如果全部使用C代码构建用户界面,当组件成百上千时,这将是一场灾难。因此Gtk使用xml进行配置用户界面。
示例如下:
#include <gtk/gtk.h>
#include <glib/gstdio.h>
static void
print_hello (GtkWidget *widget,
gpointer data)
{
g_print ("Hello World\n");
}
static void
quit_cb (GtkWindow *window)
{
gtk_window_close (window);
}
static void
activate (GtkApplication *app,
gpointer user_data)
{
/* Construct a GtkBuilder instance and load our UI description */
GtkBuilder *builder = gtk_builder_new ();
gtk_builder_add_from_file (builder, "builder.ui", NULL);
/* Connect signal handlers to the constructed widgets. */
GObject *window = gtk_builder_get_object (builder, "window");
gtk_window_set_application (GTK_WINDOW (window), app);
GObject *button = gtk_builder_get_object (builder, "button1");
g_signal_connect (button, "clicked", G_CALLBACK (print_hello), NULL);
button = gtk_builder_get_object (builder, "button2");
g_signal_connect (button, "clicked", G_CALLBACK (print_hello), NULL);
button = gtk_builder_get_object (builder, "quit");
g_signal_connect_swapped (button, "clicked", G_CALLBACK (quit_cb), window);
gtk_widget_show (GTK_WIDGET (window));
/* We do not need the builder any more */
g_object_unref (builder);
}
int
main (int argc,
char *argv[])
{
#ifdef GTK_SRCDIR
g_chdir (GTK_SRCDIR);
#endif
GtkApplication *app = gtk_application_new ("org.gtk.example", G_APPLICATION_DEFAULT_FLAGS);
g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
int status = g_application_run (G_APPLICATION (app), argc, argv);
g_object_unref (app);
return status;
}
在源码路径下创建builder.ui
文件,并将以下内容写入文件:
<?xml version="1.0" encoding="UTF-8"?>
<interface>
<object id="window" class="GtkWindow">
<property name="title">Grid</property>
<child>
<object id="grid" class="GtkGrid">
<child>
<object id="button1" class="GtkButton">
<property name="label">Button 1</property>
<layout>
<property name="column">0</property>
<property name="row">0</property>
</layout>
</object>
</child>
<child>
<object id="button2" class="GtkButton">
<property name="label">Button 2</property>
<layout>
<property name="column">1</property>
<property name="row">0</property>
</layout>
</object>
</child>
<child>
<object id="quit" class="GtkButton">
<property name="label">Quit</property>
<layout>
<property name="column">0</property>
<property name="row">1</property>
<property name="column-span">2</property>
</layout>
</object>
</child>
</object>
</child>
</object>
</interface>
GtkBuilder
不仅可以用于创建组件对象,还可以创建其他对象,例如树模型,调整树等。