gtktextbuffer.c

/* GTK - The GIMP Toolkit
 * gtktextbuffer.c Copyright (C) 2000 Red Hat, Inc.
 *                 Copyright (C) 2004 Nokia Corporation
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library. If not, see <http://www.gnu.org/licenses/>.
 */

/*
 * Modified by the GTK+ Team and others 1997-2000.  See the AUTHORS
 * file for a list of people on the GTK+ Team.  See the ChangeLog
 * files for a list of changes.  These files are distributed with
 * GTK+ at ftp://ftp.gtk.org/pub/gtk/.
 */

#include "config.h"
#include <string.h>
#include <stdarg.h>

#define GTK_TEXT_USE_INTERNAL_UNSUPPORTED_API
#include "gtkclipboard.h"
#include "gtkdnd.h"
#include "gtkinvisible.h"
#include "gtkmarshalers.h"
#include "gtktextbuffer.h"
#include "gtktextbufferprivate.h"
#include "gtktextbufferrichtext.h"
#include "gtktextbtree.h"
#include "gtktextiterprivate.h"
#include "gtktexttagprivate.h"
#include "gtktexttagtableprivate.h"
#include "gtkprivate.h"
#include "gtkintl.h"

/**
 * SECTION:gtktextbuffer
 * @Short_description: Stores attributed text for display in a GtkTextView
 * @Title: GtkTextBuffer
 * @See_also: #GtkTextView, #GtkTextIter, #GtkTextMark
 *
 * You may wish to begin by reading the
 * [text widget conceptual overview][TextWidget]
 * which gives an overview of all the objects and data
 * types related to the text widget and how they work together.
 */

typedef struct _GtkTextLogAttrCache GtkTextLogAttrCache;

struct _GtkTextBufferPrivate
{
  GtkTargetList  *copy_target_list;
  GtkTargetEntry *copy_target_entries;
  GtkTargetList  *paste_target_list;
  GtkTargetEntry *paste_target_entries;

  gint            n_copy_target_entries;
  gint            n_paste_target_entries;

  GtkTextTagTable *tag_table;
  GtkTextBTree *btree;

  GSList *clipboard_contents_buffers;
  GSList *selection_clipboards;

  GtkTextLogAttrCache *log_attr_cache;

  guint user_action_count;

  /* Whether the buffer has been modified since last save */
  guint modified : 1;
  guint has_selection : 1;
};

typedef struct _ClipboardRequest ClipboardRequest;

struct _ClipboardRequest
{
  GtkTextBuffer *buffer;
  guint interactive : 1;
  guint default_editable : 1;
  guint replace_selection : 1;
};

enum {
  INSERT_TEXT,
  INSERT_PIXBUF,
  INSERT_CHILD_ANCHOR,
  DELETE_RANGE,
  CHANGED,
  MODIFIED_CHANGED,
  MARK_SET,
  MARK_DELETED,
  APPLY_TAG,
  REMOVE_TAG,
  BEGIN_USER_ACTION,
  END_USER_ACTION,
  PASTE_DONE,
  LAST_SIGNAL
};

enum {
  PROP_0,

  /* Construct */
  PROP_TAG_TABLE,

  /* Normal */
  PROP_TEXT,
  PROP_HAS_SELECTION,
  PROP_CURSOR_POSITION,
  PROP_COPY_TARGET_LIST,
  PROP_PASTE_TARGET_LIST,
  LAST_PROP
};

static void gtk_text_buffer_finalize   (GObject            *object);

static void gtk_text_buffer_real_insert_text           (GtkTextBuffer     *buffer,
                                                        GtkTextIter       *iter,
                                                        const gchar       *text,
                                                        gint               len);
static void gtk_text_buffer_real_insert_pixbuf         (GtkTextBuffer     *buffer,
                                                        GtkTextIter       *iter,
                                                        GdkPixbuf         *pixbuf);
static void gtk_text_buffer_real_insert_anchor         (GtkTextBuffer     *buffer,
                                                        GtkTextIter       *iter,
                                                        GtkTextChildAnchor *anchor);
static void gtk_text_buffer_real_delete_range          (GtkTextBuffer     *buffer,
                                                        GtkTextIter       *start,
                                                        GtkTextIter       *end);
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 void gtk_text_buffer_real_changed               (GtkTextBuffer     *buffer);
static void gtk_text_buffer_real_mark_set              (GtkTextBuffer     *buffer,
                                                        const GtkTextIter *iter,
                                                        GtkTextMark       *mark);

