<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >The Button Widget</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REL="HOME" TITLE="GTK+ 2.0 Tutorial" HREF="book1.html"><LINK REL="PREVIOUS" TITLE="Widgets Without Windows" HREF="x481.html"><LINK REL="NEXT" TITLE="Toggle Buttons" HREF="x518.html"></HEAD ><BODY CLASS="CHAPTER" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >GTK+ 2.0 Tutorial</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="x481.html" ACCESSKEY="P" ><<< Previous</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="x518.html" ACCESSKEY="N" >Next >>></A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="CHAPTER" ><H1 ><A NAME="CH-BUTTONWIDGET" ></A >The Button Widget</H1 ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="SEC-NORMALBUTTONS" >Normal Buttons</A ></H1 ><P >We've almost seen all there is to see of the button widget. It's pretty simple. There is however more than one way to create a button. You can use the gtk_button_new_with_label() or gtk_button_new_with_mnemonic() to create a button with a label, use gtk_button_new_from_stock() to create a button containing the image and text from a stock item or use gtk_button_new() to create a blank button. It's then up to you to pack a label or pixmap into this new button. To do this, create a new box, and then pack your objects into this box using the usual gtk_box_pack_start(), and then use gtk_container_add() to pack the box into the button.</P ><P >Here's an example of using gtk_button_new() to create a button with a image and a label in it. I've broken up the code to create a box from the rest so you can use it in your programs. There are further examples of using images later in the tutorial.</P ><P ><SPAN CLASS="INLINEMEDIAOBJECT" ><IMG SRC="images/buttons.png"></SPAN ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" WIDTH="100%" ><TR ><TD ><PRE CLASS="PROGRAMLISTING" > #include <stdlib.h> #include <gtk/gtk.h> /* Create a new hbox with an image and a label packed into it * and return the box. */ static GtkWidget *xpm_label_box( gchar *xpm_filename, gchar *label_text ) { GtkWidget *box; GtkWidget *label; GtkWidget *image; /* Create box for image and label */ box = gtk_hbox_new (FALSE, 0); gtk_container_set_border_width (GTK_CONTAINER (box), 2); /* Now on to the image stuff */ image = gtk_image_new_from_file (xpm_filename); /* Create a label for the button */ label = gtk_label_new (label_text); /* Pack the image and label into the box */ gtk_box_pack_start (GTK_BOX (box), image, FALSE, FALSE, 3); gtk_box_pack_start (GTK_BOX (box), label, FALSE, FALSE, 3); gtk_widget_show (image); gtk_widget_show (label); return box; } /* Our usual callback function */ static void callback( GtkWidget *widget, gpointer data ) { g_print ("Hello again - %s was pressed\n", (char *) data); } int main( int argc, char *argv[] ) { /* GtkWidget is the storage type for widgets */ GtkWidget *window; GtkWidget *button; GtkWidget *box; gtk_init (&argc, &argv); /* Create a new window */ window = gtk_window_new (GTK_WINDOW_TOPLEVEL); gtk_window_set_title (GTK_WINDOW (window), "Pixmap'd Buttons!"); /* It's a good idea to do this for all windows. */ g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit), NULL); g_signal_connect (window, "delete-event", G_CALLBACK (gtk_main_quit), NULL); /* Sets the border width of the window. */ gtk_container_set_border_width (GTK_CONTAINER (window), 10); /* Create a new button */ button = gtk_button_new (); /* Connect the "clicked" signal of the button to our callback */ g_signal_connect (button, "clicked", G_CALLBACK (callback), (gpointer) "cool button"); /* This calls our box creating function */ box = xpm_label_box ("info.xpm", "cool button"); /* Pack and show all our widgets */ gtk_widget_show (box); gtk_container_add (GTK_CONTAINER (button), box); gtk_widget_show (button); gtk_container_add (GTK_CONTAINER (window), button); gtk_widget_show (window); /* Rest in gtk_main and wait for the fun to begin! */ gtk_main (); return 0; }</PRE ></TD ></TR ></TABLE ><P >The xpm_label_box() function could be used to pack images and labels into any widget that can be a container.</P ><P >The Button widget has the following signals:</P ><P ></P ><UL ><LI ><P ><TT CLASS="LITERAL" >pressed</TT > - emitted when pointer button is pressed within Button widget</P ></LI ><LI ><P ><TT CLASS="LITERAL" >released</TT > - emitted when pointer button is released within Button widget</P ></LI ><LI ><P ><TT CLASS="LITERAL" >clicked</TT > - emitted when pointer button is pressed and then released within Button widget</P ></LI ><LI ><P ><TT CLASS="LITERAL" >enter</TT > - emitted when pointer enters Button widget</P ></LI ><LI ><P ><TT CLASS="LITERAL" >leave</TT > - emitted when pointer leaves Button widget</P ></LI ></UL ></DIV ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="x481.html" ACCESSKEY="P" ><<< Previous</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="book1.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="x518.html" ACCESSKEY="N" >Next >>></A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Widgets Without Windows</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" > </TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Toggle Buttons</TD ></TR ></TABLE ></DIV ></BODY ></HTML >