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Functions
gboolean | g_action_name_is_valid () |
const gchar * | g_action_get_name () |
const GVariantType * | g_action_get_parameter_type () |
const GVariantType * | g_action_get_state_type () |
GVariant * | g_action_get_state_hint () |
gboolean | g_action_get_enabled () |
GVariant * | g_action_get_state () |
void | g_action_change_state () |
void | g_action_activate () |
gboolean | g_action_parse_detailed_name () |
gchar * | g_action_print_detailed_name () |
Properties
gboolean | enabled | Read |
gchar * | name | Read |
GVariantType * | parameter-type | Read |
GVariant * | state | Read |
GVariantType * | state-type | Read |
Description
GAction represents a single named action.
The main interface to an action is that it can be activated with
g_action_activate()
. This results in the 'activate' signal being
emitted. An activation has a GVariant parameter (which may be
NULL
). The correct type for the parameter is determined by a static
parameter type (which is given at construction time).
An action may optionally have a state, in which case the state may be
set with g_action_change_state()
. This call takes a GVariant. The
correct type for the state is determined by a static state type
(which is given at construction time).
The state may have a hint associated with it, specifying its valid range.
GAction is merely the interface to the concept of an action, as described above. Various implementations of actions exist, including GSimpleAction.
In all cases, the implementing class is responsible for storing the
name of the action, the parameter type, the enabled state, the
optional state type and the state and emitting the appropriate
signals when these change. The implementor responsible for filtering
calls to g_action_activate()
and g_action_change_state()
for type
safety and for the state being enabled.
Probably the only useful thing to do with a GAction is to put it inside of a GSimpleActionGroup.
Functions
g_action_name_is_valid ()
gboolean
g_action_name_is_valid (const gchar *action_name
);
Checks if action_name
is valid.
action_name
is valid if it consists only of alphanumeric characters,
plus '-' and '.'. The empty string is not a valid action name.
It is an error to call this function with a non-utf8 action_name
.
action_name
must not be NULL
.
Since 2.38
g_action_get_name ()
const gchar *
g_action_get_name (GAction *action
);
Queries the name of action
.
Since 2.28
g_action_get_parameter_type ()
const GVariantType *
g_action_get_parameter_type (GAction *action
);
Queries the type of the parameter that must be given when activating
action
.
When activating the action using g_action_activate()
, the GVariant
given to that function must be of the type returned by this function.
In the case that this function returns NULL
, you must not give any
GVariant, but NULL
instead.
Since 2.28
g_action_get_state_type ()
const GVariantType *
g_action_get_state_type (GAction *action
);
Queries the type of the state of action
.
If the action is stateful (e.g. created with
g_simple_action_new_stateful()
) then this function returns the
GVariantType of the state. This is the type of the initial value
given as the state. All calls to g_action_change_state()
must give a
GVariant of this type and g_action_get_state()
will return a
GVariant of the same type.
If the action is not stateful (e.g. created with g_simple_action_new()
)
then this function will return NULL
. In that case, g_action_get_state()
will return NULL
and you must not call g_action_change_state()
.
Since 2.28
g_action_get_state_hint ()
GVariant *
g_action_get_state_hint (GAction *action
);
Requests a hint about the valid range of values for the state of
action
.
If NULL
is returned it either means that the action is not stateful
or that there is no hint about the valid range of values for the
state of the action.
If a GVariant array is returned then each item in the array is a possible value for the state. If a GVariant pair (ie: two-tuple) is returned then the tuple specifies the inclusive lower and upper bound of valid values for the state.
In any case, the information is merely a hint. It may be possible to have a state value outside of the hinted range and setting a value within the range may fail.
The return value (if non-NULL
) should be freed with
g_variant_unref()
when it is no longer required.
Since 2.28
g_action_get_enabled ()
gboolean
g_action_get_enabled (GAction *action
);
Checks if action
is currently enabled.
An action must be enabled in order to be activated or in order to have its state changed from outside callers.
Since 2.28
g_action_get_state ()
GVariant *
g_action_get_state (GAction *action
);
Queries the current state of action
.
If the action is not stateful then NULL
will be returned. If the
action is stateful then the type of the return value is the type
given by g_action_get_state_type()
.
The return value (if non-NULL
) should be freed with
g_variant_unref()
when it is no longer required.
