Index

Package: Action_Group

Description

package Glib.Action_Group is

Glib.Action_Group.Gaction_Group represents a group of actions. Actions can be used to expose functionality in a structured way, either from one part of a program to another, or to the outside world. Action groups are often used together with a Glib.Menu_Model.Gmenu_Model that provides additional representation data for displaying the actions to the user, e.g. in a menu.

The main way to interact with the actions in a GActionGroup is to activate them with Glib.Action_Group.Activate_Action. Activating an action may require a Glib.Variant.Gvariant parameter. The required type of the parameter can be inquired with Glib.Action_Group.Get_Action_Parameter_Type.

Actions may be disabled, see Glib.Action_Group.Get_Action_Enabled.

Activating a disabled action has no effect.

Actions may optionally have a state in the form of a Glib.Variant.Gvariant. The current state of an action can be inquired with Glib.Action_Group.Get_Action_State. Activating a stateful action may change its state, but it is also possible to set the state by calling Glib.Action_Group.Change_Action_State.

As typical example, consider a text editing application which has an option to change the current font to 'bold'. A good way to represent this would be a stateful action, with a boolean state. Activating the action would toggle the state.

Each action in the group has a unique name (which is a string). All method calls, except Glib.Action_Group.List_Actions take the name of an action as an argument.

The Glib.Action_Group.Gaction_Group API is meant to be the 'public' API to the action group. The calls here are exactly the interaction that 'external forces' (eg: UI, incoming D-Bus messages, etc.) are supposed to have with actions. 'Internal' APIs (ie: ones meant only to be accessed by the action group implementation) are found on subclasses. This is why you will find - for example - Glib.Action_Group.Get_Action_Enabled but not an equivalent <function>set</function> call.

Signals are emitted on the action group in response to state changes on individual actions.

Implementations of Glib.Action_Group.Gaction_Group should provide implementations for the virtual functions Glib.Action_Group.List_Actions and Glib.Action_Group.Query_Action. The other virtual functions should not be implemented - their "wrappers" are actually implemented with calls to Glib.Action_Group.Query_Action.

Types

Gaction_Group

type Gaction_Group is new Glib.Types.GType_Interface;

Cb_Gaction_Group_UTF8_String_Void

type Cb_Gaction_Group_UTF8_String_Void is not null access procedure
     (Self        : Gaction_Group;
      Action_Name : UTF8_String);

Cb_GObject_UTF8_String_Void

type Cb_GObject_UTF8_String_Void is not null access procedure
     (Self        : access Glib.Object.GObject_Record'Class;
      Action_Name : UTF8_String);

Cb_Gaction_Group_UTF8_String_Boolean_Void

type Cb_Gaction_Group_UTF8_String_Boolean_Void is not null access procedure
     (Self        : Gaction_Group;
      Action_Name : UTF8_String;
      Enabled     : Boolean);

Cb_GObject_UTF8_String_Boolean_Void

type Cb_GObject_UTF8_String_Boolean_Void is not null access procedure
     (Self        : access Glib.Object.GObject_Record'Class;
      Action_Name : UTF8_String;
      Enabled     : Boolean);

Cb_Gaction_Group_UTF8_String_Gvariant_Void

type Cb_Gaction_Group_UTF8_String_Gvariant_Void is not null access procedure
     (Self        : Gaction_Group;
      Action_Name : UTF8_String;
      Value       : Glib.Variant.Gvariant);

Cb_GObject_UTF8_String_Gvariant_Void

type Cb_GObject_UTF8_String_Gvariant_Void is not null access procedure
     (Self        : access Glib.Object.GObject_Record'Class;
      Action_Name : UTF8_String;
      Value       : Glib.Variant.Gvariant);

Constants & Global variables

Null_Gaction_Group (Gaction_Group)

Null_Gaction_Group : constant Gaction_Group;

Signal_Action_Added (Glib.Signal_Name)

Signal_Action_Added : constant Glib.Signal_Name := "action-added";

Signal_Action_Enabled_Changed (Glib.Signal_Name)

Signal_Action_Enabled_Changed : constant Glib.Signal_Name := "action-enabled-changed";

Signal_Action_Removed (Glib.Signal_Name)

Signal_Action_Removed : constant Glib.Signal_Name := "action-removed";

Signal_Action_State_Changed (Glib.Signal_Name)

Signal_Action_State_Changed : constant Glib.Signal_Name := "action-state-changed";

Subprograms & Entries

Get_Type

function Get_Type return Glib.GType;

