Package org.gnome.gio

Class Application

java.lang.Object

io.github.jwharm.javagi.base.ProxyInstance

org.gnome.gobject.TypeInstance

org.gnome.gobject.GObject

org.gnome.gio.Application

All Implemented Interfaces:

Proxy, ActionGroup, ActionMap

Direct Known Subclasses:

Application

@Generated("io.github.jwharm.JavaGI")
public class Application
extends GObject
implements ActionGroup, ActionMap

GApplication is the core class for application support.

A GApplication is the foundation of an application. It wraps some low-level platform-specific services and is intended to act as the foundation for higher-level application classes such as GtkApplication or MxApplication. In general, you should not use this class outside of a higher level framework.

GApplication provides convenient life-cycle management by maintaining a "use count" for the primary application instance. The use count can be changed using hold() and release(). If it drops to zero, the application exits. Higher-level classes such as GtkApplication employ the use count to ensure that the application stays alive as long as it has any opened windows.

Another feature that GApplication (optionally) provides is process uniqueness. Applications can make use of this functionality by providing a unique application ID. If given, only one application with this ID can be running at a time per session. The session concept is platform-dependent, but corresponds roughly to a graphical desktop login. When your application is launched again, its arguments are passed through platform communication to the already running program. The already running instance of the program is called the "primary instance"; for non-unique applications this is always the current instance. On Linux, the D-Bus session bus is used for communication.

The use of GApplication differs from some other commonly-used uniqueness libraries (such as libunique) in important ways. The application is not expected to manually register itself and check if it is the primary instance. Instead, the main() function of a GApplication should do very little more than instantiating the application instance, possibly connecting signal handlers, then calling run(java.lang.String[]). All checks for uniqueness are done internally. If the application is the primary instance then the startup signal is emitted and the mainloop runs. If the application is not the primary instance then a signal is sent to the primary instance and run(java.lang.String[]) promptly returns. See the code examples below.

If used, the expected form of an application identifier is the same as that of a D-Bus well-known bus name. Examples include: com.example.MyApp, org.example.internal_apps.Calculator, org._7_zip.Archiver. For details on valid application identifiers, see idIsValid(java.lang.String).

On Linux, the application identifier is claimed as a well-known bus name on the user's session bus. This means that the uniqueness of your application is scoped to the current session. It also means that your application may provide additional services (through registration of other object paths) at that bus name. The registration of these object paths should be done with the shared GDBus session bus. Note that due to the internal architecture of GDBus, method calls can be dispatched at any time (even if a main loop is not running). For this reason, you must ensure that any object paths that you wish to register are registered before GApplication attempts to acquire the bus name of your application (which happens in register(org.gnome.gio.Cancellable)). Unfortunately, this means that you cannot use Gio.Application:is-remote to decide if you want to register object paths.

GApplication also implements the ActionGroup and ActionMap interfaces and lets you easily export actions by adding them with ActionMap.addAction(org.gnome.gio.Action). When invoking an action by calling ActionGroup.activateAction(java.lang.String, org.gnome.glib.Variant) on the application, it is always invoked in the primary instance. The actions are also exported on the session bus, and GIO provides the DBusActionGroup wrapper to conveniently access them remotely. GIO provides a DBusMenuModel wrapper for remote access to exported MenuModels.

Note: Due to the fact that actions are exported on the session bus, using maybe parameters is not supported, since D-Bus does not support maybe types.

There is a number of different entry points into a GApplication:

• via 'Activate' (i.e. just starting the application)

• via 'Open' (i.e. opening some files)

• by handling a command-line

• via activating an action

The Gio.Application::startup signal lets you handle the application initialization for all of these in a single place.

Regardless of which of these entry points is used to start the application, GApplication passes some ‘platform data’ from the launching instance to the primary instance, in the form of a GLib.Variant dictionary mapping strings to variants. To use platform data, override the beforeEmit(org.gnome.glib.Variant) or afterEmit(org.gnome.glib.Variant) virtual functions in your GApplication subclass. When dealing with ApplicationCommandLine objects, the platform data is directly available via ApplicationCommandLine.getCwd(), ApplicationCommandLine.getEnviron() and ApplicationCommandLine.getPlatformData().

As the name indicates, the platform data may vary depending on the operating system, but it always includes the current directory (key cwd), and optionally the environment (ie the set of environment variables and their values) of the calling process (key environ). The environment is only added to the platform data if the G_APPLICATION_SEND_ENVIRONMENT flag is set. GApplication subclasses can add their own platform data by overriding the addPlatformData(org.gnome.glib.VariantBuilder) virtual function. For instance, GtkApplication adds startup notification data in this way.

To parse commandline arguments you may handle the Gio.Application::command-line signal or override the localCommandLine(java.lang.String[], io.github.jwharm.javagi.base.Out<java.lang.Integer>) virtual function, to parse them in either the primary instance or the local instance, respectively.

For an example of opening files with a GApplication, see gapplication-example-open.c.

For an example of using actions with GApplication, see gapplication-example-actions.c.

For an example of using extra D-Bus hooks with GApplication, see gapplication-example-dbushooks.c.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	Application.ActivateCallback	Functional interface declaration of the ActivateCallback callback.
static class	Application.ApplicationClass	Virtual function table for GApplication.
static class	Application.Builder<B extends Application.Builder<B>>	Inner class implementing a builder pattern to construct a GObject with properties.
static interface	Application.CommandLineCallback	Functional interface declaration of the CommandLineCallback callback.
static interface	Application.HandleLocalOptionsCallback	Functional interface declaration of the HandleLocalOptionsCallback callback.
static interface	Application.NameLostCallback	Functional interface declaration of the NameLostCallback callback.
static interface	Application.OpenCallback	Functional interface declaration of the OpenCallback callback.
static interface	Application.ShutdownCallback	Functional interface declaration of the ShutdownCallback callback.
static interface	Application.StartupCallback	Functional interface declaration of the StartupCallback callback.

