Adding upstream version 2.10.36.upstream/2.10.36

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1866 insertions, 0 deletions

diff --git a/app/widgets/gimptextbuffer.c b/app/widgets/gimptextbuffer.c
new file mode 100644
index 0000000..ad66529
--- /dev/null
+++ b/app/widgets/gimptextbuffer.c
@@ -0,0 +1,1866 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * GimpTextBuffer
+ * Copyright (C) 2010  Michael Natterer <mitch@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpcolor/gimpcolor.h"
+
+#include "widgets-types.h"
+
+#include "gimptextbuffer.h"
+#include "gimptextbuffer-serialize.h"
+#include "gimptexttag.h"
+#include "gimpwidgets-utils.h"
+
+#include "gimp-intl.h"
+
+
+enum
+{
+  COLOR_APPLIED,
+  LAST_SIGNAL
+};
+
+
+/*  local function prototypes  */
+
+static void   gimp_text_buffer_constructed (GObject           *object);
+static void   gimp_text_buffer_dispose     (GObject           *object);
+static void   gimp_text_buffer_finalize    (GObject           *object);
+
+static void   gimp_text_buffer_mark_set    (GtkTextBuffer     *buffer,
+                                            const GtkTextIter *location,
+                                            GtkTextMark       *mark);
+
+
+G_DEFINE_TYPE (GimpTextBuffer, gimp_text_buffer, GTK_TYPE_TEXT_BUFFER)
+
+#define parent_class gimp_text_buffer_parent_class
+
+static guint buffer_signals[LAST_SIGNAL] = { 0, };
+
+
+static void
+gimp_text_buffer_class_init (GimpTextBufferClass *klass)
+{
+  GObjectClass       *object_class = G_OBJECT_CLASS (klass);
+  GtkTextBufferClass *buffer_class = GTK_TEXT_BUFFER_CLASS (klass);
+
+  object_class->constructed = gimp_text_buffer_constructed;
+  object_class->dispose     = gimp_text_buffer_dispose;
+  object_class->finalize    = gimp_text_buffer_finalize;
+
+  buffer_class->mark_set    = gimp_text_buffer_mark_set;
+
+  buffer_signals[COLOR_APPLIED] =
+    g_signal_new ("color-applied",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpTextBufferClass, color_applied),
+                  NULL, NULL,
+                  g_cclosure_marshal_VOID__BOXED,
+                  G_TYPE_NONE, 1,
+                  GIMP_TYPE_RGB);
+}
+
+static void
+gimp_text_buffer_init (GimpTextBuffer *buffer)
+{
+  buffer->markup_atom =
+    gtk_text_buffer_register_serialize_format (GTK_TEXT_BUFFER (buffer),
+                                               "application/x-gimp-pango-markup",
+                                               gimp_text_buffer_serialize,
+                                               NULL, NULL);
+
+  gtk_text_buffer_register_deserialize_format (GTK_TEXT_BUFFER (buffer),
+                                               "application/x-gimp-pango-markup",
+                                               gimp_text_buffer_deserialize,
+                                               NULL, NULL);
+}
+
+static void
+gimp_text_buffer_constructed (GObject *object)
+{
+  GimpTextBuffer *buffer = GIMP_TEXT_BUFFER (object);
+
+  G_OBJECT_CLASS (parent_class)->constructed (object);
+
+  gtk_text_buffer_set_text (GTK_TEXT_BUFFER (buffer), "", -1);
+
+  buffer->bold_tag = gtk_text_buffer_create_tag (GTK_TEXT_BUFFER (buffer),
+                                                 "bold",
+                                                 "weight", PANGO_WEIGHT_BOLD,
+                                                 NULL);
+
+  buffer->italic_tag = gtk_text_buffer_create_tag (GTK_TEXT_BUFFER (buffer),
+                                                   "italic",
+                                                   "style", PANGO_STYLE_ITALIC,
+                                                   NULL);
+
+  buffer->underline_tag = gtk_text_buffer_create_tag (GTK_TEXT_BUFFER (buffer),
+                                                      "underline",
+                                                      "underline", PANGO_UNDERLINE_SINGLE,
+                                                      NULL);
+
+  buffer->preedit_underline_tag = gtk_text_buffer_create_tag (GTK_TEXT_BUFFER (buffer),
+                                                              "preedit-underline",
+                                                              "underline", PANGO_UNDERLINE_SINGLE,
+                                                              NULL);
+
+  buffer->strikethrough_tag = gtk_text_buffer_create_tag (GTK_TEXT_BUFFER (buffer),
+                                                          "strikethrough",
+                                                          "strikethrough", TRUE,
+                                                          NULL);
+}
+
+static void
+gimp_text_buffer_dispose (GObject *object)
+{
+  /* GimpTextBuffer *buffer = GIMP_TEXT_BUFFER (object); */
+
+  G_OBJECT_CLASS (parent_class)->dispose (object);
+}
+
+static void
+gimp_text_buffer_finalize (GObject *object)
+{
+  GimpTextBuffer *buffer = GIMP_TEXT_BUFFER (object);
+
+  if (buffer->size_tags)
+    {
+      g_list_free (buffer->size_tags);
+      buffer->size_tags = NULL;
+    }
+
+  if (buffer->baseline_tags)
+    {
+      g_list_free (buffer->baseline_tags);
+      buffer->baseline_tags = NULL;
+    }
+
+  if (buffer->kerning_tags)
+    {
+      g_list_free (buffer->kerning_tags);
+      buffer->kerning_tags = NULL;
+    }
+
+  if (buffer->font_tags)
+    {
+      g_list_free (buffer->font_tags);
+      buffer->font_tags = NULL;
+    }
+
+  if (buffer->color_tags)
+    {
+      g_list_free (buffer->color_tags);
+      buffer->color_tags = NULL;
+    }
+
+  if (buffer->preedit_color_tags)
+    {
+      g_list_free (buffer->preedit_color_tags);
+      buffer->preedit_color_tags = NULL;
+    }
+
+  if (buffer->preedit_bg_color_tags)
+    {
+      g_list_free (buffer->preedit_bg_color_tags);
+      buffer->preedit_bg_color_tags = NULL;
+    }
+
+  gimp_text_buffer_clear_insert_tags (buffer);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_text_buffer_mark_set (GtkTextBuffer     *buffer,
+                           const GtkTextIter *location,
+                           GtkTextMark       *mark)
+{
+  gimp_text_buffer_clear_insert_tags (GIMP_TEXT_BUFFER (buffer));
+
+  GTK_TEXT_BUFFER_CLASS (parent_class)->mark_set (buffer, location, mark);
+}
+
+
+/*  public functions  */
+
+GimpTextBuffer *
+gimp_text_buffer_new (void)
+{
+  return g_object_new (GIMP_TYPE_TEXT_BUFFER, NULL);
+}
+
+void
+gimp_text_buffer_set_text (GimpTextBuffer *buffer,
+                           const gchar    *text)
+{
+  g_return_if_fail (GIMP_IS_TEXT_BUFFER (buffer));
+
