TScreen class

In unit Forms

Provides information about screen displays in an application.

Declaration

pascal

TScreen = class(TLCLComponent)

Inheritance

TScreen
TLCLComponent
TComponent

Description

TScreen is a TLCLComponent descendant which provides information about multiple monitors in an LCL application. TScreen allows the GUI for an application to be managed on multiple monitors. It includes the size and resolution for a screen, and allows mapping the virtual Desktop and Workareas to the physical Monitors known to the application.

TScreen also provides access to objects displayed on a given screen, including: Forms, Cursors, and Fonts. For Delphi compatibility, non-visual DataModules are also included in the TScreen information. Properties are provided in the class with the currently active Form, Control and Cursor for a screen.

TScreen is the type used for the Screen singleton in an LCL application.

Properties

`MagnetManager`	protected	Manages screen / form snapping behavior for the screen.
`ActiveControl`	public	The control which has the focus on the active form for the screen.
`ActiveCustomForm`	public	The TCustomForm instance which has the focus.
`ActiveForm`	public	The TForm instance which has the focus.
`Cursor`	public	Indicates the current mouse cursor shape.
`RealCursor`	public	Gets the value for the Cursor property taking temporary cursors into account.
`Cursors`	public	Provides indexed access to the available mouse cursor shapes for the screen.
`CustomFormCount`	public	Number of TCustomForm form instances in the CustomForms property.
`CustomForms`	public	Provides indexed access to the TCustomForm instances on the screen.
`CustomFormZOrderCount`	public	Number of custom forms instances in the CustomFormsZOrdered property.
`CustomFormsZOrdered`	public	The list of Custom Forms, indexed by Z-order (zero is top-most).
`DesktopLeft`	public	The left-most coordinate of the desktop.
`DesktopTop`	public	The top-most coordinate for the desktop.
`DesktopHeight`	public	The total vertical size for the desktop.
`DesktopWidth`	public	The total horizontal size for the desktop.
`DesktopRect`	public	Bounds rectangle for the desktop spanning all monitors.
`FocusedForm`	public	The form that has Focus on the screen.
`FormCount`	public	The number of Forms on the screen.
`Forms`	public	Provides indexed access to TForm instances on the screen.
`DataModuleCount`	public	The number of data modules for the screen.
`DataModules`	public	Provides thread-safe indexed access to data modules on the screen.
`HintFont`	public	The font used to display Hints.
`IconFont`	public	The font used for desktop icons.
`MenuFont`	public	The font used in menus.
`SystemFont`	public	The default font used for system task dialogs and controls like TSpeedButton.
`Fonts`	public	The names for the available (installed) fonts.
`Height`	public	The height of the primary monitor.
`MonitorCount`	public	The number of available Monitors.
`Monitors`	public	Provides indexed access to the available monitors in the class instance.
`PixelsPerInch`	public	The number of screen pixels per virtual inch (DPI) for the screen.
`PrimaryMonitor`	public	The primary monitor which typically includes the task bar area.
`Width`	public	The width of the primary monitor.
`WorkAreaRect`	public	The usable display area on the primary monitor excluding the task bar.
`WorkAreaHeight`	public	The usable height of the primary monitor excluding the system task bar.
`WorkAreaLeft`	public	The usable left coordinate on the primary monitor.
`WorkAreaTop`	public	The usable top coordinate on the primary monitor.
`WorkAreaWidth`	public	The usable width for the WorkAreaRect.

