Scrolling event

1. offizieller Beitrag

    Hello,

    I use WPTools 4.25.
    I want to hook external Scrollbars to WPRich text components, but they are windows native and I can't hook them directly to WPRichtext. Is there any event in RichText component that is fired when scrolling (Mosewheel, line down, page down) that I can use to programaticaly implement scrolling?

    Thanks

    Hi Julian,

    Since there is no such an event, I tried to hook standard delphi scrollbar to Richtext component and to use its event for scrolling with 3rd party scrollbar and this can work except... I set property visible of standard scrollbar to false, because I want to see only 3rd party scroll, but still this standard scrollbar is visible. Is there possibility not to force visible property of hooked external scroolbar in rich text?

    Thanks

    Yes, it didn't help, but I found in WPRichText.pas in function TWPCustomRichText.DoSetVScrollRange line
    FVScroll.Visible := TRUE;
    When I comment this line, it is OK, external scrollbar is not vissible but I still can use its events !

    Thanks anyway

    Zitat von wpsupport

    Hi,

    ok, now also I understand - you use the external scrollbar to just get the events. Should work but I would rather use the WMSCroll messages.

    Julian

    Exactly what message do I have to intercept?

    I tried WM_HSCROLL, WM_VSCROLL but they do not work.

    Obviously it is some internal message, but how to find it?

    Alright, I fixed the problem

    this is what I did

    Code
    TVerticalScrollEvent = procedure(Sender: TObject) of object;TWPRichTextDezta = class(TWPRichText)  private     FOnVerticalScrollEvent: TNotifyEvent;     procedure OnVerticalScoll(var msg: TMessage); message WM_VSCROLL;  published      property OnVerticalScrollEvent: TNotifyEvent read FOnVerticalScrollEvent write FOnVerticalScrollEvent;end;implementationprocedure TWPRichTextDezta.OnVerticalScoll(var msg: TMessage);begin  if Assigned(FOnVerticalScrollEvent) then    FOnVerticalScrollEvent(Self);  inherited;end;

    Now I can hook the event to a procedure dynamicly using

    Code
    Editor.OnVerticalScrollEvent := ScrollBarChange;


procedure TMainForm.ScrollBarChange(Sender: TObject);
begin
  // my code
end;