Nested classes/interfaces inherited from class org.gnome.gobject.GObject

GObject.NotifyCallback, GObject.ObjectClass

Nested classes/interfaces inherited from interface org.gnome.gio.ActionGroup

ActionGroup.ActionAddedCallback, ActionGroup.ActionEnabledChangedCallback, ActionGroup.ActionGroupImpl, ActionGroup.ActionGroupInterface, ActionGroup.ActionRemovedCallback, ActionGroup.ActionStateChangedCallback

Nested classes/interfaces inherited from interface org.gnome.gio.ActionMap

ActionMap.ActionMapImpl, ActionMap.ActionMapInterface

Constructor Summary

Constructors

Constructor	Description
Application(@Nullable String applicationId, Set<ApplicationFlags> flags)	Creates a new GApplication instance.
Application(@Nullable String applicationId, ApplicationFlags... flags)	Creates a new GApplication instance.
Application(MemorySegment address)	Create a Application proxy instance for the provided memory address.

Method Summary

Modifier and Type	Method	Description
void	activate()	Activates the application.
void	addMainOption(String longName, byte shortName, Set<OptionFlags> flags, OptionArg arg, String description, @Nullable String argDescription)	Add an option to be handled by this Application.
void	addMainOption(String longName, byte shortName, OptionFlags flags, OptionArg arg, String description, @Nullable String argDescription)	Add an option to be handled by this Application.
void	addMainOptionEntries(OptionEntry[] entries)	Adds main option entries to be handled by this Application.
void	addOptionGroup(OptionGroup group)	Adds a GOptionGroup to the commandline handling of this Application.
protected void	addPlatformData(VariantBuilder builder)	invoked (locally) to add 'platform data' to be sent to the primary instance when activating, opening or invoking actions
protected void	afterEmit(Variant platformData)	invoked on the primary instance after 'activate', 'open', 'command-line' or any action invocation, gets the 'platform data' from the calling instance
protected Application	asParent()	Returns this instance as if it were its parent type.
protected void	beforeEmit(Variant platformData)	invoked on the primary instance before 'activate', 'open', 'command-line' or any action invocation, gets the 'platform data' from the calling instance
void	bindBusyProperty(GObject object, String property)	Marks this Application as busy (see g_application_mark_busy()) while property on object is true.
static Application.Builder<? extends Application.Builder>	builder()	A Application.Builder object constructs a Application with the specified properties.
protected int	commandLine(ApplicationCommandLine commandLine)	invoked on the primary instance when a command-line is not handled locally
protected boolean	dbusRegister(DBusConnection connection, String objectPath)	invoked locally during registration, if the application is using its D-Bus backend.
protected void	dbusUnregister(DBusConnection connection, String objectPath)	invoked locally during unregistration, if the application is using its D-Bus backend.
void	emitActivate()	Emits the "activate" signal.
int	emitCommandLine(ApplicationCommandLine commandLine)	Emits the "command-line" signal.
int	emitHandleLocalOptions(VariantDict options)	Emits the "handle-local-options" signal.
boolean	emitNameLost()	Emits the "name-lost" signal.
void	emitOpen(File[] files, String hint)	Emits the "open" signal.
void	emitShutdown()	Emits the "shutdown" signal.
void	emitStartup()	Emits the "startup" signal.
String	getApplicationId()	Gets the unique identifier for this Application.
DBusConnection	getDbusConnection()	Gets the GDBusConnection being used by the application, or null.
String	getDbusObjectPath()	Gets the D-Bus object path being used by the application, or null.
static Application	getDefault()	Returns the default GApplication instance for this process.
Set<ApplicationFlags>	getFlags()	Gets the flags for this Application.
int	getInactivityTimeout()	Gets the current inactivity timeout for the application.
boolean	getIsBusy()	Gets the application's current busy state, as set through g_application_mark_busy() or g_application_bind_busy_property().
boolean	getIsRegistered()	Checks if this Application is registered.
boolean	getIsRemote()	Checks if this Application is remote.
static MemoryLayout	getMemoryLayout()	The memory layout of the native struct.
String	getResourceBasePath()	Gets the resource base path of this Application.
static Type	getType()	Get the GType of the Application class
String	getVersion()	Gets the version of this Application.
protected int	handleLocalOptions(VariantDict options)	invoked locally after the parsing of the commandline options has occurred.
void	hold()	Increases the use count of this Application.
static boolean	idIsValid(String applicationId)	Checks if applicationId is a valid application identifier.
protected boolean	localCommandLine(String[] arguments, Out<Integer> exitStatus)	This virtual function is always invoked in the local instance.
void	markBusy()	Increases the busy count of this Application.
protected boolean	nameLost()	invoked when another instance is taking over the name.
SignalConnection<Application.ActivateCallback>	onActivate(Application.ActivateCallback handler)	The ::activate signal is emitted on the primary instance when an activation occurs.
SignalConnection<Application.CommandLineCallback>	onCommandLine(Application.CommandLineCallback handler)	The ::command-line signal is emitted on the primary instance when a commandline is not handled locally.
SignalConnection<Application.HandleLocalOptionsCallback>	onHandleLocalOptions(Application.HandleLocalOptionsCallback handler)	The ::handle-local-options signal is emitted on the local instance after the parsing of the commandline options has occurred.
SignalConnection<Application.NameLostCallback>	onNameLost(Application.NameLostCallback handler)	The ::name-lost signal is emitted only on the registered primary instance when a new instance has taken over.
SignalConnection<Application.OpenCallback>	onOpen(Application.OpenCallback handler)	The ::open signal is emitted on the primary instance when there are files to open.
SignalConnection<Application.ShutdownCallback>	onShutdown(Application.ShutdownCallback handler)	The ::shutdown signal is emitted only on the registered primary instance immediately after the main loop terminates.
SignalConnection<Application.StartupCallback>	onStartup(Application.StartupCallback handler)	The ::startup signal is emitted on the primary instance immediately after registration.
void	open(File[] files, String hint)	Opens the given files.
void	quit()	Immediately quits the application.
protected void	quitMainloop()	Used to be invoked on the primary instance when the use count of the application drops to zero (and after any inactivity timeout, if requested).
boolean	register(@Nullable Cancellable cancellable)	Attempts registration of the application.
void	release()	Decrease the use count of this Application.
int	run(@Nullable String[] argv)	Runs the application.
protected void	runMainloop()	Used to be invoked on the primary instance from g_application_run() if the use-count is non-zero.
void	sendNotification(@Nullable String id, Notification notification)	Sends a notification on behalf of this Application to the desktop shell.
void	setActionGroup(@Nullable ActionGroup actionGroup)	Deprecated. Use the GActionMap interface instead.
void	setApplicationId(@Nullable String applicationId)	Sets the unique identifier for this Application.
void	setDefault()	Sets or unsets the default application for the process, as returned by g_application_get_default().
void	setFlags(Set<ApplicationFlags> flags)	Sets the flags for this Application.
void	setFlags(ApplicationFlags... flags)	Sets the flags for this Application.
void	setInactivityTimeout(int inactivityTimeout)	Sets the current inactivity timeout for the application.
void	setOptionContextDescription(@Nullable String description)	Adds a description to the this Application option context.
void	setOptionContextParameterString(@Nullable String parameterString)	Sets the parameter string to be used by the commandline handling of this Application.
void	setOptionContextSummary(@Nullable String summary)	Adds a summary to the this Application option context.
void	setResourceBasePath(@Nullable String resourcePath)	Sets (or unsets) the base resource path of this Application.
void	setVersion(String version)	Sets the version number of this Application.
protected void	shutdown()	invoked only on the registered primary instance immediately after the main loop terminates
protected void	startup()	invoked on the primary instance immediately after registration
void	unbindBusyProperty(GObject object, String property)	Destroys a binding between property and the busy state of this Application that was previously created with g_application_bind_busy_property().
void	unmarkBusy()	Decreases the busy count of this Application.
void	withdrawNotification(String id)	Withdraws a notification that was sent with g_application_send_notification().

