gtk2/gtk/gtktextbuffer.c

/*  gtktextbuffer.c - the "model" in the MVC text widget architecture 
 *  Copyright (c) 2000 Red Hat, Inc.
 *  Developed by Havoc Pennington
 */

#include <string.h>

#include "gtkclipboard.h"
#include "gtkinvisible.h"
#include "gtksignal.h"
#include "gtktextbuffer.h"
#include "gtktextbtree.h"
#include "gtktextiterprivate.h"
#include <string.h>

typedef struct _ClipboardRequest ClipboardRequest;

struct _ClipboardRequest
{
  GtkTextBuffer *buffer;
  gboolean interactive;
  gboolean default_editable;
  gboolean is_clipboard;
};

enum {
  INSERT_TEXT,
  DELETE_TEXT,
  CHANGED,
  MODIFIED_CHANGED,
  MARK_SET,
  MARK_DELETED,
  APPLY_TAG,
  REMOVE_TAG,
  LAST_SIGNAL
};

enum {
  ARG_0,
  LAST_ARG
};

enum {
  TARGET_STRING,
  TARGET_TEXT,
  TARGET_COMPOUND_TEXT,
  TARGET_UTF8_STRING
};

static void gtk_text_buffer_init       (GtkTextBuffer      *tkxt_buffer);
static void gtk_text_buffer_class_init (GtkTextBufferClass *klass);
static void gtk_text_buffer_destroy    (GtkObject          *object);
static void gtk_text_buffer_finalize   (GObject            *object);


static void gtk_text_buffer_update_primary_selection   (GtkTextBuffer     *buffer);
static void gtk_text_buffer_real_insert_text           (GtkTextBuffer     *buffer,
                                                        GtkTextIter       *iter,
                                                        const gchar       *text,
                                                        gint               len,
                                                        gboolean           interactive);
static void gtk_text_buffer_real_delete_text           (GtkTextBuffer     *buffer,
                                                        GtkTextIter       *start,
                                                        GtkTextIter       *end,
                                                        gboolean           interactive);
static void gtk_text_buffer_real_apply_tag             (GtkTextBuffer     *buffer,
                                                        GtkTextTag        *tag,
                                                        const GtkTextIter *start_char,
                                                        const GtkTextIter *end_char);
static void gtk_text_buffer_real_remove_tag            (GtkTextBuffer     *buffer,
                                                        GtkTextTag        *tag,
                                                        const GtkTextIter *start_char,
                                                        const GtkTextIter *end_char);

static GtkTextBTree* get_btree (GtkTextBuffer *buffer);

void gtk_marshal_NONE__INT_POINTER_INT (GtkObject  *object,
                                        GtkSignalFunc func,
                                        gpointer func_data,
                                        GtkArg  *args);

static GtkObjectClass *parent_class = NULL;
static guint signals[LAST_SIGNAL] = { 0 };

GtkType
gtk_text_buffer_get_type (void)
{
  static GtkType our_type = 0;

  if (our_type == 0)
    {
      static const GtkTypeInfo our_info =
      {
        "GtkTextBuffer",
        sizeof (GtkTextBuffer),
        sizeof (GtkTextBufferClass),
        (GtkClassInitFunc) gtk_text_buffer_class_init,
        (GtkObjectInitFunc) gtk_text_buffer_init,
        /* reserved_1 */ NULL,
        /* reserved_2 */ NULL,
        (GtkClassInitFunc) NULL
      };

      our_type = gtk_type_unique (GTK_TYPE_OBJECT, &our_info);
    }

  return our_type;
}

static void
gtk_text_buffer_class_init (GtkTextBufferClass *klass)
{
  GtkObjectClass *object_class = (GtkObjectClass*) klass;
  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);

  parent_class = gtk_type_class (GTK_TYPE_OBJECT);
  
  signals[INSERT_TEXT] =
    gtk_signal_new ("insert_text",
                    GTK_RUN_LAST,
                    GTK_CLASS_TYPE (object_class),
                    GTK_SIGNAL_OFFSET (GtkTextBufferClass, insert_text),
                    gtk_marshal_NONE__POINTER_POINTER_INT_INT,
                    GTK_TYPE_NONE,
                    4,
                    GTK_TYPE_POINTER,
                    GTK_TYPE_POINTER,
                    GTK_TYPE_INT,
                    GTK_TYPE_BOOL);

  signals[DELETE_TEXT] =
    gtk_signal_new ("delete_text",
                    GTK_RUN_LAST,
                    GTK_CLASS_TYPE (object_class),
                    GTK_SIGNAL_OFFSET (GtkTextBufferClass, delete_text),
                    gtk_marshal_NONE__POINTER_POINTER_INT,
                    GTK_TYPE_NONE,
                    3,
                    GTK_TYPE_POINTER,
                    GTK_TYPE_POINTER,
                    GTK_TYPE_BOOL);

  signals[CHANGED] =
    gtk_signal_new ("changed",
                    GTK_RUN_LAST,
                    GTK_CLASS_TYPE (object_class),
                    GTK_SIGNAL_OFFSET (GtkTextBufferClass, changed),
                    gtk_marshal_NONE__NONE,
                    GTK_TYPE_NONE,
                    0);

  signals[MODIFIED_CHANGED] =
    gtk_signal_new ("modified_changed",
                    GTK_RUN_LAST,
                    GTK_CLASS_TYPE (object_class),
                    GTK_SIGNAL_OFFSET (GtkTextBufferClass, modified_changed),
                    gtk_marshal_NONE__NONE,
                    GTK_TYPE_NONE,
                    0);
  
  signals[MARK_SET] =
    gtk_signal_new ("mark_set",
                    GTK_RUN_LAST,
                    GTK_CLASS_TYPE (object_class),
                    GTK_SIGNAL_OFFSET (GtkTextBufferClass, mark_set),
                    gtk_marshal_NONE__POINTER_POINTER,
                    GTK_TYPE_NONE,
                    2,
                    GTK_TYPE_POINTER,
                    GTK_TYPE_POINTER);

  signals[MARK_DELETED] =
    gtk_signal_new ("mark_deleted",
                    GTK_RUN_LAST,
                    GTK_CLASS_TYPE (object_class),
                    GTK_SIGNAL_OFFSET (GtkTextBufferClass, mark_deleted),
                    gtk_marshal_NONE__POINTER,
                    GTK_TYPE_NONE,
                    1,
                    GTK_TYPE_POINTER);

  signals[APPLY_TAG] =
    gtk_signal_new ("apply_tag",
                    GTK_RUN_LAST,
                    GTK_CLASS_TYPE (object_class),
                    GTK_SIGNAL_OFFSET (GtkTextBufferClass, apply_tag),
                    gtk_marshal_NONE__POINTER_POINTER_POINTER,
                    GTK_TYPE_NONE,
                    3,
                    GTK_TYPE_POINTER,
                    GTK_TYPE_POINTER,
                    GTK_TYPE_POINTER);
    
  signals[REMOVE_TAG] =
    gtk_signal_new ("remove_tag",
                    GTK_RUN_LAST,
                    GTK_CLASS_TYPE (object_class),
                    GTK_SIGNAL_OFFSET (GtkTextBufferClass, remove_tag),
                    gtk_marshal_NONE__POINTER_POINTER_POINTER,
                    GTK_TYPE_NONE,
                    3,
                    GTK_TYPE_POINTER,
                    GTK_TYPE_POINTER,
                    GTK_TYPE_POINTER);
  
  gtk_object_class_add_signals (object_class, signals, LAST_SIGNAL);

  object_class->destroy = gtk_text_buffer_destroy;

  gobject_class->finalize = gtk_text_buffer_finalize;

  klass->insert_text = gtk_text_buffer_real_insert_text;
  klass->delete_text = gtk_text_buffer_real_delete_text;
  klass->apply_tag = gtk_text_buffer_real_apply_tag;
  klass->remove_tag = gtk_text_buffer_real_remove_tag;
}


typedef gint (*GtkSignal_NONE__INT_POINTER_INT) (GtkObject  *object,
                                                 gint pos,
                                                 const gchar *text,
                                                 gint len,
                                                 gpointer user_data);

void 
gtk_marshal_NONE__INT_POINTER_INT (GtkObject  *object,
                                   GtkSignalFunc func,
                                   gpointer func_data,
                                   GtkArg  *args)
{
  GtkSignal_NONE__INT_POINTER_INT rfunc;

  rfunc = (GtkSignal_NONE__INT_POINTER_INT) func;

