TGauge bug

bdw · Post by **bdw** » Fri May 20, 2005 5:35 am

Hello,
We have TChart VCL v7.04, the TGauge appears to have a bug where the needle is not drawn correctly at 45 and 225 along with various angles adjacent to these values. This can be demostrated in the TeeChart Pro 7 demo software. Select Chart styles, then Other, then Gauge. Click on edit, set the needle type to triangle, set the total angle to 360, circle rotation to 90, then set the value to 45 or 225......
Is there a work around for this ? Is it possible to draw the needle myself ? We dont have the source obviously......
Brett

bdw · Post by **bdw** » Fri May 20, 2005 5:37 am

I fogot to mention I was setting the ticks minimum to 0 and maximum to 360 as well...........

bdw · Post by **bdw** » Mon May 23, 2005 8:37 am

My work around for this has been to draw my own needle. However I seem to strike a probelm when I try and use the AngleToPos() function and the RotationAnlge is not set to 90 or 270, can someone explain this function ?

The angle passed to AngleToPos() is a radian value but I need to make it negative to display correctly at 90 and 270.........

Thanks for any help,
Brett.

Post by **Pep** » Thu May 26, 2005 10:40 am

Hi Brett,

We have TChart VCL v7.04, the TGauge appears to have a bug where the needle is not drawn correctly at 45 and 225 along with various angles adjacent to these values. This can be demostrated in the TeeChart Pro 7 demo software. Select Chart styles, then Other, then Gauge. Click on edit, set the needle type to triangle, set the total angle to 360, circle rotation to 90, then set the value to 45 or 225......
Is there a work around for this ? Is it possible to draw the needle myself ? We dont have the source obviously......

Yes, you're correct, it's a bug. I've added it on our defect list and a fix for it will be considered to inclusion for the next maintenance releases.
A workaround for the moment is to add a Repaint call when the Series Value has been changed :

Code: Select all

procedure TForm1.Series1Change(Sender: TObject);
begin
Series1.Repaint;
end;

bdw · Post by **bdw** » Thu May 26, 2005 8:39 pm

Thanks for the reply, I was starting to wonder if anyone read these posts. and that there may be a better way to report bugs ?

As a work around I was using the cavas technique to draw my own needle. In doing this I seem to strike a problem when I try and use the AngleToPos() function and the RotationAnlge is not set to 90 or 270, can someone explain this function ?

The angle passed to AngleToPos() is a radian value but I need to make it negative to display correctly at 90 and 270.........

I have also asked this in another post for Alternative labels, but obviously I'm drawing text not objects......

Thanks for any help,
Brett.

Narcís · Post by **Narcís** » Fri May 27, 2005 7:32 am

Hi Brett,

Thanks for the reply, I was starting to wonder if anyone read these posts. and that there may be a better way to report bugs ?

Those forums are monitored by our technical department and this is the place where you should place all your questions, reports, etc.

I have also asked this in another post for Alternative labels, but obviously I'm drawing text not objects......

I've already replied this question at your other post.