static GtkTextBTree* get_btree (GtkTextBuffer *buffer);
static void          free_log_attr_cache (GtkTextLogAttrCache *cache);

static void remove_all_selection_clipboards       (GtkTextBuffer *buffer);
static void update_selection_clipboards           (GtkTextBuffer *buffer);

static GtkTextBuffer *create_clipboard_contents_buffer (GtkTextBuffer *buffer);

static void gtk_text_buffer_free_target_lists     (GtkTextBuffer *buffer);

static void gtk_text_buffer_set_property (GObject         *object,
				          guint            prop_id,
				          const GValue    *value,
				          GParamSpec      *pspec);
static void gtk_text_buffer_get_property (GObject         *object,
				          guint            prop_id,
				          GValue          *value,
				          GParamSpec      *pspec);
static void gtk_text_buffer_notify       (GObject         *object,
                                          GParamSpec      *pspec);

static guint signals[LAST_SIGNAL] = { 0 };
static GParamSpec *text_buffer_props[LAST_PROP];

G_DEFINE_TYPE_WITH_PRIVATE (GtkTextBuffer, gtk_text_buffer, G_TYPE_OBJECT)

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

  object_class->finalize = gtk_text_buffer_finalize;
  object_class->set_property = gtk_text_buffer_set_property;
  object_class->get_property = gtk_text_buffer_get_property;
  object_class->notify       = gtk_text_buffer_notify;
 
  klass->insert_text = gtk_text_buffer_real_insert_text;
  klass->insert_pixbuf = gtk_text_buffer_real_insert_pixbuf;
  klass->insert_child_anchor = gtk_text_buffer_real_insert_anchor;
  klass->delete_range = gtk_text_buffer_real_delete_range;
  klass->apply_tag = gtk_text_buffer_real_apply_tag;
  klass->remove_tag = gtk_text_buffer_real_remove_tag;
  klass->changed = gtk_text_buffer_real_changed;
  klass->mark_set = gtk_text_buffer_real_mark_set;

  /* Construct */
  text_buffer_props[PROP_TAG_TABLE] =
      g_param_spec_object ("tag-table",
                           P_("Tag Table"),
                           P_("Text Tag Table"),
                           GTK_TYPE_TEXT_TAG_TABLE,
                           GTK_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY);

  /* Normal properties */

  /**
   * GtkTextBuffer:text:
   *
   * The text content of the buffer. Without child widgets and images,
   * see gtk_text_buffer_get_text() for more information.
   *
   * Since: 2.8
   */
  text_buffer_props[PROP_TEXT] =
      g_param_spec_string ("text",
                           P_("Text"),
                           P_("Current text of the buffer"),
                           "",
                           GTK_PARAM_READWRITE);

  /**
   * GtkTextBuffer:has-selection:
   *
   * Whether the buffer has some text currently selected.
   *
   * Since: 2.10
   */
  text_buffer_props[PROP_HAS_SELECTION] =
      g_param_spec_boolean ("has-selection",
                            P_("Has selection"),
                            P_("Whether the buffer has some text currently selected"),
                            FALSE,
                            GTK_PARAM_READABLE);

  /**
   * GtkTextBuffer:cursor-position:
   *
   * The position of the insert mark (as offset from the beginning
   * of the buffer). It is useful for getting notified when the
   * cursor moves.
   *
   * Since: 2.10
   */
  text_buffer_props[PROP_CURSOR_POSITION] =
      g_param_spec_int ("cursor-position",
                        P_("Cursor position"),
                        P_("The position of the insert mark (as offset from the beginning of the buffer)"),
			0, G_MAXINT,
                        0,
                        GTK_PARAM_READABLE);

