Trying to implement panning/scroling

[cjacoby78]

Hi all.

As I want more control about panning, and as the default panning provided doesn't work well, I tried to implement panning myself using gestures in FireMonkey. Here is what I got so far for the X axis only:

Code: Select all

procedure TMultiEPGFrame.FrameGesture(Sender: TObject;
  const EventInfo: TGestureEventInfo; var Handled: Boolean);
var
  lGlobalWidth: Double;
  lLocalWidth: Double;
begin
  if EventInfo.GestureID = igiPan then
  begin
    lGlobalWidth := self.Width;
    lLocalWidth := fChart.BottomAxis.Maximum - fChart.BottomAxis.Minimum;

    if fLastPosition.X < EventInfo.Location.X then
    begin
      fChart.BottomAxis.Minimum := fChart.BottomAxis.Minimum -
        ((EventInfo.Location.X) / lGlobalWidth);

      fChart.BottomAxis.Maximum := fChart.BottomAxis.Maximum -
        ((EventInfo.Location.X) / lGlobalWidth);
    end
    else
    begin
      fChart.BottomAxis.Minimum := fChart.BottomAxis.Minimum +
        ((EventInfo.Location.X) / lGlobalWidth);

      fChart.BottomAxis.Maximum := fChart.BottomAxis.Maximum +
        ((EventInfo.Location.X) / lGlobalWidth);
    end;

    fLastPosition := EventInfo.Location;
  end;
end;

I basically adjust the maximum and minimum of my X axis approximately by the amount my finger goes left or right ... If anyone has a better suggestion, I am all ears!

Thanks a lot!
CJ

[Yeray]

Hi CJ,

This seems to be related to this thread.
As Pep said there, setting the Left button as the ScrollMouseButton should make the default scoll feature usable in mobile applications.

[cjacoby78]

Yes, thanks this works - one more question though also asked in the other thread:

How do I block panning/scrolling to work inside some arbitrary bounds only?

Cheers,
CJ

[cjacoby78]

This is a solution I implemented which works:
http://www.teechart.net/support/viewtop ... 661#p66661

[Yeray]

Hi CJ,

We'll reply you in the other thread as soon as possible.
There's no need to maintain two threads with the same questions and answers.