Re: GtkTextBuffer : Applying tags to newly input text

[cecashon aol com]

Hi Gary,

Test setting up your callback with g_signal_connect_after. Then the location iter should be at the end of the 
insert. Then the tag can be applied to the inserted text.

Eric

    
//gcc -Wall highlight1.c -o highlight1 `pkg-config --cflags --libs gtk+-3.0`

#include <gtk/gtk.h>

static gboolean set_tag=FALSE;

static void button_toggled(GtkToggleButton *button, gpointer data)
  {
    g_print("Button Toggled\n");
    set_tag=gtk_toggle_button_get_active(button);
  }
static void insert_text(GtkTextBuffer *textbuffer, GtkTextIter *location, gchar *text, gint len, GtkTextTag * 
cyan_tag)
  {
    g_print("Insert %s Offset %i\n", text, gtk_text_iter_get_offset(location));

    if(set_tag)
      {
        GtkTextIter *start=gtk_text_iter_copy(location);
        gtk_text_iter_backward_chars(start, len);
        gtk_text_buffer_apply_tag(textbuffer, cyan_tag, start, location);
        gtk_text_iter_free(start);
      }
  }
int main(int argc, char *argv[])
  {
    gtk_init(&argc, &argv);

    GtkWidget *window=gtk_window_new(GTK_WINDOW_TOPLEVEL);
    gtk_window_set_title(GTK_WINDOW(window), "Highlight");
    gtk_window_set_default_size(GTK_WINDOW(window), 300, 300);
    gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
    gtk_container_set_border_width(GTK_CONTAINER(window), 20);
    g_signal_connect(window, "destroy", G_CALLBACK(gtk_main_quit), NULL);

    GtkWidget *textview=gtk_text_view_new();
    gtk_text_view_set_wrap_mode(GTK_TEXT_VIEW(textview), GTK_WRAP_CHAR);
    gtk_widget_set_hexpand(textview, TRUE);
    gtk_widget_set_vexpand(textview, TRUE);

    GtkTextBuffer *buffer=gtk_text_view_get_buffer(GTK_TEXT_VIEW(textview));
    GtkTextTag *cyan_tag=gtk_text_buffer_create_tag(buffer, "cyan-tag", "background", "cyan", NULL);
    g_signal_connect_after(buffer, "insert-text", G_CALLBACK(insert_text), cyan_tag); 

    GtkWidget *button=gtk_toggle_button_new_with_label("Cyan Highlight");
    g_signal_connect(button, "toggled", G_CALLBACK(button_toggled), NULL);

    GtkWidget *grid=gtk_grid_new();
    gtk_grid_attach(GTK_GRID(grid), textview, 0, 0, 1, 1);
    gtk_grid_attach(GTK_GRID(grid), button, 0, 1, 1, 1);

    gtk_container_add(GTK_CONTAINER(window), grid);

    gtk_widget_show_all(window);
    
    gtk_main();

    return 0;
  }