  (*rfunc) (object,
            GTK_VALUE_INT (args[0]),
            GTK_VALUE_POINTER (args[1]),
            GTK_VALUE_INT (args[2]),
            func_data);
}

void
gtk_text_buffer_init (GtkTextBuffer *buffer)
{
}

/**
 * gtk_text_buffer_new:
 * @table: a tag table, or NULL to create a new one
 * 
 * Creates a new text buffer.
 * 
 * Return value: a new text buffer
 **/
GtkTextBuffer*
gtk_text_buffer_new (GtkTextTagTable *table)
{
  GtkTextBuffer *text_buffer;
  
  text_buffer = GTK_TEXT_BUFFER (gtk_type_new (gtk_text_buffer_get_type ()));

  if (table)
    {
      text_buffer->tag_table = table;
      
      gtk_object_ref (GTK_OBJECT(text_buffer->tag_table));
      gtk_object_sink (GTK_OBJECT(text_buffer->tag_table));
    } 
  
  return text_buffer;
}

static void
gtk_text_buffer_destroy (GtkObject *object)
{
  GtkTextBuffer *buffer;

  buffer = GTK_TEXT_BUFFER (object);

  if (buffer->tag_table)
    {
      gtk_object_unref(GTK_OBJECT(buffer->tag_table));
      buffer->tag_table = NULL;
    }

  if (buffer->btree)
    {
      gtk_text_btree_unref(buffer->btree);
      buffer->btree = NULL;
    }
  
  (* parent_class->destroy) (object);
}

static void
gtk_text_buffer_finalize (GObject *object)
{
  GtkTextBuffer *tkxt_buffer;

  tkxt_buffer = GTK_TEXT_BUFFER (object);

  G_OBJECT_CLASS (parent_class)->finalize (object);
}

static GtkTextTagTable*
get_table (GtkTextBuffer *buffer)
{
  if (buffer->tag_table == NULL)
    {
      buffer->tag_table = gtk_text_tag_table_new ();

      gtk_object_ref (GTK_OBJECT(buffer->tag_table));
      gtk_object_sink (GTK_OBJECT(buffer->tag_table));
    }

  return buffer->tag_table;
}

static GtkTextBTree*
get_btree (GtkTextBuffer *buffer)
{
  if (buffer->btree == NULL)
    buffer->btree = gtk_text_btree_new(gtk_text_buffer_get_tag_table (buffer),
                                       buffer);
  
  return buffer->btree;
}

GtkTextBTree*
_gtk_text_buffer_get_btree (GtkTextBuffer *buffer)
{
  return get_btree (buffer);
}

/**
 * gtk_text_buffer_get_tag_table:
 * @buffer: a #GtkTextBuffer
 * 
 * Get the #GtkTextTagTable associated with this buffer.
 * 
 * Return value: the buffer's tag table
 **/
GtkTextTagTable*
gtk_text_buffer_get_tag_table (GtkTextBuffer  *buffer)
{
  g_return_val_if_fail(GTK_IS_TEXT_BUFFER(buffer), NULL);

  return get_table (buffer);
}

/**
 * gtk_text_buffer_set_text:
 * @buffer: a #GtkTextBuffer
 * @text: UTF-8 text to insert
 * @len: length of @text in bytes
 * 
 * Deletes current contents of @buffer, and inserts @text instead.  If
 * @text doesn't end with a newline, a newline is added;
 * #GtkTextBuffer contents must always end with a newline. If @text
 * ends with a newline, the new buffer contents will be exactly
 * @text. If @len is -1, @text must be nul-terminated.
 **/
void
gtk_text_buffer_set_text (GtkTextBuffer *buffer,
                          const gchar   *text,
                          gint           len)
{
  GtkTextIter start, end;
  
  g_return_if_fail (GTK_IS_TEXT_BUFFER(buffer));
  g_return_if_fail (text != NULL);

  if (len < 0)
    len = strlen (text);

  /* Chop newline, since the buffer will already have one
   * in it.
   */
  if (len > 0 && text[len-1] == '\n')
    len -= 1;

  gtk_text_buffer_get_bounds (buffer, &start, &end);
  
  gtk_text_buffer_delete (buffer, &start, &end);

  if (len > 0)
    {
      gtk_text_buffer_get_iter_at_offset (buffer, &start, 0);
      gtk_text_buffer_insert (buffer, &start, text, len);
    }
}

/*
 * Insertion
 */

static void
gtk_text_buffer_real_insert_text(GtkTextBuffer *buffer,
                                 GtkTextIter *iter,
                                 const gchar *text,
                                 gint len,
                                 gboolean interactive)
{
  g_return_if_fail(GTK_IS_TEXT_BUFFER(buffer));
  g_return_if_fail(iter != NULL);

  gtk_text_btree_insert(iter, text, len);
  
  gtk_signal_emit(GTK_OBJECT(buffer), signals[CHANGED]);

  gtk_text_buffer_set_modified(buffer, TRUE);
}

static void
gtk_text_buffer_emit_insert(GtkTextBuffer *buffer,
                            GtkTextIter *iter,
                            const gchar *text,
                            gint len,
                            gboolean interactive)
{
  g_return_if_fail(GTK_IS_TEXT_BUFFER(buffer));
  g_return_if_fail(iter != NULL);
  g_return_if_fail(text != NULL);

  if (len < 0)
    len = strlen(text);
  
  if (len > 0)
    {
      gtk_signal_emit(GTK_OBJECT(buffer), signals[INSERT_TEXT],
                      iter, text, len, interactive);
    }
}

/**
 * gtk_text_buffer_insert:
 * @buffer: a #GtkTextBuffer
 * @iter: a position in the buffer
 * @text: UTF-8 format text to insert
 * @len: length of text in bytes, or -1
 * 
 * Inserts @len bytes of @text at position @iter.  If @len is -1,
 * @text must be nul-terminated and will be inserted in its
 * entirety. Emits the "insert_text" signal; insertion actually occurs
 * in the default handler for the signal. @iter is invalidated when
 * insertion occurs (because the buffer contents change), but the
 * default signal handler revalidates it to point to the end of the
 * inserted text.
 * 
 **/
void
gtk_text_buffer_insert (GtkTextBuffer *buffer,
                        GtkTextIter *iter,
                        const gchar *text,
                        gint len)
{
  g_return_if_fail(GTK_IS_TEXT_BUFFER(buffer));
  g_return_if_fail(iter != NULL);
  g_return_if_fail(text != NULL);
  
  gtk_text_buffer_emit_insert(buffer, iter, text, len, FALSE);
}

/**
 * gtk_text_buffer_insert_at_cursor:
 * @buffer: a #GtkTextBuffer
 * @text: some text in UTF-8 format
 * @len: length of text, in bytes
 * 
 * Simply calls gtk_text_buffer_insert(), using the current
 * cursor position as the insertion point.
 **/
void
gtk_text_buffer_insert_at_cursor (GtkTextBuffer *buffer,
                                  const gchar *text,
                                  gint len)
{
  GtkTextIter iter;

  g_return_if_fail(GTK_IS_TEXT_BUFFER(buffer));
  g_return_if_fail(text != NULL);

  gtk_text_buffer_get_iter_at_mark(buffer, &iter,
                                   gtk_text_buffer_get_mark (buffer,
                                                             "insert"));

  gtk_text_buffer_insert(buffer, &iter, text, len);
}

/**
 * gtk_text_buffer_insert_interactive:
 * @buffer: a #GtkTextBuffer
 * @iter: a position in @buffer
 * @text: some UTF-8 text
 * @len: length of text in bytes, or -1
 * @default_editable: default editability of buffer
 * 
 * Like gtk_text_buffer_insert(), but the insertion will not occur if
 * @iter is at a non-editable location in the buffer.  Usually you
 * want to prevent insertions at ineditable locations if the insertion
 * results from a user action (is interactive).
 * 
 * Return value: whether text was actually inserted
 **/
gboolean
gtk_text_buffer_insert_interactive(GtkTextBuffer *buffer,
                                   GtkTextIter   *iter,
                                   const gchar   *text,
                                   gint           len,
                                   gboolean       default_editable)
{
  g_return_val_if_fail(GTK_IS_TEXT_BUFFER(buffer), FALSE);
  g_return_val_if_fail(text != NULL, FALSE);
  
  if (gtk_text_iter_editable (iter, default_editable))
    {
      gtk_text_buffer_emit_insert (buffer, iter, text, len, TRUE);
      return TRUE;
    }
  else
    return FALSE;
}