+  if (text == NULL)
+    text = "";
+
+  gtk_text_buffer_set_text (GTK_TEXT_BUFFER (buffer), text, -1);
+
+  gimp_text_buffer_clear_insert_tags (buffer);
+}
+
+gchar *
+gimp_text_buffer_get_text (GimpTextBuffer *buffer)
+{
+  GtkTextIter start, end;
+
+  g_return_val_if_fail (GIMP_IS_TEXT_BUFFER (buffer), NULL);
+
+  gtk_text_buffer_get_bounds (GTK_TEXT_BUFFER (buffer), &start, &end);
+
+  return gtk_text_buffer_get_text (GTK_TEXT_BUFFER (buffer),
+                                   &start, &end, TRUE);
+}
+
+void
+gimp_text_buffer_set_markup (GimpTextBuffer *buffer,
+                             const gchar    *markup)
+{
+  g_return_if_fail (GIMP_IS_TEXT_BUFFER (buffer));
+
+  gimp_text_buffer_set_text (buffer, NULL);
+
+  if (markup)
+    {
+      GtkTextTagTable *tag_table;
+      GtkTextBuffer   *content;
+      GtkTextIter      insert;
+      GError          *error = NULL;
+
+      tag_table = gtk_text_buffer_get_tag_table (GTK_TEXT_BUFFER (buffer));
+      content = gtk_text_buffer_new (tag_table);
+
+      gtk_text_buffer_get_start_iter (content, &insert);
+
+      if (! gtk_text_buffer_deserialize (GTK_TEXT_BUFFER (buffer),
+                                         content,
+                                         buffer->markup_atom,
+                                         &insert,
+                                         (const guint8 *) markup, -1,
+                                         &error))
+        {
+          g_printerr ("EEK: %s\n", error->message);
+          g_clear_error (&error);
+        }
+      else
+        {
+          GtkTextIter start, end;
+
+          gimp_text_buffer_post_deserialize (buffer, content);
+
+          gtk_text_buffer_get_bounds (content, &start, &end);
+          gtk_text_buffer_get_start_iter (GTK_TEXT_BUFFER (buffer), &insert);
+
+          gtk_text_buffer_insert_range (GTK_TEXT_BUFFER (buffer),
+                                        &insert, &start, &end);
+        }
+
+      g_object_unref (content);
+    }
+
+  gimp_text_buffer_clear_insert_tags (buffer);
+}
+
+gchar *
+gimp_text_buffer_get_markup (GimpTextBuffer *buffer)
+{
+  GtkTextTagTable *tag_table;
+  GtkTextBuffer   *content;
+  GtkTextIter      insert;
+  GtkTextIter      start, end;
+  gchar           *markup;
+  gsize            length;
+
+  g_return_val_if_fail (GIMP_IS_TEXT_BUFFER (buffer), NULL);
+
+  tag_table = gtk_text_buffer_get_tag_table (GTK_TEXT_BUFFER (buffer));
+  content = gtk_text_buffer_new (tag_table);
+
+  gtk_text_buffer_get_bounds (GTK_TEXT_BUFFER (buffer), &start, &end);
+  gtk_text_buffer_get_start_iter (content, &insert);
+
+  gtk_text_buffer_insert_range (content, &insert, &start, &end);
+
+  gimp_text_buffer_pre_serialize (buffer, content);
+
+  gtk_text_buffer_get_bounds (content, &start, &end);
+
+  markup = (gchar *) gtk_text_buffer_serialize (GTK_TEXT_BUFFER (buffer),
+                                                content,
+                                                buffer->markup_atom,
+                                                &start, &end,
+                                                &length);
+
+  g_object_unref (content);
+
+  return markup;
+}
+
+gboolean
+gimp_text_buffer_has_markup (GimpTextBuffer *buffer)
+{
+  GtkTextIter iter;
+
+  g_return_val_if_fail (GIMP_IS_TEXT_BUFFER (buffer), FALSE);
+
+  gtk_text_buffer_get_start_iter (GTK_TEXT_BUFFER (buffer), &iter);
+
+  do
+    {
+      GSList *tags = gtk_text_iter_get_tags (&iter);
+
+      if (tags)
+        {
+          g_slist_free (tags);
+          return TRUE;
+        }
+    }
+  while (gtk_text_iter_forward_char (&iter));
+
+  return FALSE;
+}
+
+GtkTextTag *
+gimp_text_buffer_get_iter_size (GimpTextBuffer    *buffer,
+                                const GtkTextIter *iter,
+                                gint              *size)
+{
+  GList *list;
+
+  for (list = buffer->size_tags; list; list = g_list_next (list))
+    {
+      GtkTextTag *tag = list->data;
+
+      if (gtk_text_iter_has_tag (iter, tag))
+        {
+          if (size)
+            *size = gimp_text_tag_get_size (tag);
+
+          return tag;
+        }
+    }
+
+  if (size)
+    *size = 0;
+
+  return NULL;
+}
+
+GtkTextTag *
+gimp_text_buffer_get_size_tag (GimpTextBuffer *buffer,
+                               gint            size)
+{
+  GList      *list;
+  GtkTextTag *tag;
+  gchar       name[32];
+
+  for (list = buffer->size_tags; list; list = g_list_next (list))
+    {
+      tag = list->data;
+
+      if (size == gimp_text_tag_get_size (tag))
+        return tag;
+    }
+
+  g_snprintf (name, sizeof (name), "size-%d", size);
+
+  tag = gtk_text_buffer_create_tag (GTK_TEXT_BUFFER (buffer),
+                                    name,
+                                    GIMP_TEXT_PROP_NAME_SIZE, size,
+                                    NULL);
+
+  buffer->size_tags = g_list_prepend (buffer->size_tags, tag);
+
+  return tag;
+}
+
+void
+gimp_text_buffer_set_size (GimpTextBuffer    *buffer,
+                           const GtkTextIter *start,
+                           const GtkTextIter *end,
+                           gint               size)
+{
+  GList *list;
+
+  g_return_if_fail (GIMP_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_buffer_begin_user_action (GTK_TEXT_BUFFER (buffer));
+
+  for (list = buffer->size_tags; list; list = g_list_next (list))
+    {
+      gtk_text_buffer_remove_tag (GTK_TEXT_BUFFER (buffer), list->data,
+                                  start, end);
+    }
+
+  if (size != 0)
+    {
+      GtkTextTag *tag;
+
+      tag = gimp_text_buffer_get_size_tag (buffer, size);
+
+      gtk_text_buffer_apply_tag (GTK_TEXT_BUFFER (buffer), tag,
+                                 start, end);
+    }
+
+  gtk_text_buffer_end_user_action (GTK_TEXT_BUFFER (buffer));
+}
+
+void
+gimp_text_buffer_change_size (GimpTextBuffer    *buffer,
+                              const GtkTextIter *start,
+                              const GtkTextIter *end,
+                              gint               count)
+{
+  GtkTextIter  iter;
+  GtkTextIter  span_start;
+  GtkTextIter  span_end;
+  GtkTextTag  *span_tag;
+  gint         span_size;
+
+  g_return_if_fail (GIMP_IS_TEXT_BUFFER (buffer));
+  g_return_if_fail (start != NULL);
+  g_return_if_fail (end != NULL);
+
+  if (gtk_text_iter_equal (start, end))
+    return;
+
+  iter       = *start;
+  span_start = *start;
+  span_tag   = gimp_text_buffer_get_iter_size (buffer, &iter,
+                                               &span_size);
+
