

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95

#include <gtk/gtk.h>
void enter_callback( GtkWidget *widget,
GtkWidget *entry )
{
gchar *entry_text;
entry_text = gtk_entry_get_text(GTK_ENTRY(entry));
printf("Entry contents: %s\n", entry_text);
}
static do_something_on_click(GtkWidget *frame)

{
gint *data1,*data2,data3;
data3=*data1*(*data2);
}
int main( int argc,
char *argv[] )
{
GtkWidget *window;
GtkWidget *vbox;
GtkWidget *hbox1;
GtkWidget *hbox2;
GtkWidget *frame;
GtkWidget *entry;
GtkWidget *button;
GtkWidget *bbox;
static gint *data1,*data2,data3;
gtk_init (&argc, &argv);
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

vbox = gtk_vbox_new (FALSE, 0);
gtk_container_set_border_width (GTK_CONTAINER (vbox), 10);
gtk_container_add (GTK_CONTAINER (window), vbox);
gtk_container_set_border_width (GTK_CONTAINER (window), 20);

hbox1 = gtk_hbox_new (FALSE, 5);
gtk_container_add (GTK_CONTAINER (vbox), hbox1);
gtk_box_pack_start (GTK_BOX (vbox), hbox1, FALSE, FALSE, 0);
gtk_container_set_border_width (GTK_CONTAINER (vbox), 5);

entry = gtk_entry_new_with_max_length (50);
gtk_signal_connect(GTK_OBJECT(entry), "activate",
GTK_SIGNAL_FUNC(enter_callback),
entry);
gtk_entry_set_text (GTK_ENTRY (entry), "data1");
gtk_entry_select_region (GTK_ENTRY (entry),
0, GTK_ENTRY(entry)->text_length);
data1 = gtk_entry_get_text(GTK_ENTRY(entry));
gtk_box_pack_start (GTK_BOX (hbox1), entry, FALSE, FALSE, 0);

hbox2 = gtk_hbox_new (FALSE, 5);
gtk_container_add (GTK_CONTAINER (vbox), hbox2);
gtk_box_pack_start (GTK_BOX (vbox), hbox2, FALSE, FALSE, 0);
gtk_container_set_border_width (GTK_CONTAINER (vbox), 5);

entry = gtk_entry_new_with_max_length (50);
gtk_signal_connect(GTK_OBJECT(entry), "activate",
GTK_SIGNAL_FUNC(enter_callback),
entry);
gtk_entry_set_text (GTK_ENTRY (entry), "data2");
gtk_entry_select_region (GTK_ENTRY (entry),
0, GTK_ENTRY(entry)->text_length);
data2 = gtk_entry_get_text(GTK_ENTRY(entry));
gtk_box_pack_start (GTK_BOX (hbox2), entry, FALSE, FALSE, 0);

frame = gtk_frame_new (NULL);
bbox = gtk_hbutton_box_new ();
gtk_container_set_border_width (GTK_CONTAINER (bbox), 5);
gtk_container_add (GTK_CONTAINER (frame), bbox);
gtk_button_box_set_child_size (GTK_BUTTON_BOX (bbox), 85, 20);
button = gtk_button_new_with_label ("Compute");
gtk_signal_connect_object (GTK_OBJECT (button), "clicked",
GTK_SIGNAL_FUNC(do_something_on_click),
GTK_OBJECT (window));
gtk_container_add (GTK_CONTAINER (bbox), button);
gtk_box_pack_start (GTK_BOX (vbox),frame,TRUE,TRUE,0);

frame = gtk_frame_new (NULL);
gtk_container_set_border_width (GTK_CONTAINER (vbox), 10);
gtk_frame_set_label( GTK_FRAME(frame), "Results of the computaion \nto come below in this frame.");
gtk_frame_set_label_align( GTK_FRAME(frame), 0.0, 0.0);
gtk_container_add (GTK_CONTAINER (vbox), frame);
gtk_box_pack_start (GTK_BOX (vbox),frame,TRUE,TRUE,0);

gtk_widget_show_all (window);
gtk_main ();

return(0);
}
/* example-end */

Added CodeBB -dreblen

Last edited by Turtel on Thu Mar 11, 2010 9:58 am; edited 1 time in total

owl102 · GTK+ Geek Joined: 23 May 2008 Posts: 68

Turtel · Posted: Thu Mar 11, 2010 10:07 am Post subject:

I have corrected the pointer issue. But your second suggestion does not work. Non of compilation error have gone.In fact I am wondering whether it is possible to do things that is possible in C programming through a gtk+ GUI?

tadeboro · Posted: Thu Mar 11, 2010 1:44 pm Post subject:

Hello.