/**
 * gtk_text_buffer_insert_interactive_at_cursor:
 * @buffer: a #GtkTextBuffer
 * @text: text in UTF-8 format
 * @len: length of text in bytes, or -1
 * @default_editable: default editability of buffer
 * 
 * Calls gtk_text_buffer_insert_interactive() at the cursor
 * position.
 * 
 * Return value: whether text was actually inserted
 **/
gboolean
gtk_text_buffer_insert_interactive_at_cursor (GtkTextBuffer *buffer,
                                              const gchar   *text,
                                              gint           len,
                                              gboolean       default_editable)
{
  GtkTextIter iter;

  g_return_val_if_fail(GTK_IS_TEXT_BUFFER(buffer), FALSE);
  g_return_val_if_fail(text != NULL, FALSE);
  
  gtk_text_buffer_get_iter_at_mark(buffer, &iter,
                                   gtk_text_buffer_get_mark (buffer,
                                                             "insert"));

  return gtk_text_buffer_insert_interactive (buffer, &iter, text, len,
                                             default_editable);
}


/**
 * gtk_text_buffer_insert_range:
 * @buffer: a #GtkTextBuffer
 * @iter: a position in @buffer
 * @start: a position in a #GtkTextBuffer
 * @end: another position in the same buffer as @start
 *
 * Copies text, tags, and pixbufs between @start and @end (the order
 * of @start and @end doesn't matter) and inserts the copy at @iter.
 * Used instead of simply getting/inserting text because it preserves
 * images and tags. If @start and @end are in a different buffer
 * from @buffer, the two buffers must share the same tag table.
 *
 * Implemented via multiple emissions of the insert_text and
 * apply_tag signals, so expect those.
 **/
void
gtk_text_buffer_insert_range (GtkTextBuffer     *buffer,
                              GtkTextIter       *iter,
                              const GtkTextIter *start,
                              const GtkTextIter *end)
{
  g_return_if_fail (GTK_IS_TEXT_BUFFER (buffer));
  g_return_if_fail (iter != NULL);
  g_return_if_fail (start != NULL);
  g_return_if_fail (end != NULL);
  g_return_if_fail (gtk_text_iter_get_buffer (start) !=
                    gtk_text_iter_get_buffer (end));
  g_return_if_fail (gtk_text_iter_get_buffer (start)->tag_table !=
                    buffer->tag_table);

  /* FIXME */
}

gboolean
gtk_text_buffer_insert_range_interactive (GtkTextBuffer     *buffer,
                                          GtkTextIter       *iter,
                                          const GtkTextIter *start,
                                          const GtkTextIter *end,
                                          gboolean           default_editable)
{
  g_return_val_if_fail (GTK_IS_TEXT_BUFFER (buffer), FALSE);
  g_return_val_if_fail (iter != NULL, FALSE);
  g_return_val_if_fail (start != NULL, FALSE);
  g_return_val_if_fail (end != NULL, FALSE);
  g_return_val_if_fail (gtk_text_iter_get_buffer (start) !=
                        gtk_text_iter_get_buffer (end), FALSE);
  g_return_val_if_fail (gtk_text_iter_get_buffer (start)->tag_table !=
                        buffer->tag_table, FALSE);


  /* FIXME */
  
  return FALSE;
}

/**
 * gtk_text_buffer_insert_with_tags:
 * @buffer: a #GtkTextBuffer
 * @iter: an iterator in @buffer
 * @text: UTF-8 text
 * @len: length of @text, or -1 
 * @first_tag: first tag to apply to @text
 * @Varargs: NULL-terminated list of tags to apply 
 * 
 * Inserts @text into @buffer at @iter, applying the list of tags to
 * the newly-inserted text. The last tag specified must be NULL to
 * terminate the list. Equivalent to calling gtk_text_buffer_insert(),
 * then gtk_text_buffer_apply_tag() on the inserted text;
 * gtk_text_buffer_insert_with_tags() is just a convenience function.
 **/
void
gtk_text_buffer_insert_with_tags (GtkTextBuffer *buffer,
                                  GtkTextIter   *iter,
                                  const gchar   *text,
                                  gint           len,
                                  GtkTextTag    *first_tag,
                                  ...)
{
  gint start_offset;
  GtkTextIter start;
  va_list args;
  GtkTextTag *tag;
  
  g_return_if_fail (GTK_IS_TEXT_BUFFER(buffer));
  g_return_if_fail (iter != NULL);
  g_return_if_fail (text != NULL);

  start_offset = gtk_text_iter_get_offset (iter);
  
  gtk_text_buffer_insert (buffer, iter, text, len);

  if (first_tag == NULL)
    return;
  
  gtk_text_buffer_get_iter_at_offset (buffer, &start, start_offset);
  
  va_start (args, first_tag);
  tag = first_tag;
  while (tag)
    {
      gtk_text_buffer_apply_tag (buffer, tag, &start, iter);

      tag = va_arg (args, GtkTextTag*);
    }

  va_end (args);
}

/**
 * gtk_text_buffer_insert_with_tags_by_name:
 * @buffer: a #GtkTextBuffer
 * @iter: position in @buffer
 * @text: UTF-8 text
 * @len: length of @text, or -1
 * @first_tag_name: name of a tag to apply to @text
 * @Varargs: more tag names
 * 
 * Same as gtk_text_buffer_insert_with_tags(), but allows you
 * to pass in tag names instead of tag objects.
 **/
void
gtk_text_buffer_insert_with_tags_by_name  (GtkTextBuffer *buffer,
                                           GtkTextIter   *iter,
                                           const gchar   *text,
                                           gint           len,
                                           const gchar   *first_tag_name,
                                           ...)
{
  gint start_offset;
  GtkTextIter start;
  va_list args;
  const gchar *tag_name;
  
  g_return_if_fail (GTK_IS_TEXT_BUFFER(buffer));
  g_return_if_fail (iter != NULL);
  g_return_if_fail (text != NULL);

  start_offset = gtk_text_iter_get_offset (iter);
  
  gtk_text_buffer_insert (buffer, iter, text, len);

  if (first_tag_name == NULL)
    return;
  
  gtk_text_buffer_get_iter_at_offset (buffer, &start, start_offset);
  
  va_start (args, first_tag_name);
  tag_name = first_tag_name;
  while (tag_name)
    {
      GtkTextTag *tag;

      tag = gtk_text_tag_table_lookup (buffer->tag_table,
                                       tag_name);

      if (tag == NULL)
        {
          g_warning ("%s: no tag with name '%s'!", G_STRLOC, tag_name);
          return;
        }
      
      gtk_text_buffer_apply_tag (buffer, tag, &start, iter);

      tag_name = va_arg (args, const gchar*);
    }

  va_end (args);
}


/*
 * Deletion
 */

static void
gtk_text_buffer_real_delete_text(GtkTextBuffer *buffer,
                                 GtkTextIter *start,
                                 GtkTextIter *end,
                                 gboolean interactive)
{
  g_return_if_fail(GTK_IS_TEXT_BUFFER(buffer));
  g_return_if_fail(start != NULL);
  g_return_if_fail(end != NULL);
  
  gtk_text_btree_delete(start, end);

