CreateScrollBar - ProGUI Reference Manual

Syntax

ScrollBarWidget = CreateScrollBar(x, y, Width, Height, Minimum, Maximum, PageSize, Flags=#Null)

Description

Creates a ProGUI scroll bar widget. This is a standard ProGUI widget (not an OS control wrapper) rendered using ProGUI's drawing and skinning system. It's typically used internally by layouts when content overflows but can be created manually.

Parameters

x, y, Width, Height
Initial position and ideal size hints (in DIPs), similar to CreateWidget(). The layout engine will determine the final size and position.

Minimum
The minimum scroll position value (Integer).

Maximum
The maximum scroll position value (Integer). The actual scrollable range is `Maximum - PageSize`.

PageSize
The amount the scroll position changes during a page up/down operation (e.g., clicking the track background). Also affects the size of the scroll thumb.

Flags (optional)
Flags to control the scroll bar's orientation and behavior. Default is 0 (horizontal).

#PG_ScrollBar_Vertical : Creates a vertical scroll bar instead of the default horizontal one.
; Plus standard widget flags like #PG_Widget_Hide, etc.

Return Value

Returns a handle to the newly created scroll bar widget object if successful, or #Null if creation failed.

Remarks

The scroll bar widget generates #PG_Event_Action events when its position changes. The event data (`*EventData`) will contain the new scroll position (as an integer). Use ScrollBarSetValues() to programmatically change the scroll bar's position, range, or page size after creation. The appearance is controlled by the skin assigned via WidgetSetClass() (typically class "scrollbar") and its various components ("thumb1", "thumb2", "trackbar").

Example

IncludeFile "ProGUI_PB.pbi"

StartProGUI()

; Event handler for scroll bar action
Procedure ScrollBarHandler(Widget, EventType, *EventData, *UserData)
  If EventType = #PG_Event_Action
    NewPosition = *EventData ; EventData directly holds the new position for scrollbar action
    Debug "Scroll Bar Position: " + Str(NewPosition)
  EndIf
EndProcedure

MyWindow = CreateWindow(0, 0, 400, 400, "Scroll Bar Example")
RootLayout = WindowGetLayout(MyWindow)
LayoutSetPadding(RootLayout, 20)

If MyWindow
  ; Create a horizontal scroll bar
  HScrollBar = CreateScrollBar(0, 0, 200, 0, 0, 100, 20) ; 0 = Auto width/height via layout
  WidgetSetHeight(HScrollBar, 20) ; Set specific height
  AddEventHandler(HScrollBar, #PG_Event_Action, @ScrollBarHandler())
  Debug "Horizontal ScrollBar created."

  ; Create a vertical scroll bar
  VScrollBar = CreateScrollBar(0, 20, 0, 0, 0, 200, 50, #PG_ScrollBar_Vertical)
  WidgetSetWidth(VScrollBar, 20) ; Set specific width
  WidgetSetHeight(VScrollBar, 200) ; Set specific height
  AddEventHandler(VScrollBar, #PG_Event_Action, @ScrollBarHandler())
  Debug "Vertical ScrollBar created."

  WindowShow(MyWindow, #True, #PG_Window_ScreenCentered)

  Repeat
    Event = WaitWindowEvent()
  Until Event = #PB_Event_CloseWindow
EndIf

StopProGUI()

Supported OS

Windows, Linux