Learning_GTK4_tree/demos/gtk-demo/textundo.c

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2023-12-12 11:36:42 +01:00
/* Text View/Undo and Redo
*
* The GtkTextView supports undo and redo through the use of a
* GtkTextBuffer. You can enable or disable undo support using
* gtk_text_buffer_set_enable_undo().
*
* Use Control+z to undo and Control+Shift+z or Control+y to
* redo previously undone operations.
*/
#include <gtk/gtk.h>
#include <stdlib.h> /* for exit() */
GtkWidget *
do_textundo (GtkWidget *do_widget)
{
static GtkWidget *window = NULL;
if (!window)
{
GtkWidget *view;
GtkWidget *sw;
GtkTextBuffer *buffer;
GtkTextIter iter;
window = gtk_window_new ();
gtk_window_set_display (GTK_WINDOW (window),
gtk_widget_get_display (do_widget));
gtk_window_set_default_size (GTK_WINDOW (window), 330, 330);
gtk_window_set_resizable (GTK_WINDOW (window), FALSE);
g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
gtk_window_set_title (GTK_WINDOW (window), "Undo and Redo");
view = gtk_text_view_new ();
gtk_text_view_set_wrap_mode (GTK_TEXT_VIEW (view), GTK_WRAP_WORD);
gtk_text_view_set_pixels_below_lines (GTK_TEXT_VIEW (view), 10);
gtk_text_view_set_left_margin (GTK_TEXT_VIEW (view), 20);
gtk_text_view_set_right_margin (GTK_TEXT_VIEW (view), 20);
gtk_text_view_set_top_margin (GTK_TEXT_VIEW (view), 20);
gtk_text_view_set_bottom_margin (GTK_TEXT_VIEW (view), 20);
buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (view));
gtk_text_buffer_set_enable_undo (buffer, TRUE);
/* this text cannot be undone */
gtk_text_buffer_begin_irreversible_action (buffer);
gtk_text_buffer_get_start_iter (buffer, &iter);
gtk_text_buffer_insert (buffer, &iter,
"The GtkTextView supports undo and redo through the use of a "
"GtkTextBuffer. You can enable or disable undo support using "
"gtk_text_buffer_set_enable_undo().\n"
"Type to add more text.\n"
"Use Control+z to undo and Control+Shift+z or Control+y to "
"redo previously undone operations.",
-1);
gtk_text_buffer_end_irreversible_action (buffer);
sw = gtk_scrolled_window_new ();
gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (sw),
GTK_POLICY_AUTOMATIC,
GTK_POLICY_AUTOMATIC);
gtk_window_set_child (GTK_WINDOW (window), sw);
gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw), view);
}
if (!gtk_widget_get_visible (window))
{
gtk_widget_set_visible (window, TRUE);
}
else
{
gtk_window_destroy (GTK_WINDOW (window));
window = NULL;
}
return window;
}