[Overview][Constants][Types][Classes][Procedures and functions][Variables][Index] | Reference for unit 'Forms' (#lcl)

# TApplication

[Properties (by Name)] [Methods (by Name)] [Events (by Name)]

TApplication - the whole current program, described as an object

## Declaration

Source position: forms.pp line 1174

`type TApplication = class(TCustomApplication)`
`protected`
`function GetConsoleApplication; override;` |  | GetConsoleApplication - returns True if this is a Console application (ie text-mode, non-GUI)
`procedure NotifyIdleHandler();` |  | NotifyIdleHandler - method for sending message to Idle handler (sends True if process is done)
`procedure NotifyIdleEndHandler;` |  | NotifyIdleEndHandler - method for sending message to handler for end of idle state
`procedure NotifyActivateHandler;` |  | NotifyActivateHandler - method for sending message to handler for activation
`procedure NotifyDeactivateHandler;` |  | NotifyDeactivateHandler - method for sending message to handler for deactivation
`procedure NotifyCustomForms();`
`function IsHintMsg();` |  | IsHintMsg - returns True if specified message is a valid Hint
`function DoOnHelp(); virtual;`
`procedure DoOnMouseMove; virtual;` |  | DoOnMouseMove - method for the OnMouseMove event
`procedure ShowHintWindow();` |  | ShowHintWindow - method for showing a hint window
`procedure OnHintTimer();` |  | OnHintTimer - event handler for timing the duration of hints
`procedure SetTitle(); override;` |  | SetTitle - method for writing the specified title string to local store
`procedure StartHintTimer();` |  | StartHintTimer - method for starting the timer for display of a hint message
`procedure UpdateVisible;` |  | UpdateVisible - update all visible components
`procedure DoIdleActions;` |  | DoIdleActions - perform the actions that remain idle
`procedure MenuPopupHandler();` |  | MenuPopupHandler - method for dealing with menu popups
`procedure ProcessAsyncCallQueue;` |  | ProcessAsyncCallQueue - method to process a queue of asynchronous calls
`procedure FreeComponent();` |  | FreeComponent - method for freeing a component
`procedure ReleaseComponents;`
`procedure DoBeforeFinalization;` |  | DoBeforeFinalization - the things to be done before finalisation of the application
`function GetParams(); override;` |  | GetParams - find the application's parameters (typically by parsing the command line that invoked the application)
`public`
`constructor Create(); override;` |  | Create - constructor for TApplication: initialises a large number of local variables and properties, then calls inherited Create
`destructor Destroy; override;` |  | Destroy - destructor for TApplication: frees various handles and flags, then cals inherited Destroy
`procedure ActivateHint();`
`function GetControlAtMouse;` |  |
`procedure ControlDestroyed();` |  | Method for dealing with a control that has been destroyed
`function BigIconHandle;` |  | BigIconHandle - system Handle for large Icon
`function SmallIconHandle;` |  | SmallIconHandle - system handle for small Icon
`procedure BringToFront;` |  | BringToFront - Use the selected widget set's method to bring the application's form(s) to the front
`procedure CreateForm();` |  | Create Form or any other kind of component
`procedure UpdateMainForm();` |  | UpdateMainForm - update the Application's main form
`procedure QueueAsyncCall();` |  | Insert a given asynchronous call into the queue
`procedure RemoveAsyncCalls();`
`procedure ReleaseComponent();` |  | ReleaseComponent - method to release the specified component
`function ExecuteAction(); override;` |  | ExecuteAction - calls the OnActionExecute event hndler if it is assigned
`function UpdateAction(); override;` |  | UpdateAction - calls the OnUpdateAction event handler if it is assigned
`procedure HandleException(); override;` |  | HandleException method for handling an exception; attempts to maintain program execution if possible, otherwise exits gracefully
`procedure HandleMessage;` |  | Process all events according to the method defined for the widget set
`function HelpCommand();`
