/*
* Copyright (c) 2006-2009 Openismus GmbH
*
* 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.
*/
#include "gtkimcontextmultipress.h"
#include <string.h>
#include <gtk/gtk.h>
#include <gdk/gdkkeysyms.h>
#include <gtk/gtkimmodule.h>
#include <config.h>
#define AUTOMATIC_COMPOSE_TIMEOUT 1 /* seconds */
#define CONFIGURATION_FILENAME MULTIPRESS_CONFDIR G_DIR_SEPARATOR_S "im-multipress.conf"
/* This contains rows of characters that can be entered by pressing
* a particular key repeatedly. Each row has one key (such as GDK_a),
* and an array of character strings, such as "a".
*/
typedef struct
{
gchar **characters; /* array of strings */
gsize n_characters; /* number of strings in the array */
}
KeySequence;
static GObjectClass *im_context_multipress_parent_class = NULL;
static GType im_context_multipress_type = 0;
static void im_context_multipress_class_init (GtkImContextMultipressClass *klass);
static void im_context_multipress_init (GtkImContextMultipress *self);
static void im_context_multipress_finalize (GObject *obj);
static void load_config (GtkImContextMultipress *self);
static gboolean vfunc_filter_keypress (GtkIMContext *context,
GdkEventKey *event);
static void vfunc_reset (GtkIMContext *context);
static void vfunc_get_preedit_string (GtkIMContext *context,
gchar **str,
PangoAttrList **attrs,
gint *cursor_pos);
/* Notice that we have a *_register_type(GTypeModule*) function instead of a
* *_get_type() function, because we must use g_type_module_register_type(),
* providing the GTypeModule* that was provided to im_context_init(). That
* is also why we are not using G_DEFINE_TYPE().
*/
void
gtk_im_context_multipress_register_type (GTypeModule* type_module)
{
const GTypeInfo im_context_multipress_info =
{
sizeof (GtkImContextMultipressClass),
(GBaseInitFunc) NULL,
(GBaseFinalizeFunc) NULL,
(GClassInitFunc) &im_context_multipress_class_init,
NULL,
NULL,
sizeof (GtkImContextMultipress),
0,
(GInstanceInitFunc) &im_context_multipress_init,
0,
};
im_context_multipress_type =
g_type_module_register_type (type_module,
GTK_TYPE_IM_CONTEXT,
"GtkImContextMultipress",
&im_context_multipress_info, 0);
}
GType
gtk_im_context_multipress_get_type (void)
{
g_assert (im_context_multipress_type != 0);
return im_context_multipress_type;
}
static void
key_sequence_free (gpointer value)
{
KeySequence *seq = value;
if (seq != NULL)
{
g_strfreev (seq->characters);
g_slice_free (KeySequence, seq);
}
}
static void
im_context_multipress_class_init (GtkImContextMultipressClass *klass)
{
GtkIMContextClass *im_context_class;
/* Set this so we can use it later: */
im_context_multipress_parent_class = g_type_class_peek_parent (klass);
/* Specify our vfunc implementations: */
im_context_class = GTK_IM_CONTEXT_CLASS (klass);
im_context_class->filter_keypress = &vfunc_filter_keypress;
im_context_class->reset = &vfunc_reset;
im_context_class->get_preedit_string = &vfunc_get_preedit_string;
G_OBJECT_CLASS (klass)->finalize = &im_context_multipress_finalize;
}
static void
im_context_multipress_init (GtkImContextMultipress *self)
{
self->key_sequences = g_hash_table_new_full (&g_direct_hash, &g_direct_equal,
NULL, &key_sequence_free);
load_config (self);
}
static void
im_context_multipress_finalize (GObject *obj)
{
GtkImContextMultipress *self;
self = GTK_IM_CONTEXT_MULTIPRESS (obj);
/* Release the configuration data: */
if (self->key_sequences != NULL)
{
g_hash_table_destroy (self->key_sequences);
self->key_sequences = NULL;
}
(*im_context_multipress_parent_class->finalize) (obj);
}
GtkIMContext *
gtk_im_context_multipress_new (void)
{
return (GtkIMContext *)g_object_new (GTK_TYPE_IM_CONTEXT_MULTIPRESS, NULL);
}
static void
cancel_automatic_timeout_commit (GtkImContextMultipress *multipress_context)
{
if (multipress_context->timeout_id)
g_source_remove (multipress_context->timeout_id);
multipress_context->timeout_id = 0;
}
/* Clear the compose buffer, so we are ready to compose the next character.