Methods inherited from class org.gnome.gobject.GObject

addToggleRef, addWeakPointer, bindProperty, bindProperty, bindProperty, bindPropertyFull, bindPropertyFull, bindPropertyWithClosures, bindPropertyWithClosures, compatControl, connect, connect, connect, constructed, disconnect, dispatchPropertiesChanged, dispose, dupData, dupQdata, emit, emitNotify, finalize_, forceFloating, freezeNotify, get, getData, getProperty, getProperty, getProperty, getQdata, getv, interfaceFindProperty, interfaceInstallProperty, interfaceListProperties, isFloating, newInstance, newInstance, newInstance, newInstance, newv, notify_, notify_, notifyByPspec, onNotify, ref, refSink, removeToggleRef, removeWeakPointer, replaceData, replaceQdata, runDispose, set, setData, setDataFull, setProperty, setProperty, setProperty, setQdata, setQdataFull, setv, stealData, stealQdata, takeRef, thawNotify, unref, watchClosure, weakRef, weakUnref, withProperties

Methods inherited from class org.gnome.gobject.TypeInstance

callParent, callParent, getPrivate, readGClass, writeGClass

Methods inherited from class io.github.jwharm.javagi.base.ProxyInstance

equals, handle, hashCode

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.gnome.gio.ActionGroup

actionAdded, actionEnabledChanged, actionRemoved, actionStateChanged, activateAction, changeActionState, emitActionAdded, emitActionEnabledChanged, emitActionRemoved, emitActionStateChanged, getActionEnabled, getActionParameterType, getActionState, getActionStateHint, getActionStateType, hasAction, listActions, onActionAdded, onActionEnabledChanged, onActionRemoved, onActionStateChanged, queryAction

Methods inherited from interface org.gnome.gio.ActionMap

addAction, addActionEntries, lookupAction, removeAction, removeActionEntries

Methods inherited from interface io.github.jwharm.javagi.base.Proxy

handle

Constructor Details

Application

public Application(MemorySegment address)

Create a Application proxy instance for the provided memory address.

Parameters:

address - the memory address of the native object

Application

public Application(@Nullable
 @Nullable String applicationId,
 Set<ApplicationFlags> flags)

Creates a new GApplication instance.

If non-null, the application id must be valid. See g_application_id_is_valid().

If no application ID is given then some features of GApplication (most notably application uniqueness) will be disabled.

Parameters:

applicationId - the application id

flags - the application flags

Application

public Application(@Nullable
 @Nullable String applicationId,
 ApplicationFlags... flags)

Creates a new GApplication instance.

If non-null, the application id must be valid. See g_application_id_is_valid().

If no application ID is given then some features of GApplication (most notably application uniqueness) will be disabled.

Parameters:

applicationId - the application id

flags - the application flags

Method Details

getType

public static Type getType()

Get the GType of the Application class

Returns:

the GType

getMemoryLayout

public static MemoryLayout getMemoryLayout()

The memory layout of the native struct.

Returns:

the memory layout

asParent

protected Application asParent()

Returns this instance as if it were its parent type. This is mostly synonymous to the Java super keyword, but will set the native typeclass function pointers to the parent type. When overriding a native virtual method in Java, "chaining up" with super.methodName() doesn't work, because it invokes the overridden function pointer again. To chain up, call asParent().methodName(). This will call the native function pointer of this virtual method in the typeclass of the parent type.

Overrides:

asParent in class GObject

getDefault

public static Application getDefault()

Returns the default GApplication instance for this process.

Normally there is only one GApplication per process and it becomes the default when it is created. You can exercise more control over this by using g_application_set_default().

If there is no default application then null is returned.

Returns:

the default application for this process, or null

idIsValid

public static boolean idIsValid(String applicationId)

Checks if applicationId is a valid application identifier.

A valid ID is required for calls to g_application_new() and g_application_set_application_id().