  /**
   * GtkTextBuffer:copy-target-list:
   *
   * The list of targets this buffer supports for clipboard copying
   * and as DND source.
   *
   * Since: 2.10
   */
  text_buffer_props[PROP_COPY_TARGET_LIST] =
      g_param_spec_boxed ("copy-target-list",
                          P_("Copy target list"),
                          P_("The list of targets this buffer supports for clipboard copying and DND source"),
                          GTK_TYPE_TARGET_LIST,
                          GTK_PARAM_READABLE);

  /**
   * GtkTextBuffer:paste-target-list:
   *
   * The list of targets this buffer supports for clipboard pasting
   * and as DND destination.
   *
   * Since: 2.10
   */
  text_buffer_props[PROP_PASTE_TARGET_LIST] =
      g_param_spec_boxed ("paste-target-list",
                          P_("Paste target list"),
                          P_("The list of targets this buffer supports for clipboard pasting and DND destination"),
                          GTK_TYPE_TARGET_LIST,
                          GTK_PARAM_READABLE);

  g_object_class_install_properties (object_class, LAST_PROP, text_buffer_props);

  /**
   * GtkTextBuffer::insert-text:
   * @textbuffer: the object which received the signal
   * @location: position to insert @text in @textbuffer
   * @text: the UTF-8 text to be inserted
   * @len: length of the inserted text in bytes
   * 
   * The ::insert-text signal is emitted to insert text in a #GtkTextBuffer.
   * Insertion actually occurs in the default handler.  
   * 
   * Note that if your handler runs before the default handler it must not 
   * invalidate the @location iter (or has to revalidate it). 
   * The default signal handler revalidates it to point to the end of the 
   * inserted text.
   * 
   * See also: 
   * gtk_text_buffer_insert(), 
   * gtk_text_buffer_insert_range().
   */
  signals[INSERT_TEXT] =
    g_signal_new (I_("insert-text"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (GtkTextBufferClass, insert_text),
                  NULL, NULL,
                  _gtk_marshal_VOID__BOXED_STRING_INT,
                  G_TYPE_NONE,
                  3,
                  GTK_TYPE_TEXT_ITER | G_SIGNAL_TYPE_STATIC_SCOPE,
                  G_TYPE_STRING | G_SIGNAL_TYPE_STATIC_SCOPE,
                  G_TYPE_INT);
  g_signal_set_va_marshaller (signals[INSERT_TEXT], G_TYPE_FROM_CLASS (klass),
                              _gtk_marshal_VOID__BOXED_STRING_INTv);

  /**
   * GtkTextBuffer::insert-pixbuf:
   * @textbuffer: the object which received the signal
   * @location: position to insert @pixbuf in @textbuffer
   * @pixbuf: the #GdkPixbuf to be inserted
   * 
   * The ::insert-pixbuf signal is emitted to insert a #GdkPixbuf 
   * in a #GtkTextBuffer. Insertion actually occurs in the default handler.
   * 
   * Note that if your handler runs before the default handler it must not 
   * invalidate the @location iter (or has to revalidate it). 
   * The default signal handler revalidates it to be placed after the 
   * inserted @pixbuf.
   * 
   * See also: gtk_text_buffer_insert_pixbuf().
   */
  signals[INSERT_PIXBUF] =
    g_signal_new (I_("insert-pixbuf"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (GtkTextBufferClass, insert_pixbuf),
                  NULL, NULL,
                  _gtk_marshal_VOID__BOXED_OBJECT,
                  G_TYPE_NONE,
                  2,
                  GTK_TYPE_TEXT_ITER | G_SIGNAL_TYPE_STATIC_SCOPE,
                  GDK_TYPE_PIXBUF);
  g_signal_set_va_marshaller (signals[INSERT_PIXBUF],
                              G_TYPE_FROM_CLASS (klass),
                              _gtk_marshal_VOID__BOXED_OBJECTv);


