Lua:Class:WinControl

{} Class

class WinControl : Control

The WinControl class represents a visual control that can own child controls and receive keyboard focus.

WinControl inherits from Control, Component, and Object. It is commonly used as a base class for forms, panels, group boxes, list boxes, edit controls, and other windowed controls.

Inheritance

Class	Inherits From	Description
WinControl	Control	Base class for controls that have a window handle, can contain child controls, and can receive focus.
Control	Component	Base class for visual controls.
Component	Object	Base class for owned components.
Object	None	Base class for Lua-exposed objects.

Properties

Property	Type	Description
Handle	Integer	The internal Windows handle of the control.
DoubleBuffered	Boolean	When enabled, graphical updates are first drawn to an offscreen bitmap and then shown on screen. This may reduce flickering.
ControlCount	Integer	The number of child controls attached to this WinControl.
Control[index]	Control	Array-style access to a child control.
OnEnter	Function	Function to call when the WinControl gains focus.
OnExit	Function	Function to call when the WinControl loses focus.

Methods

Method	Return Type	Description
getControlCount()	Integer	Returns the number of controls attached to this WinControl.
getControl(index)	Control	Returns the child control at the specified index.
getControlAtPos(x, y)	Control	Returns the child control at the given x and y position relative to the WinControl.
canFocus()	Boolean	Returns true if the control can receive keyboard focus.
focused()	Boolean	Returns true if the control currently has focus.
setFocus()	void	Tries to set keyboard focus to the control.
setShape(region)	void	Sets the specified Region object as the new shape for this WinControl.
setShape(bitmap)	void	Sets the specified Bitmap object as the new shape for this WinControl.
setOnEnter(function)	void	Sets the OnEnter event handler. The event is triggered when the WinControl gains focus.
getOnEnter()	Function	Returns the current OnEnter event handler.
setOnExit(function)	void	Sets the OnExit event handler. The event is triggered when the WinControl loses focus.
getOnExit()	Function	Returns the current OnExit event handler.
setLayeredAttributes(key, alpha, flags)	void	Sets layered window attributes for the control if possible. Flags can be a combination of LWA_ALPHA and/or LWA_COLORKEY.

Method Parameters

getControl

Parameter	Type	Description
index	Integer	The zero-based index of the child control.

getControlAtPos

Parameter	Type	Description
x	Integer	The x coordinate relative to the WinControl.
y	Integer	The y coordinate relative to the WinControl.

setShape

Parameter	Type	Description
region	Region	The region object to use as the new shape.
bitmap	Bitmap	The bitmap object to use as the new shape.

setOnEnter / setOnExit

Parameter	Type	Description
function	Function	The event handler function to assign.

setLayeredAttributes

Parameter	Type	Description
key	Integer	The color key value used when LWA_COLORKEY is included in the flags.
alpha	Integer	The alpha value used when LWA_ALPHA is included in the flags.
flags	Integer	A combination of layered attribute flags, such as LWA_ALPHA and/or LWA_COLORKEY.

Notes

setLayeredAttributes depends on operating system support. On Windows 7 and earlier, only forms are supported.

Examples

Get the handle of a WinControl

1 local form = createForm(false)
2 local button = createButton(form)
3 
4 print("Button handle: " .. tostring(button.Handle))
5 
6 form.destroy()

Enable DoubleBuffered on a panel

1 local form = createForm(false)
2 local panel = createPanel(form)
3 
4 panel.DoubleBuffered = true
5 
6 form.show()

Count child controls

1 local form = createForm(false)
2 createButton(form)
3 createEdit(form)
4 
5 local count = form.ControlCount
6 
7 print("Child controls: " .. tostring(count))
8 
9 form.destroy()

Access child controls by index

 1 local form = createForm(false)
 2 createButton(form)
 3 createEdit(form)
 4 
 5 for i = 0, form.ControlCount - 1 do
 6   local control = form.Control[i]
 7   print(control.ClassName)
 8 end
 9 
10 form.destroy()

Use getControlCount and getControl

 1 local form = createForm(false)
 2 createButton(form)
 3 createEdit(form)
 4 
 5 local count = form.getControlCount()
 6 
 7 for i = 0, count - 1 do
 8   local control = form.getControl(i)
 9   print(control.ClassName)
10 end
11 
12 form.destroy()

Get the control at a relative position

 1 local form = createForm(false)
 2 local button = createButton(form)
 3 button.Left = 10
 4 button.Top = 10
 5 
 6 local control = form.getControlAtPos(15, 15)
 7 
 8 if control ~= nil then
 9   print("Control at position: " .. control.ClassName)
10 end
11 
12 form.destroy()

Check whether a control can receive focus

1 local form = createForm(false)
2 local edit = createEdit(form)
3 
4 if edit.canFocus() then
5   print("Edit can receive focus")
6 end
7 
8 form.destroy()

Set keyboard focus

1 local form = createForm(false)
2 local edit = createEdit(form)
3 
4 form.show()
5 
6 if edit.canFocus() then
7   edit.setFocus()
8 end

Check whether a control is focused

1 local form = createForm(false)
2 local edit = createEdit(form)
3 
4 print("Focused: " .. tostring(edit.focused()))
5 
6 form.destroy()

Assign OnEnter and OnExit events through properties

 1 local form = createForm(false)
 2 local edit = createEdit(form)
 3 
 4 edit.OnEnter = function(sender)
 5   print("Focus entered")
 6 end
 7 
 8 edit.OnExit = function(sender)
 9   print("Focus lost")
10 end
11 
12 form.show()

Assign OnEnter and OnExit events through methods

 1 local form = createForm(false)
 2 local edit = createEdit(form)
 3 
 4 edit.setOnEnter(function(sender)
 5   print("Focus entered")
 6 end)
 7 
 8 edit.setOnExit(function(sender)
 9   print("Focus lost")
10 end)
11 
12 form.show()

Read assigned focus event handlers

 1 local form = createForm(false)
 2 local edit = createEdit(form)
 3 
 4 edit.OnEnter = function(sender) print("Enter") end
 5 
 6 local onEnter = edit.getOnEnter()
 7 local onExit = edit.getOnExit()
 8 
 9 print("OnEnter assigned: " .. tostring(onEnter ~= nil))
10 print("OnExit assigned: " .. tostring(onExit ~= nil))
11 
12 form.destroy()

Set a Region as the shape

1 local form = createForm(false)
2 local region = createRegion()
3 
4 form.Width = 300
5 form.setShape(region)
6 
7 form.show()

Set layered alpha attributes

1 local form = createForm(false)
2 form.Width = 300
3 form.Height = 200
4 form.show()
5 
6 form.setLayeredAttributes(0, 180, LWA_ALPHA)

Main Pages

Core Lua documentation entry points

◆ Lua
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