+  gtk_text_buffer_begin_user_action (GTK_TEXT_BUFFER (buffer));
+
+  do
+    {
+      GtkTextTag *iter_tag;
+      gint        iter_size;
+
+      gtk_text_iter_forward_char (&iter);
+
+      iter_tag = gimp_text_buffer_get_iter_size (buffer, &iter,
+                                                 &iter_size);
+
+      span_end = iter;
+
+      if (iter_size != span_size ||
+          gtk_text_iter_compare (&iter, end) >= 0)
+        {
+          if (span_size != 0)
+            {
+              gtk_text_buffer_remove_tag (GTK_TEXT_BUFFER (buffer), span_tag,
+                                          &span_start, &span_end);
+            }
+
+          if ((span_size + count) > 0)
+            {
+              span_tag = gimp_text_buffer_get_size_tag (buffer,
+                                                        span_size + count);
+
+              gtk_text_buffer_apply_tag (GTK_TEXT_BUFFER (buffer), span_tag,
+                                         &span_start, &span_end);
+            }
+
+          span_start = iter;
+          span_size  = iter_size;
+          span_tag   = iter_tag;
+        }
+
+      /* We might have moved too far */
+      if (gtk_text_iter_compare (&iter, end) > 0)
+        iter = *end;
+    }
+  while (! gtk_text_iter_equal (&iter, end));
+
+  gtk_text_buffer_end_user_action (GTK_TEXT_BUFFER (buffer));
+}
+
+GtkTextTag *
+gimp_text_buffer_get_iter_baseline (GimpTextBuffer    *buffer,
+                                    const GtkTextIter *iter,
+                                    gint              *baseline)
+{
+  GList *list;
+
+  for (list = buffer->baseline_tags; list; list = g_list_next (list))
+    {
+      GtkTextTag *tag = list->data;
+
+      if (gtk_text_iter_has_tag (iter, tag))
+        {
+          if (baseline)
+            *baseline = gimp_text_tag_get_baseline (tag);
+
+          return tag;
+        }
+    }
+
+  if (baseline)
+    *baseline = 0;
+
+  return NULL;
+}
+
+static GtkTextTag *
+gimp_text_buffer_get_baseline_tag (GimpTextBuffer *buffer,
+                                   gint            baseline)
+{
+  GList      *list;
+  GtkTextTag *tag;
+  gchar       name[32];
+
+  for (list = buffer->baseline_tags; list; list = g_list_next (list))
+    {
+      tag = list->data;
+
+      if (baseline == gimp_text_tag_get_baseline (tag))
+        return tag;
+    }
+
+  g_snprintf (name, sizeof (name), "baseline-%d", baseline);
+
+  tag = gtk_text_buffer_create_tag (GTK_TEXT_BUFFER (buffer),
+                                    name,
+                                    GIMP_TEXT_PROP_NAME_BASELINE, baseline,
+                                    NULL);
+
+  buffer->baseline_tags = g_list_prepend (buffer->baseline_tags, tag);
+
+  return tag;
+}
+
+void
+gimp_text_buffer_set_baseline (GimpTextBuffer    *buffer,
+                               const GtkTextIter *start,
+                               const GtkTextIter *end,
+                               gint               baseline)
+{
+  GList *list;
+
+  g_return_if_fail (GIMP_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_buffer_begin_user_action (GTK_TEXT_BUFFER (buffer));
+
+  for (list = buffer->baseline_tags; list; list = g_list_next (list))
+    {
+      gtk_text_buffer_remove_tag (GTK_TEXT_BUFFER (buffer), list->data,
+                                  start, end);
+    }
+
+  if (baseline != 0)
+    {
+      GtkTextTag *tag;
+
+      tag = gimp_text_buffer_get_baseline_tag (buffer, baseline);
+
+      gtk_text_buffer_apply_tag (GTK_TEXT_BUFFER (buffer), tag,
+                                 start, end);
+    }
+
+  gtk_text_buffer_end_user_action (GTK_TEXT_BUFFER (buffer));
+}
+
+void
+gimp_text_buffer_change_baseline (GimpTextBuffer    *buffer,
+                                  const GtkTextIter *start,
+                                  const GtkTextIter *end,
+                                  gint               count)
+{
+  GtkTextIter  iter;
+  GtkTextIter  span_start;
+  GtkTextIter  span_end;
+  GtkTextTag  *span_tag;
+  gint         span_baseline;
+
+  g_return_if_fail (GIMP_IS_TEXT_BUFFER (buffer));
+  g_return_if_fail (start != NULL);
+  g_return_if_fail (end != NULL);
+
+  if (gtk_text_iter_equal (start, end))
+    return;
+
+  iter       = *start;
+  span_start = *start;
+  span_tag   = gimp_text_buffer_get_iter_baseline (buffer, &iter,
+                                                   &span_baseline);
+
+  gtk_text_buffer_begin_user_action (GTK_TEXT_BUFFER (buffer));
+
+  do
+    {
+      GtkTextTag *iter_tag;
+      gint        iter_baseline;
+
+      gtk_text_iter_forward_char (&iter);
+
+      iter_tag = gimp_text_buffer_get_iter_baseline (buffer, &iter,
+                                                     &iter_baseline);
+
+      span_end = iter;
+
+      if (iter_baseline != span_baseline ||
+          gtk_text_iter_compare (&iter, end) >= 0)
+        {
+          if (span_baseline != 0)
+            {
+              gtk_text_buffer_remove_tag (GTK_TEXT_BUFFER (buffer), span_tag,
+                                          &span_start, &span_end);
+            }
+
+          if (span_baseline + count != 0)
+            {
+              span_tag = gimp_text_buffer_get_baseline_tag (buffer,
+                                                            span_baseline + count);
+
+              gtk_text_buffer_apply_tag (GTK_TEXT_BUFFER (buffer), span_tag,
+                                         &span_start, &span_end);
+            }
+
+          span_start    = iter;
+          span_baseline = iter_baseline;
+          span_tag      = iter_tag;
+        }
+
+      /* We might have moved too far */
+      if (gtk_text_iter_compare (&iter, end) > 0)
+        iter = *end;
+    }
+  while (! gtk_text_iter_equal (&iter, end));
+
+  gtk_text_buffer_end_user_action (GTK_TEXT_BUFFER (buffer));
+}
+
+GtkTextTag *
+gimp_text_buffer_get_iter_kerning (GimpTextBuffer    *buffer,
+                                   const GtkTextIter *iter,
+                                   gint              *kerning)
+{
+  GList *list;
+
+  for (list = buffer->kerning_tags; list; list = g_list_next (list))
+    {
+      GtkTextTag *tag = list->data;
+
+      if (gtk_text_iter_has_tag (iter, tag))
+        {
+          if (kerning)
+            *kerning = gimp_text_tag_get_kerning (tag);
+
+          return tag;
+        }
+    }
+
+  if (kerning)
+    *kerning = 0;
+
+  return NULL;
+}
+
+static GtkTextTag *
+gimp_text_buffer_get_kerning_tag (GimpTextBuffer *buffer,
+                                  gint            kerning)
