TppViewer and MouseWheel event

rbuser

Hi,

I'm looking for an example or advice how to apply Mouse Wheel Event to
TppViewer component. I've tried

ppViewer.ScrollBox.OnMouseWheel := myMouseWheelEvent;

But no good luck. What's wrong?

Thanks in advance

Michael

nicocizik

Hi Michael,

Below is some code one of our customers used to enable the mouse wheel at
runtime for the report previewer. Hopefully this will help you get on the
right track.

unit AJBPreviewPlugIn;

interface

uses
Messages, Controls, Classes, Types, ExtCtrls,
ppPreview, ppTypes, Forms;

type

TAJBPreviewPlugIn = class(TppPreview)
private
protected
public
procedure BeforePreview; override;
procedure MyMouseWheel(Sender: TObject; Shift: TShiftState; WheelDelta:
Integer;
MousePos: TPoint; var Handled: Boolean);

end;

TAJBCustomWheel = class(TControl)
public
property OnMouseWheel;
end;

implementation

uses
SysUtils, Dialogs, ppViewr;

procedure TAJBPreviewPlugIn.BeforePreview;
begin
inherited BeforePreview;
TAJBCustomWheel(Viewer.Owner).OnMouseWheel := MyMouseWheel;
end;

procedure TAJBPreviewPlugIn.MyMouseWheel(Sender: TObject; Shift:
TShiftState;
WheelDelta: Integer; MousePos: TPoint; var Handled: Boolean);
var
lScrollBar: TControlScrollBar;
begin
lscrollbar := Viewer.ScrollBox.VertScrollBar;
lScrollBar.Position := lScrollBar.Position - (WheelDelta div 5);
end;

initialization
TppPreviewPlugIn.Register(TAJBPreviewPlugIn);
finalization
TppPreviewPlugIn.UnRegister(TAJBPreviewPlugIn);
end.


--

rbuser

Thank you, Nico

Michael