Action
- class Action(*args, **kwargs)
Implementations: PropertyAction
, SimpleAction
GAction
represents a single named action.
The main interface to an action is that it can be activated with
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 change_state
. This call takes a Variant
. 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
SimpleAction
.
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 is responsible for filtering calls to
activate
and 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 SimpleActionGroup
.
Methods
- class Action
- activate(parameter: Variant | None = None) None
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 wasNULL
thenparameter
must also beNULL
.If the
parameter
Variant
is floating, it is consumed.Added in version 2.28.
- Parameters:
parameter – the parameter to the activation
- change_state(value: Variant) None
Request for the state of
action
to be changed tovalue
.The action must be stateful and
value
must be of the correct type. Seeget_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
. Seeget_state_hint
.If the
value
Variant
is floating, it is consumed.Added in version 2.30.
- Parameters:
value – the new state
- get_enabled() bool
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.
Added in version 2.28.
- get_parameter_type() VariantType | None
Queries the type of the parameter that must be given when activating
action
.When activating the action using
activate
, theVariant
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 anyVariant
, butNULL
instead.Added in version 2.28.
- get_state() Variant | None
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 byget_state_type
.The return value (if non-
NULL
) should be freed withunref
when it is no longer required.Added in version 2.28.
- get_state_hint() Variant | None
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
Variant
array is returned then each item in the array is a possible value for the state. If aVariant
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 withunref
when it is no longer required.Added in version 2.28.
- get_state_type() VariantType | None
Queries the type of the state of
action
.If the action is stateful (e.g. created with
new_stateful
) then this function returns theVariantType
of the state. This is the type of the initial value given as the state. All calls tochange_state
must give aVariant
of this type andget_state
will return aVariant
of the same type.If the action is not stateful (e.g. created with
new
) then this function will returnNULL
. In that case,get_state
will returnNULL
and you must not callchange_state
.Added in version 2.28.
- name_is_valid(action_name: str) bool
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-UTF-8
action_name
.action_name
must not beNULL
.Added in version 2.38.
- Parameters:
action_name – a potential action name
- parse_detailed_name(detailed_name: str) tuple[bool, str, Variant]
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 usingparse
. 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.
.If this function returns
TRUE
, a non-NULL
value is guaranteed to be returned inaction_name
(if a pointer is passed in). ANULL
value may still be returned intarget_value
, as thedetailed_name
may not contain a target.If returned, the
Variant
intarget_value
is guaranteed to not be floating.Added in version 2.38.
- Parameters:
detailed_name – a detailed action name
- print_detailed_name(action_name: str, target_value: Variant | None = None) str
Formats a detailed action name from
action_name
andtarget_value
.It is an error to call this function with an invalid action name.
This function is the opposite of
parse_detailed_name
. It will produce a string that can be parsed back to theaction_name
andtarget_value
by that function.See that function for the types of strings that will be printed by this function.
Added in version 2.38.
- Parameters:
action_name – a valid action name
target_value – a
Variant
target value, orNULL
Properties
- class Action
-
- props.parameter_type: VariantType
The type of the None singleton.
Added in version 2.28.
- props.state_type: VariantType
The type of the None singleton.
Added in version 2.28.
Virtual Methods
- class Action
- do_activate(parameter: Variant | None = None) None
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 wasNULL
thenparameter
must also beNULL
.If the
parameter
Variant
is floating, it is consumed.Added in version 2.28.
- Parameters:
parameter – the parameter to the activation
- do_change_state(value: Variant) None
Request for the state of
action
to be changed tovalue
.The action must be stateful and
value
must be of the correct type. Seeget_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
. Seeget_state_hint
.If the
value
Variant
is floating, it is consumed.Added in version 2.30.
- Parameters:
value – the new state
- do_get_enabled() bool
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.
Added in version 2.28.
- do_get_parameter_type() VariantType | None
Queries the type of the parameter that must be given when activating
action
.When activating the action using
activate
, theVariant
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 anyVariant
, butNULL
instead.Added in version 2.28.
- do_get_state() Variant | None
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 byget_state_type
.The return value (if non-
NULL
) should be freed withunref
when it is no longer required.Added in version 2.28.
- do_get_state_hint() Variant | None
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
Variant
array is returned then each item in the array is a possible value for the state. If aVariant
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 withunref
when it is no longer required.Added in version 2.28.
- do_get_state_type() VariantType | None
Queries the type of the state of
action
.If the action is stateful (e.g. created with
new_stateful
) then this function returns theVariantType
of the state. This is the type of the initial value given as the state. All calls tochange_state
must give aVariant
of this type andget_state
will return aVariant
of the same type.If the action is not stateful (e.g. created with
new
) then this function will returnNULL
. In that case,get_state
will returnNULL
and you must not callchange_state
.Added in version 2.28.