Methods

`GetHintFont`	protected	Gets the value for the HintFont property.
`GetIconFont`	protected	Gets the value for the IconFont property.
`GetMenuFont`	protected	Gets the value for the MenuFont property.
`GetSystemFont`	protected	Gets the value for the SystemFont property.
`Notification`	protected	Performs actions when the specified component is added to or removed from the class instance.
`Create`	public	Constructor for the class instance.
`Destroy`	public	Destructor for the class instance.
`CustomFormIndex`	public	Gets the ordinal position in CustomForms for the requested form.
`FormIndex`	public	Gets the ordinal position in Forms for the requested form.
`CustomFormZIndex`	public	Gets the position in CustomFormsZOrdered for the specified form.
`MoveFormToFocusFront`	public	Moves the specified form to the front of all other forms.
`MoveFormToZFront`	public	Moves the form to the front of the Z-order in the CustomFormsZOrdered property.
`NewFormWasCreated`	public	Notifies handler(s) when a new form is created for the TScreen instance.
`GetCurrentModalForm`	public	Returns the Modal form at the top of the Z-order for the screen.
`GetCurrentModalFormZIndex`	public	Returns the index of the top-most modal form in CustomFormsZOrdered.
`CustomFormBelongsToActiveGroup`	public	Checks whether the specified form is present in the Z-ordered list of forms.
`FindNonDesignerForm`	public	Finds the form with the specified name, excluding designer forms.
`FindForm`	public	Finds a form on the screen by its name.
`FindNonDesignerDataModule`	public	Finds a data module with the specified name, excluding designer data modules.
`FindDataModule`	public	Finds the data module with the specified name.
`UpdateMonitors`	public	Rebuilds the list of available monitors.
`UpdateScreen`	public	Updates the value for the PixelsPerInch property.
`RemoveAllHandlersOfObject`	public	Removes all handler routines for the specified object regardless of notification type.
`AddHandlerNewFormCreated`	public	Adds the specified handler routine to the new form handlers for the screen instance.
`RemoveHandlerNewFormCreated`	public	Removes the specified handler routine from the new form handlers for the screen instance.
`AddHandlerFormAdded`	public	Adds a form added notification handler to the class instance.
`RemoveHandlerFormAdded`	public	Removes a form added notification handler.
`AddHandlerRemoveForm`	public	Adds a form removed notification handler.
`RemoveHandlerRemoveForm`	public	Removes a from removed notification handler.
`AddHandlerActiveControlChanged`	public	Adds a control changed notification handler.
`RemoveHandlerActiveControlChanged`	public	Removes a control changed notification handler.
`AddHandlerActiveFormChanged`	public	Adds a form changed notification handler.
`RemoveHandlerActiveFormChanged`	public	Removes a form changed notification handler.
`AddHandlerFormVisibleChanged`	public	Adds a visible changed notification handler.
`RemoveHandlerFormVisibleChanged`	public	Removes a visible changed notification handler.
`DisableForms`	public	Disables all forms except for SkipForm.
`EnableForms`	public	Re-enables forms disabled in the DisableForms method.
`MonitorFromPoint`	public	Finds the monitor containing the given screen coordinates.
`MonitorFromRect`	public	Finds the monitor where the specified rectangle is located.
`MonitorFromWindow`	public	Finds the monitor containing the form with the given window handle.
`BeginTempCursor`	public	Sets the Cursor property to a temporary shape. Use EndTempCursor to release it.
`EndTempCursor`	public	Releases a temporary mouse cursor set with BeginTempCursor.
`BeginWaitCursor`	public	Sets the cursor to the shape in crHourGlass.
`EndWaitCursor`	public	Removes the crHourGlass mouse cursor shape.
`BeginScreenCursor`	public	Changes the active cursor to the most recent shape in the internal list of cursors.
`EndScreenCursor`	public	Removes the current mouse cursor shape from the internal list, and restores the previous cursor shape.

Events

`OnActiveControlChange`	public	Event handler signalled when the active form control for the screen has been changed.
`OnActiveFormChange`	public	Event handler signalled when the active form on the screen has been changed.

Inherited

From TLCLComponent (7)

DecLCLRefCount GetWSComponentClass IncLCLRefCount LCLRefCount NewInstance WidgetSetClass WSRegisterClass

An experiment, built from Lazarus main 2dfa93c66e of 10-22-2026. Not the official Lazarus documentation.