Action_Added

procedure Action_Added 
(Self: Gaction_Group;
Action_Name: UTF8_String);
Emits the Glib.Action_Group.Gaction_Group::action-added signal on Action_Group. This function should only be called by Glib.Action_Group.Gaction_Group implementations. Since: gtk+ 2.28 "action_name": the name of an action in the group

Action_Enabled_Changed

procedure Action_Enabled_Changed 
(Self: Gaction_Group;
Action_Name: UTF8_String;
Enabled: Boolean);
Emits the Glib.Action_Group.Gaction_Group::action-enabled-changed signal on Action_Group. This function should only be called by Glib.Action_Group.Gaction_Group implementations. Since: gtk+ 2.28 "action_name": the name of an action in the group "enabled": whether or not the action is now enabled

Action_Removed

procedure Action_Removed 
(Self: Gaction_Group;
Action_Name: UTF8_String);
Emits the Glib.Action_Group.Gaction_Group::action-removed signal on Action_Group. This function should only be called by Glib.Action_Group.Gaction_Group implementations. Since: gtk+ 2.28 "action_name": the name of an action in the group

Action_State_Changed

procedure Action_State_Changed 
(Self: Gaction_Group;
Action_Name: UTF8_String;
State: Glib.Variant.Gvariant);
Emits the Glib.Action_Group.Gaction_Group::action-state-changed signal on Action_Group. This function should only be called by Glib.Action_Group.Gaction_Group implementations. Since: gtk+ 2.28 "action_name": the name of an action in the group "state": the new state of the named action

Activate_Action

procedure Activate_Action 
(Self: Gaction_Group;
Action_Name: UTF8_String;
Parameter: Glib.Variant.Gvariant);
Activate the named action within Action_Group. If the action is expecting a parameter, then the correct type of parameter must be given as Parameter. If the action is expecting no parameters then Parameter must be null. See Glib.Action_Group.Get_Action_Parameter_Type. Since: gtk+ 2.28 "action_name": the name of the action to activate "parameter": parameters to the activation

Change_Action_State

procedure Change_Action_State 
(Self: Gaction_Group;
Action_Name: UTF8_String;
Value: Glib.Variant.Gvariant);
Request for the state of the named action within Action_Group to be changed to Value. The action must be stateful and Value must be of the correct type. See Glib.Action_Group.Get_Action_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 Glib.Action_Group.Get_Action_State_Hint. If the Value GVariant is floating, it is consumed. Since: gtk+ 2.28 "action_name": the name of the action to request the change on "value": the new state

Get_Action_Enabled

function Get_Action_Enabled 
(Self: Gaction_Group;
Action_Name: UTF8_String) return Boolean;
Checks if the named action within Action_Group 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: gtk+ 2.28 "action_name": the name of the action to query

Get_Action_Parameter_Type

function Get_Action_Parameter_Type 
(Self: Gaction_Group;
Action_Name: UTF8_String) return Glib.Variant.Gvariant_Type;
Queries the type of the parameter that must be given when activating the named action within Action_Group. When activating the action using Glib.Action_Group.Activate_Action, the Glib.Variant.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 Glib.Variant.Gvariant, but null instead. The parameter type of a particular action will never change but it is possible for an action to be removed and for a new action to be added with the same name but a different parameter type. Since: gtk+ 2.28 "action_name": the name of the action to query

Get_Action_State

function Get_Action_State 
(Self: Gaction_Group;
Action_Name: UTF8_String) return Glib.Variant.Gvariant;
Queries the current state of the named action within Action_Group. 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 Glib.Action_Group.Get_Action_State_Type. The return value (if non-null) should be freed with Glib.Variant.Unref when it is no longer required. Since: gtk+ 2.28 "action_name": the name of the action to query

Get_Action_State_Hint

function Get_Action_State_Hint 
(Self: Gaction_Group;
Action_Name: UTF8_String) return Glib.Variant.Gvariant;
Requests a hint about the valid range of values for the state of the named action within Action_Group. 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 Glib.Variant.Gvariant array is returned then each item in the array is a possible value for the state. If a Glib.Variant.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 Glib.Variant.Unref when it is no longer required. Since: gtk+ 2.28 "action_name": the name of the action to query

Get_Action_State_Type

function Get_Action_State_Type 
(Self: Gaction_Group;
Action_Name: UTF8_String) return Glib.Variant.Gvariant_Type;
Queries the type of the state of the named action within Action_Group. If the action is stateful then this function returns the Glib.Variant.Gvariant_Type of the state. All calls to Glib.Action_Group.Change_Action_State must give a Glib.Variant.Gvariant of this type and Glib.Action_Group.Get_Action_State will return a Glib.Variant.Gvariant of the same type. If the action is not stateful then this function will return null. In that case, Glib.Action_Group.Get_Action_State will return null and you must not call Glib.Action_Group.Change_Action_State. The state type of a particular action will never change but it is possible for an action to be removed and for a new action to be added with the same name but a different state type. Since: gtk+ 2.28 "action_name": the name of the action to query