  /* may have deleted the selection... */
  gtk_text_buffer_update_primary_selection(buffer);
  
  gtk_signal_emit(GTK_OBJECT(buffer), signals[CHANGED]);
  
  gtk_text_buffer_set_modified(buffer, TRUE);
}

static void
gtk_text_buffer_emit_delete (GtkTextBuffer *buffer,
                             GtkTextIter *start,
                             GtkTextIter *end,
                             gboolean interactive)
{
  g_return_if_fail(GTK_IS_TEXT_BUFFER(buffer));
  g_return_if_fail(start != NULL);
  g_return_if_fail(end != NULL);

  if (gtk_text_iter_equal(start, end))
    return;

  gtk_text_iter_reorder (start, end);

  /* Somewhat annoyingly, if you try to delete the final newline
   * the BTree will put it back; which means you can't deduce the
   * final contents of the buffer purely by monitoring insert/delete
   * signals on the buffer. But if you delete the final newline, any
   * tags on the newline will go away, oddly. See comment in
   * gtktextbtree.c. This is all sort of annoying, but really hard
   * to fix.
   */
  gtk_signal_emit(GTK_OBJECT(buffer),
                  signals[DELETE_TEXT],
                  start, end,
                  interactive);
}

/**
 * gtk_text_buffer_delete:
 * @buffer: a #GtkTextBuffer
 * @start: a position in @buffer
 * @end: another position in @buffer
 *
 * Deletes text between @start and @end. The order of @start and @end
 * is not actually relevant; gtk_text_buffer_delete() will reorder
 * them. This function actually emits the "delete_text" signal, and
 * the default handler of that signal deletes the text. Because the
 * buffer is modified, all outstanding iterators become invalid after
 * calling this function; however, the @start and @end will be
 * re-initialized to point to the location where text was deleted.
 *
 * Note that the final newline in the buffer may not be deleted; a
 * #GtkTextBuffer always contains at least one newline.  You can
 * safely include the final newline in the range [@start,@end) but it
 * won't be affected by the deletion.
 * 
 **/
void
gtk_text_buffer_delete (GtkTextBuffer *buffer,
                        GtkTextIter *start,
                        GtkTextIter *end)
{
  g_return_if_fail(GTK_IS_TEXT_BUFFER(buffer));
  g_return_if_fail(start != NULL);
  g_return_if_fail(end != NULL);
  
  gtk_text_buffer_emit_delete(buffer, start, end, FALSE);
}

/**
 * gtk_text_buffer_delete_interactive:
 * @buffer: a #GtkTextBuffer
 * @start_iter: start of range to delete
 * @end_iter: end of range
 * @default_editable: whether the buffer is editable by default 
 * 
 * Deletes all <emphasis>editable</emphasis> text in the given range.
 * Calls gtk_text_buffer_delete() for each editable sub-range of
 * [@start,@end).
 * 
 * Return value: whether some text was actually deleted
 **/
gboolean
gtk_text_buffer_delete_interactive (GtkTextBuffer *buffer,
                                    GtkTextIter   *start_iter,
                                    GtkTextIter   *end_iter,
                                    gboolean       default_editable)
{
  GtkTextMark *end_mark;
  GtkTextMark *start_mark;
  GtkTextIter iter;
  gboolean current_state;
  gboolean deleted_stuff = FALSE;

  /* Delete all editable text in the range start_iter, end_iter */
  
  g_return_val_if_fail(GTK_IS_TEXT_BUFFER(buffer), FALSE);
  g_return_val_if_fail (start_iter != NULL, FALSE);
  g_return_val_if_fail (end_iter != NULL, FALSE);

  gtk_text_iter_reorder (start_iter, end_iter);
  
  start_mark = gtk_text_buffer_create_mark (buffer, NULL, 
                                            start_iter, TRUE);
  end_mark = gtk_text_buffer_create_mark (buffer, NULL, 
                                          end_iter, FALSE);
  iter = *start_iter;
  
  current_state = gtk_text_iter_editable (&iter, default_editable);
  
  while (TRUE)
    {
      gboolean new_state;
      gboolean done = FALSE;
      GtkTextIter end;

      gtk_text_iter_forward_to_tag_toggle (&iter, NULL);
      
      gtk_text_buffer_get_iter_at_mark (buffer, &end, end_mark);
      
      if (gtk_text_iter_compare (&iter, &end) >= 0)
        {
          done = TRUE;
          iter = end; /* clamp to the last boundary */
        }

      new_state = gtk_text_iter_editable (&iter, default_editable);

      if (current_state == new_state)
        {
          if (done)
            {
              if (current_state)
                {
                  /* We're ending an editable region. Delete said region. */
                  GtkTextIter start;
                  
                  gtk_text_buffer_get_iter_at_mark (buffer, &start, start_mark);
                  
                  gtk_text_buffer_emit_delete (buffer, &start, &iter, TRUE);
                  
                  deleted_stuff = TRUE;
                }

              break;
            }
          else
            continue;
        }

      if (current_state && !new_state)
        {
          /* End of an editable region. Delete it. */
          GtkTextIter start;
          
          gtk_text_buffer_get_iter_at_mark (buffer, &start, start_mark);
          
          gtk_text_buffer_emit_delete (buffer, &start, &iter, TRUE);

          current_state = FALSE;
          deleted_stuff = TRUE;
        }
      else
        {
          /* We are at the start of an editable region. We won't be deleting
           * the previous region. Move start mark to start of this region.
           */

          g_assert (!current_state && new_state);          
          
          gtk_text_buffer_move_mark (buffer, start_mark,
                                     &iter);


          current_state = TRUE;
        }

      if (done)
        break;
    }

  
  gtk_text_buffer_delete_mark (buffer, start_mark);
  gtk_text_buffer_delete_mark (buffer, end_mark);
  
  return deleted_stuff;
}

/*
 * Extracting textual buffer contents
 */

/**
 * gtk_text_buffer_get_text:
 * @buffer: a #GtkTextBuffer
 * @start: start of a range
 * @end: end of a range
 * @include_hidden_chars: whether to include invisible text
 * 
 * Returns the text in the range [@start,@end). Excludes undisplayed
 * text (text marked with tags that set the invisibility attribute) if
 * @include_hidden_chars is FALSE. Does not include characters
 * representing embedded images, so byte and character indexes into
 * the returned string do <emphasis>not</emphasis> correspond to byte
 * and character indexes into the buffer. Contrast with
 * gtk_text_buffer_get_slice().
 * 
 * Return value: an allocated UTF-8 string
 **/
gchar*
gtk_text_buffer_get_text (GtkTextBuffer      *buffer,
                          const GtkTextIter *start,
                          const GtkTextIter *end,
                          gboolean             include_hidden_chars)
{
  g_return_val_if_fail(GTK_IS_TEXT_BUFFER(buffer), NULL);
  g_return_val_if_fail(start != NULL, NULL);
  g_return_val_if_fail(end != NULL, NULL);

  if (include_hidden_chars)
    return gtk_text_iter_get_text(start, end);
  else
    return gtk_text_iter_get_visible_text(start, end);
}

/**
 * gtk_text_buffer_get_slice:
 * @buffer: a #GtkTextBuffer
 * @start: start of a range
 * @end: end of a range
 * @include_hidden_chars: whether to include invisible text 
 *
 * Returns the text in the range [@start,@end). Excludes undisplayed
 * text (text marked with tags that set the invisibility attribute) if
 * @include_hidden_chars is FALSE. The returned string includes a
 * 0xFFFD character whenever the buffer contains
 * embedded images, so byte and character indexes into
 * the returned string <emphasis>do</emphasis> correspond to byte
 * and character indexes into the buffer. Contrast with
 * gtk_text_buffer_get_text().
 * 
 * Return value: an allocated UTF-8 string
 **/
gchar*
gtk_text_buffer_get_slice (GtkTextBuffer      *buffer,
                           const GtkTextIter *start,
                           const GtkTextIter *end,
                           gboolean             include_hidden_chars)
{
  g_return_val_if_fail(GTK_IS_TEXT_BUFFER(buffer), NULL);
  g_return_val_if_fail(start != NULL, NULL);
  g_return_val_if_fail(end != NULL, NULL);

  if (include_hidden_chars)
    return gtk_text_iter_get_slice(start, end);
  else
    return gtk_text_iter_get_visible_slice(start, end);
}