Since 2.28
g_action_change_state ()
void g_action_change_state (GAction *action
,GVariant *value
);
Request for the state of action
to be changed to value
.
The action must be stateful and value
must be of the correct type.
See g_action_get_state_type()
.
This call merely requests a change. The action may refuse to change
its state or may change its state to something other than value
.
See g_action_get_state_hint()
.
If the value
GVariant is floating, it is consumed.
Since 2.30
g_action_activate ()
void g_action_activate (GAction *action
,GVariant *parameter
);
Activates the action.
parameter
must be the correct type of parameter for the action (ie:
the parameter type given at construction time). If the parameter
type was NULL
then parameter
must also be NULL
.
If the parameter
GVariant is floating, it is consumed.
Since 2.28
g_action_parse_detailed_name ()
gboolean g_action_parse_detailed_name (const gchar *detailed_name
,gchar **action_name
,GVariant **target_value
,GError **error
);
Parses a detailed action name into its separate name and target components.
Detailed action names can have three formats.
The first format is used to represent an action name with no target value and consists of just an action name containing no whitespace nor the characters ':', '(' or ')'. For example: "app.action".
The second format is used to represent an action with a target value that is a non-empty string consisting only of alphanumerics, plus '-' and '.'. In that case, the action name and target value are separated by a double colon ("::"). For example: "app.action::target".
The third format is used to represent an action with any type of
target value, including strings. The target value follows the action
name, surrounded in parens. For example: "app.action(42)". The
target value is parsed using g_variant_parse()
. If a tuple-typed
value is desired, it must be specified in the same way, resulting in
two sets of parens, for example: "app.action((1,2,3))". A string
target can be specified this way as well: "app.action('target')".
For strings, this third format must be used if * target value is
empty or contains characters other than alphanumerics, '-' and '.'.
Since 2.38
g_action_print_detailed_name ()
gchar * g_action_print_detailed_name (const gchar *action_name
,GVariant *target_value
);
Formats a detailed action name from action_name
and target_value
.
It is an error to call this function with an invalid action name.
This function is the opposite of
g_action_parse_detailed_action_name()
. It will produce a string that
can be parsed back to the action_name
and target_value
by that
function.
See that function for the types of strings that will be printed by this function.
Since 2.38
Types and Values
GAction
typedef struct _GAction GAction;
GAction is an opaque data structure and can only be accessed using the following functions.
struct GActionInterface
struct GActionInterface { GTypeInterface g_iface; /* virtual functions */ const gchar * (* get_name) (GAction *action); const GVariantType * (* get_parameter_type) (GAction *action); const GVariantType * (* get_state_type) (GAction *action); GVariant * (* get_state_hint) (GAction *action); gboolean (* get_enabled) (GAction *action); GVariant * (* get_state) (GAction *action); void (* change_state) (GAction *action, GVariant *value); void (* activate) (GAction *action, GVariant *parameter); };
The virtual function table for GAction.
Members
GTypeInterface |
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the virtual function pointer for |
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the virtual function pointer for |
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the virtual function pointer for |
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the virtual function pointer for |
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the virtual function pointer for |
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the virtual function pointer for |
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the virtual function pointer for |
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the virtual function pointer for |
Since 2.28
Property Details
The “enabled”
property
“enabled” gboolean
If action
is currently enabled.
If the action is disabled then calls to g_action_activate()
and
g_action_change_state()
have no effect.
Flags: Read
Default value: TRUE
Since 2.28
The “name”
property
“name” gchar *
The name of the action. This is mostly meaningful for identifying the action once it has been added to a GActionGroup. It is immutable.
Flags: Read
Default value: NULL
Since 2.28
The “parameter-type”
property
“parameter-type” GVariantType *
The type of the parameter that must be given when activating the
action. This is immutable, and may be NULL
if no parameter is needed when
activating the action.
Flags: Read
Since 2.28
The “state”
property
“state” GVariant *
The state of the action, or NULL
if the action is stateless.
Flags: Read
Allowed values: GVariant<*>
Default value: NULL
Since 2.28
The “state-type”
property
“state-type” GVariantType *
The GVariantType of the state that the action has, or NULL
if the
action is stateless. This is immutable.
Flags: Read
Since 2.28