Has_Action

function Has_Action 
(Self: Gaction_Group;
Action_Name: UTF8_String) return Boolean;
Checks if the named action exists within Action_Group. Since: gtk+ 2.28 "action_name": the name of the action to check for

List_Actions

function List_Actions 
(Self: Gaction_Group) return GNAT.Strings.String_List;
Lists the actions contained within Action_Group. The caller is responsible for freeing the list with g_strfreev when it is no longer required. Since: gtk+ 2.28

Query_Action

function Query_Action 
(Self: Gaction_Group;
Action_Name: UTF8_String;
Enabled: access Boolean;
Parameter_Type: access Glib.Variant.Gvariant_Type;
State_Type: access Glib.Variant.Gvariant_Type;
State_Hint: access Glib.Variant.Gvariant;
State: access Glib.Variant.Gvariant) return Boolean;
Queries all aspects of the named action within an Action_Group. This function acquires the information available from Glib.Action_Group.Has_Action, Glib.Action_Group.Get_Action_Enabled, Glib.Action_Group.Get_Action_Parameter_Type, Glib.Action_Group.Get_Action_State_Type, Glib.Action_Group.Get_Action_State_Hint and Glib.Action_Group.Get_Action_State with a single function call. This provides two main benefits. The first is the improvement in efficiency that comes with not having to perform repeated lookups of the action in order to discover different things about it. The second is that implementing Glib.Action_Group.Gaction_Group can now be done by only overriding this one virtual function. The interface provides a default implementation of this function that calls the individual functions, as required, to fetch the information. The interface also provides default implementations of those functions that call this function. All implementations, therefore, must override either this function or all of the others. If the action exists, True is returned and any of the requested fields (as indicated by having a non-null reference passed in) are filled. If the action doesn't exist, False is returned and the fields may or may not have been modified. Since: gtk+ 2.32 "action_name": the name of an action in the group "enabled": if the action is presently enabled "parameter_type": the parameter type, or null if none needed "state_type": the state type, or null if stateless "state_hint": the state hint, or null if none "state": the current state, or null if stateless

On_Action_Added

procedure On_Action_Added 
(Self: Gaction_Group;
Call: Cb_Gaction_Group_UTF8_String_Void;
After: Boolean := False);

On_Action_Added

procedure On_Action_Added 
(Self: Gaction_Group;
Call: Cb_GObject_UTF8_String_Void;
Slot: not null access Glib.Object.GObject_Record'Class;
After: Boolean := False);
Signals that a new action was just added to the group. This signal is emitted after the action has been added and is now visible.

On_Action_Enabled_Changed

procedure On_Action_Enabled_Changed 
(Self: Gaction_Group;
Call: Cb_Gaction_Group_UTF8_String_Boolean_Void;
After: Boolean := False);

On_Action_Enabled_Changed

procedure On_Action_Enabled_Changed 
(Self: Gaction_Group;
Call: Cb_GObject_UTF8_String_Boolean_Void;
Slot: not null access Glib.Object.GObject_Record'Class;
After: Boolean := False);
Signals that the enabled status of the named action has changed. Callback parameters: -- "action_name": the name of the action in Action_Group -- "enabled": whether the action is enabled or not

On_Action_Removed

procedure On_Action_Removed 
(Self: Gaction_Group;
Call: Cb_Gaction_Group_UTF8_String_Void;
After: Boolean := False);

On_Action_Removed

procedure On_Action_Removed 
(Self: Gaction_Group;
Call: Cb_GObject_UTF8_String_Void;
Slot: not null access Glib.Object.GObject_Record'Class;
After: Boolean := False);
Signals that an action is just about to be removed from the group. This signal is emitted before the action is removed, so the action is still visible and can be queried from the signal handler.

On_Action_State_Changed

procedure On_Action_State_Changed 
(Self: Gaction_Group;
Call: Cb_Gaction_Group_UTF8_String_Gvariant_Void;
After: Boolean := False);

On_Action_State_Changed

procedure On_Action_State_Changed 
(Self: Gaction_Group;
Call: Cb_GObject_UTF8_String_Gvariant_Void;
Slot: not null access Glib.Object.GObject_Record'Class;
After: Boolean := False);
Signals that the state of the named action has changed. Callback parameters: -- "action_name": the name of the action in Action_Group -- "value": the new value of the state

+

function "+" 
(W: Gaction_Group) return Gaction_Group;