* 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.
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
+#include "config.h"
+#include <string.h>
#include "gtkimcontext.h"
-#include "gtksignal.h"
+#include "gtkprivate.h"
+#include "gtktypebuiltins.h"
+#include "gtkmarshalers.h"
+#include "gtkintl.h"
+
+/**
+ * SECTION:gtkimcontext
+ * @title: GtkIMContext
+ * @short_description: Base class for input method contexts
+ * @include: gtk/gtk.h,gtk/gtkimmodule.h
+ *
+ * #GtkIMContext defines the interface for GTK+ input methods. An input method
+ * is used by GTK+ text input widgets like #GtkEntry to map from key events to
+ * Unicode character strings.
+ *
+ * The user may change the current input method via a context menu, unless the
+ * #GtkSettings:gtk-show-input-method-menu GtkSettings property is set to FALSE.
+ * The default input method can be set programmatically via the
+ * #GtkSettings:gtk-im-module GtkSettings property. Alternatively, you may set
+ * the GTK_IM_MODULE environment variable as documented in #gtk-running.
+ *
+ * The #GtkEntry #GtkEntry:im-module and #GtkTextView #GtkTextView:im-module
+ * properties may also be used to set input methods for specific widget
+ * instances. For instance, a certain entry widget might be expected to contain
+ * certain characters which would be easier to input with a certain input
+ * method.
+ *
+ * An input method may consume multiple key events in sequence and finally
+ * output the composed result. This is called preediting, and an input method
+ * may provide feedback about this process by displaying the intermediate
+ * composition states as preedit text. For instance, the default GTK+ input
+ * method implements the input of arbitrary Unicode code points by holding down
+ * the Control and Shift keys and then typing "U" followed by the hexadecimal
+ * digits of the code point. When releasing the Control and Shift keys,
+ * preediting ends and the character is inserted as text. Ctrl+Shift+u20AC for
+ * example results in the € sign.
+ *
+ * Additional input methods can be made available for use by GTK+ widgets as
+ * loadable modules. An input method module is a small shared library which
+ * implements a subclass of #GtkIMContext or #GtkIMContextSimple and exports
+ * these four functions:
+ *
+ * <informalexample><programlisting>
+ * void im_module_init(#GTypeModule *module);
+ * </programlisting></informalexample>
+ * This function should register the #GType of the #GtkIMContext subclass which
+ * implements the input method by means of g_type_module_register_type(). Note
+ * that g_type_register_static() cannot be used as the type needs to be
+ * registered dynamically.
+ *
+ * <informalexample><programlisting>
+ * void im_module_exit(void);
+ * </programlisting></informalexample>
+ * Here goes any cleanup code your input method might require on module unload.
+ *
+ * <informalexample><programlisting>
+ * void im_module_list(const #GtkIMContextInfo ***contexts, int *n_contexts)
+ * {
+ * *contexts = info_list;
+ * *n_contexts = G_N_ELEMENTS (info_list);
+ * }
+ * </programlisting></informalexample>
+ * This function returns the list of input methods provided by the module. The
+ * example implementation above shows a common solution and simply returns a
+ * pointer to statically defined array of #GtkIMContextInfo items for each
+ * provided input method.
+ *
+ * <informalexample><programlisting>
+ * #GtkIMContext * im_module_create(const #gchar *context_id);
+ * </programlisting></informalexample>
+ * This function should return a pointer to a newly created instance of the
+ * #GtkIMContext subclass identified by @context_id. The context ID is the same
+ * as specified in the #GtkIMContextInfo array returned by im_module_list().
+ *
+ * After a new loadable input method module has been installed on the system,
+ * the configuration file <filename>gtk.immodules</filename> needs to be
+ * regenerated by <link linkend="gtk-query-immodules-3.0">gtk-query-immodules-3.0</link>,
+ * in order for the new input method to become available to GTK+ applications.
