/* GTK - The GIMP Toolkit * Copyright (C) 2000 Red Hat, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library. If not, see . */ #include "config.h" #include #include "gtkimcontext.h" #include "gtkprivate.h" #include "gtktypebuiltins.h" #include "gtkmarshalers.h" #include "gdk/gdkeventsprivate.h" /** * GtkIMContext: * * `GtkIMContext` defines the interface for GTK input methods. * * `GtkIMContext` is used by GTK text input widgets like `GtkText` * to map from key events to Unicode character strings. * * An input method may consume multiple key events in sequence before finally * outputting 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. To do so, the `GtkIMContext` will emit * [signal@Gtk.IMContext::preedit-start], [signal@Gtk.IMContext::preedit-changed] * and [signal@Gtk.IMContext::preedit-end] signals. * * For instance, the built-in GTK input method [class@Gtk.IMContextSimple] * 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. For example, * * Ctrl+Shift+u 2 0 A C * * 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 * provides a `GIOExtension` for the extension point named "gtk-im-module". * * To connect a widget to the users preferred input method, you should use * [class@Gtk.IMMulticontext]. */ enum { PREEDIT_START, PREEDIT_END, PREEDIT_CHANGED, COMMIT, RETRIEVE_SURROUNDING, DELETE_SURROUNDING, LAST_SIGNAL }; enum { PROP_INPUT_PURPOSE = 1, PROP_INPUT_HINTS, LAST_PROPERTY }; static guint im_context_signals[LAST_SIGNAL] = { 0, }; static GParamSpec *properties[LAST_PROPERTY] = { NULL, }; typedef struct _GtkIMContextPrivate GtkIMContextPrivate; struct _GtkIMContextPrivate { GtkInputPurpose purpose; GtkInputHints hints; }; static void gtk_im_context_real_get_preedit_string (GtkIMContext *context, char **str, PangoAttrList **attrs, int *cursor_pos); static gboolean gtk_im_context_real_filter_keypress (GtkIMContext *context, GdkEvent *event); static gboolean gtk_im_context_real_get_surrounding_with_selection (GtkIMContext *context, char **text, int *cursor_index, int *selection_bound); static void gtk_im_context_real_set_surrounding_with_selection (GtkIMContext *context, const char *text, int len, int cursor_index, int selection_bound); 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); G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GtkIMContext, gtk_im_context, G_TYPE_OBJECT) /** * GtkIMContextClass: * @preedit_start: Default handler of the [signal@Gtk.IMContext::preedit-start] signal. * @preedit_end: Default handler of the [signal@Gtk.IMContext::preedit-end] signal. * @preedit_changed: Default handler of the [signal@Gtk.IMContext::preedit-changed] * signal. * @commit: Default handler of the [signal@Gtk.IMContext::commit] signal. * @retrieve_surrounding: Default handler of the * [signal@Gtk.IMContext::retrieve-surrounding] signal. * @delete_surrounding: Default handler of the * [signal@Gtk.IMContext::delete-surrounding] signal. * @set_client_widget: Called via [method@Gtk.IMContext.set_client_widget] 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 [method@Gtk.IMContext.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 [method@Gtk.IMContext.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 [signal@Gtk.IMContext::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 [method@Gtk.IMContext.focus_in] when the input widget * has gained focus. May be overridden to keep track of the current focus. * @focus_out: Called via [method@Gtk.IMContext.focus_out] when the input widget * has lost focus. May be overridden to keep track of the current focus. * @reset: Called via [method@Gtk.IMContext.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 [method@Gtk.IMContext.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 [method@Gtk.IMContext.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 [method@Gtk.IMContext.set_surrounding] in * response to [signal@Gtk.IMContext::retrieve-surrounding] signal 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 * [method@Gtk.IMContext.get_surrounding] to work. * @get_surrounding: Called via [method@Gtk.IMContext.