+{
+  GList      *list;
+  GtkTextTag *tag;
+  gchar       name[32];
+
+  for (list = buffer->kerning_tags; list; list = g_list_next (list))
+    {
+      tag = list->data;
+
+      if (kerning == gimp_text_tag_get_kerning (tag))
+        return tag;
+    }
+
+  g_snprintf (name, sizeof (name), "kerning-%d", kerning);
+
+  tag = gtk_text_buffer_create_tag (GTK_TEXT_BUFFER (buffer),
+                                    name,
+                                    GIMP_TEXT_PROP_NAME_KERNING, kerning,
+                                    NULL);
+
+  buffer->kerning_tags = g_list_prepend (buffer->kerning_tags, tag);
+
+  return tag;
+}
+
+void
+gimp_text_buffer_set_kerning (GimpTextBuffer    *buffer,
+                              const GtkTextIter *start,
+                              const GtkTextIter *end,
+                              gint               kerning)
+{
+  GList *list;
+
+  g_return_if_fail (GIMP_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_buffer_begin_user_action (GTK_TEXT_BUFFER (buffer));
+
+  for (list = buffer->kerning_tags; list; list = g_list_next (list))
+    {
+      gtk_text_buffer_remove_tag (GTK_TEXT_BUFFER (buffer), list->data,
+                                  start, end);
+    }
+
+  if (kerning != 0)
+    {
+      GtkTextTag *tag;
+
+      tag = gimp_text_buffer_get_kerning_tag (buffer, kerning);
+
+      gtk_text_buffer_apply_tag (GTK_TEXT_BUFFER (buffer), tag,
+                                 start, end);
+    }
+
+  gtk_text_buffer_end_user_action (GTK_TEXT_BUFFER (buffer));
+}
+
+void
+gimp_text_buffer_change_kerning (GimpTextBuffer    *buffer,
+                                 const GtkTextIter *start,
+                                 const GtkTextIter *end,
+                                 gint               count)
+{
+  GtkTextIter  iter;
+  GtkTextIter  span_start;
+  GtkTextIter  span_end;
+  GtkTextTag  *span_tag;
+  gint         span_kerning;
+
+  g_return_if_fail (GIMP_IS_TEXT_BUFFER (buffer));
+  g_return_if_fail (start != NULL);
+  g_return_if_fail (end != NULL);
+
+  if (gtk_text_iter_equal (start, end))
+    return;
+
+  iter       = *start;
+  span_start = *start;
+  span_tag   = gimp_text_buffer_get_iter_kerning (buffer, &iter,
+                                                  &span_kerning);
+
+  gtk_text_buffer_begin_user_action (GTK_TEXT_BUFFER (buffer));
+
+  do
+    {
+      GtkTextTag *iter_tag;
+      gint        iter_kerning;
+
+      gtk_text_iter_forward_char (&iter);
+
+      iter_tag = gimp_text_buffer_get_iter_kerning (buffer, &iter,
+                                                    &iter_kerning);
+
+      span_end = iter;
+
+      if (iter_kerning != span_kerning ||
+          gtk_text_iter_compare (&iter, end) >= 0)
+        {
+          if (span_kerning != 0)
+            {
+              gtk_text_buffer_remove_tag (GTK_TEXT_BUFFER (buffer), span_tag,
+                                          &span_start, &span_end);
+            }
+
+          if (span_kerning + count != 0)
+            {
+              span_tag = gimp_text_buffer_get_kerning_tag (buffer,
+                                                           span_kerning + count);
+
+              gtk_text_buffer_apply_tag (GTK_TEXT_BUFFER (buffer), span_tag,
+                                         &span_start, &span_end);
+            }
+
+          span_start   = iter;
+          span_kerning = iter_kerning;
+          span_tag     = iter_tag;
+        }
+
+      /* We might have moved too far */
+      if (gtk_text_iter_compare (&iter, end) > 0)
+        iter = *end;
+    }
+  while (! gtk_text_iter_equal (&iter, end));
+
+  gtk_text_buffer_end_user_action (GTK_TEXT_BUFFER (buffer));
+}
+
+GtkTextTag *
+gimp_text_buffer_get_iter_font (GimpTextBuffer     *buffer,
+                                const GtkTextIter  *iter,
+                                gchar             **font)
+{
+  GList *list;
+
+  for (list = buffer->font_tags; list; list = g_list_next (list))
+    {
+      GtkTextTag *tag = list->data;
+
+      if (gtk_text_iter_has_tag (iter, tag))
+        {
+          if (font)
+            *font = gimp_text_tag_get_font (tag);
+
+          return tag;
+        }
+    }
+
+  if (font)
+    *font = NULL;
+
+  return NULL;
+}
+
+GtkTextTag *
+gimp_text_buffer_get_font_tag (GimpTextBuffer *buffer,
+                               const gchar    *font)
+{
+  GList      *list;
+  GtkTextTag *tag;
+  gchar       name[256];
+  PangoFontDescription *pfd = pango_font_description_from_string (font);
+  char *description = pango_font_description_to_string (pfd);
+
+  pango_font_description_free (pfd);
+
+  for (list = buffer->font_tags; list; list = g_list_next (list))
+    {
+      gchar *tag_font;
+
+      tag = list->data;
+
+      tag_font = gimp_text_tag_get_font (tag);
+
+      if (! strcmp (description, tag_font))
+        {
+          g_free (tag_font);
+          g_free (description);
+          return tag;
+        }
+
+      g_free (tag_font);
+    }
+
+  g_snprintf (name, sizeof (name), "font-%s", description);
+
+  tag = gtk_text_buffer_create_tag (GTK_TEXT_BUFFER (buffer),
+                                    name,
+                                    "font", description,
+                                    NULL);
+  gtk_text_tag_set_priority (tag, 0);
+  g_free (description);
+  buffer->font_tags = g_list_prepend (buffer->font_tags, tag);
+
+  return tag;
+}
+
+void
+gimp_text_buffer_set_font (GimpTextBuffer    *buffer,
+                           const GtkTextIter *start,
+                           const GtkTextIter *end,
+                           const gchar       *font)
+{
+  GList *list;
+
+  g_return_if_fail (GIMP_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_buffer_begin_user_action (GTK_TEXT_BUFFER (buffer));
+
+  for (list = buffer->font_tags; list; list = g_list_next (list))
+    {
+      gtk_text_buffer_remove_tag (GTK_TEXT_BUFFER (buffer), list->data,
+                                  start, end);
+    }
+
+  if (font)
+    {
+      GtkTextTag *tag = gimp_text_buffer_get_font_tag (buffer, font);
+
+      gtk_text_buffer_apply_tag (GTK_TEXT_BUFFER (buffer), tag,
+                                 start, end);
+    }
+
+  gtk_text_buffer_end_user_action (GTK_TEXT_BUFFER (buffer));
+}
+
+GtkTextTag *
+gimp_text_buffer_get_iter_color (GimpTextBuffer    *buffer,
+                                 const GtkTextIter *iter,
+                                 GimpRGB           *color)
+{
+  GList *list;
+
