mutter/clutter/clutter-entry.c

/*
 * Clutter.
 *
 * An OpenGL based 'interactive canvas' library.
 *
 * Authored By Matthew Allum  <mallum@openedhand.com>
 *             Neil Jagdish Patel <njp@o-hand.com
 *
 * Copyright (C) 2006 OpenedHand
 *
 * 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, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/**
 * SECTION:clutter-entry
 * @short_description: A single line text entry actor
 *
 * #ClutterEntry is a #ClutterTexture that allows single line text entry
 */

#include "config.h"

#include "clutter-entry.h"

#include "clutter-debug.h"
#include "clutter-enum-types.h"
#include "clutter-keysyms.h"
#include "clutter-main.h"
#include "clutter-private.h"
#include "clutter-rectangle.h"
#include "clutter-units.h"
#include "pangoclutter.h"

#define DEFAULT_FONT_NAME	"Sans 10"

G_DEFINE_TYPE (ClutterEntry, clutter_entry, CLUTTER_TYPE_ACTOR);

/* Probably move into main */
static PangoClutterFontMap  *_font_map = NULL;
static PangoContext         *_context  = NULL;

enum
{
  PROP_0,
  PROP_FONT_NAME,
  PROP_TEXT,
  PROP_COLOR,
  PROP_ALIGNMENT, 		/* FIXME */
  PROP_POSITION,
  PROP_CURSOR
};

#define CLUTTER_ENTRY_GET_PRIVATE(obj) \
(G_TYPE_INSTANCE_GET_PRIVATE ((obj), CLUTTER_TYPE_ENTRY, ClutterEntryPrivate))

struct _ClutterEntryPrivate
{
  PangoContext         *context;
  PangoFontDescription *desc;
  
  ClutterColor          fgcol;
  
  gchar                *text;
  gchar                *font_name;
  
  gint                  extents_width;
  gint                  extents_height;

  guint                 alignment        : 2;
  guint                 wrap             : 1;
  guint                 use_underline    : 1;
  guint                 use_markup       : 1;
  guint                 ellipsize        : 3;
  guint                 single_line_mode : 1;
  guint                 wrap_mode        : 3;
  gint                  position;

  PangoAttrList        *attrs;
  PangoAttrList        *effective_attrs;
  PangoLayout          *layout;
  gint                  width_chars;
  
  PangoRectangle        cursor_pos;
  ClutterActor         *cursor;
  gboolean              show_cursor;
};


static void
clutter_entry_set_property (GObject      *object, 
			    guint         prop_id,
			    const GValue *value, 
			    GParamSpec   *pspec)
{
  ClutterEntry        *entry;
  ClutterEntryPrivate *priv;

  entry = CLUTTER_ENTRY(object);
  priv = entry->priv;

  switch (prop_id) 
    {
    case PROP_FONT_NAME:
      clutter_entry_set_font_name (entry, g_value_get_string (value));
      break;
    case PROP_TEXT:
      clutter_entry_set_text (entry, g_value_get_string (value));
      break;
    case PROP_COLOR:
      clutter_entry_set_color (entry, g_value_get_boxed (value));
      break;
    case PROP_ALIGNMENT:
      clutter_entry_set_alignment (entry, g_value_get_enum (value));
      break;
    case PROP_POSITION:
      clutter_entry_set_position (entry, g_value_get_int (value));
      break;
    case PROP_CURSOR:
      clutter_entry_set_visible_cursor (entry, g_value_get_boolean (value));
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
clutter_entry_get_property (GObject    *object, 
			    guint       prop_id,
			    GValue     *value, 
			    GParamSpec *pspec)
{
  ClutterEntry        *entry;
  ClutterEntryPrivate *priv;
  ClutterColor         color;

  entry = CLUTTER_ENTRY(object);
  priv = entry->priv;

  switch (prop_id) 
    {
    case PROP_FONT_NAME:
      g_value_set_string (value, priv->font_name);
      break;
    case PROP_TEXT:
      g_value_set_string (value, priv->text);
      break;
    case PROP_COLOR:
      clutter_entry_get_color (entry, &color);
      g_value_set_boxed (value, &color);
      break;
    case PROP_ALIGNMENT:
      g_value_set_enum (value, priv->alignment);
      break;
    case PROP_POSITION:
      g_value_set_int (value, priv->position);
      break;
    case PROP_CURSOR:
      g_value_set_boolean (value, priv->show_cursor);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
    } 
}

