gtk2/demos/gtk-demo/textview.c

/* Text Widget
 *
 * The GtkTextView widget displays a GtkTextBuffer. One GtkTextBuffer
 * can be displayed by multiple GtkTextViews. This demo has two views
 * displaying a single buffer, and shows off the widget's text
 * formatting features.
 *
 */

#include <gtk/gtk.h>

/* Don't copy this bad example; inline RGB data is always a better
 * idea than inline XPMs.
 */
static char  *book_closed_xpm[] = {
"16 16 6 1",
"       c None s None",
".      c black",
"X      c red",
"o      c yellow",
"O      c #808080",
"#      c white",
"                ",
"       ..       ",
"     ..XX.      ",
"   ..XXXXX.     ",
" ..XXXXXXXX.    ",
".ooXXXXXXXXX.   ",
"..ooXXXXXXXXX.  ",
".X.ooXXXXXXXXX. ",
".XX.ooXXXXXX..  ",
" .XX.ooXXX..#O  ",
"  .XX.oo..##OO. ",
"   .XX..##OO..  ",
"    .X.#OO..    ",
"     ..O..      ",
"      ..        ",
"                "
};


#define gray50_width 2
#define gray50_height 2
static char gray50_bits[] = {
  0x02, 0x01
};

static void
create_tags (GtkTextBuffer *buffer)
{
  GtkTextTag *tag;
  GdkBitmap *stipple;

  /* Create a bunch of tags. Note that it's also possible to
   * create tags with gtk_text_tag_new() then add them to the
   * tag table for the buffer, gtk_text_buffer_create_tag() is
   * just a convenience function. Also note that you don't have
   * to give tags a name; pass NULL for the name to create an
   * anonymous tag.
   *
   * In any real app, another useful optimization would be to create
   * a GtkTextTagTable in advance, and reuse the same tag table for
   * all the buffers with the same tag set, instead of creating
   * new copies of the same tags for every buffer.
   *
   * Tags are assigned default priorities in order of addition to the
   * tag table.  That is, tags created later that affect the same
   * text property as an earlier tag will override the earlier tag.
   * You can modify tag priorities with gtk_text_tag_set_priority().
   */

  tag = gtk_text_buffer_create_tag (buffer, "italic");
  g_object_set (G_OBJECT (tag), "style", PANGO_STYLE_ITALIC, NULL);

  tag = gtk_text_buffer_create_tag (buffer, "bold");
  g_object_set (G_OBJECT (tag), "weight", PANGO_WEIGHT_BOLD, NULL);  

  tag = gtk_text_buffer_create_tag (buffer, "big");
  /* 70 points times the PANGO_SCALE factor */
  g_object_set (G_OBJECT (tag), "size", 45 * PANGO_SCALE, NULL);
  
  tag = gtk_text_buffer_create_tag (buffer, "blue_foreground");
  g_object_set (G_OBJECT (tag), "foreground", "blue", NULL);  

  tag = gtk_text_buffer_create_tag (buffer, "red_background");
  g_object_set (G_OBJECT (tag), "background", "red", NULL);

  stipple = gdk_bitmap_create_from_data (NULL,
                                         gray50_bits, gray50_width,
                                         gray50_height);
  
  tag = gtk_text_buffer_create_tag (buffer, "background_stipple");
  g_object_set (G_OBJECT (tag), "background_stipple", stipple, NULL);

  tag = gtk_text_buffer_create_tag (buffer, "foreground_stipple");
  g_object_set (G_OBJECT (tag), "foreground_stipple", stipple, NULL);

  g_object_unref (G_OBJECT (stipple));

  tag = gtk_text_buffer_create_tag (buffer, "big_gap_before_line");
  g_object_set (G_OBJECT (tag), "pixels_above_lines", 30, NULL);

  tag = gtk_text_buffer_create_tag (buffer, "big_gap_after_line");
  g_object_set (G_OBJECT (tag), "pixels_below_lines", 30, NULL);

  tag = gtk_text_buffer_create_tag (buffer, "double_spaced_line");
  g_object_set (G_OBJECT (tag), "pixels_inside_wrap", 10, NULL);

  tag = gtk_text_buffer_create_tag (buffer, "not_editable");
  g_object_set (G_OBJECT (tag), "editable", FALSE, NULL);
  
  tag = gtk_text_buffer_create_tag (buffer, "word_wrap");
  g_object_set (G_OBJECT (tag), "wrap_mode", GTK_WRAP_WORD, NULL);