+  for (list = buffer->color_tags; list; list = g_list_next (list))
+    {
+      GtkTextTag *tag = list->data;
+
+      if (gtk_text_iter_has_tag (iter, tag))
+        {
+          if (color)
+            gimp_text_tag_get_fg_color (tag, color);
+
+          return tag;
+        }
+    }
+
+  return NULL;
+}
+
+GtkTextTag *
+gimp_text_buffer_get_color_tag (GimpTextBuffer *buffer,
+                                const GimpRGB  *color)
+{
+  GList      *list;
+  GtkTextTag *tag;
+  gchar       name[256];
+  GdkColor    gdk_color;
+  guchar      r, g, b;
+
+  gimp_rgb_get_uchar (color, &r, &g, &b);
+
+  for (list = buffer->color_tags; list; list = g_list_next (list))
+    {
+      GimpRGB tag_color;
+      guchar  tag_r, tag_g, tag_b;
+
+      tag = list->data;
+
+      gimp_text_tag_get_fg_color (tag, &tag_color);
+
+      gimp_rgb_get_uchar (&tag_color, &tag_r, &tag_g, &tag_b);
+
+      /* Do not compare the alpha channel, since it's unused */
+      if (tag_r == r &&
+          tag_g == g &&
+          tag_b == b)
+        {
+          return tag;
+        }
+    }
+
+  g_snprintf (name, sizeof (name), "color-#%02x%02x%02x",
+              r, g, b);
+
+  gimp_rgb_get_gdk_color (color, &gdk_color);
+
+  tag = gtk_text_buffer_create_tag (GTK_TEXT_BUFFER (buffer),
+                                    name,
+                                    "foreground-gdk", &gdk_color,
+                                    "foreground-set", TRUE,
+                                    NULL);
+
+  buffer->color_tags = g_list_prepend (buffer->color_tags, tag);
+
+  return tag;
+}
+
+void
+gimp_text_buffer_set_color (GimpTextBuffer    *buffer,
+                            const GtkTextIter *start,
+                            const GtkTextIter *end,
+                            const GimpRGB     *color)
+{
+  GList *list;
+
+  g_return_if_fail (GIMP_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_buffer_begin_user_action (GTK_TEXT_BUFFER (buffer));
+
+  for (list = buffer->color_tags; list; list = g_list_next (list))
+    {
+      gtk_text_buffer_remove_tag (GTK_TEXT_BUFFER (buffer), list->data,
+                                  start, end);
+    }
+
+  if (color)
+    {
+      GtkTextTag *tag = gimp_text_buffer_get_color_tag (buffer, color);
+
+      gtk_text_buffer_apply_tag (GTK_TEXT_BUFFER (buffer), tag,
+                                 start, end);
+
+      g_signal_emit (buffer, buffer_signals[COLOR_APPLIED], 0, color);
+    }
+
+  gtk_text_buffer_end_user_action (GTK_TEXT_BUFFER (buffer));
+}
+
+GtkTextTag *
+gimp_text_buffer_get_preedit_color_tag (GimpTextBuffer *buffer,
+                                        const GimpRGB  *color)
+{
+  GList      *list;
+  GtkTextTag *tag;
+  gchar       name[256];
+  GdkColor    gdk_color;
+  guchar      r, g, b;
+
+  gimp_rgb_get_uchar (color, &r, &g, &b);
+
+  for (list = buffer->preedit_color_tags; list; list = g_list_next (list))
+    {
+      GimpRGB tag_color;
+      guchar  tag_r, tag_g, tag_b;
+
+      tag = list->data;
+
+      gimp_text_tag_get_fg_color (tag, &tag_color);
+
+      gimp_rgb_get_uchar (&tag_color, &tag_r, &tag_g, &tag_b);
+
+      /* Do not compare the alpha channel, since it's unused */
+      if (tag_r == r &&
+          tag_g == g &&
+          tag_b == b)
+        {
+          return tag;
+        }
+    }
+
+  g_snprintf (name, sizeof (name), "preedit-color-#%02x%02x%02x",
+              r, g, b);
+
+  gimp_rgb_get_gdk_color (color, &gdk_color);
+
+  tag = gtk_text_buffer_create_tag (GTK_TEXT_BUFFER (buffer),
+                                    name,
+                                    "foreground-gdk", &gdk_color,
+                                    "foreground-set", TRUE,
+                                    NULL);
+
+  buffer->preedit_color_tags = g_list_prepend (buffer->preedit_color_tags, tag);
+
+  return tag;
+}
+
+void
+gimp_text_buffer_set_preedit_color (GimpTextBuffer    *buffer,
+                                    const GtkTextIter *start,
+                                    const GtkTextIter *end,
+                                    const GimpRGB     *color)
+{
+  GList *list;
+
+  g_return_if_fail (GIMP_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_buffer_begin_user_action (GTK_TEXT_BUFFER (buffer));
+
+  for (list = buffer->preedit_color_tags; list; list = g_list_next (list))
+    {
+      gtk_text_buffer_remove_tag (GTK_TEXT_BUFFER (buffer), list->data,
+                                  start, end);
+    }
+
+  if (color)
+    {
+      GtkTextTag *tag = gimp_text_buffer_get_preedit_color_tag (buffer, color);
+
+      gtk_text_buffer_apply_tag (GTK_TEXT_BUFFER (buffer), tag,
+                                 start, end);
+    }
+
+  gtk_text_buffer_end_user_action (GTK_TEXT_BUFFER (buffer));
+}
+
+GtkTextTag *
+gimp_text_buffer_get_preedit_bg_color_tag (GimpTextBuffer *buffer,
+                                           const GimpRGB  *color)
+{
+  GList      *list;
+  GtkTextTag *tag;
+  gchar       name[256];
+  GdkColor    gdk_color;
+  guchar      r, g, b;
+
+  gimp_rgb_get_uchar (color, &r, &g, &b);
+
+  for (list = buffer->preedit_bg_color_tags; list; list = g_list_next (list))
+    {
+      GimpRGB tag_color;
+      guchar  tag_r, tag_g, tag_b;
+
+      tag = list->data;
+
+      gimp_text_tag_get_bg_color (tag, &tag_color);
+
+      gimp_rgb_get_uchar (&tag_color, &tag_r, &tag_g, &tag_b);
+
+      /* Do not compare the alpha channel, since it's unused */
+      if (tag_r == r &&
+          tag_g == g &&
+          tag_b == b)
+        {
+          return tag;
+        }
+    }
+
+  g_snprintf (name, sizeof (name), "bg-color-#%02x%02x%02x",
+              r, g, b);
+
+  gimp_rgb_get_gdk_color (color, &gdk_color);
+
+  tag = gtk_text_buffer_create_tag (GTK_TEXT_BUFFER (buffer),
+                                    name,
+                                    "background-gdk", &gdk_color,
+                                    "background-set", TRUE,
+                                    NULL);
+
+  buffer->preedit_bg_color_tags = g_list_prepend (buffer->preedit_bg_color_tags, tag);
+
+  return tag;
+}
+
+void
+gimp_text_buffer_set_preedit_bg_color (GimpTextBuffer    *buffer,
+                                       const GtkTextIter *start,
+                                       const GtkTextIter *end,
+                                       const GimpRGB     *color)
+{
+  GList *list;
+
+  g_return_if_fail (GIMP_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_buffer_begin_user_action (GTK_TEXT_BUFFER (buffer));
+