Application identifiers follow the same format as D-Bus well-known bus names. For convenience, the restrictions on application identifiers are reproduced here:

• Application identifiers are composed of 1 or more elements separated by a period (.) character. All elements must contain at least one character.

• Each element must only contain the ASCII characters [A-Z][a-z][0-9]_-, with - discouraged in new application identifiers. Each element must not begin with a digit.

• Application identifiers must contain at least one . (period) character (and thus at least two elements).

• Application identifiers must not begin with a . (period) character.

• Application identifiers must not exceed 255 characters.

Note that the hyphen (-) character is allowed in application identifiers, but is problematic or not allowed in various specifications and APIs that refer to D-Bus, such as Flatpak application IDs, the DBusActivatable interface in the Desktop Entry Specification, and the convention that an application's "main" interface and object path resemble its application identifier and bus name. To avoid situations that require special-case handling, it is recommended that new application identifiers consistently replace hyphens with underscores.

Like D-Bus interface names, application identifiers should start with the reversed DNS domain name of the author of the interface (in lower-case), and it is conventional for the rest of the application identifier to consist of words run together, with initial capital letters.

As with D-Bus interface names, if the author's DNS domain name contains hyphen/minus characters they should be replaced by underscores, and if it contains leading digits they should be escaped by prepending an underscore. For example, if the owner of 7-zip.org used an application identifier for an archiving application, it might be named org._7_zip.Archiver.

Parameters:

applicationId - a potential application identifier

Returns:

true if applicationId is valid

activate

public void activate()

Activates the application.

In essence, this results in the GApplication::activate signal being emitted in the primary instance.

The application must be registered before calling this function.

addMainOption

public void addMainOption(String longName,
 byte shortName,
 Set<OptionFlags> flags,
 OptionArg arg,
 String description,
 @Nullable
 @Nullable String argDescription)

Add an option to be handled by this Application.

Calling this function is the equivalent of calling g_application_add_main_option_entries() with a single GOptionEntry that has its arg_data member set to null.

The parsed arguments will be packed into a GVariantDict which is passed to GApplication::handle-local-options. If ApplicationFlags.HANDLES_COMMAND_LINE is set, then it will also be sent to the primary instance. See g_application_add_main_option_entries() for more details.

See GOptionEntry for more documentation of the arguments.

Parameters:

longName - the long name of an option used to specify it in a commandline

shortName - the short name of an option

flags - flags from GOptionFlags

arg - the type of the option, as a GOptionArg

description - the description for the option in --help output

argDescription - the placeholder to use for the extra argument parsed by the option in --help output

addMainOption

public void addMainOption(String longName,
 byte shortName,
 OptionFlags flags,
 OptionArg arg,
 String description,
 @Nullable
 @Nullable String argDescription)

Add an option to be handled by this Application.

Calling this function is the equivalent of calling g_application_add_main_option_entries() with a single GOptionEntry that has its arg_data member set to null.

The parsed arguments will be packed into a GVariantDict which is passed to GApplication::handle-local-options. If ApplicationFlags.HANDLES_COMMAND_LINE is set, then it will also be sent to the primary instance. See g_application_add_main_option_entries() for more details.

See GOptionEntry for more documentation of the arguments.

Parameters:

longName - the long name of an option used to specify it in a commandline

shortName - the short name of an option

flags - flags from GOptionFlags

arg - the type of the option, as a GOptionArg

description - the description for the option in --help output

argDescription - the placeholder to use for the extra argument parsed by the option in --help output

addMainOptionEntries

public void addMainOptionEntries(OptionEntry[] entries)

Adds main option entries to be handled by this Application.

This function is comparable to g_option_context_add_main_entries().

After the commandline arguments are parsed, the GApplication::handle-local-options signal will be emitted. At this point, the application can inspect the values pointed to by argData in the given GOptionEntrys.

Unlike GOptionContext, GApplication supports giving a null argData for a non-callback GOptionEntry. This results in the argument in question being packed into a GVariantDict which is also passed to GApplication::handle-local-options, where it can be inspected and modified. If ApplicationFlags.HANDLES_COMMAND_LINE is set, then the resulting dictionary is sent to the primary instance, where g_application_command_line_get_options_dict() will return it. As it has been passed outside the process at this point, the types of all values in the options dict must be checked before being used. This "packing" is done according to the type of the argument -- booleans for normal flags, strings for strings, bytestrings for filenames, etc. The packing only occurs if the flag is given (ie: we do not pack a "false" GVariant in the case that a flag is missing).

In general, it is recommended that all commandline arguments are parsed locally. The options dictionary should then be used to transmit the result of the parsing to the primary instance, where g_variant_dict_lookup() can be used. For local options, it is possible to either use argData in the usual way, or to consult (and potentially remove) the option from the options dictionary.

This function is new in GLib 2.40. Before then, the only real choice was to send all of the commandline arguments (options and all) to the primary instance for handling. GApplication ignored them completely on the local side. Calling this function "opts in" to the new behaviour, and in particular, means that unrecognized options will be treated as errors. Unrecognized options have never been ignored when ApplicationFlags.HANDLES_COMMAND_LINE is unset.

If GApplication::handle-local-options needs to see the list of filenames, then the use of G_OPTION_REMAINING is recommended. If argData is null then G_OPTION_REMAINING can be used as a key into the options dictionary. If you do use G_OPTION_REMAINING then you need to handle these arguments for yourself because once they are consumed, they will no longer be visible to the default handling (which treats them as filenames to be opened).

It is important to use the proper GVariant format when retrieving the options with g_variant_dict_lookup():

• for OptionArg.NONE, use b
• for OptionArg.STRING, use &s
• for OptionArg.INT, use i
• for OptionArg.INT64, use x
• for OptionArg.DOUBLE, use d
• for OptionArg.FILENAME, use ^&ay
• for OptionArg.STRING_ARRAY, use ^a&s
• for OptionArg.FILENAME_ARRAY, use ^a&ay

Parameters:

entries - the main options for the application

addOptionGroup

public void addOptionGroup(OptionGroup group)

Adds a GOptionGroup to the commandline handling of this Application.

