Lua:Class:Control

{} Class

class Control : Component

The Control class represents a visual GUI control.

A Control inherits from Component and Object. It provides common visual properties such as position, size, caption, visibility, color, font, parent control, and click handling.

Inheritance

Class	Inherits From	Description
Control	Component	Base class for visual controls.
Component	Object	Base class for components.

Properties

Property	Type	Description
Caption	String	The text of the control.
Top	Integer	The vertical position of the control relative to its parent.
Left	Integer	The horizontal position of the control relative to its parent.
Width	Integer	The width of the control.
Height	Integer	The height of the control.
ClientWidth	Integer	The usable width inside the control, excluding borders.
ClientHeight	Integer	The usable height inside the control, excluding borders.
Align	AlignmentOption	The alignment of the control.
Enabled	Boolean	Determines whether the control is usable or disabled.
Visible	Boolean	Determines whether the control is visible.
Color	ColorDefinition or RGBInteger	The color of the control. This does not affect the caption text.
RGBColor	RGBInteger	The color of the control in RGB format.
Parent	WinControl	The parent of this control.
PopupMenu	PopupMenu	The popup menu that is shown when right-clicking the control.
Font	Font	The Font object associated with the control.
OnClick	Function	The function to call when the control is clicked.
OnChangeBounds	Function	The function to call when the size or position of the control changes.

Event Properties

Event	Function Signature	Description
OnClick	function(sender)	Called when the control is clicked.
OnChangeBounds	function(sender)	Called when the size or position of the control changes.

Methods

Method	Return Type	Description
getLeft()	Integer	Returns the horizontal position of the control.
setLeft(integer)	void	Sets the horizontal position of the control.
getTop()	Integer	Returns the vertical position of the control.
setTop(integer)	void	Sets the vertical position of the control.
getWidth()	Integer	Returns the width of the control.
setWidth(integer)	void	Sets the width of the control.
getHeight()	Integer	Returns the height of the control.
setHeight(integer)	void	Sets the height of the control.
setCaption(caption)	void	Sets the text of the control.
getCaption()	String	Returns the text of the control.
setPosition(x, y)	void	Sets the x and y position of the control based on the top-left position, relative to the client area of the parent object.
getPosition()	Integer, Integer	Returns the x and y position of the control, relative to the client area of the parent object.
setSize(width, height)	void	Sets the width and height of the control.
getSize()	Integer, Integer	Returns the width and height of the control.
setAlign(alignmentoption)	void	Sets the alignment of the control.
getAlign()	AlignmentOption	Returns the alignment of the control.
getEnabled()	Boolean	Returns the enabled state of the control.
setEnabled(boolean)	void	Sets the enabled state of the control.
getVisible()	Boolean	Returns the visible state of the control.
setVisible(boolean)	void	Sets the visible state of the control.
getColor()	ColorDefinition or RGBInteger	Returns the color of the control.
setColor(rgb)	void	Sets the color of the control.
getParent()	WinControl or nil	Returns the parent object, or nil if no parent is assigned.
setParent(wincontrol)	void	Sets the parent of this control.
getPopupMenu()	PopupMenu	Returns the assigned popup menu.
setPopupMenu(popupmenu)	void	Sets the popup menu for this control.
getFont()	Font	Returns the Font object of this control.
setFont(font)	void	Assigns a new Font object. This is not recommended; usually, the existing Font object should be modified instead.
repaint()	void	Invalidates the graphical area of the control and forces an update.
refresh()	void	Updates the control. Usually causes a repaint.
update()	void	Only updates invalidated areas.
setOnClick(functionnameorstring)	void	Sets the OnClick routine.
getOnClick()	Function	Returns the current OnClick function.
doClick()	void	Executes the current OnClick function.
bringToFront()	void	Changes the z-order of the control so it is at the front.
sendToBack()	void	Changes the z-order of the control so it is at the back.
screenToClient(x, y)	Integer, Integer	Converts screen coordinates to coordinates relative to the control.
clientToScreen(x, y)	Integer, Integer	Converts coordinates relative to the control to screen coordinates.

Examples

 1 local form = createForm()
 2 form.Caption = "Control Example"
 3 form.Width = 400
 4 form.Height = 250
 5 
 6 local button = createButton(form)
 7 button.Parent = form
 8 button.Caption = "Click me"
 9 button.Left = 20
10 button.Top = 20
11 button.Width = 120
12 button.Height = 30
13 
14 button.OnClick = function(sender)
15   print(sender.Caption .. " clicked")
16 end
17 
18 form.show()

 1 local form = createForm()
 2 form.Caption = "Position and Size Example"
 3 
 4 local label = createLabel(form)
 5 label.Parent = form
 6 label.Caption = "Hello"
 7 label.setPosition(20, 30)
 8 label.setSize(200, 24)
 9 
10 local x, y = label.getPosition()
11 local w, h = label.getSize()
12 
13 print("Position: " .. tostring(x) .. ", " .. tostring(y))
14 print("Size: " .. tostring(w) .. " x " .. tostring(h))
15 
16 form.show()

 1 local form = createForm()
 2 form.Caption = "Visibility Example"
 3 
 4 local button = createButton(form)
 5 button.Parent = form
 6 button.Caption = "Disabled Button"
 7 button.Enabled = false
 8 
 9 print("Enabled: " .. tostring(button.getEnabled()))
10 print("Visible: " .. tostring(button.getVisible()))
11 
12 form.show()

 1 local form = createForm()
 2 form.Caption = "Font and Color Example"
 3 
 4 local label = createLabel(form)
 5 label.Parent = form
 6 label.Caption = "Styled text"
 7 label.Left = 20
 8 label.Top = 20
 9 label.Color = 0xFFFFFF
10 label.Font.Size = 14
11 label.Font.Style = "[fsBold]"
12 
13 form.show()

 1 local form = createForm()
 2 form.Caption = "Coordinate Example"
 3 
 4 local button = createButton(form)
 5 button.Parent = form
 6 button.Caption = "Coordinates"
 7 button.Left = 50
 8 button.Top = 50
 9 
10 local screenX, screenY = button.clientToScreen(0, 0)
11 local clientX, clientY = button.screenToClient(screenX, screenY)
12 
13 print("Screen: " .. tostring(screenX) .. ", " .. tostring(screenY))
14 print("Client: " .. tostring(clientX) .. ", " .. tostring(clientY))
15 
16 form.show()

Notes

• Left is the horizontal x position.
• Top is the vertical y position.
• Position values are relative to the client area of the parent control.
• Many GUI classes inherit from Control and therefore share these properties and methods.
• For font changes, it is usually better to modify the existing Font object instead of replacing it with setFont().

Main Pages

Core Lua documentation entry points

◆ Lua
◆ Script Engine

Form Related Functions

◆ getForm
◆ getFormCount
◆ getMainForm
◆ getSettingsForm
◆ getLuaEngine
◆ registerFormAddNotification

Form Related Classes

◆ Form
◆ Component
◆ Control
◆ WinControl
◆ Application
◆ Object