+  for (list = buffer->preedit_bg_color_tags; list; list = g_list_next (list))
+    {
+      gtk_text_buffer_remove_tag (GTK_TEXT_BUFFER (buffer), list->data,
+                                  start, end);
+    }
+
+  if (color)
+    {
+      GtkTextTag *tag = gimp_text_buffer_get_preedit_bg_color_tag (buffer, color);
+
+      gtk_text_buffer_apply_tag (GTK_TEXT_BUFFER (buffer), tag,
+                                 start, end);
+    }
+
+  gtk_text_buffer_end_user_action (GTK_TEXT_BUFFER (buffer));
+}
+
+/*  Pango markup attribute names  */
+
+#define GIMP_TEXT_ATTR_NAME_SIZE      "size"
+#define GIMP_TEXT_ATTR_NAME_BASELINE  "rise"
+#define GIMP_TEXT_ATTR_NAME_KERNING   "letter_spacing"
+#define GIMP_TEXT_ATTR_NAME_FONT      "font"
+#define GIMP_TEXT_ATTR_NAME_STYLE     "style"
+#define GIMP_TEXT_ATTR_NAME_COLOR     "foreground"
+#define GIMP_TEXT_ATTR_NAME_FG_COLOR  "fgcolor"
+#define GIMP_TEXT_ATTR_NAME_BG_COLOR  "background"
+#define GIMP_TEXT_ATTR_NAME_UNDERLINE "underline"
+
+const gchar *
+gimp_text_buffer_tag_to_name (GimpTextBuffer  *buffer,
+                              GtkTextTag      *tag,
+                              const gchar    **attribute,
+                              gchar          **value)
+{
+  g_return_val_if_fail (GIMP_IS_TEXT_BUFFER (buffer), NULL);
+  g_return_val_if_fail (GTK_IS_TEXT_TAG (tag), NULL);
+
+  if (attribute)
+    *attribute = NULL;
+
+  if (value)
+    *value = NULL;
+
+  if (tag == buffer->bold_tag)
+    {
+      return "b";
+    }
+  else if (tag == buffer->italic_tag)
+    {
+      return "i";
+    }
+  else if (tag == buffer->underline_tag)
+    {
+      return "u";
+    }
+  else if (tag == buffer->strikethrough_tag)
+    {
+      return "s";
+    }
+  else if (g_list_find (buffer->size_tags, tag))
+    {
+      if (attribute)
+        *attribute = GIMP_TEXT_ATTR_NAME_SIZE;
+
+      if (value)
+        *value = g_strdup_printf ("%d", gimp_text_tag_get_size (tag));
+
+      return "span";
+    }
+  else if (g_list_find (buffer->baseline_tags, tag))
+    {
+      if (attribute)
+        *attribute = GIMP_TEXT_ATTR_NAME_BASELINE;
+
+      if (value)
+        *value = g_strdup_printf ("%d", gimp_text_tag_get_baseline (tag));
+
+      return "span";
+    }
+  else if (g_list_find (buffer->kerning_tags, tag))
+    {
+      if (attribute)
+        *attribute = GIMP_TEXT_ATTR_NAME_KERNING;
+
+      if (value)
+        *value = g_strdup_printf ("%d", gimp_text_tag_get_kerning (tag));
+
+      return "span";
+    }
+  else if (g_list_find (buffer->font_tags, tag))
+    {
+      if (attribute)
+        *attribute = GIMP_TEXT_ATTR_NAME_FONT;
+
+      if (value)
+        *value = gimp_text_tag_get_font (tag);
+
+      return "span";
+    }
+  else if (g_list_find (buffer->color_tags, tag))
+    {
+      if (attribute)
+        *attribute = GIMP_TEXT_ATTR_NAME_COLOR;
+
+      if (value)
+        {
+          GimpRGB color;
+          guchar  r, g, b;
+
+          gimp_text_tag_get_fg_color (tag, &color);
+          gimp_rgb_get_uchar (&color, &r, &g, &b);
+
+          *value = g_strdup_printf ("#%02x%02x%02x", r, g, b);
+        }
+
+      return "span";
+    }
+  else if (g_list_find (buffer->preedit_color_tags, tag))
+    {
+      /* "foreground" and "fgcolor" attributes are similar, but I use
+       * one or the other as a trick to differentiate the color chosen
+       * from the user and a display color for preedit. */
+      if (attribute)
+        *attribute = GIMP_TEXT_ATTR_NAME_FG_COLOR;
+
+      if (value)
+        {
+          GimpRGB color;
+          guchar  r, g, b;
+
+          gimp_text_tag_get_fg_color (tag, &color);
+          gimp_rgb_get_uchar (&color, &r, &g, &b);
+
+          *value = g_strdup_printf ("#%02x%02x%02x", r, g, b);
+        }
+
+      return "span";
+    }
+  else if (g_list_find (buffer->preedit_bg_color_tags, tag))
+    {
+      if (attribute)
+        *attribute = GIMP_TEXT_ATTR_NAME_BG_COLOR;
+
+      if (value)
+        {
+          GimpRGB color;
+          guchar  r, g, b;
+
+          gimp_text_tag_get_bg_color (tag, &color);
+          gimp_rgb_get_uchar (&color, &r, &g, &b);
+
+          *value = g_strdup_printf ("#%02x%02x%02x", r, g, b);
+        }
+
+      return "span";
+    }
+  else if (tag == buffer->preedit_underline_tag)
+    {
+      if (attribute)
+        *attribute = GIMP_TEXT_ATTR_NAME_UNDERLINE;
+
+      if (value)
+        *value = g_strdup ("single");
+
+      return "span";
+    }
+
+  return NULL;
+}
+
+GtkTextTag *
+gimp_text_buffer_name_to_tag (GimpTextBuffer *buffer,
+                              const gchar    *name,
+                              const gchar    *attribute,
+                              const gchar    *value)
+{
+  g_return_val_if_fail (GIMP_IS_TEXT_BUFFER (buffer), NULL);
+  g_return_val_if_fail (name != NULL, NULL);
+
+  if (! strcmp (name, "b"))
+    {
+      return buffer->bold_tag;
+    }
+  else if (! strcmp (name, "i"))
+    {
+      return buffer->italic_tag;
+    }
+  else if (! strcmp (name, "u"))
+    {
+      return buffer->underline_tag;
+    }
+  else if (! strcmp (name, "s"))
+    {
+      return buffer->strikethrough_tag;
+    }
+  else if (! strcmp (name, "span") &&
+           attribute != NULL       &&
+           value     != NULL)
+    {
+      if (! strcmp (attribute, GIMP_TEXT_ATTR_NAME_SIZE))
+        {
+          return gimp_text_buffer_get_size_tag (buffer, atoi (value));
+        }
+      else if (! strcmp (attribute, GIMP_TEXT_ATTR_NAME_BASELINE))
+        {
+          return gimp_text_buffer_get_baseline_tag (buffer, atoi (value));
+        }
+      else if (! strcmp (attribute, GIMP_TEXT_ATTR_NAME_KERNING))
+        {
+          return gimp_text_buffer_get_kerning_tag (buffer, atoi (value));
+        }
+      else if (! strcmp (attribute, GIMP_TEXT_ATTR_NAME_FONT))
+        {
+          return gimp_text_buffer_get_font_tag (buffer, value);
+        }
+      else if (! strcmp (attribute, GIMP_TEXT_ATTR_NAME_COLOR))
+        {
+          GimpRGB color;
+          guint   r, g, b;
+
+          sscanf (value, "#%02x%02x%02x", &r, &g, &b);
+
+          gimp_rgb_set_uchar (&color, r, g, b);
+
+          return gimp_text_buffer_get_color_tag (buffer, &color);
+        }
+    }
+
+  return NULL;
+}
+
+void
+gimp_text_buffer_set_insert_tags (GimpTextBuffer *buffer,
+                                  GList          *insert_tags,
+                                  GList          *remove_tags)
+{
+  g_return_if_fail (GIMP_IS_TEXT_BUFFER (buffer));
+
+  buffer->insert_tags_set = TRUE;