/*
 * Pixmaps
 */

void
gtk_text_buffer_insert_pixbuf         (GtkTextBuffer      *buffer,
                                       GtkTextIter        *iter,
                                       GdkPixbuf          *pixbuf)
{
  g_return_if_fail (GTK_IS_TEXT_BUFFER(buffer));
  g_return_if_fail (iter != NULL);
  g_return_if_fail (GDK_IS_PIXBUF (pixbuf));
  
  gtk_text_btree_insert_pixbuf (iter, pixbuf);

  /* FIXME pixbuf-specific signal like insert_text */
  
  gtk_signal_emit (GTK_OBJECT(buffer), signals[CHANGED]);
  
  gtk_text_buffer_set_modified (buffer, TRUE);
}

/*
 * Mark manipulation
 */

static void
gtk_text_buffer_mark_set (GtkTextBuffer     *buffer,
			  const GtkTextIter *location,
                          GtkTextMark       *mark)
{
  /* IMO this should NOT work like insert_text and delete_text,
     where the real action happens in the default handler.

     The reason is that the default handler would be _required_,
     i.e. the whole widget would start breaking and segfaulting
     if the default handler didn't get run. So you can't really
     override the default handler or stop the emission; that is,
     this signal is purely for notification, and not to allow users
     to modify the default behavior. */

  gtk_text_mark_ref (mark);
  
  gtk_signal_emit(GTK_OBJECT(buffer),
                  signals[MARK_SET],
                  location,
                  mark);

  gtk_text_mark_unref (mark);
}

/**
 * gtk_text_buffer_set_mark:
 * @buffer:       a #GtkTextBuffer
 * @mark_name:    name of the mark
 * @iter:         location for the mark.
 * @left_gravity: if the mark is created by this function, gravity for the new
 *                mark.
 * @should_exist: if %TRUE, warn if the mark does not exist, and return
 *                immediately.
 * 
 * Move the mark to the given position, if not @should_exist, create the mark.
 * 
 * Return value: mark
 **/
static GtkTextMark*
gtk_text_buffer_set_mark (GtkTextBuffer *buffer,
                          GtkTextMark *existing_mark,
                          const gchar *mark_name,
                          const GtkTextIter *iter,
                          gboolean left_gravity,
                          gboolean should_exist)
{
  GtkTextIter location;
  GtkTextMark *mark;
  
  mark = gtk_text_btree_set_mark(get_btree (buffer),
                                 existing_mark,
                                 mark_name,
                                 left_gravity,
                                 iter,
                                 should_exist);

  if (gtk_text_btree_mark_is_insert(get_btree (buffer), mark) ||
      gtk_text_btree_mark_is_selection_bound (get_btree (buffer), mark))
    {
      gtk_text_buffer_update_primary_selection (buffer);
    }
  
  gtk_text_btree_get_iter_at_mark (get_btree (buffer),
                                   &location,
                                   mark);
  
  gtk_text_buffer_mark_set (buffer, &location, mark);

  return (GtkTextMark*)mark;
}

/**
 * gtk_text_buffer_create_mark:
 * @buffer: a #GtkTextBuffer
 * @mark_name: name for mark, or %NULL
 * @where: location to place mark
 * @left_gravity: whether the mark has left gravity
 * 
 * Creates a mark at position @where. If @mark_name is %NULL, the mark
 * is anonymous; otherwise, the mark can be retrieved by name using
 * gtk_text_buffer_get_mark(). If a mark has left gravity, and text is
 * inserted at the mark's current location, the mark will be moved to
 * the left of the newly-inserted text. If the mark has right gravity
 * (@left_gravity = %FALSE), the mark will end up on the right of
 * newly-inserted text. The standard left-to-right cursor is a mark
 * with right gravity (when you type, the cursor stays on the right
 * side of the text you're typing).
 *
 * The caller of this function does <emphasis>not</emphasis> own a reference
 * to the returned #GtkTextMark, so you can ignore the return value
 * if you like. Marks are owned by the buffer and go away when the
 * buffer does.
 *
 * Emits the "mark_set" signal as notification of the mark's initial
 * placement.
 * 
 * Return value: the new #GtkTextMark object
 **/
GtkTextMark*
gtk_text_buffer_create_mark(GtkTextBuffer *buffer,
                            const gchar *mark_name,
                            const GtkTextIter *where,
                            gboolean left_gravity)
{
  g_return_val_if_fail (GTK_IS_TEXT_BUFFER(buffer), NULL);
  
  return gtk_text_buffer_set_mark (buffer, NULL, mark_name, where,
                                   left_gravity, FALSE);
}

/**
 * gtk_text_buffer_move_mark:
 * @buffer: a #GtkTextBuffer
 * @mark: a #GtkTextMark
 * @where: new location for @mark in @buffer
 * 
 * Moves @mark to the new location @where. Emits the "mark_set" signal
 * as notification of the move.
 **/
void
gtk_text_buffer_move_mark (GtkTextBuffer *buffer,
                           GtkTextMark *mark,
                           const GtkTextIter *where)
{
  g_return_if_fail (mark != NULL);
  g_return_if_fail (!gtk_text_mark_get_deleted (mark));
  g_return_if_fail (GTK_IS_TEXT_BUFFER(buffer));
  
  gtk_text_buffer_set_mark (buffer, mark, NULL, where, FALSE, TRUE);
}

/**
 * gtk_text_buffer_get_iter_at_mark:
 * @buffer: a #GtkTextBuffer
 * @iter: iterator to initialize
 * @mark: a #GtkTextMark in @buffer
 * 
 * Initializes @iter with the current position of @mark.
 **/
void
gtk_text_buffer_get_iter_at_mark (GtkTextBuffer *buffer,
                                  GtkTextIter *iter,
                                  GtkTextMark *mark)
{
  g_return_if_fail (mark != NULL);
  g_return_if_fail (!gtk_text_mark_get_deleted (mark));
  g_return_if_fail (GTK_IS_TEXT_BUFFER(buffer));

  gtk_text_btree_get_iter_at_mark (get_btree (buffer),
                                   iter,
                                   mark);
}

/**
 * gtk_text_buffer_delete_mark:
 * @buffer: a #GtkTextBuffer
 * @mark: a #GtkTextMark in @buffer 
 * 
 * Deletes @mark, so that it's no longer located anywhere in the
 * buffer. Removes the reference the buffer holds to the mark, so if
 * you haven't called gtk_text_mark_ref() the mark will be freed. Even
 * if the mark isn't freed, most operations on @mark become
 * invalid. There is no way to undelete a
 * mark. gtk_text_mark_get_deleted() will return TRUE after this
 * function has been called on a mark; gtk_text_mark_get_deleted()
 * indicates that a mark no longer belongs to a buffer. The "mark_deleted"
 * signal will be emitted as notification after the mark is deleted.
 **/
void
gtk_text_buffer_delete_mark(GtkTextBuffer *buffer,
                            GtkTextMark   *mark)
{
  g_return_if_fail (mark != NULL);
  g_return_if_fail (!gtk_text_mark_get_deleted (mark));
  g_return_if_fail (GTK_IS_TEXT_BUFFER (buffer));
  
  gtk_text_mark_ref (mark);
  
  gtk_text_btree_remove_mark (get_btree (buffer), mark);

