Appendix A: QSCROLLBAR

QSCROLLBAR Component

QScrollBar is a Windows scroll bar, used to scroll contents of a window, form, or control. It can also act as a simple trackbar.

QScrollBar Properties

Field	Type	R/W	Default	Support
Align	INTEGER	RW	alNone	W
	Align determines how the control aligns within its parent control.
Cursor	INTEGER	RW	crDefault	W
Enabled	INTEGER	RW	True	WX
Handle	INTEGER	R		W
Height	INTEGER	RW		WX
Hint	STRING	RW		WX
Kind	INTEGER	RW	sbHorizontal	WX
	Kind specifies whether the scrollbar is horizontal or vertical. 0 = sbHorizontal -- Scrollbar is horizontal. 1 = sbVertical -- Scrollbar is vertical.
LargeChange	INTEGER	RW	1	WX
	LargeChange determines how much Position changes when the user clicks on the scrollbar on either side of the thumb or pressed PageUp or PageDown.
Left	INTEGER	RW	0	WX
Max	INTEGER	RW	100	WX
Min	INTEGER	RW	0	WX
PageSize	INTEGER	RW	1	W
	PageSize specifies the distance along the trackbar.
Parent	QFORM/QPANEL/QTABCONTROL	W		WX
PopupMenu	QPOPUPMENU	W		W
Position	INTEGER	RW	0	WX
ShowHint	INTEGER	RW	False	WX
SmallChange	INTEGER	RW	1	WX
	SmallChange determines how much Position changes when the user clicks the arrow buttons on the scrollbar or presses the arrow keys.
TabOrder	INTEGER	RW		W
Tag	INTEGER	RW		WXG
Top	INTEGER	RW	0	WX
Width	INTEGER	RW		WX
Visible	INTEGER	RW	True	WX

QScrollBar Events

Event	Type	Occurs when...	Params	Support
OnChange	VOID	Scroll position changes	0	WX
OnKeyDown	SUB (Key AS Word, Shift AS INTEGER)	Key held down	2	W
OnKeyPress	SUB (Key AS BYTE)	User presses a key	1	W
OnKeyUp	SUB (Key AS Word, Shift AS INTEGER)	User releases a key	2	W
OnScroll	SUB (ScrollCode AS BYTE, ScrollPos AS LONG)	Scrolling	2	W

QScrollBar Examples

' Color Palette for Rapid-Q by William Yu


DECLARE SUB ColorChange
DECLARE SUB Paint

CONST False = 0
CONST True = NOT False

'' Here's something that will convert your standard RGB to Rapid-Q's BGR.
'' And quite useless because an RGB function is already implemented!
FUNCTION ConvertRGB(R AS INTEGER, G AS INTEGER, B AS INTEGER) AS INTEGER
  ConvertRGB = (B SHL 16) OR (G SHL 8) OR R
END FUNCTION

CREATE Form AS QForm
  CREATE LabelRed AS QLabel
    Left = 10
    Top = 22
    Caption = "Red:"
  END CREATE
  CREATE LabelGreen AS QLabel
    Left = 5
    Top = 52
    Caption = "Green:"
  END CREATE
  CREATE LabelBlue AS QLabel
    Left = 10
    Top = 82
    Caption = "Blue:"
  END CREATE
  CREATE LabelNum1 AS QLabel
    Left = 270
    Top = 22
    Caption = "0"
  END CREATE
  CREATE LabelNum2 AS QLabel
    Left = 270
    Top = 52
    Caption = "0"
  END CREATE
  CREATE LabelNum3 AS QLabel
    Left = 270
    Top = 82
    Caption = "0"
  END CREATE
  CREATE ScrollRed AS QScrollBar
    Left = 50
    Top = 20
    Width = 200
    Height = 20
    Min = 0: Max = 255
    ShowHint =  True
    Hint = "Red Attribute"
    OnChange = ColorChange
  END CREATE
  CREATE ScrollGreen AS QScrollBar
    Left = 50
    Top = 50
    Width = 200
    Height = 20
    Min = 0: Max = 255
    ShowHint =  True
    Hint = "Green Attribute"
    OnChange = ColorChange
  END CREATE
  CREATE ScrollBlue AS QScrollBar
    Left = 50
    Top = 80
    Width = 200
    Height = 20
    Min = 0: Max = 255
    ShowHint =  True
    Hint = "Blue Attribute"
    OnChange = ColorChange
  END CREATE
  CREATE PaintBox AS QCanvas
    Left = 50
    Top = 110
    Height = 90
    Width = 200
    OnPaint = Paint
  END CREATE
  Caption = "Color Palette"
  Center
  ShowModal
END CREATE

SUB ColorChange
  LabelNum1.Caption = STR$(ScrollRed.Position)
  LabelNum2.Caption = STR$(ScrollGreen.Position)
  LabelNum3.Caption = STR$(ScrollBlue.Position)
  Paint
END SUB

SUB Paint
  PaintBox.Paint(0,0,ConvertRGB(ScrollRed.Position, ScrollGreen.Position, ScrollBlue.Position),&HFFFFFF)
END SUB

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