static void
clutter_entry_ensure_layout (ClutterEntry *entry, gint width)
{
  ClutterEntryPrivate  *priv;

  priv   = entry->priv;

  if (!priv->layout)
    {
      priv->layout = pango_layout_new (_context);

      if (priv->effective_attrs)
	pango_layout_set_attributes (priv->layout, priv->effective_attrs);
  
      pango_layout_set_alignment (priv->layout, priv->alignment);
      pango_layout_set_ellipsize (priv->layout, priv->ellipsize);
      pango_layout_set_single_paragraph_mode (priv->layout, 
					      priv->single_line_mode);
      
      pango_layout_set_font_description (priv->layout, priv->desc);
      
      if (!priv->use_markup)
        pango_layout_set_text (priv->layout, priv->text, -1);
      else
        pango_layout_set_markup (priv->layout, priv->text, -1);
      
      if (priv->wrap)
	pango_layout_set_wrap  (priv->layout, priv->wrap_mode);
      
      if (priv->wrap && width > 0)
	{
	  pango_layout_set_width (priv->layout, width * PANGO_SCALE);
	}
      else
	pango_layout_set_width (priv->layout, -1);
    }
}

static void
clutter_entry_clear_layout (ClutterEntry *entry)
{
  if (entry->priv->layout)
    {
      g_object_unref (entry->priv->layout);
      entry->priv->layout = NULL;
    }
}

static void
clutter_entry_ensure_cursor_position (ClutterEntry *entry)
{
  ClutterEntryPrivate  *priv;
  gint index;
  
  priv = entry->priv;
  
  if (priv->position == -1)
    index = g_utf8_strlen (priv->text, -1);
  else
    index = priv->position;
  
  pango_layout_get_cursor_pos (priv->layout, index, 
                               &priv->cursor_pos, NULL);

  clutter_actor_set_size (CLUTTER_ACTOR (priv->cursor), 
                          1, priv->cursor_pos.height/ PANGO_SCALE);
  
  clutter_actor_set_position (priv->cursor,
                              priv->cursor_pos.x/ PANGO_SCALE,
                              priv->cursor_pos.y/ PANGO_SCALE);
}

void
clutter_entry_paint (ClutterActor *self)
{
  ClutterEntry         *entry;
  ClutterEntryPrivate  *priv;

  entry  = CLUTTER_ENTRY(self);
  priv   = entry->priv;

  if (priv->desc == NULL || priv->text == NULL)
    {
      CLUTTER_NOTE (ACTOR, "layout: %p , desc: %p, text %p",
		    priv->layout,
		    priv->desc,
		    priv->text);
      return;
    }

  clutter_entry_ensure_layout (entry, clutter_actor_get_width(self));
  priv->fgcol.alpha   =  clutter_actor_get_opacity(self);

  pango_clutter_render_layout (priv->layout, 0, 0, &priv->fgcol, 0);
  
  if (priv->show_cursor)
    {
      clutter_entry_ensure_cursor_position (entry);
      clutter_actor_paint (priv->cursor);
    }
}

static void
clutter_entry_request_coords (ClutterActor        *self,
			      ClutterActorBox     *box)
{
  /* do we need to do anything ? */
  clutter_entry_clear_layout (CLUTTER_ENTRY(self));
}

static void 
clutter_entry_dispose (GObject *object)
{
  ClutterEntry         *self = CLUTTER_ENTRY(object);
  ClutterEntryPrivate  *priv;  

  priv = self->priv;
  
  if (priv->layout)
    {
      g_object_unref (priv->layout);
      priv->layout = NULL;
    }
  
  if (priv->desc)
    {
      pango_font_description_free (priv->desc);    
      priv->desc = NULL;
    }

  g_free (priv->text);
  priv->text = NULL;

  g_free (priv->font_name);
  priv->font_name = NULL;
      
  if (priv->context)
    {
      g_object_unref (priv->context);
      priv->context = NULL;
    }