  /* See rationale above for MARK_SET on why we emit this after
   * removing the mark, rather than removing the mark in a default
   * handler.
   */
  gtk_signal_emit (GTK_OBJECT(buffer), signals[MARK_DELETED],
                   mark);

  gtk_text_mark_unref (mark);
}

/**
 * gtk_text_buffer_get_mark:
 * @buffer: a #GtkTextBuffer
 * @name: a mark name
 * 
 * Returns the mark named @name in buffer @buffer, or NULL if no such
 * mark exists in the buffer.
 * 
 * Return value: a #GtkTextMark, or NULL
 **/
GtkTextMark*
gtk_text_buffer_get_mark (GtkTextBuffer      *buffer,
                          const gchar         *name)
{
  GtkTextMark *mark;

  g_return_val_if_fail (GTK_IS_TEXT_BUFFER(buffer), NULL);
  g_return_val_if_fail (name != NULL, NULL);
  
  mark = gtk_text_btree_get_mark_by_name (get_btree (buffer), name);

  return mark;
}


/**
 * gtk_text_buffer_move_mark_by_name:
 * @buffer: a #GtkTextBuffer 
 * @name: name of a mark
 * @where: new location for mark
 * 
 * Moves the mark named @name (which must exist) to location @where.
 * See gtk_text_buffer_move_mark() for details.
 **/
void
gtk_text_buffer_move_mark_by_name (GtkTextBuffer     *buffer,
                                   const gchar       *name,
                                   const GtkTextIter *where)
{
  GtkTextMark *mark;

  g_return_if_fail (GTK_IS_TEXT_BUFFER(buffer));
  g_return_if_fail (name != NULL);
  
  mark = gtk_text_btree_get_mark_by_name (get_btree (buffer), name);  

  if (mark == NULL)
    {
      g_warning ("%s: no mark named '%s'", G_STRLOC, name);
      return;
    }
  
  gtk_text_buffer_move_mark (buffer, mark, where);
}

/**
 * gtk_text_buffer_delete_mark_by_name:
 * @buffer: a #GtkTextBuffer
 * @name: name of a mark in @buffer
 * 
 * Deletes the mark named @name; the mark must exist. See
 * gtk_text_buffer_delete_mark() for details.
 **/
void
gtk_text_buffer_delete_mark_by_name (GtkTextBuffer     *buffer,
                                     const gchar       *name)
{
  GtkTextMark *mark;

  g_return_if_fail (GTK_IS_TEXT_BUFFER(buffer));
  g_return_if_fail (name != NULL);
  
  mark = gtk_text_btree_get_mark_by_name (get_btree (buffer), name);  

  if (mark == NULL)
    {
      g_warning ("%s: no mark named '%s'", G_STRLOC, name);
      return;
    }
  
  gtk_text_buffer_delete_mark (buffer, mark);
}

/**
 * gtk_text_buffer_get_insert:
 * @buffer: a #GtkTextBuffer
 * 
 * Returns the mark that represents the cursor (insertion point).
 * Equivalent to calling gtk_text_buffer_get_mark() to get the mark
 * name "insert," but very slightly more efficient, and involves less
 * typing.
 * 
 * Return value: insertion point mark
 **/
GtkTextMark*
gtk_text_buffer_get_insert (GtkTextBuffer *buffer)
{
  g_return_val_if_fail(GTK_IS_TEXT_BUFFER(buffer), NULL);

  /* FIXME use struct member in btree */
  return gtk_text_buffer_get_mark (buffer, "insert");
}

/**
 * gtk_text_buffer_get_selection_bound:
 * @buffer: a #GtkTextBuffer
 * 
 * Returns the mark that represents the selection bound.  Equivalent
 * to calling gtk_text_buffer_get_mark() to get the mark name
 * "selection_bound," but very slightly more efficient, and involves
 * less typing.
 *
 * The currently-selected text in @buffer is the region between the
 * "selection_bound" and "insert" marks. If "selection_bound" and
 * "insert" are in the same place, then there is no current selection.
 * gtk_text_buffer_get_selection_bounds() is another convenient function
 * for handling the selection, if you just want to know whether there's a
 * selection and what its bounds are.
 * 
 * Return value: selection bound mark
 **/
GtkTextMark*
gtk_text_buffer_get_selection_bound (GtkTextBuffer *buffer)
{
  g_return_val_if_fail(GTK_IS_TEXT_BUFFER(buffer), NULL);

  /* FIXME use struct member in btree */
  return gtk_text_buffer_get_mark (buffer, "selection_bound");
}

/**
 * gtk_text_buffer_place_cursor:
 * @buffer: a #GtkTextBuffer 
 * @where: where to put the cursor
 * 
 * This function moves the "insert" and "selection_bound" marks
 * simultaneously.  If you move them to the same place in two steps
 * with gtk_text_buffer_move_mark(), you will temporarily select a
 * region in between their old and new locations, which can be pretty
 * inefficient since the temporarily-selected region will force stuff
 * to be recalculated. This function moves them as a unit, which can
 * be optimized.
 **/
void
gtk_text_buffer_place_cursor (GtkTextBuffer     *buffer,
                              const GtkTextIter *where)
{
  GtkTextIter real;
  
  g_return_if_fail(GTK_IS_TEXT_BUFFER(buffer));

  real = *where;
  
  if (gtk_text_iter_is_last (&real))
    gtk_text_iter_prev_char (&real);
  
  gtk_text_btree_place_cursor (get_btree (buffer), &real);
  gtk_text_buffer_mark_set (buffer, &real,
                            gtk_text_buffer_get_mark (buffer,
                                                      "insert"));
  gtk_text_buffer_mark_set (buffer, &real,
                            gtk_text_buffer_get_mark (buffer,
                                                      "selection_bound"));
}

/*
 * Tags
 */

/**
 * gtk_text_buffer_create_tag:
 * @buffer: a #GtkTextBuffer
 * @tag_name: name of the new tag, or %NULL
 * 
 * Creates a tag and adds it to the tag table for @buffer.
 * Equivalent to calling gtk_text_tag_new() and then adding the
 * tag to the buffer's tag table. The returned tag has its refcount
 * incremented, as if you'd called gtk_text_tag_new().
 *
 * If @tag_name is %NULL, the tag is anonymous.
 * 
 * Return value: a new tag
 **/
GtkTextTag*
gtk_text_buffer_create_tag(GtkTextBuffer *buffer,
                           const gchar *tag_name)
{
  GtkTextTag *tag;
  
  g_return_val_if_fail(GTK_IS_TEXT_BUFFER(buffer), NULL);
  
  tag = gtk_text_tag_new(tag_name);

  gtk_text_tag_table_add(get_table (buffer), tag);

  return tag;
}

static void
gtk_text_buffer_real_apply_tag (GtkTextBuffer *buffer,
                                GtkTextTag *tag,
                                const GtkTextIter *start,
                                const GtkTextIter *end)
{
  gtk_text_btree_tag(start, end, tag, TRUE);
}

static void
gtk_text_buffer_real_remove_tag (GtkTextBuffer *buffer,
                                 GtkTextTag *tag,
                                 const GtkTextIter *start,
                                 const GtkTextIter *end)
{
  gtk_text_btree_tag(start, end, tag, FALSE);
}


static void
gtk_text_buffer_emit_tag(GtkTextBuffer *buffer,
                         GtkTextTag *tag,
                         gboolean apply,
                         const GtkTextIter *start,
                         const GtkTextIter *end)
{
  g_return_if_fail(tag != NULL);

  if (apply)
    gtk_signal_emit(GTK_OBJECT(buffer), signals[APPLY_TAG],
                    tag, start, end);
  else
    gtk_signal_emit(GTK_OBJECT(buffer), signals[REMOVE_TAG],
                    tag, start, end);
}


void
gtk_text_buffer_apply_tag(GtkTextBuffer *buffer,
                          GtkTextTag    *tag,
                          const GtkTextIter *start,
                          const GtkTextIter *end)
{
  g_return_if_fail(GTK_IS_TEXT_BUFFER(buffer));
  g_return_if_fail(GTK_IS_TEXT_TAG (tag));
  g_return_if_fail(start != NULL);
  g_return_if_fail(end != NULL);  

  gtk_text_buffer_emit_tag(buffer, tag, TRUE, start, end);
}

void
gtk_text_buffer_remove_tag(GtkTextBuffer *buffer,
                           GtkTextTag    *tag,
                           const GtkTextIter *start,
                           const GtkTextIter *end)