+
+  g_list_free (buffer->insert_tags);
+  g_list_free (buffer->remove_tags);
+  buffer->insert_tags = insert_tags;
+  buffer->remove_tags = remove_tags;
+}
+
+void
+gimp_text_buffer_clear_insert_tags (GimpTextBuffer *buffer)
+{
+  g_return_if_fail (GIMP_IS_TEXT_BUFFER (buffer));
+
+  buffer->insert_tags_set = FALSE;
+
+  g_list_free (buffer->insert_tags);
+  g_list_free (buffer->remove_tags);
+  buffer->insert_tags = NULL;
+  buffer->remove_tags = NULL;
+}
+
+void
+gimp_text_buffer_insert (GimpTextBuffer *buffer,
+                         const gchar    *text)
+{
+  GtkTextIter  iter, start;
+  gint         start_offset;
+  gboolean     insert_tags_set;
+  GList       *insert_tags;
+  GList       *remove_tags;
+  GSList      *tags_off = NULL;
+  GimpRGB      color;
+
+  g_return_if_fail (GIMP_IS_TEXT_BUFFER (buffer));
+
+  gtk_text_buffer_get_iter_at_mark (GTK_TEXT_BUFFER (buffer), &iter,
+                                    gtk_text_buffer_get_insert (GTK_TEXT_BUFFER (buffer)));
+
+  start_offset = gtk_text_iter_get_offset (&iter);
+
+  insert_tags_set = buffer->insert_tags_set;
+  insert_tags     = buffer->insert_tags;
+  remove_tags     = buffer->remove_tags;
+
+  buffer->insert_tags_set = FALSE;
+  buffer->insert_tags     = NULL;
+  buffer->remove_tags     = NULL;
+
+  tags_off = gtk_text_iter_get_toggled_tags (&iter, FALSE);
+
+  gtk_text_buffer_begin_user_action (GTK_TEXT_BUFFER (buffer));
+
+  gtk_text_buffer_insert (GTK_TEXT_BUFFER (buffer), &iter, text, -1);
+
+  gtk_text_buffer_get_iter_at_offset (GTK_TEXT_BUFFER (buffer), &start,
+                                      start_offset);
+
+  if (insert_tags_set)
+    {
+      GList *list;
+
+      for (list = remove_tags; list; list = g_list_next (list))
+        {
+          GtkTextTag *tag = list->data;
+
+          gtk_text_buffer_remove_tag (GTK_TEXT_BUFFER (buffer), tag,
+                                      &start, &iter);
+        }
+
+      for (list = insert_tags; list; list = g_list_next (list))
+        {
+          GtkTextTag *tag = list->data;
+
+          gtk_text_buffer_apply_tag (GTK_TEXT_BUFFER (buffer), tag,
+                                     &start, &iter);
+        }
+    }
+
+  if (tags_off)
+    {
+      GSList *slist;
+
+      for (slist = tags_off; slist; slist = g_slist_next (slist))
+        {
+          GtkTextTag *tag = slist->data;
+
+          if (! g_list_find (remove_tags, tag) &&
+              ! g_list_find (buffer->kerning_tags, tag))
+            {
+              gtk_text_buffer_apply_tag (GTK_TEXT_BUFFER (buffer), tag,
+                                         &start, &iter);
+            }
+        }
+
+      g_slist_free (tags_off);
+    }
+
+  g_list_free (remove_tags);
+  g_list_free (insert_tags);
+
+  if (gimp_text_buffer_get_iter_color (buffer, &start, &color))
+    {
+      g_signal_emit (buffer, buffer_signals[COLOR_APPLIED], 0, &color);
+    }
+
+  gtk_text_buffer_end_user_action (GTK_TEXT_BUFFER (buffer));
+}
+
+gint
+gimp_text_buffer_get_iter_index (GimpTextBuffer *buffer,
+                                 GtkTextIter    *iter,
+                                 gboolean        layout_index)
+{
+  GtkTextIter  start;
+  gchar       *string;
+  gint         index;
+
+  g_return_val_if_fail (GIMP_IS_TEXT_BUFFER (buffer), 0);
+
+  gtk_text_buffer_get_start_iter (GTK_TEXT_BUFFER (buffer), &start);
+
+  string = gtk_text_buffer_get_text (GTK_TEXT_BUFFER (buffer),
+                                     &start, iter, TRUE);
+  index = strlen (string);
+  g_free (string);
+
+  if (layout_index)
+    {
+      do
+        {
+          GSList *tags = gtk_text_iter_get_tags (&start);
+          GSList *list;
+
+          for (list = tags; list; list = g_slist_next (list))
+            {
+              GtkTextTag *tag = list->data;
+
+              if (g_list_find (buffer->kerning_tags, tag))
+                {
+                  index += WORD_JOINER_LENGTH;
+
+                  break;
+                }
+            }
+
+          g_slist_free (tags);
+
+          gtk_text_iter_forward_char (&start);
+
+          /* We might have moved too far */
+          if (gtk_text_iter_compare (&start, iter) > 0)
+            start = *iter;
+        }
+      while (! gtk_text_iter_equal (&start, iter));
+    }
+
+  return index;
+}
+
+void
+gimp_text_buffer_get_iter_at_index (GimpTextBuffer *buffer,
+                                    GtkTextIter    *iter,
+                                    gint            index,
+                                    gboolean        layout_index)
+{
+  GtkTextIter  start;
+  GtkTextIter  end;
+  gchar       *string;
+
+  g_return_if_fail (GIMP_IS_TEXT_BUFFER (buffer));
+
+  gtk_text_buffer_get_bounds (GTK_TEXT_BUFFER (buffer), &start, &end);
+
+  string = gtk_text_buffer_get_text (GTK_TEXT_BUFFER (buffer),
+                                     &start, &end, TRUE);
+
+  if (layout_index)
+    {
+      gchar *my_string = string;
+      gint   my_index  = 0;
+      gchar *tmp;
+
+      do
+        {
+          GSList *tags = gtk_text_iter_get_tags (&start);
+          GSList *list;
+
+          tmp = g_utf8_next_char (my_string);
+          my_index += (tmp - my_string);
+          my_string = tmp;
+
+          for (list = tags; list; list = g_slist_next (list))
+            {
+              GtkTextTag *tag = list->data;
+
+              if (g_list_find (buffer->kerning_tags, tag))
+                {
+                  index = MAX (0, index - WORD_JOINER_LENGTH);
+
+                  break;
+                }
+            }
+
+          g_slist_free (tags);
+
+          gtk_text_iter_forward_char (&start);
+
+          /* We might have moved too far */
+          if (gtk_text_iter_compare (&start, &end) > 0)
+            start = end;
+        }
+      while (my_index < index &&
+             ! gtk_text_iter_equal (&start, &end));
+    }
+
+  string[index] = '\0';
+
+  gtk_text_buffer_get_iter_at_offset (GTK_TEXT_BUFFER (buffer), iter,
+                                      g_utf8_strlen (string, -1));
+
+  g_free (string);
+}
+
+gboolean
+gimp_text_buffer_load (GimpTextBuffer *buffer,
+                       GFile          *file,
+                       GError        **error)
+{
+  GInputStream *input;
+  gchar         buf[2048];
+  gint          to_read;
+  gsize         bytes_read;
+  gsize         total_read = 0;
+  gint          remaining  = 0;
+  GtkTextIter   iter;
+  GError       *my_error = NULL;
+
+  g_return_val_if_fail (GIMP_IS_TEXT_BUFFER (buffer), FALSE);