  G_OBJECT_CLASS (clutter_entry_parent_class)->dispose (object);
}

static void 
clutter_entry_finalize (GObject *object)
{
  G_OBJECT_CLASS (clutter_entry_parent_class)->finalize (object);
}

static void
clutter_entry_class_init (ClutterEntryClass *klass)
{
  GObjectClass        *gobject_class = G_OBJECT_CLASS (klass);
  ClutterActorClass *actor_class = CLUTTER_ACTOR_CLASS (klass);

  actor_class->paint           = clutter_entry_paint;
  actor_class->request_coords  = clutter_entry_request_coords;
  
  gobject_class->finalize   = clutter_entry_finalize;
  gobject_class->dispose    = clutter_entry_dispose;
  gobject_class->set_property = clutter_entry_set_property;
  gobject_class->get_property = clutter_entry_get_property;

  g_object_class_install_property
    (gobject_class, PROP_FONT_NAME,
     g_param_spec_string ("font-name",
			  "Font Name",
			  "Pango font description",
			  NULL,
			  G_PARAM_CONSTRUCT | CLUTTER_PARAM_READWRITE));

  g_object_class_install_property
    (gobject_class, PROP_TEXT,
     g_param_spec_string ("text",
			  "Text",
			  "Text to render",
			  NULL,
			  G_PARAM_CONSTRUCT | CLUTTER_PARAM_READWRITE));

  g_object_class_install_property
    (gobject_class, PROP_COLOR,
     g_param_spec_boxed ("color",
			 "Font Colour",
			 "Font Colour",
			 CLUTTER_TYPE_COLOR,
			 CLUTTER_PARAM_READWRITE));

  g_object_class_install_property 
    (gobject_class, PROP_ALIGNMENT,
     g_param_spec_enum ( "alignment",
			 "Alignment",
			 "The preferred alignment for the string,",
			 PANGO_TYPE_ALIGNMENT,
			 PANGO_ALIGN_LEFT,
			 CLUTTER_PARAM_READWRITE));

  g_object_class_install_property 
    (gobject_class, PROP_POSITION,
     g_param_spec_int ( "position",
			"Position",
			"The cursor position",
			-1, G_MAXINT,
			-1,
			CLUTTER_PARAM_READWRITE));
			
  g_object_class_install_property 
    (gobject_class, PROP_CURSOR,
     g_param_spec_boolean ( "cursor-visible",
			"Cursor Visible",
			"Whether the input cursor is visible ",
			TRUE,
			CLUTTER_PARAM_READWRITE));

  g_type_class_add_private (gobject_class, sizeof (ClutterEntryPrivate));
}

static void
clutter_entry_init (ClutterEntry *self)
{
  ClutterEntryPrivate *priv;
  
  self->priv = priv = CLUTTER_ENTRY_GET_PRIVATE (self);

  if (_context == NULL)
    {
      _font_map = PANGO_CLUTTER_FONT_MAP (pango_clutter_font_map_new ());
      /* pango_clutter_font_map_set_resolution (font_map, 96.0, 96.0); */
      _context = pango_clutter_font_map_create_context (_font_map);
    }

  priv->alignment     = PANGO_ALIGN_LEFT;
  priv->wrap          = FALSE;
  priv->wrap_mode     = PANGO_WRAP_WORD;
  priv->ellipsize     = PANGO_ELLIPSIZE_NONE;
  priv->use_underline = FALSE;
  priv->use_markup    = FALSE;
  priv->layout        = NULL;
  priv->text          = NULL;
  priv->attrs         = NULL;
  priv->position      = -1;

  priv->fgcol.red     = 0;
  priv->fgcol.green   = 0;
  priv->fgcol.blue    = 0;
  priv->fgcol.alpha   = 255;

  priv->font_name     = g_strdup (DEFAULT_FONT_NAME);
  priv->desc          = pango_font_description_from_string (priv->font_name);
  
  priv->cursor        = clutter_rectangle_new_with_color (&priv->fgcol);
  clutter_actor_set_parent (priv->cursor, CLUTTER_ACTOR (self));
  priv->show_cursor   = TRUE;

  CLUTTER_MARK();
}

/**
 * clutter_entry_new_with_text:
 * @font_name: the name (and size) of the font to be used
 * @text: the text to be displayed
 *
 * Creates a new #ClutterEntry displaying @text using @font_name.
 *
 * Return value: a #ClutterEntry
 */
ClutterActor*
clutter_entry_new_with_text (const gchar *font_name,
		             const gchar *text)
{
  ClutterActor *entry;