This function is comparable to g_option_context_add_group().

Unlike g_application_add_main_option_entries(), this function does not deal with null argData and never transmits options to the primary instance.

The reason for that is because, by the time the options arrive at the primary instance, it is typically too late to do anything with them. Taking the GTK option group as an example: GTK will already have been initialised by the time the GApplication::command-line handler runs. In the case that this is not the first-running instance of the application, the existing instance may already have been running for a very long time.

This means that the options from GOptionGroup are only really usable in the case that the instance of the application being run is the first instance. Passing options like --display= or --gdk-debug= on future runs will have no effect on the existing primary instance.

Calling this function will cause the options in the supplied option group to be parsed, but it does not cause you to be "opted in" to the new functionality whereby unrecognized options are rejected even if ApplicationFlags.HANDLES_COMMAND_LINE was given.

Parameters:

group - a GOptionGroup

bindBusyProperty

public void bindBusyProperty(GObject object,
 String property)

Marks this Application as busy (see g_application_mark_busy()) while property on object is true.

The binding holds a reference to this Application while it is active, but not to object. Instead, the binding is destroyed when object is finalized.

Parameters:

object - a GObject

property - the name of a boolean property of object

getApplicationId

public String getApplicationId()

Gets the unique identifier for this Application.

Returns:

the identifier for this Application, owned by this Application

getDbusConnection

public DBusConnection getDbusConnection()

Gets the GDBusConnection being used by the application, or null.

If GApplication is using its D-Bus backend then this function will return the GDBusConnection being used for uniqueness and communication with the desktop environment and other instances of the application.

If GApplication is not using D-Bus then this function will return null. This includes the situation where the D-Bus backend would normally be in use but we were unable to connect to the bus.

This function must not be called before the application has been registered. See g_application_get_is_registered().

Returns:

a GDBusConnection, or null

getDbusObjectPath

public String getDbusObjectPath()

Gets the D-Bus object path being used by the application, or null.

If GApplication is using its D-Bus backend then this function will return the D-Bus object path that GApplication is using. If the application is the primary instance then there is an object published at this path. If the application is not the primary instance then the result of this function is undefined.

If GApplication is not using D-Bus then this function will return null. This includes the situation where the D-Bus backend would normally be in use but we were unable to connect to the bus.

This function must not be called before the application has been registered. See g_application_get_is_registered().

Returns:

the object path, or null

getFlags

public Set<ApplicationFlags> getFlags()

Gets the flags for this Application.

See GApplicationFlags.

Returns:

the flags for this Application

getInactivityTimeout

public int getInactivityTimeout()

Gets the current inactivity timeout for the application.

This is the amount of time (in milliseconds) after the last call to g_application_release() before the application stops running.

Returns:

the timeout, in milliseconds

getIsBusy

public boolean getIsBusy()

Gets the application's current busy state, as set through g_application_mark_busy() or g_application_bind_busy_property().

Returns:

true if this Application is currently marked as busy

getIsRegistered

public boolean getIsRegistered()

Checks if this Application is registered.

An application is registered if g_application_register() has been successfully called.

Returns:

true if this Application is registered

getIsRemote

public boolean getIsRemote()

Checks if this Application is remote.

If this Application is remote then it means that another instance of application already exists (the 'primary' instance). Calls to perform actions on this Application will result in the actions being performed by the primary instance.

The value of this property cannot be accessed before g_application_register() has been called. See g_application_get_is_registered().

Returns:

true if this Application is remote

getResourceBasePath

public String getResourceBasePath()

Gets the resource base path of this Application.

See g_application_set_resource_base_path() for more information.

Returns:

the base resource path, if one is set

getVersion

public String getVersion()

Gets the version of this Application.

Returns:

the version of this Application

hold

public void hold()

Increases the use count of this Application.

Use this function to indicate that the application has a reason to continue to run. For example, g_application_hold() is called by GTK when a toplevel window is on the screen.

To cancel the hold, call g_application_release().

markBusy

public void markBusy()

Increases the busy count of this Application.

Use this function to indicate that the application is busy, for instance while a long running operation is pending.

The busy state will be exposed to other processes, so a session shell will use that information to indicate the state to the user (e.g. with a spinner).

To cancel the busy indication, use g_application_unmark_busy().

The application must be registered before calling this function.

open

public void open(File[] files,
 String hint)

Opens the given files.

In essence, this results in the GApplication::open signal being emitted in the primary instance.

nFiles must be greater than zero.

hint is simply passed through to the ::open signal. It is intended to be used by applications that have multiple modes for opening files (eg: "view" vs "edit", etc). Unless you have a need for this functionality, you should use "".

The application must be registered before calling this function and it must have the ApplicationFlags.HANDLES_OPEN flag set.

Parameters:

files - an array of GFiles to open

hint - a hint (or ""), but never null

quit

public void quit()

Immediately quits the application.

Upon return to the mainloop, g_application_run() will return, calling only the 'shutdown' function before doing so.

The hold count is ignored. Take care if your code has called g_application_hold() on the application and is therefore still expecting it to exist. (Note that you may have called g_application_hold() indirectly, for example through gtk_application_add_window().)

The result of calling g_application_run() again after it returns is unspecified.

register

public boolean register(@Nullable
 @Nullable Cancellable cancellable)
                 throws GErrorException

Attempts registration of the application.

This is the point at which the application discovers if it is the primary instance or merely acting as a remote for an already-existing primary instance. This is implemented by attempting to acquire the application identifier as a unique bus name on the session bus using GDBus.

If there is no application ID or if ApplicationFlags.NON_UNIQUE was given, then this process will always become the primary instance.

Due to the internal architecture of GDBus, method calls can be dispatched at any time (even if a main loop is not running). For this reason, you must ensure that any object paths that you wish to register are registered before calling this function.

If the application has already been registered then true is returned with no work performed.