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 [signal@Gtk.IMContext::retrieve-surrounding] * and records the context received by the subsequent invocation of * [vfunc@Gtk.IMContext.get_surrounding]. * @set_surrounding_with_selection: Called via * [method@Gtk.IMContext.set_surrounding_with_selection] in response to the * [signal@Gtk.IMContext::retrieve-surrounding] signal 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 * [method@Gtk.IMContext.get_surrounding] to work. * @get_surrounding_with_selection: Called via * [method@Gtk.IMContext.get_surrounding_with_selection] 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 * [signal@Gtk.IMContext::retrieve-surrounding] and records the context * received by the subsequent invocation of [vfunc@Gtk.IMContext.get_surrounding]. */ static void gtk_im_context_class_init (GtkIMContextClass *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_with_selection = gtk_im_context_real_get_surrounding_with_selection; klass->set_surrounding_with_selection = gtk_im_context_real_set_surrounding_with_selection; /** * 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] = g_signal_new (I_("preedit-start"), G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GtkIMContextClass, preedit_start), NULL, NULL, NULL, 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] = g_signal_new (I_("preedit-end"), G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GtkIMContextClass, preedit_end), NULL, NULL, NULL, 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 * [method@Gtk.IMContext.get_preedit_string] returns the empty string. */ im_context_signals[PREEDIT_CHANGED] = g_signal_new (I_("preedit-changed"), G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GtkIMContextClass, preedit_changed), NULL, NULL, NULL, 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. * * If the commit comes after a preediting sequence, the * ::commit signal is emitted after ::preedit-end. * * This can be a single character immediately after a key press or * the final result of preediting. */ im_context_signals[COMMIT] = g_signal_new (I_("commit"), G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GtkIMContextClass, commit), NULL, NULL, NULL, 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 [method@Gtk.IMContext.set_surrounding] method. * * Returns: %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); g_signal_set_va_marshaller (im_context_signals[RETRIEVE_SURROUNDING], G_TYPE_FROM_CLASS (klass), _gtk_marshal_BOOLEAN__VOIDv); /** * 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. * * Returns: %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); g_signal_set_va_marshaller (im_context_signals[DELETE_SURROUNDING], G_TYPE_FROM_CLASS (klass), _gtk_marshal_BOOLEAN__INT_INTv); /** * GtkIMContext:input-purpose: * * The purpose of the text field that the `GtkIMContext is connected to. * * This property can be used by on-screen keyboards and other input * methods to adjust their behaviour. */ properties[PROP_INPUT_PURPOSE] = g_param_spec_enum ("input-purpose", NULL, NULL, GTK_TYPE_INPUT_PURPOSE, GTK_INPUT_PURPOSE_FREE_FORM, G_PARAM_READWRITE|G_PARAM_STATIC_STRINGS|G_PARAM_EXPLICIT_NOTIFY); /** * GtkIMContext:input-hints: * * Additional hints that allow input methods to fine-tune * their behaviour. */ properties[PROP_INPUT_HINTS] = g_param_spec_flags ("input-hints", NULL, NULL, GTK_TYPE_INPUT_HINTS, GTK_INPUT_HINT_NONE, G_PARAM_READWRITE|G_PARAM_STATIC_STRINGS|G_PARAM_EXPLICIT_NOTIFY); g_object_class_install_properties (object_class, LAST_PROPERTY, properties); } static void gtk_im_context_init (GtkIMContext *im_context) { } static void gtk_im_context_real_get_preedit_string (GtkIMContext *context, char **str, PangoAttrList **attrs, int *cursor_pos) { if (str) *str = g_strdup (""); if (attrs) *attrs = pango_attr_list_new (); if (cursor_pos) *cursor_pos = 0; } static gboolean gtk_im_context_real_filter_keypress (GtkIMContext *context, GdkEvent *event) { return FALSE; } typedef struct { char *text; int cursor_index; int selection_bound; } SurroundingInfo; static void gtk_im_context_real_set_surrounding_with_selection (GtkIMContext *context, const char *text, int len, int cursor_index, int selection_bound) { 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; info->selection_bound = selection_bound; } } static gboolean gtk_im_context_real_get_surrounding_with_selection (GtkIMContext *context, char **text, int *cursor_index, int *selection_bound) { 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; *selection_bound = info->selection_bound; } else { *text = NULL; *cursor_index = 0; *selection_bound = 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_widget: * @context: a `GtkIMContext` * @widget: (nullable): the client widget. This may be %NULL to indicate * that the previous client widget no longer exists. * * Set the client widget for the input context. * * This is the `GtkWidget` holding the input focus. This widget is * used in order to correctly position status windows, and may * also be used for purposes internal to the input method. */ void gtk_im_context_set_client_widget (GtkIMContext *context, GtkWidget *widget) { GtkIMContextClass *klass; g_return_if_fail (GTK_IS_IM_CONTEXT (context)); klass = GTK_IM_CONTEXT_GET_CLASS (context); if (klass->set_client_widget) klass->set_client_widget (context, widget); } /** * gtk_im_context_get_preedit_string: * @context: a `GtkIMContext` * @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 [method@Pango.AttrList.