  CLUTTER_MARK();

  entry = clutter_entry_new ();

  clutter_entry_set_font_name (CLUTTER_ENTRY(entry), font_name);
  clutter_entry_set_text (CLUTTER_ENTRY(entry), text);

  return entry;
}

/**
 * clutter_entry_new_full:
 * @font_name: the name (and size) of the font to be used
 * @text: the text to be displayed
 * @color: #ClutterColor for text
 *
 * Creates a new #ClutterEntry displaying @text with color @color 
 * using @font_name.
 *
 * Return value: a #ClutterEntry
 */
ClutterActor*
clutter_entry_new_full (const gchar  *font_name,
			const gchar  *text,
			ClutterColor *color)
{
  /* FIXME: really new_with_text should take color argument... */
  ClutterActor *entry;

  entry = clutter_entry_new_with_text (font_name, text);
  clutter_entry_set_color (CLUTTER_ENTRY(entry), color);

  return entry;
}

/**
 * clutter_entry_new:
 *
 * Creates a new, empty #ClutterEntry.
 *
 * Returns: the newly created #ClutterEntry
 */
ClutterActor *
clutter_entry_new (void)
{
  return g_object_new (CLUTTER_TYPE_ENTRY, NULL);
}

/**
 * clutter_entry_get_text:
 * @entry: a #ClutterEntry
 *
 * Retrieves the text displayed by @entry
 *
 * Return value: the text of the entry.  The returned string is
 * owned by #ClutterEntry and should not be modified or freed.
 */
G_CONST_RETURN gchar *
clutter_entry_get_text (ClutterEntry *entry)
{
  g_return_val_if_fail (CLUTTER_IS_ENTRY (entry), NULL);

  return entry->priv->text;
}

/**
 * clutter_entry_set_text:
 * @entry: a #ClutterEntry
 * @text: the text to be displayed
 *
 * Sets @text as the text to be displayed by @entry.
 */
void
clutter_entry_set_text (ClutterEntry *entry,
		        const gchar  *text)
{
  ClutterEntryPrivate  *priv;  

  g_return_if_fail (CLUTTER_IS_ENTRY (entry));

  priv = entry->priv;

  g_object_ref (entry);

  g_free (priv->text);
  priv->text = g_strdup (text);

  clutter_entry_clear_layout (entry);   

  if (CLUTTER_ACTOR_IS_VISIBLE (CLUTTER_ACTOR(entry)))
    clutter_actor_queue_redraw (CLUTTER_ACTOR(entry));

  g_object_notify (G_OBJECT (entry), "text");
  g_object_unref (entry);
}

/**
 * clutter_entry_get_font_name:
 * @entry: a #ClutterEntry
 *
 * Retrieves the font used by @entry.
 *
 * Return value: a string containing the font name, in a format
 *   understandable by pango_font_description_from_string().  The
 *   string is owned by #ClutterEntry and should not be modified
 *   or freed.
 */
G_CONST_RETURN gchar *
clutter_entry_get_font_name (ClutterEntry *entry)
{
  g_return_val_if_fail (CLUTTER_IS_ENTRY (entry), NULL);
  
  return entry->priv->font_name;
}

/**
 * clutter_entry_set_font_name:
 * @entry: a #ClutterEntry
 * @font_name: a font name and size, or %NULL for the default font
 *
 * Sets @font_name as the font used by @entry.
 *
 * @font_name must be a string containing the font name and its
 * size, similarly to what you would feed to the
 * pango_font_description_from_string() function.
 */
void
clutter_entry_set_font_name (ClutterEntry *entry,
		             const gchar  *font_name)
{
  ClutterEntryPrivate *priv;
  PangoFontDescription *desc;

  g_return_if_fail (CLUTTER_IS_ENTRY (entry));
  
  if (!font_name || font_name[0] == '\0')
    font_name = DEFAULT_FONT_NAME;

  priv = entry->priv;

  if (strcmp (priv->font_name, font_name) == 0)
    return;

  desc = pango_font_description_from_string (font_name);
  if (!desc)
    {
      g_warning ("Attempting to create a PangoFontDescription for "
		 "font name `%s', but failed.",
		 font_name);
      return;
    }

  g_object_ref (entry);

  g_free (priv->font_name);
  priv->font_name = g_strdup (font_name);
  
  if (priv->desc)
    pango_font_description_free (priv->desc);

  priv->desc = desc;

  if (entry->priv->text && entry->priv->text[0] != '\0')
    {
      clutter_entry_clear_layout (entry);      

      if (CLUTTER_ACTOR_IS_VISIBLE (CLUTTER_ACTOR(entry)))
	clutter_actor_queue_redraw (CLUTTER_ACTOR(entry));
    }
  