  tag = gtk_text_buffer_create_tag (buffer, "char_wrap");
  g_object_set (G_OBJECT (tag), "wrap_mode", GTK_WRAP_CHAR, NULL);

  tag = gtk_text_buffer_create_tag (buffer, "no_wrap");
  g_object_set (G_OBJECT (tag), "wrap_mode", GTK_WRAP_NONE, NULL);
  
  tag = gtk_text_buffer_create_tag (buffer, "center");
  g_object_set (G_OBJECT (tag), "justification", GTK_JUSTIFY_CENTER, NULL);

  tag = gtk_text_buffer_create_tag (buffer, "right_justify");
  g_object_set (G_OBJECT (tag), "justification", GTK_JUSTIFY_RIGHT, NULL);

  tag = gtk_text_buffer_create_tag (buffer, "wide_margins");
  g_object_set (G_OBJECT (tag),
                "left_margin", 50, "right_margin", 50,
                NULL);

  tag = gtk_text_buffer_create_tag (buffer, "strikethrough");
  g_object_set (G_OBJECT (tag), "strikethrough", TRUE, NULL);
  
  tag = gtk_text_buffer_create_tag (buffer, "underline");
  g_object_set (G_OBJECT (tag), "underline", PANGO_UNDERLINE_SINGLE, NULL);

  tag = gtk_text_buffer_create_tag (buffer, "double_underline");
  g_object_set (G_OBJECT (tag), "underline", PANGO_UNDERLINE_DOUBLE, NULL);

  tag = gtk_text_buffer_create_tag (buffer, "superscript");
  g_object_set (G_OBJECT (tag),
                "rise", 10 * PANGO_SCALE,   /* 10 pixels */
                "size", 8 * PANGO_SCALE,    /* 8 points */
                NULL);
  
  tag = gtk_text_buffer_create_tag (buffer, "subscript");
  g_object_set (G_OBJECT (tag),
                "rise", -10 * PANGO_SCALE,   /* 10 pixels */
                "size", 8 * PANGO_SCALE,     /* 8 points */
                NULL); 
}

static void
insert_text (GtkTextBuffer *buffer)
{
  GtkTextIter iter;
  GtkTextIter start, end;
  GdkPixbuf *pixbuf;

  pixbuf = gdk_pixbuf_new_from_xpm_data ((const char **) book_closed_xpm);
  
  /* get start of buffer; each insertion will revalidate the
   * iterator to point to just after the inserted text.
   */
  gtk_text_buffer_get_iter_at_offset (buffer, &iter, 0);

  gtk_text_buffer_insert (buffer, &iter, "The text widget can display text with all kinds of nifty attributes.\n", -1);

  gtk_text_buffer_insert (buffer, &iter, "For example, you can have ", -1);
  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "italic", -1,
                                            "italic", NULL);
  gtk_text_buffer_insert (buffer, &iter, ", ", -1);  
  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "bold", -1,
                                            "bold", NULL);
  gtk_text_buffer_insert (buffer, &iter, ", or ", -1);  
  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "huge", -1,
                                            "big", NULL);
  gtk_text_buffer_insert (buffer, &iter, " text. ", -1);

  gtk_text_buffer_insert (buffer, &iter, "Also, colors such as ", -1);  
  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "a blue foreground", -1,
                                            "blue_foreground", NULL);
  gtk_text_buffer_insert (buffer, &iter, " or ", -1);  
  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "a red background", -1,
                                            "red_background", NULL);
  gtk_text_buffer_insert (buffer, &iter, " or even ", -1);  
  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "a stippled red background", -1,
                                            "red_background",
                                            "background_stipple",
                                            NULL);

  gtk_text_buffer_insert (buffer, &iter, " or ", -1);  
  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "a stippled blue foreground on solid red background", -1,
                                            "blue_foreground",
                                            "red_background",
                                            "foreground_stipple",
                                            NULL);
  gtk_text_buffer_insert (buffer, &iter, " (select that to read it) can be used.\n", -1);  

  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "Strikethrough", -1,
                                            "strikethrough", NULL);
  gtk_text_buffer_insert (buffer, &iter, ", ", -1);
  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "underline", -1,
                                            "underline", NULL);
  gtk_text_buffer_insert (buffer, &iter, ", ", -1);
  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "double underline", -1, 
                                            "double_underline", NULL);
  gtk_text_buffer_insert (buffer, &iter, ", ", -1);
  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "superscript", -1,
                                            "superscript", NULL);
  gtk_text_buffer_insert (buffer, &iter, ", and ", -1);
  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "subscript", -1,
                                            "subscript", NULL);
  gtk_text_buffer_insert (buffer, &iter, ".\n", -1);

  gtk_text_buffer_insert (buffer, &iter, "The buffer can have images in it: ", -1);
  gtk_text_buffer_insert_pixbuf (buffer, &iter, pixbuf);
  gtk_text_buffer_insert_pixbuf (buffer, &iter, pixbuf);
  gtk_text_buffer_insert_pixbuf (buffer, &iter, pixbuf);
  gtk_text_buffer_insert (buffer, &iter, ".\n", -1);
  
