Magnify tool

Andrew S · Post by **Andrew S** » Wed Aug 22, 2007 6:02 pm

I notice that when I use the magnify chart tool, it doesn't magnify any of the lines that I've drawn on the chart using the colorLine tool. Is there any way to get it to do that?

Andrew

Narcís · Post by **Narcís** » Thu Aug 23, 2007 8:03 am

Hi Andrew,

This works fine for me here. However, as the tool's default pen width is 1 and the lines are either vertical or horizontal it is not easily appreciated. Try increasing the ColorLine's pen width and you'll see much clearer that it is magnified.

If this doesn't help don't hesitate to let us know.

Andrew S · Post by **Andrew S** » Thu Aug 23, 2007 7:01 pm

No, I don't think it's the pen width that's throwing me off, though it is 1px wide. If you watch the contents of the magnified window as you drag it around, the contents slide back and forth at a faster rate than the un-magnified surroundings (a natural side-effect of zoom). However, the lines that I've drawn with the line chart tool do not slide at all. they remain perfectly aligned horizontally. I would expect the zoomed portion of that line to be offset to match the rest of the magnified chart.

Does that make sense? I'm not sure if I explained it clearly. I can attach some screenshots to describe what I'm talking about if that would help.

Note that I do have some additional stuff that I draw manually in the OnAfterDraw events which isn't magnified either. I'm not surprised about that one, as I imagine the magnify window is created before the OnAfterDraw event is called. That does raise the question though: at what point in the draw process is the magnify window created? If I drew some lines manually in the OnBeforeDrawSeries event, would that be included in the magnification?

-A

Narcís · Post by **Narcís** » Fri Aug 24, 2007 7:51 am

Hi Andrew,

No, I don't think it's the pen width that's throwing me off, though it is 1px wide. If you watch the contents of the magnified window as you drag it around, the contents slide back and forth at a faster rate than the un-magnified surroundings (a natural side-effect of zoom). However, the lines that I've drawn with the line chart tool do not slide at all. they remain perfectly aligned horizontally. I would expect the zoomed portion of that line to be offset to match the rest of the magnified chart.

Does that make sense? I'm not sure if I explained it clearly. I can attach some screenshots to describe what I'm talking about if that would help.

Thanks for the information. Yes, your explanation was clear to me and that works fine here using our current v8 sources as you can see here in the image below. Is that what you mean?

If you want you can send us your screenshots at news://www.steema.net/steema.public.attachments newsgroup or at our upload page.

Note that I do have some additional stuff that I draw manually in the OnAfterDraw events which isn't magnified either. I'm not surprised about that one, as I imagine the magnify window is created before the OnAfterDraw event is called. That does raise the question though: at what point in the draw process is the magnify window created? If I drew some lines manually in the OnBeforeDrawSeries event, would that be included in the magnification?

Yes, the tool is drawn after all TeeChart elements have been drawn and thus all them should be magnified. However, it isn't magnified what's drawn in the OnAfterDraw event as it's drawn after the tool. In the image below you can see the left-top diagonal line being drawn in the OnBeforeDrawSeries which is magnified. The other diagonal line is drawn in the AfterDrawEvent and isn't magnified.

Andrew S · Post by **Andrew S** » Tue Aug 28, 2007 2:46 pm

Sorry for the delay in my reply. I was trying to figure out what was going on, sadly to no avail. As I mentioned in my previous email, I have custom OnClickBackground and OnAfterDraw events which calculate and draw a few custom items. After your initial response, I went back and disabled both of those events and confirmed that the magnify window does indeed zoom lines drawn with the line chart tool. However, whenever I enable my OnClickBackground event, for some reason it does not work. I have no idea why. I've tried commenting out certain parts of code with no effect. I've even tried creating a brand new project and dropping chunks of code into a new chart to see if I could find the offending line(s)... without any luck. Do you have any suggestions as to where I could look, or what could be causing this?

-A

Narcís · Post by **Narcís** » Tue Aug 28, 2007 3:51 pm

Hi Andrew,

I'm afraid not unless we can reproduce the issue here. I've tried also custom drawing in the OnClickBackground event but couldn't reproduce the problem here. However, combining this event with TMagnifyTool makes the drawings made on that event disappearing when dragging the tool as the event is masked by the tool's dragging.

It would be very helpful if you could send us a simple example project we can run "as-is" to reproduce the problem here. You can either post your files at news://www.steema.net/steema.public.attachments newsgroup or at our upload page.

Thanks in advance.