  g_object_notify (G_OBJECT (entry), "font-name");
  g_object_unref (entry);
}


/**
 * clutter_entry_set_color:
 * @entry: a #ClutterEntry
 * @color: a #ClutterColor
 *
 * Sets the color of @entry.
 */
void
clutter_entry_set_color (ClutterEntry       *entry,
		         const ClutterColor *color)
{
  ClutterActor *actor;
  ClutterEntryPrivate *priv;

  g_return_if_fail (CLUTTER_IS_ENTRY (entry));
  g_return_if_fail (color != NULL);

  priv = entry->priv;

  g_object_ref (entry);

  priv->fgcol.red = color->red;
  priv->fgcol.green = color->green;
  priv->fgcol.blue = color->blue;
  priv->fgcol.alpha = color->alpha;

  actor = CLUTTER_ACTOR (entry);

  clutter_actor_set_opacity (actor, priv->fgcol.alpha);
  
  clutter_rectangle_set_color (CLUTTER_RECTANGLE (priv->cursor), &priv->fgcol);

  if (CLUTTER_ACTOR_IS_VISIBLE (actor))
    clutter_actor_queue_redraw (actor);

  g_object_notify (G_OBJECT (entry), "color");
  g_object_unref (entry);
}

/**
 * clutter_entry_get_color:
 * @entry: a #ClutterEntry
 * @color: return location for a #ClutterColor
 *
 * Retrieves the color of @entry.
 */
void
clutter_entry_get_color (ClutterEntry *entry,
			 ClutterColor *color)
{
  ClutterEntryPrivate *priv;

  g_return_if_fail (CLUTTER_IS_ENTRY (entry));
  g_return_if_fail (color != NULL);

  priv = entry->priv;

  color->red = priv->fgcol.red;
  color->green = priv->fgcol.green;
  color->blue = priv->fgcol.blue;
  color->alpha = priv->fgcol.alpha;
}

/**
 * clutter_entry_get_layout:
 * @entry: a #ClutterEntry
 * 
 * Gets the #PangoLayout used to display the entry.
 * The layout is useful to e.g. convert text positions to
 * pixel positions.
 * The returned layout is owned by the entry so need not be
 * freed by the caller.
 * 
 * Return value: the #PangoLayout for this entry
 *
 * Since: 0.2
 **/
PangoLayout*
clutter_entry_get_layout (ClutterEntry *entry)
{
  g_return_val_if_fail (CLUTTER_IS_ENTRY (entry), NULL);

  clutter_entry_ensure_layout (entry, -1);

  return entry->priv->layout;
}

/**
 * clutter_entry_set_alignment:
 * @entry: a #ClutterEntry
 * @alignment: A #PangoAlignment
 *
 * Sets text alignment of the entry.
 **/
void
clutter_entry_set_alignment (ClutterEntry   *entry,
			     PangoAlignment  alignment)
{
  ClutterEntryPrivate *priv;

  g_return_if_fail (CLUTTER_IS_ENTRY (entry));

  priv = entry->priv;

  if (priv->alignment != alignment)
    {
      g_object_ref (entry);

      priv->alignment = alignment;
      clutter_entry_clear_layout (entry);

      if (CLUTTER_ACTOR_IS_VISIBLE (CLUTTER_ACTOR (entry)))
	clutter_actor_queue_redraw (CLUTTER_ACTOR (entry));

      g_object_notify (G_OBJECT (entry), "alignment");
      g_object_unref (entry);
    }
}

/**
 * clutter_entry_get_alignment:
 * @entry: a #ClutterEntry
 *
 * Returns the entry's text alignment
 *
 * Return value: The entrys #PangoAlignment
 *
 * Since 0.2
 **/
PangoAlignment
clutter_entry_get_alignment (ClutterEntry *entry)
{
  g_return_val_if_fail (CLUTTER_IS_ENTRY (entry), FALSE);
  
  return entry->priv->alignment;
}

/**
 * clutter_entry_set_position:
 * @entry: a #ClutterEntry
 * @position: the position of the cursor. The cursor is displayed before 
 * the character with the given (base 0) index.
 * The value must be less than or equal to the number of 
 * characters in the entry. A value of -1 indicates that the position should
 * be set after the last character in the entry. 
 * Note that this position is in characters, not in bytes.
 * 
 **/
void
clutter_entry_set_position (ClutterEntry *entry, gint position)
{
  ClutterEntryPrivate *priv;
  gint len;
  
  g_return_if_fail (CLUTTER_IS_ENTRY (entry));
  
  priv = entry->priv;
  
  if (priv->text == NULL)
    return;
  
  len = g_utf8_strlen (priv->text, -1);
  
  if (position < 0 || position >= len)
    priv->position = -1;
  else
    priv->position = position;

  if (CLUTTER_ACTOR_IS_VISIBLE (CLUTTER_ACTOR(entry)))
    clutter_actor_queue_redraw (CLUTTER_ACTOR(entry));
}