+ */
enum {
PREEDIT_START,
PREEDIT_END,
PREEDIT_CHANGED,
COMMIT,
+ RETRIEVE_SURROUNDING,
+ DELETE_SURROUNDING,
LAST_SIGNAL
};
-static guint im_context_signals[LAST_SIGNAL] = { 0 };
+enum {
+ PROP_INPUT_PURPOSE = 1,
+ PROP_INPUT_HINTS,
+ LAST_PROPERTY
+};
+
+static guint im_context_signals[LAST_SIGNAL] = { 0, };
+static GParamSpec *properties[LAST_PROPERTY] = { NULL, };
-static void gtk_im_context_class_init (GtkIMContextClass *class);
-static void gtk_im_context_init (GtkIMContext *im_context);
+typedef struct _GtkIMContextPrivate GtkIMContextPrivate;
+struct _GtkIMContextPrivate {
+ GtkInputPurpose purpose;
+ GtkInputHints hints;
+};
-static void gtk_im_context_real_get_preedit_string (GtkIMContext *context,
- gchar **str,
- PangoAttrList **attrs,
- gint *cursor_pos);
-static gboolean gtk_im_context_real_filter_keypress (GtkIMContext *context,
- GdkEventKey *event);
+static void gtk_im_context_real_get_preedit_string (GtkIMContext *context,
+ gchar **str,
+ PangoAttrList **attrs,
+ gint *cursor_pos);
+static gboolean gtk_im_context_real_filter_keypress (GtkIMContext *context,
+ GdkEventKey *event);
+static gboolean gtk_im_context_real_get_surrounding (GtkIMContext *context,
+ gchar **text,
+ gint *cursor_index);
+static void gtk_im_context_real_set_surrounding (GtkIMContext *context,
+ const char *text,
+ gint len,
+ gint cursor_index);
-GtkType
-gtk_im_context_get_type (void)
-{
- static GtkType im_context_type = 0;
+static void gtk_im_context_get_property (GObject *obj,
+ guint property_id,
+ GValue *value,
+ GParamSpec *pspec);
+static void gtk_im_context_set_property (GObject *obj,
+ guint property_id,
+ const GValue *value,
+ GParamSpec *pspec);
- if (!im_context_type)
- {
- static const GtkTypeInfo im_context_info =
- {
- "GtkIMContext",
- sizeof (GtkIMContext),
- sizeof (GtkIMContextClass),
- (GtkClassInitFunc) gtk_im_context_class_init,
- (GtkObjectInitFunc) gtk_im_context_init,
- /* reserved_1 */ NULL,
- /* reserved_2 */ NULL,
- (GtkClassInitFunc) NULL,
- };
-
- im_context_type = gtk_type_unique (GTK_TYPE_OBJECT, &im_context_info);
- }
- return im_context_type;
-}
+G_DEFINE_ABSTRACT_TYPE (GtkIMContext, gtk_im_context, G_TYPE_OBJECT)
+/**
+ * GtkIMContextClass:
+ * @preedit_start: Default handler of the #GtkIMContext::preedit-start signal.
+ * @preedit_end: Default handler of the #GtkIMContext::preedit-end signal.
+ * @preedit_changed: Default handler of the #GtkIMContext::preedit-changed
+ * signal.
+ * @commit: Default handler of the #GtkIMContext::commit signal.
+ * @retrieve_surrounding: Default handler of the
+ * #GtkIMContext::retrieve-surrounding signal.
+ * @delete_surrounding: Default handler of the
+ * #GtkIMContext::delete-surrounding signal.
+ * @set_client_window: Called via gtk_im_context_set_client_window() when the
+ * input window where the entered text will appear changes. Override this to
+ * keep track of the current input window, for instance for the purpose of
+ * positioning a status display of your input method.
+ * @get_preedit_string: Called via gtk_im_context_get_preedit_string() to
+ * retrieve the text currently being preedited for display at the cursor
+ * position. Any input method which composes complex characters or any
+ * other compositions from multiple sequential key presses should override
+ * this method to provide feedback.