The GApplication::startup signal is emitted if registration succeeds and this Application is the primary instance (including the non-unique case).

In the event of an error (such as cancellable being cancelled, or a failure to connect to the session bus), false is returned and error is set appropriately.

Note: the return value of this function is not an indicator that this instance is or is not the primary instance of the application. See g_application_get_is_remote() for that.

Parameters:

cancellable - a GCancellable, or null

Returns:

true if registration succeeded

Throws:

GErrorException - see GError

release

public void release()

Decrease the use count of this Application.

When the use count reaches zero, the application will stop running.

Never call this function except to cancel the effect of a previous call to g_application_hold().

run

public int run(@Nullable
 @Nullable String[] argv)

Runs the application.

This function is intended to be run from main() and its return value is intended to be returned by main(). Although you are expected to pass the argc, argv parameters from main() to this function, it is possible to pass null if argv is not available or commandline handling is not required. Note that on Windows, argc and argv are ignored, and g_win32_get_command_line() is called internally (for proper support of Unicode commandline arguments).

GApplication will attempt to parse the commandline arguments. You can add commandline flags to the list of recognised options by way of g_application_add_main_option_entries(). After this, the GApplication::handle-local-options signal is emitted, from which the application can inspect the values of its GOptionEntrys.

GApplication::handle-local-options is a good place to handle options such as --version, where an immediate reply from the local process is desired (instead of communicating with an already-running instance). A GApplication::handle-local-options handler can stop further processing by returning a non-negative value, which then becomes the exit status of the process.

What happens next depends on the flags: if ApplicationFlags.HANDLES_COMMAND_LINE was specified then the remaining commandline arguments are sent to the primary instance, where a GApplication::command-line signal is emitted. Otherwise, the remaining commandline arguments are assumed to be a list of files. If there are no files listed, the application is activated via the GApplication::activate signal. If there are one or more files, and ApplicationFlags.HANDLES_OPEN was specified then the files are opened via the GApplication::open signal.

If you are interested in doing more complicated local handling of the commandline then you should implement your own GApplication subclass and override local_command_line(). In this case, you most likely want to return true from your local_command_line() implementation to suppress the default handling. See [gapplication-example-cmdline2.c][https://gitlab.gnome.org/GNOME/glib/-/blob/HEAD/gio/tests/gapplication-example-cmdline2.c] for an example.

If, after the above is done, the use count of the application is zero then the exit status is returned immediately. If the use count is non-zero then the default main context is iterated until the use count falls to zero, at which point 0 is returned.

If the ApplicationFlags.IS_SERVICE flag is set, then the service will run for as much as 10 seconds with a use count of zero while waiting for the message that caused the activation to arrive. After that, if the use count falls to zero the application will exit immediately, except in the case that g_application_set_inactivity_timeout() is in use.

This function sets the prgname (g_set_prgname()), if not already set, to the basename of argv[0].

Much like g_main_loop_run(), this function will acquire the main context for the duration that the application is running.

Since 2.40, applications that are not explicitly flagged as services or launchers (ie: neither ApplicationFlags.IS_SERVICE or ApplicationFlags.IS_LAUNCHER are given as flags) will check (from the default handler for local_command_line) if "--gapplication-service" was given in the command line. If this flag is present then normal commandline processing is interrupted and the ApplicationFlags.IS_SERVICE flag is set. This provides a "compromise" solution whereby running an application directly from the commandline will invoke it in the normal way (which can be useful for debugging) while still allowing applications to be D-Bus activated in service mode. The D-Bus service file should invoke the executable with "--gapplication-service" as the sole commandline argument. This approach is suitable for use by most graphical applications but should not be used from applications like editors that need precise control over when processes invoked via the commandline will exit and what their exit status will be.

Parameters:

argv - the argv from main(), or null

Returns:

the exit status

sendNotification

public void sendNotification(@Nullable
 @Nullable String id,
 Notification notification)

Sends a notification on behalf of this Application to the desktop shell. There is no guarantee that the notification is displayed immediately, or even at all.

Notifications may persist after the application exits. It will be D-Bus-activated when the notification or one of its actions is activated.

Modifying notification after this call has no effect. However, the object can be reused for a later call to this function.

id may be any string that uniquely identifies the event for the application. It does not need to be in any special format. For example, "new-message" might be appropriate for a notification about new messages.

If a previous notification was sent with the same id, it will be replaced with notification and shown again as if it was a new notification. This works even for notifications sent from a previous execution of the application, as long as id is the same string.

id may be NULL, but it is impossible to replace or withdraw notifications without an id.

If notification is no longer relevant, it can be withdrawn with withdrawNotification(java.lang.String).

It is an error to call this function if this Application has no application ID.

Parameters:

id - id of the notification, or null

notification - the GNotification to send

setActionGroup

@Deprecated
public void setActionGroup(@Nullable
 @Nullable ActionGroup actionGroup)

Deprecated.

Use the GActionMap interface instead. Never ever mix use of this API with use of GActionMap on the same this Application or things will go very badly wrong. This function is known to introduce buggy behaviour (ie: signals not emitted on changes to the action group), so you should really use GActionMap instead.

This used to be how actions were associated with a GApplication. Now there is GActionMap for that.

Parameters:

actionGroup - a GActionGroup, or null

setApplicationId

public void setApplicationId(@Nullable
 @Nullable String applicationId)

Sets the unique identifier for this Application.

The application id can only be modified if this Application has not yet been registered.

If non-null, the application id must be valid. See g_application_id_is_valid().

Parameters:

applicationId - the identifier for this Application

setDefault

public void setDefault()

Sets or unsets the default application for the process, as returned by g_application_get_default().

This function does not take its own reference on this Application. If this Application is destroyed then the default application will revert back to null.

setFlags

public void setFlags(Set<ApplicationFlags> flags)

Sets the flags for this Application.

The flags can only be modified if this Application has not yet been registered.

See GApplicationFlags.

Parameters:

flags - the flags for this Application

setFlags

public void setFlags(ApplicationFlags... flags)

Sets the flags for this Application.