  /**
   * GtkTextBuffer::insert-child-anchor:
   * @textbuffer: the object which received the signal
   * @location: position to insert @anchor in @textbuffer
   * @anchor: the #GtkTextChildAnchor to be inserted
   * 
   * The ::insert-child-anchor signal is emitted to insert a
   * #GtkTextChildAnchor in a #GtkTextBuffer.
   * Insertion actually occurs in the default handler.
   * 
   * Note that if your handler runs before the default handler it must
   * not invalidate the @location iter (or has to revalidate it). 
   * The default signal handler revalidates it to be placed after the 
   * inserted @anchor.
   * 
   * See also: gtk_text_buffer_insert_child_anchor().
   */
  signals[INSERT_CHILD_ANCHOR] =
    g_signal_new (I_("insert-child-anchor"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (GtkTextBufferClass, insert_child_anchor),
                  NULL, NULL,
                  _gtk_marshal_VOID__BOXED_OBJECT,
                  G_TYPE_NONE,
                  2,
                  GTK_TYPE_TEXT_ITER | G_SIGNAL_TYPE_STATIC_SCOPE,
                  GTK_TYPE_TEXT_CHILD_ANCHOR);
  g_signal_set_va_marshaller (signals[INSERT_CHILD_ANCHOR],
                              G_TYPE_FROM_CLASS (klass),
                              _gtk_marshal_VOID__BOXED_OBJECTv);
  
  /**
   * GtkTextBuffer::delete-range:
   * @textbuffer: the object which received the signal
   * @start: the start of the range to be deleted
   * @end: the end of the range to be deleted
   * 
   * The ::delete-range signal is emitted to delete a range 
   * from a #GtkTextBuffer. 
   * 
   * Note that if your handler runs before the default handler it must not 
   * invalidate the @start and @end iters (or has to revalidate them). 
   * The default signal handler revalidates the @start and @end iters to 
   * both point to the location where text was deleted. Handlers
   * which run after the default handler (see g_signal_connect_after())
   * do not have access to the deleted text.
   * 
   * See also: gtk_text_buffer_delete().
   */
  signals[DELETE_RANGE] =
    g_signal_new (I_("delete-range"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (GtkTextBufferClass, delete_range),
                  NULL, NULL,
                  _gtk_marshal_VOID__BOXED_BOXED,
                  G_TYPE_NONE,
                  2,
                  GTK_TYPE_TEXT_ITER | G_SIGNAL_TYPE_STATIC_SCOPE,
                  GTK_TYPE_TEXT_ITER | G_SIGNAL_TYPE_STATIC_SCOPE);
  g_signal_set_va_marshaller (signals[DELETE_RANGE],
                              G_TYPE_FROM_CLASS (klass),
                              _gtk_marshal_VOID__BOXED_BOXEDv);

  /**
   * GtkTextBuffer::changed:
   * @textbuffer: the object which received the signal
   * 
   * The ::changed signal is emitted when the content of a #GtkTextBuffer 
   * has changed.
   */
  signals[CHANGED] =
    g_signal_new (I_("changed"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,                   
                  G_STRUCT_OFFSET (GtkTextBufferClass, changed),
                  NULL, NULL,
                  NULL,
                  G_TYPE_NONE,
                  0);

  /**
   * GtkTextBuffer::modified-changed:
   * @textbuffer: the object which received the signal
   * 
   * The ::modified-changed signal is emitted when the modified bit of a 
   * #GtkTextBuffer flips.
   * 
   * See also:
   * gtk_text_buffer_set_modified().
   */
  signals[MODIFIED_CHANGED] =
    g_signal_new (I_("modified-changed"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (GtkTextBufferClass, modified_changed),
                  NULL, NULL,
                  NULL,
                  G_TYPE_NONE,
                  0);

  /**
   * GtkTextBuffer::mark-set:
   * @textbuffer: the object which received the signal
   * @location: The location of @mark in @textbuffer
   * @mark: The mark that is set
   * 
   * The ::mark-set signal is emitted as notification
   * after a #GtkTextMark is set.
   * 
   * See also: 
   * gtk_text_buffer_create_mark(),
   * gtk_text_buffer_move_mark().
   */
  signals[MARK_SET] =
    g_signal_new (I_("mark-set"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (GtkTextBufferClass, mark_set),
                  NULL, NULL,
                  _gtk_marshal_VOID__BOXED_OBJECT,
                  G_TYPE_NONE,
                  2,
                  GTK_TYPE_TEXT_ITER,
                  GTK_TYPE_TEXT_MARK);
  g_signal_set_va_marshaller (signals[MARK_SET],
                              G_TYPE_FROM_CLASS (klass),
                              _gtk_marshal_VOID__BOXED_OBJECTv);