+ * @filter_keypress: Called via gtk_im_context_filter_keypress() on every
+ * key press or release event. Every non-trivial input method needs to
+ * override this in order to implement the mapping from key events to text.
+ * A return value of %TRUE indicates to the caller that the event was
+ * consumed by the input method. In that case, the #GtkIMContext::commit
+ * signal should be emitted upon completion of a key sequence to pass the
+ * resulting text back to the input widget. Alternatively, %FALSE may be
+ * returned to indicate that the event wasn't handled by the input method.
+ * If a builtin mapping exists for the key, it is used to produce a
+ * character.
+ * @focus_in: Called via gtk_im_context_focus_in() when the input widget
+ * has gained focus. May be overridden to keep track of the current focus.
+ * @focus_out: Called via gtk_im_context_focus_out() when the input widget
+ * has lost focus. May be overridden to keep track of the current focus.
+ * @reset: Called via gtk_im_context_reset() to signal a change such as a
+ * change in cursor position. An input method that implements preediting
+ * should override this method to clear the preedit state on reset.
+ * @set_cursor_location: Called via gtk_im_context_set_cursor_location()
+ * to inform the input method of the current cursor location relative to
+ * the client window. May be overridden to implement the display of popup
+ * windows at the cursor position.
+ * @set_use_preedit: Called via gtk_im_context_set_use_preedit() to control
+ * the use of the preedit string. Override this to display feedback by some
+ * other means if turned off.
+ * @set_surrounding: Called via gtk_im_context_set_surrounding() in response
+ * to signal #GtkIMContext::retrieve-surrounding to update the input
+ * method's idea of the context around the cursor. It is not necessary to
+ * override this method even with input methods which implement
+ * context-dependent behavior. The base implementation is sufficient for
+ * gtk_im_context_get_surrounding() to work.
+ * @get_surrounding: Called via gtk_im_context_get_surrounding() to update
+ * the context around the cursor location. It is not necessary to override
+ * this method even with input methods which implement context-dependent
+ * behavior. The base implementation emits
+ * #GtkIMContext::retrieve-surrounding and records the context received
+ * by the subsequent invocation of @get_surrounding.
+ */
static void
gtk_im_context_class_init (GtkIMContextClass *klass)
{
- GtkObjectClass *object_class;
-
- object_class = (GtkObjectClass*) klass;
+ GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+ object_class->get_property = gtk_im_context_get_property;
+ object_class->set_property = gtk_im_context_set_property;
klass->get_preedit_string = gtk_im_context_real_get_preedit_string;
klass->filter_keypress = gtk_im_context_real_filter_keypress;
+ klass->get_surrounding = gtk_im_context_real_get_surrounding;
+ klass->set_surrounding = gtk_im_context_real_set_surrounding;
+ /**
+ * GtkIMContext::preedit-start:
+ * @context: the object on which the signal is emitted
+ *
+ * The ::preedit-start signal is emitted when a new preediting sequence
+ * starts.
+ */
im_context_signals[PREEDIT_START] =
- gtk_signal_new ("preedit_start",
- GTK_RUN_LAST,
- GTK_CLASS_TYPE (object_class),
- GTK_SIGNAL_OFFSET (GtkIMContextClass, preedit_start),
- gtk_marshal_VOID__VOID,
- GTK_TYPE_NONE, 0);
-
+ g_signal_new (I_("preedit-start"),
+ G_TYPE_FROM_CLASS (klass),
+ G_SIGNAL_RUN_LAST,
+ G_STRUCT_OFFSET (GtkIMContextClass, preedit_start),
+ NULL, NULL,
+ _gtk_marshal_VOID__VOID,
+ G_TYPE_NONE, 0);
+ /**
+ * GtkIMContext::preedit-end:
+ * @context: the object on which the signal is emitted
+ *
+ * The ::preedit-end signal is emitted when a preediting sequence
+ * has been completed or canceled.