*/
static void
clear_compose_buffer (GtkImContextMultipress *multipress_context)
{
multipress_context->key_last_entered = 0;
multipress_context->compose_count = 0;
cancel_automatic_timeout_commit (multipress_context);
if (multipress_context->tentative_match)
{
multipress_context->tentative_match = NULL;
g_signal_emit_by_name (multipress_context, "preedit-changed");
g_signal_emit_by_name (multipress_context, "preedit-end");
}
}
/* Finish composing, provide the character, and clear our compose buffer.
*/
static void
accept_character (GtkImContextMultipress *multipress_context, const gchar *characters)
{
/* Clear the compose buffer, so we are ready to compose the next character.
* Note that if we emit "preedit-changed" after "commit", there's a segfault/
* invalid-write with GtkTextView in gtk_text_layout_free_line_display(), when
* destroying a PangoLayout (this can also be avoided by not using any Pango
* attributes in get_preedit_string(). */
clear_compose_buffer (multipress_context);
/* Provide the character to GTK+ */
g_signal_emit_by_name (multipress_context, "commit", characters);
}
static gboolean
on_timeout (gpointer data)
{
GtkImContextMultipress *multipress_context;
GDK_THREADS_ENTER ();
multipress_context = GTK_IM_CONTEXT_MULTIPRESS (data);
/* A certain amount of time has passed, so we will assume that the user
* really wants the currently chosen character */
accept_character (multipress_context, multipress_context->tentative_match);
multipress_context->timeout_id = 0;
GDK_THREADS_LEAVE ();
return FALSE; /* don't call me again */
}
static gboolean
vfunc_filter_keypress (GtkIMContext *context, GdkEventKey *event)
{
GtkIMContextClass *parent;
GtkImContextMultipress *multipress_context;
multipress_context = GTK_IM_CONTEXT_MULTIPRESS (context);
if (event->type == GDK_KEY_PRESS)
{
KeySequence *possible;
/* Check whether the current key is the same as previously entered, because
* if it is not then we should accept the previous one, and start a new
* character. */
if (multipress_context->compose_count > 0
&& multipress_context->key_last_entered != event->keyval
&& multipress_context->tentative_match != NULL)
{
/* Accept the previously chosen character. This wipes
* the compose_count and key_last_entered. */
accept_character (multipress_context,
multipress_context->tentative_match);
}
/* Decide what character this key press would choose: */
possible = g_hash_table_lookup (multipress_context->key_sequences,
GUINT_TO_POINTER (event->keyval));
if (possible != NULL)
{
if (multipress_context->compose_count == 0)
g_signal_emit_by_name (multipress_context, "preedit-start");
/* Check whether we are at the end of a compose sequence, with no more
* possible characters. Cycle back to the start if necessary. */
if (multipress_context->compose_count >= possible->n_characters)
multipress_context->compose_count = 0;
/* Store the last key pressed in the compose sequence. */
multipress_context->key_last_entered = event->keyval;
/* Get the possible match for this number of presses of the key.
