TCustomScrollBar.SetParams procedure
Updates the Min and Max values, the size of the page, and the position in the scrollbar.
Declaration
procedure SetParams(APosition: Integer; AMin: Integer; AMax: Integer;
APageSize: Integer)
procedure SetParams(APosition: Integer; AMin: Integer; AMax: Integer)Arguments
APosition | Value applied to the scrollbar position. |
AMin | Value applied to the scrollbar minimum value. |
AMax | Value applied to the scrollbar maximum value. |
APageSize | Value applied to the scrollbar page size. |
Description
SetParams is an overloaded procedure used to update the values in
the
TScrollInfo structure passed to the widgetset class. Values
passed in parameters are stored in the TScrollInfo instance, and used to
validate the new settings for the scrollbar.
SetParams raises an EInvalidOperation exception if the value in
AMax is smaller than the value in AMin.
The value in APosition is normalized to ensure that it is in the
range specified by AMin and AMax.
APageSize is set to 0 (zero) if it contains a negative value.
When any of the parameter values differ from the current values in the class
instance, the class instance is updated. SetScrollInfo is called
to apply the changed values when a handle has been allocated for the control.
SetScrollPos is called when APosition contains a value different
than the one in the class instance. The Change method is called to
process the updated values in the control and signal the OnChange
event handler (when assigned). The SetParams method in the
widgetset class is called to synchronize the changes.
SetParams is called when a new value is assigned to the Position,
Min, Max, or PageSize property.
See also
An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.