  /**
   * GtkTextBuffer::mark-deleted:
   * @textbuffer: the object which received the signal
   * @mark: The mark that was deleted
   * 
   * The ::mark-deleted signal is emitted as notification
   * after a #GtkTextMark is deleted. 
   * 
   * See also:
   * gtk_text_buffer_delete_mark().
   */
  signals[MARK_DELETED] =
    g_signal_new (I_("mark-deleted"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,                   
                  G_STRUCT_OFFSET (GtkTextBufferClass, mark_deleted),
                  NULL, NULL,
                  NULL,
                  G_TYPE_NONE,
                  1,
                  GTK_TYPE_TEXT_MARK);

   /**
   * GtkTextBuffer::apply-tag:
   * @textbuffer: the object which received the signal
   * @tag: the applied tag
   * @start: the start of the range the tag is applied to
   * @end: the end of the range the tag is applied to
   * 
   * The ::apply-tag signal is emitted to apply a tag to a
   * range of text in a #GtkTextBuffer. 
   * Applying actually occurs in the default handler.
   * 
   * Note that if your handler runs before the default handler it must not 
   * invalidate the @start and @end iters (or has to revalidate them). 
   * 
   * See also: 
   * gtk_text_buffer_apply_tag(),
   * gtk_text_buffer_insert_with_tags(),
   * gtk_text_buffer_insert_range().
   */ 
  signals[APPLY_TAG] =
    g_signal_new (I_("apply-tag"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (GtkTextBufferClass, apply_tag),
                  NULL, NULL,
                  _gtk_marshal_VOID__OBJECT_BOXED_BOXED,
                  G_TYPE_NONE,
                  3,
                  GTK_TYPE_TEXT_TAG,
                  GTK_TYPE_TEXT_ITER,
                  GTK_TYPE_TEXT_ITER);
  g_signal_set_va_marshaller (signals[APPLY_TAG],
                              G_TYPE_FROM_CLASS (klass),
                              _gtk_marshal_VOID__OBJECT_BOXED_BOXEDv);


   /**
   * GtkTextBuffer::remove-tag:
   * @textbuffer: the object which received the signal
   * @tag: the tag to be removed
   * @start: the start of the range the tag is removed from
   * @end: the end of the range the tag is removed from
   * 
   * The ::remove-tag signal is emitted to remove all occurrences of @tag from
   * a range of text in a #GtkTextBuffer. 
   * Removal actually occurs in the default handler.
   * 
   * Note that if your handler runs before the default handler it must not 
   * invalidate the @start and @end iters (or has to revalidate them). 
   * 
   * See also: 
   * gtk_text_buffer_remove_tag(). 
   */ 
  signals[REMOVE_TAG] =
    g_signal_new (I_("remove-tag"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (GtkTextBufferClass, remove_tag),
                  NULL, NULL,
                  _gtk_marshal_VOID__OBJECT_BOXED_BOXED,
                  G_TYPE_NONE,
                  3,
                  GTK_TYPE_TEXT_TAG,
                  GTK_TYPE_TEXT_ITER,
                  GTK_TYPE_TEXT_ITER);
  g_signal_set_va_marshaller (signals[REMOVE_TAG],
                              G_TYPE_FROM_CLASS (klass),
                              _gtk_marshal_VOID__OBJECT_BOXED_BOXEDv);

   /**
   * GtkTextBuffer::begin-user-action:
   * @textbuffer: the object which received the signal
   * 
   * The ::begin-user-action signal is emitted at the beginning of a single
   * user-visible operation on a #GtkTextBuffer.
   * 
   * See also: 
   * gtk_text_buffer_begin_user_action(),
   * gtk_text_buffer_insert_interactive(),
   * gtk_text_buffer_insert_range_interactive(),
   * gtk_text_buffer_delete_interactive(),
   * gtk_text_buffer_backspace(),
   * gtk_text_buffer_delete_selection().
   */ 
  signals[BEGIN_USER_ACTION] =
    g_signal_new (I_("begin-user-action"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,                   
                  G_STRUCT_OFFSET (GtkTextBufferClass, begin_user_action),
                  NULL, NULL,
                  NULL,
                  G_TYPE_NONE,
                  0);

