GTK+ Forums

hari · Joined: 01 Mar 2007 Posts: 1

I'm new to GTK and started programming in C language.
While doing with text entries, I'm getting problem. My problem is..
How to add two numbers when each number is taken from the entry boxes and display the answer there itself in the Window when the add button is pressed...... [Just like Calculator]..Please Help me..

Micah Carrick · Posted: Thu Mar 01, 2007 8:09 pm Post subject:

Well, there are lots of ways to do it. For example, you callback function can have a static variable to hold the previous value and use the g_strtod to convert the value in the entry into a numeric.

simple example... not tested, just off the top of my head:

Code: (Plaintext)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17	gdouble previous_value; gdouble value; gchar new_text; value = g_strtod (gtk_entry_get_text ( GTK_ENTRY (widget) ); if (previous_value) { value += previous_value; previous_value = null; new_text = g_strdup_printf ("%f", value); gtk_entry_set_text (GTK_ENTRY (widget), new_text); /* don't free new_text, it's owned by the entry */ } else { previous_value = value; }