Keyboard Handling

Keyboard Handling

Types and Values

struct GdkKeymap
struct GdkKeymapKey

Object Hierarchy

    GObject
    ╰── GdkKeymap

Includes

#include <gdk/gdk.h>

Description

Functions

gdk_keymap_get_default ()

GdkKeymap *
gdk_keymap_get_default (void);

Returns the GdkKeymap attached to the default display.

Parameters

returns

the GdkKeymap attached to the default display.

 

gdk_keymap_get_for_display ()

GdkKeymap *
gdk_keymap_get_for_display (GdkDisplay *display);

Returns the GdkKeymap attached to display .

Parameters

display

the GdkDisplay.

 

returns

the GdkKeymap attached to display .

 

Since: 2.2


gdk_keymap_lookup_key ()

guint
gdk_keymap_lookup_key (GdkKeymap *keymap,
                       const GdkKeymapKey *key);

Looks up the keyval mapped to a keycode/group/level triplet. If no keyval is bound to key , returns 0. For normal user input, you want to use gdk_keymap_translate_keyboard_state() instead of this function, since the effective group/level may not be the same as the current keyboard state.

Note that passing NULL for keymap is deprecated and will stop to work in GTK+ 3.0. Use gdk_keymap_get_for_display() instead.

Parameters

keymap

a GdkKeymap or NULL to use the default keymap

 

key

a GdkKeymapKey with keycode, group, and level initialized

 

Returns

a keyval, or 0 if none was mapped to the given key


gdk_keymap_translate_keyboard_state ()

gboolean
gdk_keymap_translate_keyboard_state (GdkKeymap *keymap,
                                     guint hardware_keycode,
                                     GdkModifierType state,
                                     gint group,
                                     guint *keyval,
                                     gint *effective_group,
                                     gint *level,
                                     GdkModifierType *consumed_modifiers);

Translates the contents of a GdkEventKey into a keyval, effective group, and level. Modifiers that affected the translation and are thus unavailable for application use are returned in consumed_modifiers . See ??? for an explanation of groups and levels. The effective_group is the group that was actually used for the translation; some keys such as Enter are not affected by the active keyboard group. The level is derived from state . For convenience, GdkEventKey already contains the translated keyval, so this function isn't as useful as you might think.

consumed_modifiers gives modifiers that should be masked out from state when comparing this key press to a hot key. For instance, on a US keyboard, the plus symbol is shifted, so when comparing a key press to a <Control>plus accelerator <Shift> should be masked out.

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/* We want to ignore irrelevant modifiers like ScrollLock */
#define ALL_ACCELS_MASK (GDK_CONTROL_MASK | GDK_SHIFT_MASK | GDK_MOD1_MASK)
gdk_keymap_translate_keyboard_state (keymap, event->hardware_keycode,
                                     event->state, event->group,
                                     &keyval, NULL, NULL, &consumed);
if (keyval == GDK_PLUS &&
    (event->state & ~consumed & ALL_ACCELS_MASK) == GDK_CONTROL_MASK)
  /* Control was pressed */

An older interpretation consumed_modifiers was that it contained all modifiers that might affect the translation of the key; this allowed accelerators to be stored with irrelevant consumed modifiers, by doing:

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/* XXX Don't do this XXX */
if (keyval == accel_keyval &&
    (event->state & ~consumed & ALL_ACCELS_MASK) == (accel_mods & ~consumed))
  /* Accelerator was pressed */

However, this did not work if multi-modifier combinations were used in the keymap, since, for instance, <Control> would be masked out even if only <Control><Alt> was used in the keymap. To support this usage as well as well as possible, all single modifier combinations that could affect the key for any combination of modifiers will be returned in consumed_modifiers; multi-modifier combinations are returned only when actually found in state. When you store accelerators, you should always store them with consumed modifiers removed. Store <Control>plus, not <Control><Shift>plus,

Note that passing NULL for keymap is deprecated and will stop to work in GTK+ 3.0. Use gdk_keymap_get_for_display() instead.

Parameters

keymap

a GdkKeymap, or NULL to use the default.

[allow-none]

hardware_keycode

a keycode

 

state

a modifier state

 

group

active keyboard group

 

keyval

return location for keyval, or NULL.

[out][allow-none]

effective_group

return location for effective group, or NULL.

[out][allow-none]

level

return location for level, or NULL.