You're using a bunch of deprecated functions, a lot of stuff is duplicated inside your code, some widgets are being added into containers twice, ...

I cleaned your code and made it do some calculations. As you can see, you can do all of the thing that are possible in plain C using GTK+ too (this should come as no surprise, since GTK+ is merely an add-on library like any other).

Code: (C)

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96

#include <gtk/gtk.h>

typedef struct _Data
{
GtkEntry *e1,
*e2;
GtkLabel *res;
}
Data;

static void
calculate( Data *data )
{
gdouble d1 = g_strtod( gtk_entry_get_text( data->e1 ), NULL );
gdouble d2 = g_strtod( gtk_entry_get_text( data->e2 ), NULL );
gchar *result = g_strdup_printf( "Multiplication: %f\n"
"Division: %f\n"
"Sum: %f\n"
"Difference: %f",
d1 * d2, d1 / d2, d1 + d2, d1 - d2 );
gtk_label_set_label( data->res, result );
g_free( result );
}

int main( int argc,
char *argv[] )
{
GtkWidget *window;
GtkWidget *vbox;
GtkWidget *hbox1;
GtkWidget *hbox2;
GtkWidget *frame;
GtkWidget *entry;
GtkWidget *button;
GtkWidget *bbox;
GtkWidget *label;
Data *data;

data = g_slice_new0( Data );

gtk_init (&argc, &argv);
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
g_signal_connect( G_OBJECT( window ), "destroy",
G_CALLBACK( gtk_main_quit ), NULL );
gtk_container_set_border_width (GTK_CONTAINER (window), 20);

vbox = gtk_vbox_new (FALSE, 0);
gtk_container_set_border_width (GTK_CONTAINER (vbox), 5);
gtk_container_add (GTK_CONTAINER (window), vbox);

hbox1 = gtk_hbox_new (FALSE, 5);
gtk_box_pack_start (GTK_BOX (vbox), hbox1, FALSE, FALSE, 0);

entry = gtk_entry_new();
gtk_entry_set_max_length( GTK_ENTRY( entry ), 50 );
gtk_entry_set_text (GTK_ENTRY (entry), "3");
gtk_editable_select_region (GTK_EDITABLE (entry), 0, -1);
gtk_box_pack_start (GTK_BOX (hbox1), entry, FALSE, FALSE, 0);
data->e1 = GTK_ENTRY( entry );

hbox2 = gtk_hbox_new (FALSE, 5);
gtk_box_pack_start (GTK_BOX (vbox), hbox2, FALSE, FALSE, 0);

entry = gtk_entry_new();
gtk_entry_set_max_length( GTK_ENTRY( entry ), 50 );
gtk_entry_set_text (GTK_ENTRY (entry), "2");
gtk_editable_select_region (GTK_EDITABLE (entry), 0, -1);
gtk_box_pack_start (GTK_BOX (hbox1), entry, FALSE, FALSE, 0);
data->e2 = GTK_ENTRY( entry );

frame = gtk_frame_new (NULL);
gtk_box_pack_start (GTK_BOX (vbox),frame,TRUE,TRUE,0);

bbox = gtk_hbutton_box_new ();
gtk_container_set_border_width (GTK_CONTAINER (bbox), 5);
gtk_container_add (GTK_CONTAINER (frame), bbox);

button = gtk_button_new_with_label ("Compute");
g_signal_connect_swapped (G_OBJECT (button), "clicked",
G_CALLBACK( calculate ), data);
gtk_container_add (GTK_CONTAINER (bbox), button);

frame = gtk_frame_new (NULL);
gtk_frame_set_label_align( GTK_FRAME(frame), 0.0, 0.0);
gtk_box_pack_start (GTK_BOX (vbox),frame,TRUE,TRUE,0);

label = gtk_label_new( "Results of calculation appear here" );
gtk_container_add( GTK_CONTAINER( frame ), label );
data->res = GTK_LABEL( label );

gtk_widget_show_all( window );
gtk_main ();

return(0);
}
/* example-end */

Tadej