/**
 * clutter_entry_get_position:
 * @entry: a #ClutterEntry
 *
 * Returns the entry's text alignment
 *
 * Return value: the position of the cursor. 
 * The cursor is displayed before the character with the given (base 0) index 
 * in the widget. The value will be less than or equal to the number of 
 * characters in the widget. Note that this position is in characters, 
 * not in bytes.
 *
 **/
gint
clutter_entry_get_position (ClutterEntry *entry)
{
  ClutterEntryPrivate *priv;

  g_return_val_if_fail (CLUTTER_IS_ENTRY (entry), 0);

  priv = entry->priv;
  
  return priv->position;
}

/**
 * clutter_entry_handle_key_event:
 * @entry: a #ClutterEntry
 * @kev: a #ClutterKeyEvent
 *
 * This function will handle a #ClutterKeyEvent, like those returned in a 
 * key-press/release-event, and will translate it for the @entry. This includes
 * non-alphanumeric keys, such as the arrows keys, which will move the
 * input cursor.
 *
 **/
void
clutter_entry_handle_key_event (ClutterEntry *entry, ClutterKeyEvent *kev)
{
  ClutterEntryPrivate *priv;
  gint pos = 0;
  gint len = 0;
  gint keyval = clutter_key_event_symbol (kev);

  g_return_if_fail (CLUTTER_IS_ENTRY (entry));

  priv = entry->priv;  
  
  pos = priv->position;
  if (priv->text)
    len = g_utf8_strlen (priv->text, -1);
  
  switch (keyval)
    {
      case CLUTTER_Return:
      case CLUTTER_KP_Enter:
      case CLUTTER_ISO_Enter:
      case CLUTTER_Escape:
      case CLUTTER_Shift_L:
      case CLUTTER_Shift_R:
        break;
      case CLUTTER_BackSpace:
        if (pos != 0 && len != 0)
          clutter_entry_remove (entry, 1);
        break;
      case CLUTTER_Delete:
      case CLUTTER_KP_Delete:
        if (len && pos != -1)
          {
            clutter_entry_delete_text (entry, pos, pos+1);;
          }
        break;
      case CLUTTER_Left:
      case CLUTTER_KP_Left:
        if (pos != 0 && len != 0)
          {
            if (pos == -1)
              {
                clutter_entry_set_position (entry, len-1);  
              }
            else
              clutter_entry_set_position (entry, pos - 1);  
          }         
        break;
      case CLUTTER_Right:
      case CLUTTER_KP_Right:
        if (pos != -1 && len != 0)
          {
            if (pos != len)
              clutter_entry_set_position (entry, pos +1);  
          } 
        break;
      case CLUTTER_End:
      case CLUTTER_KP_End:
        clutter_entry_set_position (entry, -1);  
        break;
      case CLUTTER_Begin:
      case CLUTTER_Home:
      case CLUTTER_KP_Home:
        clutter_entry_set_position (entry, 0);
        break;
      default:
        clutter_entry_add (entry, clutter_keysym_to_unicode (keyval));
        break;
    }
}

/**
 * clutter_entry_add:
 * @entry: a #ClutterEntry
 * @utf8: the character to add.
 *
 * Insert a character to the right of the current position of the cursor.
 * 
 **/
void
clutter_entry_add (ClutterEntry *entry, gunichar wc)
{
  ClutterEntryPrivate *priv;
  GString *new = NULL;

  g_return_if_fail (CLUTTER_IS_ENTRY (entry));
  g_return_if_fail (g_unichar_validate (wc));

  priv = entry->priv;

  g_object_ref (entry);
  
  new = g_string_new (priv->text);
  
  new = g_string_insert_unichar (new, priv->position, wc);
  
  clutter_entry_set_text (entry, new->str);