[out][allow-none]

consumed_modifiers

return location for modifiers that were used to determine the group or level, or NULL.

[out][allow-none]

Returns

TRUE if there was a keyval bound to the keycode/state/group


gdk_keymap_get_entries_for_keyval ()

gboolean
gdk_keymap_get_entries_for_keyval (GdkKeymap *keymap,
                                   guint keyval,
                                   GdkKeymapKey **keys,
                                   gint *n_keys);

Obtains a list of keycode/group/level combinations that will generate keyval . Groups and levels are two kinds of keyboard mode; in general, the level determines whether the top or bottom symbol on a key is used, and the group determines whether the left or right symbol is used. On US keyboards, the shift key changes the keyboard level, and there are no groups. A group switch key might convert a keyboard between Hebrew to English modes, for example. GdkEventKey contains a group field that indicates the active keyboard group. The level is computed from the modifier mask. The returned array should be freed with g_free().

Note that passing NULL for keymap is deprecated and will stop to work in GTK+ 3.0. Use gdk_keymap_get_for_display() instead.

Parameters

keymap

a GdkKeymap, or NULL to use the default keymap.

[allow-none]

keyval

a keyval, such as GDK_a, GDK_Up, GDK_Return, etc.

 

keys

return location for an array of GdkKeymapKey.

[out]

n_keys

return location for number of elements in returned array.

[out]

Returns

TRUE if keys were found and returned


gdk_keymap_get_entries_for_keycode ()

gboolean
gdk_keymap_get_entries_for_keycode (GdkKeymap *keymap,
                                    guint hardware_keycode,
                                    GdkKeymapKey **keys,
                                    guint **keyvals,
                                    gint *n_entries);

Returns the keyvals bound to hardware_keycode . The Nth GdkKeymapKey in keys is bound to the Nth keyval in keyvals . Free the returned arrays with g_free(). When a keycode is pressed by the user, the keyval from this list of entries is selected by considering the effective keyboard group and level. See gdk_keymap_translate_keyboard_state().

Note that passing NULL for keymap is deprecated and will stop to work in GTK+ 3.0. Use gdk_keymap_get_for_display() instead.

Parameters

keymap

a GdkKeymap or NULL to use the default keymap.

[allow-none]

hardware_keycode

a keycode

 

keys

return location for array of GdkKeymapKey, or NULL.

[out]

keyvals

return location for array of keyvals, or NULL.

[out]

n_entries

length of keys and keyvals

 

Returns

TRUE if there were any entries


gdk_keymap_get_direction ()

PangoDirection
gdk_keymap_get_direction (GdkKeymap *keymap);

Returns the direction of effective layout of the keymap.

Note that passing NULL for keymap is deprecated and will stop to work in GTK+ 3.0. Use gdk_keymap_get_for_display() instead.

Parameters

keymap

a GdkKeymap or NULL to use the default keymap

 

Returns

PANGO_DIRECTION_LTR or PANGO_DIRECTION_RTL if it can determine the direction. PANGO_DIRECTION_NEUTRAL otherwise.


gdk_keymap_have_bidi_layouts ()

gboolean
gdk_keymap_have_bidi_layouts (GdkKeymap *keymap);

Determines if keyboard layouts for both right-to-left and left-to-right languages are in use.

Note that passing NULL for keymap is deprecated and will stop to work in GTK+ 3.0. Use gdk_keymap_get_for_display() instead.

Parameters

keymap

a GdkKeymap or NULL to use the default keymap

 

Returns

TRUE if there are layouts in both directions, FALSE otherwise

Since: 2.12


gdk_keymap_get_caps_lock_state ()

gboolean
gdk_keymap_get_caps_lock_state (GdkKeymap *keymap);

Returns whether the Caps Lock modifer is locked.

Parameters

keymap

a GdkKeymap

 

Returns

TRUE if Caps Lock is on

Since: 2.16


gdk_keymap_add_virtual_modifiers ()

void
gdk_keymap_add_virtual_modifiers (GdkKeymap *keymap,
                                  GdkModifierType *state);

Adds virtual modifiers (i.e. Super, Hyper and Meta) which correspond to the real modifiers (i.e Mod2, Mod3, ...) in modifiers . are set in state to their non-virtual counterparts (i.e. Mod2, Mod3,...) and set the corresponding bits in state .

GDK already does this before delivering key events, but for compatibility reasons, it only sets the first virtual modifier it finds, whereas this function sets all matching virtual modifiers.