The flags can only be modified if this Application has not yet been registered.

See GApplicationFlags.

Parameters:

flags - the flags for this Application

setInactivityTimeout

public void setInactivityTimeout(int inactivityTimeout)

Sets the current inactivity timeout for the application.

This is the amount of time (in milliseconds) after the last call to g_application_release() before the application stops running.

This call has no side effects of its own. The value set here is only used for next time g_application_release() drops the use count to zero. Any timeouts currently in progress are not impacted.

Parameters:

inactivityTimeout - the timeout, in milliseconds

setOptionContextDescription

public void setOptionContextDescription(@Nullable
 @Nullable String description)

Adds a description to the this Application option context.

See g_option_context_set_description() for more information.

Parameters:

description - a string to be shown in --help output after the list of options, or null

setOptionContextParameterString

public void setOptionContextParameterString(@Nullable
 @Nullable String parameterString)

Sets the parameter string to be used by the commandline handling of this Application.

This function registers the argument to be passed to g_option_context_new() when the internal GOptionContext of this Application is created.

See g_option_context_new() for more information about parameterString.

Parameters:

parameterString - a string which is displayed in the first line of --help output, after the usage summary programname [OPTION...].

setOptionContextSummary

public void setOptionContextSummary(@Nullable
 @Nullable String summary)

Adds a summary to the this Application option context.

See g_option_context_set_summary() for more information.

Parameters:

summary - a string to be shown in --help output before the list of options, or null

setResourceBasePath

public void setResourceBasePath(@Nullable
 @Nullable String resourcePath)

Sets (or unsets) the base resource path of this Application.

The path is used to automatically load various [application resources][gresource] such as menu layouts and action descriptions. The various types of resources will be found at fixed names relative to the given base path.

By default, the resource base path is determined from the application ID by prefixing '/' and replacing each '.' with '/'. This is done at the time that the GApplication object is constructed. Changes to the application ID after that point will not have an impact on the resource base path.

As an example, if the application has an ID of "org.example.app" then the default resource base path will be "/org/example/app". If this is a GtkApplication (and you have not manually changed the path) then Gtk will then search for the menus of the application at "/org/example/app/gtk/menus.ui".

See GResource for more information about adding resources to your application.

You can disable automatic resource loading functionality by setting the path to null.

Changing the resource base path once the application is running is not recommended. The point at which the resource path is consulted for forming paths for various purposes is unspecified. When writing a sub-class of GApplication you should either set the GApplication:resource-base-path property at construction time, or call this function during the instance initialization. Alternatively, you can call this function in the GApplicationClass.startup virtual function, before chaining up to the parent implementation.

Parameters:

resourcePath - the resource path to use

setVersion

public void setVersion(String version)

Sets the version number of this Application. This will be used to implement a --version command line argument

The application version can only be modified if this Application has not yet been registered.

Parameters:

version - the version of this Application

unbindBusyProperty

public void unbindBusyProperty(GObject object,
 String property)

Destroys a binding between property and the busy state of this Application that was previously created with g_application_bind_busy_property().

Parameters:

object - a GObject

property - the name of a boolean property of object

unmarkBusy

public void unmarkBusy()

Decreases the busy count of this Application.

When the busy count reaches zero, the new state will be propagated to other processes.

This function must only be called to cancel the effect of a previous call to g_application_mark_busy().

withdrawNotification

public void withdrawNotification(String id)

Withdraws a notification that was sent with g_application_send_notification().

This call does nothing if a notification with id doesn't exist or the notification was never sent.

This function works even for notifications sent in previous executions of this application, as long id is the same as it was for the sent notification.

Note that notifications are dismissed when the user clicks on one of the buttons in a notification or triggers its default action, so there is no need to explicitly withdraw the notification in that case.

Parameters:

id - id of a previously sent notification

addPlatformData

protected void addPlatformData(VariantBuilder builder)

invoked (locally) to add 'platform data' to be sent to the primary instance when activating, opening or invoking actions

afterEmit

protected void afterEmit(Variant platformData)

invoked on the primary instance after 'activate', 'open', 'command-line' or any action invocation, gets the 'platform data' from the calling instance

beforeEmit

protected void beforeEmit(Variant platformData)

invoked on the primary instance before 'activate', 'open', 'command-line' or any action invocation, gets the 'platform data' from the calling instance

commandLine

protected int commandLine(ApplicationCommandLine commandLine)

invoked on the primary instance when a command-line is not handled locally

dbusRegister

protected boolean dbusRegister(DBusConnection connection,
 String objectPath)
                        throws GErrorException

invoked locally during registration, if the application is using its D-Bus backend. You can use this to export extra objects on the bus, that need to exist before the application tries to own the bus name. The function is passed the GDBusConnection to to session bus, and the object path that GApplication will use to export its D-Bus API. If this function returns true, registration will proceed; otherwise registration will abort. Since: 2.34

Throws:

GErrorException - see GError

dbusUnregister

protected void dbusUnregister(DBusConnection connection,
 String objectPath)

invoked locally during unregistration, if the application is using its D-Bus backend. Use this to undo anything done by the dbusRegister vfunc. Since: 2.34

handleLocalOptions

protected int handleLocalOptions(VariantDict options)

invoked locally after the parsing of the commandline options has occurred. Since: 2.40

localCommandLine

protected boolean localCommandLine(String[] arguments,
 Out<Integer> exitStatus)

This virtual function is always invoked in the local instance. It gets passed a pointer to a null-terminated copy of argv and is expected to remove arguments that it handled (shifting up remaining arguments).

The last argument to local_command_line() is a pointer to the status variable which can used to set the exit status that is returned from g_application_run().

See g_application_run() for more details on GApplication startup.

Parameters:

arguments - array of command line arguments

exitStatus - exit status to fill after processing the command line.