+ */
im_context_signals[PREEDIT_END] =
- gtk_signal_new ("preedit_end",
- GTK_RUN_LAST,
- GTK_CLASS_TYPE (object_class),
- GTK_SIGNAL_OFFSET (GtkIMContextClass, preedit_end),
- gtk_marshal_VOID__VOID,
- GTK_TYPE_NONE, 0);
-
+ g_signal_new (I_("preedit-end"),
+ G_TYPE_FROM_CLASS (klass),
+ G_SIGNAL_RUN_LAST,
+ G_STRUCT_OFFSET (GtkIMContextClass, preedit_end),
+ NULL, NULL,
+ _gtk_marshal_VOID__VOID,
+ G_TYPE_NONE, 0);
+ /**
+ * GtkIMContext::preedit-changed:
+ * @context: the object on which the signal is emitted
+ *
+ * The ::preedit-changed signal is emitted whenever the preedit sequence
+ * currently being entered has changed. It is also emitted at the end of
+ * a preedit sequence, in which case
+ * gtk_im_context_get_preedit_string() returns the empty string.
+ */
im_context_signals[PREEDIT_CHANGED] =
- gtk_signal_new ("preedit_changed",
- GTK_RUN_LAST,
- GTK_CLASS_TYPE (object_class),
- GTK_SIGNAL_OFFSET (GtkIMContextClass, preedit_changed),
- gtk_marshal_VOID__VOID,
- GTK_TYPE_NONE, 0);
-
+ g_signal_new (I_("preedit-changed"),
+ G_TYPE_FROM_CLASS (klass),
+ G_SIGNAL_RUN_LAST,
+ G_STRUCT_OFFSET (GtkIMContextClass, preedit_changed),
+ NULL, NULL,
+ _gtk_marshal_VOID__VOID,
+ G_TYPE_NONE, 0);
+ /**
+ * GtkIMContext::commit:
+ * @context: the object on which the signal is emitted
+ * @str: the completed character(s) entered by the user
+ *
+ * The ::commit signal is emitted when a complete input sequence
+ * has been entered by the user. This can be a single character
+ * immediately after a key press or the final result of preediting.
+ */
im_context_signals[COMMIT] =
- gtk_signal_new ("commit",
- GTK_RUN_LAST,
- GTK_CLASS_TYPE (object_class),
- GTK_SIGNAL_OFFSET (GtkIMContextClass, commit),
- gtk_marshal_VOID__STRING,
- GTK_TYPE_NONE, 1,
- GTK_TYPE_STRING);
+ g_signal_new (I_("commit"),
+ G_TYPE_FROM_CLASS (klass),
+ G_SIGNAL_RUN_LAST,
+ G_STRUCT_OFFSET (GtkIMContextClass, commit),
+ NULL, NULL,
+ _gtk_marshal_VOID__STRING,
+ G_TYPE_NONE, 1,
+ G_TYPE_STRING);
+ /**
+ * GtkIMContext::retrieve-surrounding:
+ * @context: the object on which the signal is emitted
+ *
+ * The ::retrieve-surrounding signal is emitted when the input method
+ * requires the context surrounding the cursor. The callback should set
+ * the input method surrounding context by calling the
+ * gtk_im_context_set_surrounding() method.
+ *
+ * Return value: %TRUE if the signal was handled.
+ */
+ im_context_signals[RETRIEVE_SURROUNDING] =
+ g_signal_new (I_("retrieve-surrounding"),
+ G_TYPE_FROM_CLASS (klass),
+ G_SIGNAL_RUN_LAST,
+ G_STRUCT_OFFSET (GtkIMContextClass, retrieve_surrounding),
+ _gtk_boolean_handled_accumulator, NULL,
+ _gtk_marshal_BOOLEAN__VOID,
+ G_TYPE_BOOLEAN, 0);
+ /**
+ * GtkIMContext::delete-surrounding:
+ * @context: the object on which the signal is emitted
+ * @offset: the character offset from the cursor position of the text
+ * to be deleted. A negative value indicates a position before
+ * the cursor.
+ * @n_chars: the number of characters to be deleted
+ *
+ * The ::delete-surrounding signal is emitted when the input method
+ * needs to delete all or part of the context surrounding the cursor.