  if (priv->position >= 0)
    clutter_entry_set_position (entry, priv->position + 1);
  
  g_string_free (new, TRUE);
  g_object_unref (entry);
}

/**
 * clutter_entry_remove:
 * @entry: a #ClutterEntry
 * @len: the number of characters to remove.
 *
 * Characters are removed from before the current postion of the cursor.
 * 
 **/
void
clutter_entry_remove (ClutterEntry *entry, guint num)
{
  ClutterEntryPrivate *priv;
  GString *new = NULL;
  gint len;
  
  g_return_if_fail (CLUTTER_IS_ENTRY (entry));
  
  priv = entry->priv;

  g_object_ref (entry);
  
  if (priv->text == NULL)
    {
      g_object_unref (entry);
      return;
    }
  len = g_utf8_strlen (priv->text, -1);
  new = g_string_new (priv->text);
  
  if (priv->position == -1)
    new = g_string_erase (new, len-num, num);
  else
    new = g_string_erase (new, priv->position-num, num);

  clutter_entry_set_text (entry, new->str);

  if (priv->position > 0)
    clutter_entry_set_position (entry, priv->position-num);  

  g_string_free (new, TRUE);
  g_object_unref (entry);
}

/**
 * clutter_entry_insert_text:
 * @entry: a #ClutterEntry
 * @text: the text to insert
 * @position: the position at which to insert the text. A value of 0 indicates 
 * that the text will be inserted before the first character in the entrys text,
 * and a value of -1 indicates that the text will be inserted after the last
 * character in the entrys text.
 * 
 * Insert text at a specifc position.
 **/
void
clutter_entry_insert_text (ClutterEntry *entry, 
                           const gchar  *text,
                           gssize        position)
{
  ClutterEntryPrivate *priv;
  GString *new = NULL;
  
  g_return_if_fail (CLUTTER_IS_ENTRY (entry));
  
  priv = entry->priv;

  g_object_ref (entry);
  
  new = g_string_new (priv->text);
  new = g_string_insert (new, position, text);
  
  clutter_entry_set_text (entry, new->str);
  
  g_string_free (new, TRUE);
  g_object_unref (entry);
}

/**
 * clutter_entry_delete_text
 * @entry: a #ClutterEntry
 * @start_pos: the starting position. 
 * @end_pos: the end position. 
 * 
 * Deletes a sequence of characters. The characters that are deleted are those
 * characters at positions from start_pos up to, but not including end_pos. 
 * If end_pos is negative, then the the characters deleted will be those 
 * characters from start_pos to the end of the text.
 **/
void
clutter_entry_delete_text (ClutterEntry       *entry,
                           gssize              start_pos,
                           gssize              end_pos)
{
  ClutterEntryPrivate *priv;
  GString *new = NULL;

  g_return_if_fail (CLUTTER_IS_ENTRY (entry));
  
  priv = entry->priv;

  g_object_ref (entry);
  if (priv->text == NULL)
    {
      g_object_unref (entry);
      return;
    }
    
  new = g_string_new (priv->text);
  new = g_string_erase (new, start_pos, end_pos-start_pos);
  
  clutter_entry_set_text (entry, new->str);
  
  g_string_free (new, TRUE);
  g_object_unref (entry);
}

/**
 * clutter_entry_set_visible_cursor
 * @entry: a #ClutterEntry
 * @visible: whether the input cursor should be visible
 * 
 * Sets the visibility of the input cursor.
 **/
void
clutter_entry_set_visible_cursor (ClutterEntry *entry, gboolean visible)
{
  ClutterEntryPrivate *priv;
  
  g_return_if_fail (CLUTTER_IS_ENTRY (entry));
  
  priv = entry->priv;
  priv->show_cursor = visible;
  
  if (CLUTTER_ACTOR_IS_VISIBLE (CLUTTER_ACTOR(entry)))
    clutter_actor_queue_redraw (CLUTTER_ACTOR(entry));
}

/**
 * clutter_entry_get_visible_cursor
 * @entry: a #ClutterEntry
 *
 * Returns the input cursors visiblity
 *
 * Return value: whether the input cursor is visible
 * 
 **/
gboolean
clutter_entry_get_visible_cursor (ClutterEntry *entry)
{
  ClutterEntryPrivate *priv;
  
  g_return_val_if_fail (CLUTTER_IS_ENTRY (entry), FALSE);
  
  priv = entry->priv;
  
  return priv->show_cursor;
}