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, * and a list of attributes to apply to the string. * * This string should be displayed inserted at the insertion point. */ void gtk_im_context_get_preedit_string (GtkIMContext *context, char **str, PangoAttrList **attrs, int *cursor_pos) { GtkIMContextClass *klass; g_return_if_fail (GTK_IS_IM_CONTEXT (context)); klass = GTK_IM_CONTEXT_GET_CLASS (context); klass->get_preedit_string (context, str, attrs, cursor_pos); g_return_if_fail (str == NULL || g_utf8_validate (*str, -1, NULL)); } /** * gtk_im_context_filter_keypress: * @context: a `GtkIMContext` * @event: the key event * * 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. * * Returns: %TRUE if the input method handled the key event. */ gboolean gtk_im_context_filter_keypress (GtkIMContext *context, GdkEvent *key) { GtkIMContextClass *klass; g_return_val_if_fail (GTK_IS_IM_CONTEXT (context), FALSE); g_return_val_if_fail (key != NULL, FALSE); klass = GTK_IM_CONTEXT_GET_CLASS (context); return klass->filter_keypress (context, key); } /** * gtk_im_context_filter_key: * @context: a `GtkIMContext` * @press: whether to forward a key press or release event * @surface: the surface the event is for * @device: the device that the event is for * @time: the timestamp for the event * @keycode: the keycode for the event * @state: modifier state for the event * @group: the active keyboard group for the event * * Allow an input method to forward key press and release events * to another input method without necessarily having a `GdkEvent` * available. * * Returns: %TRUE if the input method handled the key event. */ gboolean gtk_im_context_filter_key (GtkIMContext *context, gboolean press, GdkSurface *surface, GdkDevice *device, guint32 time, guint keycode, GdkModifierType state, int group) { GdkTranslatedKey translated, no_lock; GdkEvent *key; gboolean ret; guint keyval; int layout; int level; GdkModifierType consumed; g_return_val_if_fail (GTK_IS_IM_CONTEXT (context), FALSE); if (!gdk_display_translate_key (gdk_surface_get_display (surface), keycode, state, group, &keyval, &layout, &level, &consumed)) return FALSE; translated.keyval = keyval; translated.layout = layout; translated.level = level; translated.consumed = consumed; if (!gdk_display_translate_key (gdk_surface_get_display (surface), keycode, state & ~GDK_LOCK_MASK, group, &keyval, &layout, &level, &consumed)) return FALSE; no_lock.keyval = keyval; no_lock.layout = layout; no_lock.level = level; no_lock.consumed = consumed; key = gdk_key_event_new (press ? GDK_KEY_PRESS : GDK_KEY_RELEASE, surface, device, time, keycode, state, FALSE, /* FIXME */ &translated, &no_lock); ret = GTK_IM_CONTEXT_GET_CLASS (context)->filter_keypress (context, key); gdk_event_unref (key); return ret; } /** * gtk_im_context_focus_in: * @context: a `GtkIMContext` * * Notify the input method that the widget to which this * input context corresponds has gained focus. * * The input method may, for example, change the displayed * feedback to reflect this change. */ void gtk_im_context_focus_in (GtkIMContext *context) { GtkIMContextClass *klass; g_return_if_fail (GTK_IS_IM_CONTEXT (context)); klass = GTK_IM_CONTEXT_GET_CLASS (context); if (klass->focus_in) klass->focus_in (context); } /** * gtk_im_context_focus_out: * @context: a `GtkIMContext` * * Notify the input method that the widget to which this * input context corresponds has lost focus. * * The input method may, for example, change the displayed * feedback or reset the contexts state to reflect this change. */ void gtk_im_context_focus_out (GtkIMContext *context) { GtkIMContextClass *klass; g_return_if_fail (GTK_IS_IM_CONTEXT (context)); klass = GTK_IM_CONTEXT_GET_CLASS (context); if (klass->focus_out) klass->focus_out (context); } /** * gtk_im_context_reset: * @context: a `GtkIMContext` * * Notify the input method that a change such as a change in cursor * position has been made. * * This will typically cause the input method to clear the preedit state. */ void gtk_im_context_reset (GtkIMContext *context) { GtkIMContextClass *klass; g_return_if_fail (GTK_IS_IM_CONTEXT (context)); klass = GTK_IM_CONTEXT_GET_CLASS (context); if (klass->reset) klass->reset (context); } /** * gtk_im_context_set_cursor_location: * @context: a `GtkIMContext` * @area: new location * * Notify the input method that a change in cursor * position has been made. * * The location is relative to the client widget. */ void gtk_im_context_set_cursor_location (GtkIMContext *context, const GdkRectangle *area) { GtkIMContextClass *klass; g_return_if_fail (GTK_IS_IM_CONTEXT (context)); klass = GTK_IM_CONTEXT_GET_CLASS (context); if (klass->set_cursor_location) klass->set_cursor_location (context, (GdkRectangle *) area); } /** * gtk_im_context_set_use_preedit: * @context: a `GtkIMContext` * @use_preedit: whether the IM context should use the preedit string. * * Sets whether the IM context should use the preedit string * to display feedback. * * If @use_preedit is %FALSE (default is %TRUE), then the IM context * may use some other method to display feedback, such as displaying * it in a child of the root window. */ void gtk_im_context_set_use_preedit (GtkIMContext *context, gboolean use_preedit) { GtkIMContextClass *klass; g_return_if_fail (GTK_IS_IM_CONTEXT (context)); klass = GTK_IM_CONTEXT_GET_CLASS (context); 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 * [signal@Gtk.IMContext::retrieve-surrounding] signal, and will * likely have no effect if called at other times. * * Deprecated: 4.2: Use [method@Gtk.IMContext.set_surrounding_with_selection] instead */ void gtk_im_context_set_surrounding (GtkIMContext *context, const char *text, int len, int cursor_index) { gtk_im_context_set_surrounding_with_selection (context, text, len, cursor_index, cursor_index); } /** * gtk_im_context_set_surrounding_with_selection: * @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 * @anchor_index: the byte index of the selection bound within @text * * Sets surrounding context around the insertion point and preedit * string. This function is expected to be called in response to the * [signal@Gtk.IMContext::retrieve_surrounding] signal, and will likely * have no effect if called at other times. * * Since: 4.2 */ void gtk_im_context_set_surrounding_with_selection (GtkIMContext *context, const char *text, int len, int cursor_index, int anchor_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_with_selection) klass->set_surrounding_with_selection (context, text, len, cursor_index, anchor_index); else 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 * [signal@Gtk.IMContext::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 * [method@Gtk.IMContext.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. * * Returns: `TRUE` if surrounding text was provided; in this case * you must free the result stored in `text`. * * Deprecated: 4.2: Use [method@Gtk.IMContext.get_surrounding_with_selection] instead. */ gboolean gtk_im_context_get_surrounding (GtkIMContext *context, char **text, int *cursor_index) { return gtk_im_context_get_surrounding_with_selection (context, text, cursor_index, NULL); } /** * gtk_im_context_get_surrounding_with_selection: * @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. * @anchor_index: (out): location to store byte index of the selection * bound 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 * [signal@Gtk.IMContext::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 * [method@Gtk.IMContext.set_surrounding_with_selection]. * * 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. * * Returns: `TRUE` if surrounding text was provided; in this case * you must free the result stored in `text`. * * Since: 4.2 */ gboolean gtk_im_context_get_surrounding_with_selection (GtkIMContext *context, char **text, int *cursor_index, int *anchor_index) { GtkIMContextClass *klass; char *local_text = NULL; int 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_with_selection) result = klass->get_surrounding_with_selection (context, text ? text : &local_text, cursor_index ? cursor_index : &local_index, anchor_index ? anchor_index : &local_index); else if (klass->get_surrounding) { result = klass->get_surrounding (context, text ? text : &local_text, &local_index); if (cursor_index) *cursor_index = local_index; if (anchor_index) *anchor_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 delete * characters around the cursor position by emitting the * `::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 * [method@Gtk.IMContext.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. * * Returns: %TRUE if the signal was handled. */ gboolean gtk_im_context_delete_surrounding (GtkIMContext *context, int offset, int 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 = gtk_im_context_get_instance_private (GTK_IM_CONTEXT (obj)); 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 = gtk_im_context_get_instance_private (GTK_IM_CONTEXT (obj)); switch (property_id) { case PROP_INPUT_PURPOSE: if (priv->purpose != g_value_get_enum (value)) { priv->purpose = g_value_get_enum (value); g_object_notify_by_pspec (obj, pspec); } break; case PROP_INPUT_HINTS: if (priv->hints != g_value_get_flags (value)) { priv->hints = g_value_get_flags (value); g_object_notify_by_pspec (obj, pspec); } break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (obj, property_id, pspec); break; } }