+ *
+ * Return value: %TRUE if the signal was handled.
+ */
+ im_context_signals[DELETE_SURROUNDING] =
+ g_signal_new (I_("delete-surrounding"),
+ G_TYPE_FROM_CLASS (klass),
+ G_SIGNAL_RUN_LAST,
+ G_STRUCT_OFFSET (GtkIMContextClass, delete_surrounding),
+ _gtk_boolean_handled_accumulator, NULL,
+ _gtk_marshal_BOOLEAN__INT_INT,
+ G_TYPE_BOOLEAN, 2,
+ G_TYPE_INT,
+ G_TYPE_INT);
+
+ properties[PROP_INPUT_PURPOSE] =
+ g_param_spec_enum ("input-purpose",
+ P_("Purpose"),
+ P_("Purpose of the text field"),
+ GTK_TYPE_INPUT_PURPOSE,
+ GTK_INPUT_PURPOSE_FREE_FORM,
+ G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
+
+ properties[PROP_INPUT_HINTS] =
+ g_param_spec_flags ("input-hints",
+ P_("hints"),
+ P_("Hints for the text field behaviour"),
+ GTK_TYPE_INPUT_HINTS,
+ GTK_INPUT_HINT_NONE,
+ G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
+
+ g_type_class_add_private (klass, sizeof (GtkIMContextPrivate));
+ g_object_class_install_properties (object_class, LAST_PROPERTY, properties);
}
static void
return FALSE;
}
+typedef struct
+{
+ gchar *text;
+ gint cursor_index;
+} SurroundingInfo;
+
+static void
+gtk_im_context_real_set_surrounding (GtkIMContext *context,
+ const gchar *text,
+ gint len,
+ gint cursor_index)
+{
+ SurroundingInfo *info = g_object_get_data (G_OBJECT (context),
+ "gtk-im-surrounding-info");
+
+ if (info)
+ {
+ g_free (info->text);
+ info->text = g_strndup (text, len);
+ info->cursor_index = cursor_index;
+ }
+}
+
+static gboolean
+gtk_im_context_real_get_surrounding (GtkIMContext *context,
+ gchar **text,
+ gint *cursor_index)
+{
+ gboolean result;
+ gboolean info_is_local = FALSE;
+ SurroundingInfo local_info = { NULL, 0 };
+ SurroundingInfo *info;
+
+ info = g_object_get_data (G_OBJECT (context), "gtk-im-surrounding-info");
+ if (!info)
+ {
+ info = &local_info;
+ g_object_set_data (G_OBJECT (context), I_("gtk-im-surrounding-info"), info);
+ info_is_local = TRUE;
+ }
+
+ g_signal_emit (context,
+ im_context_signals[RETRIEVE_SURROUNDING], 0,
+ &result);
+
+ if (result)
+ {
+ *text = g_strdup (info->text ? info->text : "");
+ *cursor_index = info->cursor_index;
+ }
+ else
+ {
+ *text = NULL;
+ *cursor_index = 0;
+ }
+
+ if (info_is_local)
+ {
+ g_free (info->text);
+ g_object_set_data (G_OBJECT (context), I_("gtk-im-surrounding-info"), NULL);
+ }
+
+ return result;
+}
+
/**
* gtk_im_context_set_client_window:
* @context: a #GtkIMContext
- * @window: the client window. This may be %NULL to indicate
+ * @window: (allow-none): the client window. This may be %NULL to indicate
* that the previous client window no longer exists.
*
* Set the client window for the input context; this is the
/**
* gtk_im_context_get_preedit_string:
* @context: a #GtkIMContext
- * @str: location to store the retrieved string. The
- * string retrieved must be freed with g_free ().
- * @attrs: location to store the retrieved attribute list.
- * When you are done with this list, you must
- * unreference it with pango_attr_list_unref().
- * @cursor_pos: location to store position of cursor (in bytes)
+ * @str: (out) (transfer full): location to store the retrieved
+ * string. The string retrieved must be freed with g_free().
