TMultiTouchRegion

Hi,

I'm using a TMultiTouchRegion (version 1.2.4.0) to view drawings. There is one Item on the region and when I zoom in quite far and then pan left, right, up or down the item reaches a point where the item disappears and i just see the touch region background. If pan back slightly the item reappears where it was but whenever it reaches the certain point it disappears until I pan back slightly. This stops me viewing the entire document in a zoomed state. I can zoom in a lot on the center of the item but when I zoom in on the outer areas it causes the item to disappear. 

It feels like a programmatic boundary is being hit but I'm not entirely sure where or why this exists so any help to stop the item from vanishing would be appreciated. Its a bit tricky to explain but I can try and add more detail/screenshots if needed.

Thanks,

Ben
     

Hi, 


We have tested this here but are not able to reproduce this, can you perhaps send us a simple sample and instructions and perhaps some screenshots indicating the issue, this would be very helpful.

Hi,


I have also had another play and narrowed down the problem a bit, I think its a content transform I am using because when I use one touch region on its own I can scale the item with no problems.

I have two touch regions on the form and use a procedure to mirror the item position and size from one touchregion to the other, I have included this below. At this stage i just have two touch regions with one item in each

procedure TForm1.HighDrawingTouchRegionItemMouseUp(Sender: TObject;
  Item: TMultiTouchItem; TouchPoints: array of TOUCHINPUT);
var
d : TD2DMatrix3x2F;
scaling : single;
begin
  if item.MainItem.CurrentRealContentWidth > 2500 then
    begin
      scaling := Item.MainItem.CurrentRealContentWidth/lowDrawingTouchRegion.Items[0].MainItem.ContentWidth;

      d._11 := scaling;
      d._12 := lowDrawingTouchRegion.Items[0].MainItem.ContentTransform._12;
      d._21 := lowDrawingTouchRegion.Items[0].MainItem.ContentTransform._21;
      d._22 := scaling;
      d._31 := Item.MainItem.ContentTransform._31;
      d._32 := Item.MainItem.ContentTransform._32;
      lowDrawingTouchRegion.Items[0].MainItem.ContentTransform := d;
    end;

end;

after completing the content transform on the second touch region (lowDrawingTouchRegion) it moves the item to the correct place in the touch region but any further manipulation of the item in the region causes the disappearing of the item. The original touch region from which I have copied the item position from continues to function correctly so it appears to be the content transform causing the issue. 

Thanks you for looking into it and getting back to me, hopefully the extra info can show you what i'm trying to do and where i'm going wrong.  

Hi, 


It seems the issue occurs in very specific circumstances and it would be helpful if you could create a sample and step-by-step instructions on how to reproduce this issue.

Hi Peter,


Looks like doing a background transform before the content transform solves the issue so i am now sorted. 

Thanks,

Ben

Thank you for your feedback.