   /**
   * GtkTextBuffer::end-user-action:
   * @textbuffer: the object which received the signal
   * 
   * The ::end-user-action signal is emitted at the end of a single
   * user-visible operation on the #GtkTextBuffer.
   * 
   * See also: 
   * gtk_text_buffer_end_user_action(),
   * gtk_text_buffer_insert_interactive(),
   * gtk_text_buffer_insert_range_interactive(),
   * gtk_text_buffer_delete_interactive(),
   * gtk_text_buffer_backspace(),
   * gtk_text_buffer_delete_selection(),
   * gtk_text_buffer_backspace().
   */ 
  signals[END_USER_ACTION] =
    g_signal_new (I_("end-user-action"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,                   
                  G_STRUCT_OFFSET (GtkTextBufferClass, end_user_action),
                  NULL, NULL,
                  NULL,
                  G_TYPE_NONE,
                  0);

   /**
   * GtkTextBuffer::paste-done:
   * @textbuffer: the object which received the signal
   * @clipboard: the #GtkClipboard pasted from
   * 
   * The paste-done signal is emitted after paste operation has been completed.
   * This is useful to properly scroll the view to the end of the pasted text.
   * See gtk_text_buffer_paste_clipboard() for more details.
   * 
   * Since: 2.16
   */ 
  signals[PASTE_DONE] =
    g_signal_new (I_("paste-done"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (GtkTextBufferClass, paste_done),
                  NULL, NULL,
                  NULL,
                  G_TYPE_NONE,
                  1,
                  GTK_TYPE_CLIPBOARD);
}

static void
gtk_text_buffer_init (GtkTextBuffer *buffer)
{
  buffer->priv = gtk_text_buffer_get_instance_private (buffer);
  buffer->priv->clipboard_contents_buffers = NULL;
  buffer->priv->tag_table = NULL;

  /* allow copying of arbiatray stuff in the internal rich text format */
  gtk_text_buffer_register_serialize_tagset (buffer, NULL);
}

static void
set_table (GtkTextBuffer *buffer, GtkTextTagTable *table)
{
  GtkTextBufferPrivate *priv = buffer->priv;

  g_return_if_fail (priv->tag_table == NULL);

  if (table)
    {
      priv->tag_table = table;
      g_object_ref (priv->tag_table);
      _gtk_text_tag_table_add_buffer (table, buffer);
    }
}

static GtkTextTagTable*
get_table (GtkTextBuffer *buffer)
{
  GtkTextBufferPrivate *priv = buffer->priv;

  if (priv->tag_table == NULL)
    {
      priv->tag_table = gtk_text_tag_table_new ();
      _gtk_text_tag_table_add_buffer (priv->tag_table, buffer);
    }

  return priv->tag_table;
}

static void
gtk_text_buffer_set_property (GObject         *object,
                              guint            prop_id,
                              const GValue    *value,
                              GParamSpec      *pspec)
{
  GtkTextBuffer *text_buffer;

  text_buffer = GTK_TEXT_BUFFER (object);

  switch (prop_id)
    {
    case PROP_TAG_TABLE:
      set_table (text_buffer, g_value_get_object (value));
      break;

    case PROP_TEXT:
      gtk_text_buffer_set_text (text_buffer,
				g_value_get_string (value), -1);
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
    }
}

static void
gtk_text_buffer_get_property (GObject         *object,
                              guint            prop_id,
                              GValue          *value,
                              GParamSpec      *pspec)
{
  GtkTextBuffer *text_buffer;
  GtkTextIter iter;

  text_buffer = GTK_TEXT_BUFFER (object);

  switch (prop_id)
    {
    case PROP_TAG_TABLE:
      g_value_set_object (value, get_table (text_buffer));
      break;

    case PROP_TEXT:
      {
        GtkTextIter start, end;

        gtk_text_buffer_get_start_iter (text_buffer, &start);
        gtk_text_buffer_get_end_iter (text_buffer, &end);