+ * @attrs: (out) (transfer full): location to store the retrieved
+ * attribute list. When you are done with this list, you
+ * must unreference it with pango_attr_list_unref().
+ * @cursor_pos: (out): location to store position of cursor (in characters)
* within the preedit string.
*
* Retrieve the current preedit string for the input context,
* @context: a #GtkIMContext
* @event: the key event
*
- * Allow an input method to internally handle a key press event.
- * if this function returns %TRUE, then no further processing
- * should be done for this keystroke.
+ * Allow an input method to internally handle key press and release
+ * events. If this function returns %TRUE, then no further processing
+ * should be done for this key event.
*
- * Return value: %TRUE if the input method handled the keystroke.
+ * Return value: %TRUE if the input method handled the key event.
*
**/
gboolean
* @context: a #GtkIMContext
*
* Notify the input method that the widget to which this
- * input context corresponds has lost gained. The input method
+ * input context corresponds has gained focus. The input method
* may, for example, change the displayed feedback to reflect
* this change.
**/
* @area: new location
*
* Notify the input method that a change in cursor
- * position has been made.
+ * position has been made. The location is relative to the client
+ * window.
**/
void
-gtk_im_context_set_cursor_location (GtkIMContext *context,
- GdkRectangle *area)
+gtk_im_context_set_cursor_location (GtkIMContext *context,
+ const GdkRectangle *area)
{
GtkIMContextClass *klass;
klass = GTK_IM_CONTEXT_GET_CLASS (context);
if (klass->set_cursor_location)
- klass->set_cursor_location (context, area);
+ klass->set_cursor_location (context, (GdkRectangle *) area);
}
/**
if (klass->set_use_preedit)
klass->set_use_preedit (context, use_preedit);
}
+
+/**
+ * gtk_im_context_set_surrounding:
+ * @context: a #GtkIMContext
+ * @text: text surrounding the insertion point, as UTF-8.
+ * the preedit string should not be included within
+ * @text.
+ * @len: the length of @text, or -1 if @text is nul-terminated
+ * @cursor_index: the byte index of the insertion cursor within @text.
+ *
+ * Sets surrounding context around the insertion point and preedit
+ * string. This function is expected to be called in response to the
+ * GtkIMContext::retrieve_surrounding signal, and will likely have no
+ * effect if called at other times.
+ **/
+void
+gtk_im_context_set_surrounding (GtkIMContext *context,
+ const gchar *text,
+ gint len,
+ gint cursor_index)
+{
+ GtkIMContextClass *klass;
+
+ g_return_if_fail (GTK_IS_IM_CONTEXT (context));
+ g_return_if_fail (text != NULL || len == 0);
+
+ if (text == NULL && len == 0)
+ text = "";
+ if (len < 0)
+ len = strlen (text);
+
+ g_return_if_fail (cursor_index >= 0 && cursor_index <= len);
+
+ klass = GTK_IM_CONTEXT_GET_CLASS (context);
+ if (klass->set_surrounding)
+ klass->set_surrounding (context, text, len, cursor_index);
+}
+
+/**
+ * gtk_im_context_get_surrounding:
+ * @context: a #GtkIMContext
+ * @text: (out) (transfer full): location to store a UTF-8 encoded
+ * string of text holding context around the insertion point.
+ * If the function returns %TRUE, then you must free the result
+ * stored in this location with g_free().
+ * @cursor_index: (out): location to store byte index of the insertion
+ * cursor within @text.
+ *
+ * Retrieves context around the insertion point. Input methods
+ * typically want context in order to constrain input text based on
+ * existing text; this is important for languages such as Thai where
+ * only some sequences of characters are allowed.
+ *
+ * This function is implemented by emitting the
+ * GtkIMContext::retrieve_surrounding signal on the input method; in
+ * response to this signal, a widget should provide as much context as
+ * is available, up to an entire paragraph, by calling
+ * gtk_im_context_set_surrounding(). Note that there is no obligation
+ * for a widget to respond to the ::retrieve_surrounding signal, so input
+ * methods must be prepared to function without context.