`function HelpContext();` |  | HelpContext - returns True if there is a specified context-dependent help message associated with the application, with an optionally specified position
`function HelpKeyword();` |  | HelpKeyword - returns True if there is a specified help keyword associated with the application, with an optionally specified position
`procedure ShowHelpForObject();` |  | ShowHelpForObject - method for displaying help messages
`procedure RemoveStayOnTop();`
`procedure RestoreStayOnTop();`
`function IsWaiting;` |  | IsWaiting - returns True if the application is awainting an event
`procedure CancelHint;` |  | Cancels a request for a hint, if there is no hint timer or no hint to display
`procedure HideHint;` |  | Don't display the hint
`procedure HintMouseMessage();` |  | HintMouseMessage - method to find the hint for the control at the mouse position
`procedure Initialize; override;` |  | Initialize - calls inherited Initialize, then initialises widget set, loads icons from Laz resources and updates screen
`function MessageBox();` |  | Message Box: a useful function to display a message.
`procedure Minimize;` |  | Minimise the form using the widget set's method
`procedure ModalStarted;`
`procedure ModalFinished;`
`procedure Restore;` |  | Restore the application's form to the size it was before minimisation or maximisation
`procedure Notification(); override;` |  | Notification if Operation is Remove, then sets any Component to nil, otherwise calls inherited Notification
`procedure ProcessMessages;` |  | ProcessMessages - method for processing system messages
`procedure Idle();` |  | Idle - method for rendering the Application Idle if Wait is True
`procedure Run;`
`procedure ShowException(); override;`
`procedure Terminate; override;`
`procedure DisableIdleHandler;` |  | DisableIdleHandler - turn off the Idle handler
`procedure EnableIdleHandler;` |  | EnableIdleHandler - turn on the Idle handler
`procedure NotifyUserInputHandler();` |  | NotifyUserInputHandler - send message t handler for user input
`procedure NotifyKeyDownBeforeHandler();` |  | NotifyKeyDownBeforeHandler - send message to handler for the condition where a key has been previously pressed (eg a Shift, Control or Alt key(
`procedure NotifyKeyDownHandler();` |  | NotifyKeyDownHandler - sends message to handler for a key pressed down
`procedure ControlKeyDown();` |  | ControlKeyDown - method for dealing with the Control Key being pressed down
`procedure ControlKeyUp();` |  | ControlKeyUp - method for dealing with a released Control key
`procedure AddOnIdleHandler();` |  | AddOnIdleHandler - method for adding a handler for the Idle state
`procedure RemoveOnIdleHandler();` |  | RemoveOnIdleHandler - method for removing a handler for the Idle state
`procedure AddOnIdleEndHandler();` |  | AddOnIdleEndHandler - method to add a handler for the end of the Idle state
`procedure RemoveOnIdleEndHandler();` |  | RemoveOnIdleEndHandler - method for removing handler for the end of the Idle state
`procedure AddOnUserInputHandler();` |  | AddOnUserInputHandler - method for adding a handler for user input
`procedure RemoveOnUserInputHandler();` |  | RemoveOnUserInputHandler - method for removing handler for user input
`procedure AddOnKeyDownBeforeHandler();` |  | AddOnKeyDownBeforeHandler - method for adding handler for the state where a key (eg Ctrl, Shift, Alt) has been already pressed
`procedure RemoveOnKeyDownBeforeHandler();` |  | RemoveOnKeyDownBeforeHandler - method for removing handler for the state where a key (eg Ctrl, Shift, Alt) has been already pressed
`procedure AddOnKeyDownHandler();` |  | AddOnKeyDownHandler - method for adding a handler for the Key Down state
`procedure RemoveOnKeyDownHandler();` |  | RemoveOnKeyDownHandler - method for removing handler for the Key Down state
`procedure AddOnActivateHandler();` |  | AddOnActivateHandler - method for adding a handler for activation
`procedure RemoveOnActivateHandler();` |  | RemoveOnActivateHandler - method for removing handler for activation
`procedure AddOnDeactivateHandler();` |  | AddOnDeactivateHandler - method for adding handler for deactivation
`procedure RemoveOnDeactivateHandler();` |  | RemoveOnDeactivateHandler - method for removing deactivation handler