* compose_count starts at 1, so that 0 can mean not composing. */
multipress_context->tentative_match =
possible->characters[multipress_context->compose_count++];
/* Indicate the current possible character. This will cause our
* vfunc_get_preedit_string() vfunc to be called, which will provide
* the current possible character for the user to see. */
g_signal_emit_by_name (multipress_context, "preedit-changed");
/* Cancel any outstanding timeout, so we can start the timer again: */
cancel_automatic_timeout_commit (multipress_context);
/* Create a timeout that will cause the currently chosen character to
* be committed, if nothing happens for a certain amount of time: */
multipress_context->timeout_id =
g_timeout_add_seconds (AUTOMATIC_COMPOSE_TIMEOUT,
&on_timeout, multipress_context);
return TRUE; /* key handled */
}
else
{
guint32 keyval_uchar;
/* Just accept all other keypresses directly, but commit the
* current preedit content first. */
if (multipress_context->compose_count > 0
&& multipress_context->tentative_match != NULL)
{
accept_character (multipress_context,
multipress_context->tentative_match);
}
keyval_uchar = gdk_keyval_to_unicode (event->keyval);
/* Convert to a string for accept_character(). */
if (keyval_uchar != 0)
{
/* max length of UTF-8 sequence = 6 + 1 for NUL termination */
gchar keyval_utf8[7];
gint length;
length = g_unichar_to_utf8 (keyval_uchar, keyval_utf8);
keyval_utf8[length] = '\0';
accept_character (multipress_context, keyval_utf8);
return TRUE; /* key handled */
}
}
}
parent = (GtkIMContextClass *)im_context_multipress_parent_class;
/* The default implementation just returns FALSE, but it is generally
* a good idea to call the base class implementation: */
if (parent->filter_keypress)
return (*parent->filter_keypress) (context, event);
return FALSE;
}
static void
vfunc_reset (GtkIMContext *context)
{
clear_compose_buffer (GTK_IM_CONTEXT_MULTIPRESS (context));
}
static void
vfunc_get_preedit_string (GtkIMContext *context,
gchar **str,
PangoAttrList **attrs,
gint *cursor_pos)
{
gsize len_bytes = 0;
gsize len_utf8_chars = 0;
/* Show the user what character he will get if he accepts: */
if (str != NULL)
{
const gchar *match;
match = GTK_IM_CONTEXT_MULTIPRESS (context)->tentative_match;
if (match == NULL)
match = ""; /* *str must not be NUL */
len_bytes = strlen (match); /* byte count */
len_utf8_chars = g_utf8_strlen (match, len_bytes); /* character count */
*str = g_strndup (match, len_bytes);
}
/* Underline it, to show the user that he is in compose mode: */
if (attrs != NULL)
{
*attrs = pango_attr_list_new ();
if (len_bytes > 0)
{
PangoAttribute *attr;
attr = pango_attr_underline_new (PANGO_UNDERLINE_SINGLE);
attr->start_index = 0;
attr->end_index = len_bytes;
pango_attr_list_insert (*attrs, attr);
}
}
if (cursor_pos)
*cursor_pos = len_utf8_chars;
}
/* Open the configuration file and fill in the key_sequences hash table
* with key/character-list pairs taken from the [keys] group of the file.
*/
static void
load_config (GtkImContextMultipress *self)
{
GKeyFile *key_file;
GError *error = NULL;
gchar **keys;
gsize n_keys = 0;
gsize i;
key_file = g_key_file_new ();
if (!g_key_file_load_from_file (key_file, CONFIGURATION_FILENAME,
G_KEY_FILE_NONE, &error))
{
g_warning ("Error while trying to open the %s configuration file: %s",
CONFIGURATION_FILENAME, error->message);
g_error_free (error);
g_key_file_free (key_file);
return;
}
keys = g_key_file_get_keys (key_file, "keys", &n_keys, &error);
if (error != NULL)
{
g_warning ("Error while trying to read the %s configuration file: %s",
CONFIGURATION_FILENAME, error->message);
g_error_free (error);
g_key_file_free (key_file);
return;
}
for (i = 0; i < n_keys; ++i)
{
KeySequence *seq;
guint keyval;
keyval = gdk_keyval_from_name (keys[i]);
if (keyval == GDK_VoidSymbol)
{
g_warning ("Error while trying to read the %s configuration file: "
"invalid key name \"%s\"",
CONFIGURATION_FILENAME, keys[i]);
continue;
}
seq = g_slice_new (KeySequence);
seq->characters = g_key_file_get_string_list (key_file, "keys", keys[i],
&seq->n_characters, &error);
if (error != NULL)
{
g_warning ("Error while trying to read the %s configuration file: %s",
CONFIGURATION_FILENAME, error->message);
g_error_free (error);
error = NULL;
g_slice_free (KeySequence, seq);
continue;
}
/* Ownership of the KeySequence is taken over by the hash table */
g_hash_table_insert (self->key_sequences, GUINT_TO_POINTER (keyval), seq);
}
g_strfreev (keys);
g_key_file_free (key_file);
}