+ *
+ * Return value: %TRUE if surrounding text was provided; in this case
+ * you must free the result stored in *text.
+ **/
+gboolean
+gtk_im_context_get_surrounding (GtkIMContext *context,
+ gchar **text,
+ gint *cursor_index)
+{
+ GtkIMContextClass *klass;
+ gchar *local_text = NULL;
+ gint local_index;
+ gboolean result = FALSE;
+
+ g_return_val_if_fail (GTK_IS_IM_CONTEXT (context), FALSE);
+
+ klass = GTK_IM_CONTEXT_GET_CLASS (context);
+ if (klass->get_surrounding)
+ result = klass->get_surrounding (context,
+ text ? text : &local_text,
+ cursor_index ? cursor_index : &local_index);
+
+ if (result)
+ g_free (local_text);
+
+ return result;
+}
+
+/**
+ * gtk_im_context_delete_surrounding:
+ * @context: a #GtkIMContext
+ * @offset: offset from cursor position in chars;
+ * a negative value means start before the cursor.
+ * @n_chars: number of characters to delete.
+ *
+ * Asks the widget that the input context is attached to to delete
+ * characters around the cursor position by emitting the
+ * GtkIMContext::delete_surrounding signal. Note that @offset and @n_chars
+ * are in characters not in bytes which differs from the usage other
+ * places in #GtkIMContext.
+ *
+ * In order to use this function, you should first call
+ * gtk_im_context_get_surrounding() to get the current context, and
+ * call this function immediately afterwards to make sure that you
+ * know what you are deleting. You should also account for the fact
+ * that even if the signal was handled, the input context might not
+ * have deleted all the characters that were requested to be deleted.
+ *
+ * This function is used by an input method that wants to make
+ * subsitutions in the existing text in response to new input. It is
+ * not useful for applications.
+ *
+ * Return value: %TRUE if the signal was handled.
+ **/
+gboolean
+gtk_im_context_delete_surrounding (GtkIMContext *context,
+ gint offset,
+ gint n_chars)
+{
+ gboolean result;
+
+ g_return_val_if_fail (GTK_IS_IM_CONTEXT (context), FALSE);
+
+ g_signal_emit (context,
+ im_context_signals[DELETE_SURROUNDING], 0,
+ offset, n_chars, &result);
+
+ return result;
+}
+
+static void
+gtk_im_context_get_property (GObject *obj,
+ guint property_id,
+ GValue *value,
+ GParamSpec *pspec)
+{
+ GtkIMContextPrivate *priv = G_TYPE_INSTANCE_GET_PRIVATE (obj, GTK_TYPE_IM_CONTEXT, GtkIMContextPrivate);
+
+ switch (property_id)
+ {
+ case PROP_INPUT_PURPOSE:
+ g_value_set_enum (value, priv->purpose);
+ break;
+ case PROP_INPUT_HINTS:
+ g_value_set_flags (value, priv->hints);
+ break;
+ default:
+ G_OBJECT_WARN_INVALID_PROPERTY_ID (obj, property_id, pspec);
+ break;
+ }
+}
+
+static void
+gtk_im_context_set_property (GObject *obj,
+ guint property_id,
+ const GValue *value,
+ GParamSpec *pspec)
+{
+ GtkIMContextPrivate *priv = G_TYPE_INSTANCE_GET_PRIVATE (obj, GTK_TYPE_IM_CONTEXT, GtkIMContextPrivate);
+
+ switch (property_id)
+ {
+ case PROP_INPUT_PURPOSE:
+ priv->purpose = g_value_get_enum (value);
+ break;
+ case PROP_INPUT_HINTS:
+ priv->hints = g_value_get_flags (value);
+ break;
+ default:
+ G_OBJECT_WARN_INVALID_PROPERTY_ID (obj, property_id, pspec);
+ break;
+ }
+}