  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "You can adjust the amount of space before each line; this line has a whole lot of space before it.\n", -1,
                                            "big_gap_before_line", NULL);
  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "You can also adjust the amount of space after each line; this line has a whole lot of space after it.\n", -1,
                                            "big_gap_after_line", NULL);
  
  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "Of course you can also adjust the amount of space between wrapped lines; this line has extra space between each wrapped line.\n", -1,
                                            "double_spaced_line", NULL);

  
  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "This line is 'locked down' and can't be edited by the user - just try it! You can't delete this line.\n", -1,
                                            "not_editable", NULL);

  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "If char wrap worked, this line would be char wrapped, but since char wrap isn't yet implemented, this line will fall back to word wrap.\n", -1,
                                            "char_wrap", NULL);

  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "This line has all wrapping turned off, so it makes the horizontal scrollbar appear.\n", -1,
                                            "no_wrap", NULL);
  
  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "This line has center justification.\n", -1,
                                            "center", NULL);

  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "This line has right justification.\n", -1,
                                            "right_justify", NULL);

  gtk_text_buffer_insert_with_tags_by_name (buffer, &iter,
                                            "This line has big wide margins. Text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text.\n", -1,
                                            "wide_margins", NULL);
  
  gtk_text_buffer_insert (buffer, &iter, "This demo doesn't even demonstrate all the GtkTextBuffer features; it leaves out, for example: invisible/hidden text, tab stops, application-drawn areas on the sides of the widget for displaying breakpoints and such...", -1);

  /* Apply word_wrap tag to whole buffer */
  gtk_text_buffer_get_bounds (buffer, &start, &end);
  gtk_text_buffer_apply_tag_by_name (buffer, "word_wrap", &start, &end);

  g_object_unref (G_OBJECT (pixbuf));
}

GtkWidget *
do_textview (void)
{
  static GtkWidget *window = NULL;

  if (!window)
    {
      GtkWidget *vpaned;
      GtkWidget *view1;
      GtkWidget *view2;
      GtkWidget *sw;
      GtkTextBuffer *buffer;
      
      window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
      gtk_window_set_default_size (GTK_WINDOW (window),
                                   300, 400);
      
      gtk_signal_connect (GTK_OBJECT (window), "destroy",
			  GTK_SIGNAL_FUNC(gtk_widget_destroyed),
			  &window);

      gtk_window_set_title (GTK_WINDOW (window), "TextView");
      gtk_container_set_border_width (GTK_CONTAINER (window), 0);

      vpaned = gtk_vpaned_new ();
      gtk_container_set_border_width (GTK_CONTAINER(vpaned), 5);
      gtk_container_add (GTK_CONTAINER (window), vpaned);

      /* For convenience, we just use the autocreated buffer from
       * the first text view; you could also create the buffer
       * by itself with gtk_text_buffer_new(), then later create
       * a view widget.
       */
      view1 = gtk_text_view_new ();
      buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (view1));
      view2 = gtk_text_view_new_with_buffer (buffer);
      
      sw = gtk_scrolled_window_new (NULL, NULL);
      gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (sw),
                                      GTK_POLICY_AUTOMATIC,
                                      GTK_POLICY_AUTOMATIC);
      gtk_paned_add1 (GTK_PANED (vpaned), sw);

      gtk_container_add (GTK_CONTAINER (sw), view1);

      sw = gtk_scrolled_window_new (NULL, NULL);
      gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (sw),
                                      GTK_POLICY_AUTOMATIC,
                                      GTK_POLICY_AUTOMATIC);
      gtk_paned_add2 (GTK_PANED (vpaned), sw);

      gtk_container_add (GTK_CONTAINER (sw), view2);

      create_tags (buffer);
      insert_text (buffer);
      
      gtk_widget_show_all (vpaned);
    }

  if (!GTK_WIDGET_VISIBLE (window))
    {
      gtk_widget_show (window);
    }
  else
    {
      gtk_widget_destroy (window);
      window = NULL;
    }

  return window;
}