TButton class

In unit StdCtrls

Implements a push button control.

Declaration

pascal

TButton = class(TCustomButton)

Inheritance

Descends from it: TButtonCellEditor

Description

TButton is a TCustomButton descendant which implements a push button control. TButton is used to perform an action when the control is clicked. An OnClick event handler is provided to perform actions needed when the push button is clicked. TButton provides support for the TBasicAction class defined in the FPC Run-time Library (RTL).

Properties are provided to control the appearance and behavior for the control. This includes whether it is the Default or Cancel button on a modal form, and the modal result returned when the push button is clicked.

The control displays a text-based caption and is drawn using a style appropriate for the platform or widgetset. An accelerator key can be defined in the caption which simulates clicking on the push button when the shortcut key is pressed.

Please note that the Caption in the control is always centered. The values in properties like BiDiMode and UseRightToLeftAlignment are ignored in the control.

Please note that the Color for the control defaults to the system-defined color used for button controls.

TButton sets the visibility for properties defined in the ancestor class, and does not introduce any new methods.

Use TBitBtn for a push button control which displays a bitmap instead of a text-based caption.

Use TSpeedButton for a push button control which can remain in the pressed or down state.

Properties

`Action`	published	The Action associated with the control.
`Align`	published	Specifies the placement of the control on its Parent control.
`Anchors`	published	The set of anchor definitions for this control.
`AutoSize`	published	Allows automatic adjustment of the size for the control, according to its content.
`BidiMode`	published	Indicates whether text controls use in bi-directional reading.
`BorderSpacing`	published	Determines the inner and outer border spacing for this control.
`Cancel`	published	True if the button is the modal Cancel button.
`Caption`	published	The text displayed for the control.
`Color`	published	Color used for the button face.
`Constraints`	published	Contains the minimum and maximum Width and Height for the control.
`Default`	published	True if the button is the default button in a modal form.
`DoubleBuffered`	published	When enabled, it reduces flicker when the control is painted.
`DragCursor`	published	The cursor shape shown during a drag operation.
`DragKind`	published	Indicates the action performed for a drag operation: drag-and-drop or drag-and-dock.
`DragMode`	published	Determines how a drag operation is started for the control.
`Enabled`	published	Determines whether the control responds to mouse or keyboard input.
`Font`	published	The font to be used for text display in this control.
`ParentBidiMode`	published	Indicates whether the BiDiMode settings in the Parent control are used.
`ModalResult`	published	Value returned when the control is clicked in a modal form.
`ParentDoubleBuffered`	published	Value for the DoubleBuffered property in a Parent control.
`ParentFont`	published	Indicates if the Font from the Parent control is used in the control.
`ParentShowHint`	published	If True, the value of ShowHint for the control will be the same as the one from the Parent. Default is True.
`PopupMenu`	published	A context-sensitive menu that pops up when the right mouse button is clicked over this control.
`ShowHint`	published	Enables Hint display for the control.
`TabOrder`	published	Indicates the navigation order for the control when the user presses the Tab or Shift+Tab key.
`TabStop`	published	Enables keyboard navigation using the Tab or Shift+Tab keys.
`Visible`	published	Allows the control, and all of its children, to be displayed or hidden.

Events

`OnChangeBounds`	published	Event handler signalled when the Bounds for the control have been changed.
`OnClick`	published	Notification handler for mouse clicks.
`OnContextPopup`	published	Invoked when a context-sensitive pop-up menu is requested.
`OnDragDrop`	published	Event handler signalled when an object is dropped onto the control.
`OnDragOver`	published	Event handler signalled when a control is dragged over the control instance.
`OnEndDrag`	published	Event handler signalled for the end of a drag-drop operation.
`OnEnter`	published	Event handler signalled when the control receives focus.
`OnExit`	published	Event handler signalled when the control loses focus.
`OnKeyDown`	published	Event handler signalled for key down keyboard events.
`OnKeyPress`	published	Event handler signalled for character data entered by the user.
`OnKeyUp`	published	Event handler signalled when a key up event has occurred for the control.
`OnMouseDown`	published	Event handler signalled when a mouse down event is handled for the control.
`OnMouseEnter`	published	Event handler signalled when the mouse pointer has entered the control.
`OnMouseLeave`	published	Event handler signalled when the mouse pointer has left the control.
`OnMouseMove`	published	Event handler signalled when the mouse pointer is moved in the control.
`OnMouseUp`	published	Event handler signalled when a mouse up event is handled for the control.
`OnMouseWheel`	published	Event handler for mouse wheel turned.
`OnMouseWheelDown`	published	Event handler signalled for a downward movement of the mouse wheel.
`OnMouseWheelUp`	published	Event handler signalled for an upward movement of the mouse wheel.
`OnResize`	published	Notification handler for a resize of the control.
`OnStartDrag`	published	Event handler signalled for the start of a dragging operation.
`OnUTF8KeyPress`	published	Handler for a character entered by the user.