`procedure AddOnExceptionHandler();` |  | AddOnExceptionHandler - method for adding exception handler
`procedure RemoveOnExceptionHandler();` |  | RemoveOnExceptionHandler - method for removing exception handler
`procedure AddOnEndSessionHandler();` |  | AddOnEndSessionHandler - method for adding handler for end of session
`procedure RemoveOnEndSessionHandler();` |  | RemoveOnEndSessionHandler - method for removing handler for end of session
`procedure AddOnQueryEndSessionHandler();` |  | AddOnQueryEndSessionHandler - method for adding handler for a query at the end of a session
`procedure RemoveOnQueryEndSessionHandler();` |  | RemoveOnQueryEndSessionHandler - method for removing handler for a query at the end of a session
`procedure AddOnMinimizeHandler();` |  | AddOnMinimizeHandler - method for adding handler for minimising component
`procedure RemoveOnMinimizeHandler();` |  | RemoveOnMinimizeHandler - method to remove handler for maximising component
`procedure AddOnModalBeginHandler();`
`procedure RemoveOnModalBeginHandler();`
`procedure AddOnModalEndHandler();`
`procedure RemoveOnModalEndHandler();`
`procedure AddOnRestoreHandler();` |  | AddOnRestoreHandler - method to add handler for Restore component
`procedure RemoveOnRestoreHandler();` |  | RemoveOnRestoreHandler - method to remove restore handler
`procedure AddOnDropFilesHandler();` |  | AddOnDropFilesHandler - method to add handler for dropped files
`procedure RemoveOnDropFilesHandler();` |  | RemoveOnDropFilesHandler - method for removing drop files handler
`procedure AddOnHelpHandler();` |  | AddOnHelpHandler - method to add Help handler
`procedure RemoveOnHelpHandler();` |  | RemoveOnHelpHandler - method to remove Help handler
`procedure AddOnHintHandler();` |  | AddOnHintHandler - method to add handler for Hints
`procedure RemoveOnHintHandler();` |  | RemoveOnHintHandler - method to remove Hint handler
`procedure AddOnShowHintHandler();` |  | AddOnShowHintHandler - method to add handler for showing Hints
`procedure RemoveOnShowHintHandler();` |  | RemoveOnShowHintHandler - method for removing handler for showing Hints
`procedure RemoveAllHandlersOfObject(); virtual;` |  | RemoveAllHandlersOfObject - method to remove all handlers of an object
`procedure DoBeforeMouseMessage();` |  | DoBeforeMouseMessage - things to be done before a mouse message is processed
`function IsShortcut();` |  | IsShortcut - returns True if specified Keyi s a shortcut
`procedure IntfQueryEndSession();` |  | IntfQueryEndSession - called by the interface when there is a query at the end of a session
`procedure IntfEndSession;` |  | IntfEndSession - called by the interface at the end of a session
`procedure IntfAppActivate;`
`procedure IntfAppDeactivate;`
`procedure IntfAppMinimize;` |  | IntfAppMinimize - called by the interface if an application is minimised
`procedure IntfAppRestore;` |  | IntfAppRestore - called by the interface when an application is being restored
`procedure IntfDropFiles();` |  | IntfDropFiles - called by the interface for dropping files
`procedure IntfThemeOptionChange();`
`function IsRTLLang();`
`function Direction();`
`procedure DoArrowKey();` |  | DoArrowKey - method for processing an arrow key
`procedure DoEscapeKey();` |  | DoEscapeKey - method for processing the Escape key
`procedure DoReturnKey();` |  | DoReturnKey - method for processing the Return (Enter) key
`procedure DoTabKey();` |  | DoTabKey - method for processing the Tab key
`property Active: Boolean; [r]` |  | Active - returns True if this is an active Application
`property ApplicationType: TApplicationType; [rw]` |  | ApplicationType - The type of the application (ie the sort of device for which it is intended)
`property BidiMode: TBiDiMode; [rw]` |  | BidiMode - whether bi-directional mode is available
`property CaptureExceptions: Boolean; [rw]` |  | CaptureExceptions - If exceptions have occurred, find out what they are, ready for processing
`property FindGlobalComponentEnabled: Boolean; [rw]` |  | FindGlobalComponentEnabled - returns True if the Find Global Component state is enabled