This function is useful when matching key events against accelerators.

Parameters

keymap

a GdkKeymap

 

state

pointer to the modifier mask to change

 

Since: 2.20


gdk_keymap_map_virtual_modifiers ()

gboolean
gdk_keymap_map_virtual_modifiers (GdkKeymap *keymap,
                                  GdkModifierType *state);

Maps the virtual modifiers (i.e. Super, Hyper and Meta) which are set in state to their non-virtual counterparts (i.e. Mod2, Mod3,...) and set the corresponding bits in state .

This function is useful when matching key events against accelerators.

Parameters

keymap

a GdkKeymap

 

state

pointer to the modifier state to map

 

Returns

TRUE if no virtual modifiers were mapped to the same non-virtual modifier. Note that FALSE is also returned if a virtual modifier is mapped to a non-virtual modifier that was already set in state .

Since: 2.20


gdk_keyval_name ()

gchar *
gdk_keyval_name (guint keyval);

Converts a key value into a symbolic name.

The names are the same as those in the <gdk/gdkkeysyms.h> header file but without the leading "GDK_KEY_".

Parameters

keyval

a key value

 

Returns

a string containing the name of the key, or NULL if keyval is not a valid key. The string should not be modified.

[transfer none]


gdk_keyval_from_name ()

guint
gdk_keyval_from_name (const gchar *keyval_name);

Converts a key name to a key value.

The names are the same as those in the <gdk/gdkkeysyms.h> header file but without the leading "GDK_KEY_".

Parameters

keyval_name

a key name

 

Returns

the corresponding key value, or GDK_KEY_VoidSymbol if the key name is not a valid key


gdk_keyval_convert_case ()

void
gdk_keyval_convert_case (guint symbol,
                         guint *lower,
                         guint *upper);

Obtains the upper- and lower-case versions of the keyval symbol . Examples of keyvals are GDK_a, GDK_Enter, GDK_F1, etc.

Parameters

symbol

a keyval

 

lower

return location for lowercase version of symbol .

[out]

upper

return location for uppercase version of symbol .

[out]

gdk_keyval_to_upper ()

guint
gdk_keyval_to_upper (guint keyval);

gdk_keyval_to_lower ()

guint
gdk_keyval_to_lower (guint keyval);

gdk_keyval_is_upper ()

gboolean
gdk_keyval_is_upper (guint keyval);

gdk_keyval_is_lower ()

gboolean
gdk_keyval_is_lower (guint keyval);

gdk_keyval_to_unicode ()

guint32
gdk_keyval_to_unicode (guint keyval);

Convert from a GDK key symbol to the corresponding ISO10646 (Unicode) character.

Parameters

keyval

a GDK key symbol

 

Returns

the corresponding unicode character, or 0 if there is no corresponding character.


gdk_unicode_to_keyval ()

guint
gdk_unicode_to_keyval (guint32 wc);

Convert from a ISO10646 character to a key symbol.

Parameters

wc

a ISO10646 encoded character

 

Returns

the corresponding GDK key symbol, if one exists. or, if there is no corresponding symbol, wc | 0x01000000

Types and Values

struct GdkKeymap

struct GdkKeymap;

struct GdkKeymapKey

struct GdkKeymapKey {
  guint keycode;
  gint  group;
  gint  level;
};

Signal Details

The “direction-changed” signal

void
user_function (GdkKeymap *keymap,
               gpointer   user_data)

The ::direction-changed signal gets emitted when the direction of the keymap changes.

Parameters

keymap

the object on which the signal is emitted

 

user_data

user data set when the signal handler was connected.

 

Flags: Run Last

Since: 2.0


The “keys-changed” signal

void
user_function (GdkKeymap *keymap,
               gpointer   user_data)

The ::keys-changed signal is emitted when the mapping represented by keymap changes.

Parameters

keymap

the object on which the signal is emitted

 

user_data

user data set when the signal handler was connected.

 

Flags: Run Last

Since: 2.2


The “state-changed” signal

void
user_function (GdkKeymap *keymap,
               gpointer   user_data)

The ::state-changed signal is emitted when the state of the keyboard changes, e.g when Caps Lock is turned on or off. See gdk_keymap_get_caps_lock_state().

Parameters

keymap

the object on which the signal is emitted

 

user_data

user data set when the signal handler was connected.

 

Flags: Run Last

Since: 2.16