{
  g_return_if_fail(GTK_IS_TEXT_BUFFER(buffer));
  g_return_if_fail(GTK_IS_TEXT_TAG (tag));
  g_return_if_fail(start != NULL);
  g_return_if_fail(end != NULL);

  gtk_text_buffer_emit_tag(buffer, tag, FALSE, start, end);
}


void
gtk_text_buffer_apply_tag_by_name (GtkTextBuffer *buffer,
                                   const gchar *name,
                                   const GtkTextIter *start,
                                   const GtkTextIter *end)
{
  GtkTextTag *tag;
  
  g_return_if_fail(GTK_IS_TEXT_BUFFER(buffer));
  g_return_if_fail(name != NULL);
  g_return_if_fail(start != NULL);
  g_return_if_fail(end != NULL);
  
  tag = gtk_text_tag_table_lookup(get_table (buffer),
                                  name);

  if (tag == NULL)
    {
      g_warning("Unknown tag `%s'", name);
      return;
    }

  gtk_text_buffer_emit_tag(buffer, tag, TRUE, start, end);
}

void
gtk_text_buffer_remove_tag_by_name (GtkTextBuffer *buffer,
                                    const gchar *name,
                                    const GtkTextIter *start,
                                    const GtkTextIter *end)
{
  GtkTextTag *tag;
  
  g_return_if_fail(GTK_IS_TEXT_BUFFER(buffer));
  g_return_if_fail(name != NULL);
  g_return_if_fail(start != NULL);
  g_return_if_fail(end != NULL);

  tag = gtk_text_tag_table_lookup(get_table (buffer),
                                  name);

  if (tag == NULL)
    {
      g_warning("Unknown tag `%s'", name);
      return;
    }
  
  gtk_text_buffer_emit_tag(buffer, tag, FALSE, start, end);
}


/*
 * Obtain various iterators
 */

void
gtk_text_buffer_get_iter_at_line_offset (GtkTextBuffer      *buffer,
                                         GtkTextIter        *iter,
                                         gint                line_number,
                                         gint                char_offset)
{  
  g_return_if_fail(iter != NULL);
  g_return_if_fail(GTK_IS_TEXT_BUFFER(buffer));

  gtk_text_btree_get_iter_at_line_char(get_btree (buffer),
                                       iter, line_number, char_offset);
}

void
gtk_text_buffer_get_iter_at_line    (GtkTextBuffer      *buffer,
                                     GtkTextIter        *iter,
                                     gint                line_number)
{
  g_return_if_fail(iter != NULL);
  g_return_if_fail(GTK_IS_TEXT_BUFFER(buffer));

  gtk_text_buffer_get_iter_at_line_offset (buffer, iter, line_number, 0);
}

void
gtk_text_buffer_get_iter_at_offset         (GtkTextBuffer      *buffer,
                                            GtkTextIter        *iter,
                                            gint                char_offset)
{
  g_return_if_fail(iter != NULL);
  g_return_if_fail(GTK_IS_TEXT_BUFFER(buffer));

  gtk_text_btree_get_iter_at_char(get_btree (buffer), iter, char_offset);
}

void
gtk_text_buffer_get_last_iter         (GtkTextBuffer      *buffer,
                                       GtkTextIter        *iter)
{  
  g_return_if_fail(iter != NULL);
  g_return_if_fail(GTK_IS_TEXT_BUFFER(buffer));

  gtk_text_btree_get_last_iter(get_btree (buffer), iter);
}

void
gtk_text_buffer_get_bounds (GtkTextBuffer *buffer,
                            GtkTextIter   *start,
                            GtkTextIter   *end)
{
  g_return_if_fail(start != NULL);
  g_return_if_fail(end != NULL);
  g_return_if_fail(GTK_IS_TEXT_BUFFER(buffer));

  gtk_text_btree_get_iter_at_char(get_btree (buffer), start, 0);
  gtk_text_btree_get_last_iter(get_btree (buffer), end);
}

/*
 * Modified flag
 */

gboolean
gtk_text_buffer_modified (GtkTextBuffer      *buffer)
{
  g_return_val_if_fail(GTK_IS_TEXT_BUFFER(buffer), FALSE);
  
  return buffer->modified;
}

void
gtk_text_buffer_set_modified (GtkTextBuffer      *buffer,
                              gboolean             setting)
{
  gboolean fixed_setting;
  
  g_return_if_fail(GTK_IS_TEXT_BUFFER(buffer));

  fixed_setting = setting != FALSE;
  
  if (buffer->modified == fixed_setting)
    return;
  else
    {
      buffer->modified = fixed_setting;
      gtk_signal_emit(GTK_OBJECT(buffer), signals[MODIFIED_CHANGED]);
    }
}


/*
 * Assorted other stuff
 */

gint
gtk_text_buffer_get_line_count(GtkTextBuffer *buffer)
{
  g_return_val_if_fail(GTK_IS_TEXT_BUFFER(buffer), 0);
  
  return gtk_text_btree_line_count(get_btree (buffer));
}

gint
gtk_text_buffer_get_char_count(GtkTextBuffer *buffer)
{
  g_return_val_if_fail(GTK_IS_TEXT_BUFFER(buffer), 0);

  return gtk_text_btree_char_count(get_btree (buffer));
}

GSList*
gtk_text_buffer_get_tags               (GtkTextBuffer      *buffer,
                                        const GtkTextIter  *iter)
{
  GSList *retval = NULL;
  GtkTextTag** tags;
  gint count = 0;
  
  tags = gtk_text_btree_get_tags(iter, &count);

  if (count > 0)
    {
      gint i;

      gtk_text_tag_array_sort(tags, count);
      
      i = 0;
      while (i < count)
        {
          retval = g_slist_prepend(retval, tags[i]);
          ++i;
        }

      retval = g_slist_reverse(retval);
    }

  if (tags)
    g_free(tags);

  return retval;
}

/* Called when we lose the primary selection.
 */
static void
clipboard_clear_cb (GtkClipboard *clipboard,
		    gpointer      data)
{
  /* Move selection_bound to the insertion point */
  GtkTextIter insert;
  GtkTextIter selection_bound;
  GtkTextBuffer *buffer = GTK_TEXT_BUFFER (data);
  
  gtk_text_buffer_get_iter_at_mark(buffer, &insert,
				   gtk_text_buffer_get_mark (buffer, "insert"));
  gtk_text_buffer_get_iter_at_mark(buffer, &selection_bound,
				   gtk_text_buffer_get_mark (buffer, "selection_bound"));
  
  if (!gtk_text_iter_equal(&insert, &selection_bound))
    gtk_text_buffer_move_mark(buffer,
			      gtk_text_buffer_get_mark (buffer, "selection_bound"),
			      &insert);
}

/* Called when we have the primary selection and someone else wants our
 * data in order to paste it.
 */
static void
clipboard_get_cb (GtkClipboard     *clipboard,
		  GtkSelectionData *selection_data,
		  guint             info,
		  gpointer          data)
{
  GtkTextBuffer *buffer = GTK_TEXT_BUFFER(data);
  gchar *str;
  GtkTextIter start, end;
  
  if (gtk_text_buffer_get_selection_bounds(buffer, &start, &end))
    {
      /* Extract the selected text */
      str = gtk_text_iter_get_visible_text(&start, &end);
      gtk_selection_data_set_text (selection_data, str);
      g_free (str);
    }
}