Returns:

true if the commandline has been completely handled

nameLost

protected boolean nameLost()

invoked when another instance is taking over the name. Since: 2.60

quitMainloop

protected void quitMainloop()

Used to be invoked on the primary instance when the use count of the application drops to zero (and after any inactivity timeout, if requested). Not used anymore since 2.32

runMainloop

protected void runMainloop()

Used to be invoked on the primary instance from g_application_run() if the use-count is non-zero. Since 2.32, GApplication is iterating the main context directly and is not using runMainloop anymore

shutdown

protected void shutdown()

invoked only on the registered primary instance immediately after the main loop terminates

startup

protected void startup()

invoked on the primary instance immediately after registration

onActivate

public SignalConnection<Application.ActivateCallback> onActivate(Application.ActivateCallback handler)

The ::activate signal is emitted on the primary instance when an activation occurs. See g_application_activate().

Parameters:

handler - the signal handler

Returns:

a signal handler ID to keep track of the signal connection

See Also:

• Application.ActivateCallback.run()

emitActivate

public void emitActivate()

Emits the "activate" signal. See onActivate(org.gnome.gio.Application.ActivateCallback).

onCommandLine

public SignalConnection<Application.CommandLineCallback> onCommandLine(Application.CommandLineCallback handler)

The ::command-line signal is emitted on the primary instance when a commandline is not handled locally. See g_application_run() and the GApplicationCommandLine documentation for more information.

Parameters:

handler - the signal handler

Returns:

a signal handler ID to keep track of the signal connection

See Also:

• Application.CommandLineCallback.run(org.gnome.gio.ApplicationCommandLine)

emitCommandLine

public int emitCommandLine(ApplicationCommandLine commandLine)

Emits the "command-line" signal. See onCommandLine(org.gnome.gio.Application.CommandLineCallback).

onHandleLocalOptions

public SignalConnection<Application.HandleLocalOptionsCallback> onHandleLocalOptions(Application.HandleLocalOptionsCallback handler)

The ::handle-local-options signal is emitted on the local instance after the parsing of the commandline options has occurred.

You can add options to be recognised during commandline option parsing using g_application_add_main_option_entries() and g_application_add_option_group().

Signal handlers can inspect options (along with values pointed to from the argData of an installed GOptionEntrys) in order to decide to perform certain actions, including direct local handling (which may be useful for options like --version).

In the event that the application is marked ApplicationFlags.HANDLES_COMMAND_LINE the "normal processing" will send the options dictionary to the primary instance where it can be read with g_application_command_line_get_options_dict(). The signal handler can modify the dictionary before returning, and the modified dictionary will be sent.

In the event that ApplicationFlags.HANDLES_COMMAND_LINE is not set, "normal processing" will treat the remaining uncollected command line arguments as filenames or URIs. If there are no arguments, the application is activated by g_application_activate(). One or more arguments results in a call to g_application_open().

If you want to handle the local commandline arguments for yourself by converting them to calls to g_application_open() or g_action_group_activate_action() then you must be sure to register the application first. You should probably not call g_application_activate() for yourself, however: just return -1 and allow the default handler to do it for you. This will ensure that the --gapplication-service switch works properly (i.e. no activation in that case).

Note that this signal is emitted from the default implementation of local_command_line(). If you override that function and don't chain up then this signal will never be emitted.

You can override local_command_line() if you need more powerful capabilities than what is provided here, but this should not normally be required.

Parameters:

handler - the signal handler

Returns:

a signal handler ID to keep track of the signal connection

See Also:

• Application.HandleLocalOptionsCallback.run(org.gnome.glib.VariantDict)

emitHandleLocalOptions

public int emitHandleLocalOptions(VariantDict options)

Emits the "handle-local-options" signal. See onHandleLocalOptions(org.gnome.gio.Application.HandleLocalOptionsCallback).

onNameLost

public SignalConnection<Application.NameLostCallback> onNameLost(Application.NameLostCallback handler)

The ::name-lost signal is emitted only on the registered primary instance when a new instance has taken over. This can only happen if the application is using the ApplicationFlags.ALLOW_REPLACEMENT flag.

The default handler for this signal calls g_application_quit().

Parameters:

handler - the signal handler

Returns:

a signal handler ID to keep track of the signal connection

See Also:

• Application.NameLostCallback.run()

emitNameLost

public boolean emitNameLost()

Emits the "name-lost" signal. See onNameLost(org.gnome.gio.Application.NameLostCallback).

onOpen

public SignalConnection<Application.OpenCallback> onOpen(Application.OpenCallback handler)

The ::open signal is emitted on the primary instance when there are files to open. See g_application_open() for more information.

Parameters:

handler - the signal handler

Returns:

a signal handler ID to keep track of the signal connection

See Also:

• Application.OpenCallback.run(org.gnome.gio.File[], java.lang.String)

emitOpen

public void emitOpen(File[] files,
 String hint)

Emits the "open" signal. See onOpen(org.gnome.gio.Application.OpenCallback).

onShutdown

public SignalConnection<Application.ShutdownCallback> onShutdown(Application.ShutdownCallback handler)

The ::shutdown signal is emitted only on the registered primary instance immediately after the main loop terminates.

Parameters:

handler - the signal handler

Returns:

a signal handler ID to keep track of the signal connection

See Also:

• Application.ShutdownCallback.run()

emitShutdown

public void emitShutdown()

Emits the "shutdown" signal. See onShutdown(org.gnome.gio.Application.ShutdownCallback).

onStartup

public SignalConnection<Application.StartupCallback> onStartup(Application.StartupCallback handler)

The ::startup signal is emitted on the primary instance immediately after registration. See g_application_register().

Parameters:

handler - the signal handler

Returns:

a signal handler ID to keep track of the signal connection

See Also:

• Application.StartupCallback.run()

emitStartup

public void emitStartup()

Emits the "startup" signal. See onStartup(org.gnome.gio.Application.StartupCallback).

builder

public static Application.Builder<? extends Application.Builder> builder()

A Application.Builder object constructs a Application with the specified properties. Use the various set...() methods to set properties, and finish construction with Application.Builder.build().