`property Flags: TApplicationFlags; [rw]` |  | Flags - the list of flags for this application
`property Hint: String; [rw]` |  | The hint associated with the main application
`property HintColor: TColor; [rw]` |  | The colour used to display the hint
`property HintHidePause: Integer; [rw]` |  | The delay period after mouse entry before the hint becomes visible
`property HintHidePausePerChar: Integer; [rw]` |  | HintHidePausePerChar - the pause period per character for hiding a hint
`property HintPause: Integer; [rw]` |  | HintPause - The length of time for which the hint is displayed
`property HintShortCuts: Boolean; [rw]` |  | HintShortCuts - If True, there are hints for short cut keys
`property HintShortPause: Integer; [rw]` |  | HintShortPause - the pause before a shortcut hint is displayed
`property Icon: TIcon; [rw]` |  | The icon to be associated with this application
`property Navigation: TApplicationNavigationOptions; [rw]` |  | Determine how the form is to be navigated
`property MainForm: TForm; [r]` |  | The Main Form used by the application for process control and for data input/output
`property ModalLevel: Integer; [r]`
`property MouseControl: TControl; [r]`
`property TaskBarBehavior: TTaskBarBehavior; [rw]`
`property OnActionExecute: TActionEvent; [rw]` |  | OnActionExecute - event handler for executing the application's main action
`property OnActionUpdate: TActionEvent; [rw]` |  | OnActionUpdate - event handler for updating the application's main action
`property OnActivate: TNotifyEvent; [rw]` |  | OnActivate - Event handler for activation of the application
`property OnDeactivate: TNotifyEvent; [rw]` |  | OnDeactivate - Event handler for deactivation of the application
`property OnIdle: TIdleEvent; [rw]` |  | OnIdle - event handler for the Idle state
`property OnIdleEnd: TNotifyEvent; [rw]` |  | OnIdleEnd - event handler for the end of the Idle state
`property OnEndSession: TNotifyEvent; [rw]` |  | OnEndSession - Event handler for ending a session of the application
`property OnQueryEndSession: TQueryEndSessionEvent; [rw]` |  | OnQueryEndSession - event handler for processing a query at the end of a session
`property OnMinimize: TNotifyEvent; [rw]` |  | OnMinimize - Event handler for minimising the application's form
`property OnModalBegin: TNotifyEvent; [rw]`
`property OnModalEnd: TNotifyEvent; [rw]`
`property OnRestore: TNotifyEvent; [rw]` |  | OnRestore - Event handler for restoring the application's form from minimised or maximised condition
`property OnDropFiles: TDropFilesEvent; [rw]` |  | OnDropFiles - The event invoked when file is dropped on one of the application forms.
`property OnHelp: THelpEvent; [rw]` |  | OnHelp - Event handler when help is required
`property OnHint: TNotifyEvent; [rw]` |  | OnHint - Event handler when a hint is required
`property OnShortcut: TShortCutEvent; [rw]` |  | OnShortcut - Event handler when a shortcut key is pressed
`property OnShowHint: TShowHintEvent; [rw]` |  | OnShowHint - Event handler for showing a hint
`property OnUserInput: TOnUserInputEvent; [rw]` |  | OnUserInput - Event handler when user input is required or is occurring
`property OnDestroy: TNotifyEvent; [rw]` |  | OnDestroy - Event handler for destruction of the application
`property ShowButtonGlyphs: TApplicationShowGlyphs; [rw]`
`property ShowMenuGlyphs: TApplicationShowGlyphs; [rw]`
`property ShowHint: Boolean; [rw]` |  | ShowHint - Is a hint required to be shown?
`property ShowMainForm: Boolean; [rw]` |  | ShowMainForm - Is the main form for the application to be shown? Default TRUE
`property Title: String; [rw]`
`end;`

## Inheritance

`TApplication` |  | TApplication - the whole current program, described as an object
`TCustomApplication`
`TComponent,IUnknown,IInterfaceComponentReference`
`TPersistent`
`TObject`

## Description

TApplication - the whole current program, described as an object.

Includes the useful function MessageBox, a simple dialog intended for displaying error messages internally, but available as an alternative to the various Message Dialogs

The latest version of this document can be found at lazarus-ccr.sourceforge.net .