/* Called when we request a paste and receive the data
 */
static void
clipboard_received (GtkClipboard *clipboard,
		    const gchar  *str,
		    gpointer      data)
{
  ClipboardRequest *request_data = data;
  GtkTextBuffer *buffer = request_data->buffer;

  if (str)
    {
      gboolean reselect;
      GtkTextIter insert_point;
      GtkTextMark *paste_point_override;

      paste_point_override = gtk_text_buffer_get_mark (buffer,
						       "gtk_paste_point_override");
      
      if (paste_point_override != NULL)
	{
	  gtk_text_buffer_get_iter_at_mark(buffer, &insert_point,
					   paste_point_override);
	  gtk_text_buffer_delete_mark(buffer,
				      gtk_text_buffer_get_mark (buffer,
								"gtk_paste_point_override"));
	}
      else
	{
	  gtk_text_buffer_get_iter_at_mark(buffer, &insert_point,
					   gtk_text_buffer_get_mark (buffer,
								     "insert"));
	}
      
      reselect = FALSE;

      /* FIXME ALL OF THIS - I think that the "best method" is that when pasting
       * with the cursor inside the selection area, you replace the selection
       * with the new text, otherwise, you simply insert the new text at
       * the point where the click occured, unselecting any selected text.
       *
       * This probably is best implemented as a "replace_selection" flag in
       * ClipboardRequest.
       */
#if 0      
      if ((TRUE/* Text is selected FIXME */) && 
	  (!buffer->have_selection || request_data->is_clipboard))
	{
	  reselect = TRUE;
	  
	  if (buffer->have_selection)
	    {
	      /* FIXME Delete currently-selected chars but don't give up X
		 selection since we'll use the newly-pasted stuff as
		 a new X selection */
	      
	    }
	  else
	    ; /* FIXME Delete selected chars and give up X selection */
	}
#endif      

      if (request_data->interactive)
	gtk_text_buffer_insert_interactive (buffer, &insert_point,
					    str, -1, request_data->default_editable);
      else
	gtk_text_buffer_insert (buffer, &insert_point,
				str, -1);
      
      if (reselect)
	; /* FIXME Select the region of text we just inserted */
    }

  g_object_unref (G_OBJECT (buffer));
  g_free (request_data);
}

static void
gtk_text_buffer_update_primary_selection (GtkTextBuffer *buffer)
{
  static const GtkTargetEntry targets[] = {
    { "STRING", 0, TARGET_STRING },
    { "TEXT",   0, TARGET_TEXT }, 
    { "COMPOUND_TEXT", 0, TARGET_COMPOUND_TEXT },
    { "UTF8_STRING", 0, TARGET_UTF8_STRING }
  };

  GtkTextIter start;
  GtkTextIter end;

  GtkClipboard *clipboard = gtk_clipboard_get (GDK_SELECTION_PRIMARY);

  /* Determine whether we have a selection and adjust X selection
   * accordingly.
   */
  
  if (!gtk_text_buffer_get_selection_bounds (buffer, &start, &end))
    {
      if (gtk_clipboard_get_owner (clipboard) == G_OBJECT (buffer))
	gtk_clipboard_clear (clipboard);
    }
  else
    {
      /* Even if we already have the selection, we need to update our
       * timestamp.
       */
      if (!gtk_clipboard_set_with_owner (clipboard, targets, G_N_ELEMENTS (targets),
					 clipboard_get_cb, clipboard_clear_cb, G_OBJECT (buffer)))
	clipboard_clear_cb (clipboard, buffer);
    }
}

static void
paste (GtkTextBuffer *buffer, 
       gboolean is_clipboard,
       gboolean interactive,
       gboolean default_editable)
{
  ClipboardRequest *data = g_new (ClipboardRequest, 1);

  data->buffer = buffer;
  g_object_ref (G_OBJECT (buffer));
  data->interactive = interactive;
  data->default_editable = default_editable;

  gtk_clipboard_request_text (gtk_clipboard_get (is_clipboard ? GDK_NONE : GDK_SELECTION_PRIMARY),
			      clipboard_received, data);
}

void
gtk_text_buffer_paste_primary (GtkTextBuffer *buffer,
			       GtkTextIter   *override_location,
			       gboolean       default_editable)
{
  if (override_location != NULL)
    gtk_text_buffer_create_mark(buffer,
                                "gtk_paste_point_override",
                                override_location, FALSE);
  
  paste (buffer, FALSE, TRUE, default_editable);
}

void
gtk_text_buffer_paste_clipboard (GtkTextBuffer *buffer,
				 gboolean       default_editable)
{
  paste (buffer, TRUE, TRUE, default_editable);
}

gboolean
gtk_text_buffer_delete_selection (GtkTextBuffer *buffer,
                                  gboolean interactive,
                                  gboolean default_editable)
{
  GtkTextIter start;
  GtkTextIter end;
  
  if (!gtk_text_buffer_get_selection_bounds(buffer, &start, &end))
    {
      return FALSE; /* No selection */
    }
  else
    {
      if (interactive)
        gtk_text_buffer_delete_interactive (buffer, &start, &end, default_editable);
      else
        gtk_text_buffer_delete (buffer, &start, &end);

      return TRUE; /* We deleted stuff */
    }
}

static void
cut_or_copy(GtkTextBuffer *buffer,
            gboolean delete_region_after,
            gboolean interactive,
            gboolean default_editable)
{
  /* We prefer to cut the selected region between selection_bound and
     insertion point. If that region is empty, then we cut the region
     between the "anchor" and the insertion point (this is for C-space
     and M-w and other Emacs-style copy/yank keys). Note that insert
     and selection_bound are guaranteed to exist, but the anchor only
     exists sometimes. */
  GtkTextIter start;
  GtkTextIter end;

  if (!gtk_text_buffer_get_selection_bounds(buffer, &start, &end))
    {
      /* Let's try the anchor thing */
      GtkTextMark * anchor = gtk_text_buffer_get_mark (buffer, "anchor");
      
      if (anchor == NULL)
        return;
      else
        {
          gtk_text_buffer_get_iter_at_mark(buffer, &end, anchor);
          gtk_text_iter_reorder(&start, &end);
        }
    }

  if (!gtk_text_iter_equal(&start, &end))
    {
      GtkClipboard *clipboard = gtk_clipboard_get (GDK_NONE);
      gchar *text;
      
      text = gtk_text_iter_get_visible_text (&start, &end);
      gtk_clipboard_set_text (clipboard, text, -1);
      g_free (text);
      
      if (delete_region_after)
        {
          if (interactive)
            gtk_text_buffer_delete_interactive (buffer, &start, &end,
                                                default_editable);
          else
            gtk_text_buffer_delete (buffer, &start, &end);
        }
    }
}

void
gtk_text_buffer_cut_clipboard (GtkTextBuffer *buffer,
			       gboolean       default_editable)
{
  cut_or_copy (buffer, TRUE, TRUE, default_editable);
}

void
gtk_text_buffer_copy_clipboard (GtkTextBuffer *buffer)
{
  cut_or_copy (buffer, FALSE, TRUE, TRUE);
}


/**
 * gtk_text_buffer_get_selection_bounds:
 * @buffer: a #GtkTextBuffer
 * @start: iterator to initialize with selection start
 * @end: iterator to initialize with selection end
 * 
 * Returns %TRUE if some text is selected; places the bounds
 * of the selection in @start and @end (if the selection has length 0,
 * then @start and @end are filled in with the same value).
 * @start and @end will be in ascending order. If @start and @end are
 * NULL, then they are not filled in, but the return value still indicates
 * whether text is selected.
 * 
 * Return value: whether the selection has nonzero length
 **/
gboolean
gtk_text_buffer_get_selection_bounds   (GtkTextBuffer      *buffer,
                                        GtkTextIter        *start,
                                        GtkTextIter        *end)
{
  g_return_val_if_fail (GTK_IS_TEXT_BUFFER (buffer), FALSE);

  return gtk_text_btree_get_selection_bounds (get_btree (buffer), start, end);
}


/*
 * Debug spew
 */

void
_gtk_text_buffer_spew(GtkTextBuffer *buffer)
{
  gtk_text_btree_spew(get_btree (buffer));
}