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<?xml version="1.0" encoding="utf-8"?>
<page xmlns="http://projectmallard.org/1.0/" xmlns:its="http://www.w3.org/2005/11/its" xmlns:xi="http://www.w3.org/2001/XInclude" type="guide" style="task" id="spinner.c" xml:lang="sv">
<info>
<title type="text">Spinner (C)</title>
<link type="guide" xref="c#display-widgets"/>
<link type="seealso" xref="togglebutton.c"/>
<revision version="0.1" date="2012-06-14" status="draft"/>
<credit type="author copyright">
<name>Monica Kochofar</name>
<email its:translate="no">monicakochofar@gmail.com</email>
<years>2012</years>
</credit>
<desc>En animerad väntesnurra</desc>
<mal:credit xmlns:mal="http://projectmallard.org/1.0/" type="translator copyright">
<mal:name>Sebastian Rasmussen</mal:name>
<mal:email>sebras@gmail.com</mal:email>
<mal:years>2019</mal:years>
</mal:credit>
<mal:credit xmlns:mal="http://projectmallard.org/1.0/" type="translator copyright">
<mal:name>Anders Jonsson</mal:name>
<mal:email>anders.jonsson@norsjovallen.se</mal:email>
<mal:years>2021</mal:years>
</mal:credit>
</info>
<title>Spinner</title>
<media type="image" mime="image/png" src="media/spinner.png"/>
<p>Denna Spinner stoppas och startas genom tryck på blankstegstangenten.</p>
<code mime="text/x-csrc" style="numbered">
#include <gtk/gtk.h>
/*Global variable used to indicate active state of the
spinner. TRUE = active, FALSE = not-active. This is because
there isn't a current function for C that does this for us*/
gboolean active;
/*This is the callback function. It is a handler function
which reacts to the signal. In this case, it will cause the
spinner to start and stop according to how many times the user
presses the spacebar.*/
static gboolean
key_pressed_event (GtkWidget *widget,
GdkEvent *event,
gpointer user_data)
{
GtkWidget *spinner = user_data;
guint keyval;
/*Extracts the keyval from an event. And stores it in the variable
"keyval" (we give the function the address). In this case, the
event is GdkEventKey, a key press event*/
gdk_event_get_keyval (event, &keyval);
/*Grabbing the boolean value from the spinner*/
g_object_get (GTK_SPINNER (spinner), "active", &active, NULL);
if (keyval == GDK_KEY_space) {
if (active) {
gtk_spinner_stop (GTK_SPINNER (spinner));
}
else {
gtk_spinner_start (GTK_SPINNER (spinner));
}
}
return TRUE;
}
static void
activate (GtkApplication *app,
gpointer user_data)
{
GtkWidget *window;
GtkWidget *spinner;
/*Create a window with a title, border width and a default size*/
window = gtk_application_window_new (app);
gtk_window_set_title (GTK_WINDOW (window), "Spinner Example");
gtk_window_set_default_size (GTK_WINDOW (window), 200, 200);
gtk_container_set_border_width (GTK_CONTAINER(window), 30);
/*Create a spinner, with extra horizontal and vertical space*/
spinner = gtk_spinner_new ();
gtk_spinner_start (GTK_SPINNER (spinner));
gtk_container_add (GTK_CONTAINER (window), spinner);
/*Connecting the key-press-event signal to the callback*/
g_signal_connect (GTK_WINDOW (window), "key-press-event",
G_CALLBACK (key_pressed_event), spinner);
gtk_widget_show_all (window);
}
int
main (int argc, char **argv)
{
GtkApplication *app;
int status;
app = gtk_application_new ("org.gtk.example", G_APPLICATION_FLAGS_NONE);
g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
status = g_application_run (G_APPLICATION (app), argc, argv);
g_object_unref (app);
return status;
}
</code>
<p>I detta exempel använde vi följande:</p>
<list>
<item><p><link href="http://developer.gnome.org/gtk3/3.4/GtkApplication.html">GtkApplication</link></p></item>
<item><p><link href="http://developer.gnome.org/gtk3/3.4/GtkWindow.html">GtkWindow</link></p></item>
<item><p><link href="http://developer.gnome.org/gobject/stable/gobject-The-Base-Object-Type.html#g-object-get">GObject</link></p></item>
<item><p><link href="http://developer.gnome.org/gtk3/stable/GtkSpinner.html">GtkSpinner</link></p></item>
</list>
</page>
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