+  g_return_val_if_fail (G_IS_FILE (file), FALSE);
+  g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
+
+  input = G_INPUT_STREAM (g_file_read (file, NULL, &my_error));
+  if (! input)
+    {
+      g_set_error (error, my_error->domain, my_error->code,
+                   _("Could not open '%s' for reading: %s"),
+                   gimp_file_get_utf8_name (file), my_error->message);
+      g_clear_error (&my_error);
+      return FALSE;
+    }
+
+  gtk_text_buffer_begin_user_action (GTK_TEXT_BUFFER (buffer));
+
+  gimp_text_buffer_set_text (buffer, NULL);
+  gtk_text_buffer_get_end_iter (GTK_TEXT_BUFFER (buffer), &iter);
+
+  do
+    {
+      gboolean    success;
+      const char *leftover;
+
+      to_read = sizeof (buf) - remaining - 1;
+
+      success = g_input_stream_read_all (input, buf + remaining, to_read,
+                                         &bytes_read, NULL, &my_error);
+
+      total_read += bytes_read;
+      buf[bytes_read + remaining] = '\0';
+
+      g_utf8_validate (buf, bytes_read + remaining, &leftover);
+
+      gtk_text_buffer_insert (GTK_TEXT_BUFFER (buffer), &iter,
+                              buf, leftover - buf);
+      gtk_text_buffer_get_end_iter (GTK_TEXT_BUFFER (buffer), &iter);
+
+      remaining = (buf + remaining + bytes_read) - leftover;
+      memmove (buf, leftover, remaining);
+
+      if (! success)
+        {
+          if (total_read > 0)
+            {
+              g_message (_("Input file '%s' appears truncated: %s"),
+                         gimp_file_get_utf8_name (file),
+                         my_error->message);
+              g_clear_error (&my_error);
+              break;
+            }
+
+          gtk_text_buffer_end_user_action (GTK_TEXT_BUFFER (buffer));
+          g_object_unref (input);
+
+          g_propagate_error (error, my_error);
+
+          return FALSE;
+        }
+    }
+  while (remaining <= 6 && bytes_read == to_read);
+
+  if (remaining)
+    g_message (_("Invalid UTF-8 data in file '%s'."),
+               gimp_file_get_utf8_name (file));
+
+  gtk_text_buffer_end_user_action (GTK_TEXT_BUFFER (buffer));
+  g_object_unref (input);
+
+  return TRUE;
+}
+
+gboolean
+gimp_text_buffer_save (GimpTextBuffer *buffer,
+                       GFile          *file,
+                       gboolean        selection_only,
+                       GError        **error)
+{
+  GOutputStream *output;
+  GtkTextIter    start_iter;
+  GtkTextIter    end_iter;
+  gchar         *text_contents;
+  GError        *my_error = NULL;
+
+  g_return_val_if_fail (GIMP_IS_TEXT_BUFFER (buffer), FALSE);
+  g_return_val_if_fail (G_IS_FILE (file), FALSE);
+  g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
+
+  output = G_OUTPUT_STREAM (g_file_replace (file,
+                                            NULL, FALSE, G_FILE_CREATE_NONE,
+                                            NULL, error));
+  if (! output)
+    return FALSE;
+
+  if (selection_only)
+    gtk_text_buffer_get_selection_bounds (GTK_TEXT_BUFFER (buffer),
+                                          &start_iter, &end_iter);
+  else
+    gtk_text_buffer_get_bounds (GTK_TEXT_BUFFER (buffer),
+                                &start_iter, &end_iter);
+
+  text_contents = gtk_text_buffer_get_text (GTK_TEXT_BUFFER (buffer),
+                                            &start_iter, &end_iter, TRUE);
+
+  if (text_contents)
+    {
+      gint text_length = strlen (text_contents);
+
+      if (! g_output_stream_write_all (output, text_contents, text_length,
+                                       NULL, NULL, &my_error))
+        {
+          GCancellable *cancellable = g_cancellable_new ();
+
+          g_set_error (error, my_error->domain, my_error->code,
+                       _("Writing text file '%s' failed: %s"),
+                       gimp_file_get_utf8_name (file), my_error->message);
+          g_clear_error (&my_error);
+          g_free (text_contents);
+
+          /* Cancel the overwrite initiated by g_file_replace(). */
+          g_cancellable_cancel (cancellable);
+          g_output_stream_close (output, cancellable, NULL);
+          g_object_unref (cancellable);
+          g_object_unref (output);
+
+          return FALSE;
+        }
+
+      g_free (text_contents);
+    }
+
+  g_object_unref (output);
+
+  return TRUE;
+}
+
+/**
+ * gimp_text_buffer_get_tags_on_iter:
+ * @buffer: a #GimpTextBuffer
+ * @iter: a position in @buffer
+ *
+ * Returns a list of tags that apply to @iter, in ascending order
+ * of priority (highest-priority tags are last). The GtkTextTag in
+ * the list don’t have a reference added, but you have to free the
+ * list itself.
+ *
+ * Returns: (element-type GtkTextTag) (transfer container): GList of #GtkTextTag
+ */
+GList *
+gimp_text_buffer_get_tags_on_iter (GimpTextBuffer    *buffer,
+                                   const GtkTextIter *iter)
+{
+  GList  *result    = NULL;
+  GSList *tag       = NULL;
+  GSList *tags_list = NULL;
+
+  g_return_val_if_fail (GIMP_IS_TEXT_BUFFER (buffer), NULL);
+  g_return_val_if_fail (iter != NULL, NULL);
+  g_return_val_if_fail (gtk_text_iter_get_buffer (iter) == GTK_TEXT_BUFFER (buffer), NULL);
+
+  tags_list = gtk_text_iter_get_tags (iter);
+  for (tag = tags_list; tag != NULL; tag = g_slist_next (tag))
+    {
+      result = g_list_prepend (result, tag->data);
+    }
+  g_slist_free (tags_list);
+
+  result = g_list_reverse (result);
+  return result;
+}
+
+/**
+ * gimp_text_buffer_get_all_tags:
+ * @buffer: a #GimpTextBuffer
+ *
+ * Returns a list of all tags for a @buffer, The GtkTextTag
+ * in the list don’t have a reference added, but you have to
+ * free the list itself.
+ *
+ * Returns: (element-type GtkTextTag) (transfer container): GList of #GtkTextTag
+ */
+GList *
+gimp_text_buffer_get_all_tags (GimpTextBuffer *buffer)
+{
+  GList *result = NULL;
+
+  g_return_val_if_fail (GIMP_IS_TEXT_BUFFER (buffer), NULL);
+
+  result = g_list_prepend (result, buffer->bold_tag);
+  result = g_list_prepend (result, buffer->italic_tag);
+  result = g_list_prepend (result, buffer->underline_tag);
+  result = g_list_prepend (result, buffer->strikethrough_tag);
+
+  result = g_list_concat (result, g_list_copy (buffer->size_tags));
+  result = g_list_concat (result, g_list_copy (buffer->baseline_tags));
+  result = g_list_concat (result, g_list_copy (buffer->kerning_tags));
+  result = g_list_concat (result, g_list_copy (buffer->font_tags));
+  result = g_list_concat (result, g_list_copy (buffer->color_tags));
+
+  return result;
+}