Rapid-Q Documentation by William Yu (c)1999-2000 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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