        g_value_take_string (value,
                            gtk_text_buffer_get_text (text_buffer,
                                                      &start, &end, FALSE));
        break;
      }

    case PROP_HAS_SELECTION:
      g_value_set_boolean (value, text_buffer->priv->has_selection);
      break;

    case PROP_CURSOR_POSITION:
      gtk_text_buffer_get_iter_at_mark (text_buffer, &iter, 
    				        gtk_text_buffer_get_insert (text_buffer));
      g_value_set_int (value, gtk_text_iter_get_offset (&iter));
      break;

    case PROP_COPY_TARGET_LIST:
      g_value_set_boxed (value, gtk_text_buffer_get_copy_target_list (text_buffer));
      break;

    case PROP_PASTE_TARGET_LIST:
      g_value_set_boxed (value, gtk_text_buffer_get_paste_target_list (text_buffer));
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
    }
}

static void
gtk_text_buffer_notify (GObject    *object,
                        GParamSpec *pspec)
{
  if (!strcmp (pspec->name, "copy-target-list") ||
      !strcmp (pspec->name, "paste-target-list"))
    {
      gtk_text_buffer_free_target_lists (GTK_TEXT_BUFFER (object));
    }
}

/**
 * gtk_text_buffer_new:
 * @table: (allow-none): a tag table, or %NULL to create a new one
 *
 * Creates a new text buffer.
 *
 * Returns: a new text buffer
 **/
GtkTextBuffer*
gtk_text_buffer_new (GtkTextTagTable *table)
{
  GtkTextBuffer *text_buffer;

  text_buffer = g_object_new (GTK_TYPE_TEXT_BUFFER, "tag-table", table, NULL);

  return text_buffer;
}

static void
gtk_text_buffer_finalize (GObject *object)
{
  GtkTextBuffer *buffer;
  GtkTextBufferPrivate *priv;

  buffer = GTK_TEXT_BUFFER (object);
  priv = buffer->priv;

  remove_all_selection_clipboards (buffer);

  if (priv->tag_table)
    {
      _gtk_text_tag_table_remove_buffer (priv->tag_table, buffer);
      g_object_unref (priv->tag_table);
      priv->tag_table = NULL;
    }

  if (priv->btree)
    {
      _gtk_text_btree_unref (priv->btree);
      priv->btree = NULL;
    }

  if (priv->log_attr_cache)
    free_log_attr_cache (priv->log_attr_cache);

  priv->log_attr_cache = NULL;

  gtk_text_buffer_free_target_lists (buffer);

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

static GtkTextBTree*
get_btree (GtkTextBuffer *buffer)
{
  GtkTextBufferPrivate *priv = buffer->priv;

  if (priv->btree == NULL)
    priv->btree = _gtk_text_btree_new (gtk_text_buffer_get_tag_table (buffer),
                                       buffer);

  return priv->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.
 *
 * Returns: (transfer none): 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
 * @len is -1, @text must be nul-terminated. @text must be valid UTF-8.
 **/
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);

  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)
{
  g_return_if_fail (GTK_IS_TEXT_BUFFER (buffer));
  g_return_if_fail (iter != NULL);
  
  _gtk_text_btree_insert (iter, text, len);

  g_signal_emit (buffer, signals[CHANGED], 0);
  g_object_notify_by_pspec (G_OBJECT (buffer), text_buffer_props[PROP_CURSOR_POSITION]);
}

static void
gtk_text_buffer_emit_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);

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

  g_return_if_fail (g_utf8_validate (text, len, NULL));
  
  if (len > 0)
    {
      g_signal_emit (buffer, signals[INSERT_TEXT], 0,
                     iter, text, len);
    }
}

/**
 * gtk_text_buffer_insert:
 * @buffer: a #GtkTextBuffer
 * @iter: a position in the buffer
 * @text: text in UTF-8 format
 * @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);
  g_return_if_fail (gtk_text_iter_get_buffer (iter) == buffer);
  
  gtk_text_buffer_emit_insert (buffer, iter, text, len);
}

/**
 * gtk_text_buffer_insert_at_cursor:
 * @buffer: a #GtkTextBuffer
 * @text: 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_insert (buffer));

  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