Series marks[SOLVED]
lazarus / 55-TAChart

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mtanner · 2015-11-16 09:22

I have a chart consisting of an area series, with the area solid
filled. Separately I have a line series where the line is not shown,
only the pointers, and the pointers have marks attached. The line
series points lie on area series contour, the purpose of the line
series being to highlight a small number of critical values and to
attach marks to these points. The frame and text of the line series
marks partly overlaps the contour and shaded area of the area seies.

The mark overwrites the area series fill, which is what I want so the
mark shows clearly. But the contour of the area is not overwritten. I
get the same effect if I use a line series instead of the are series,
the "contour" line is not overwritten. How do I get the mark to
overwrite the line? I've tried different ordfers of priority for the
series, which doesn't help - why is the area fill overwritten but not
the contour line when they are both part of the same TAreaSeries?

The same happens with the points of the line series. The area fill is
overwriiten by the line series pointer, but not the contour of the
area series.

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wp · 2015-11-16 09:35

Could you post a screenshot, or a little demo?

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mtanner · 2015-11-16 09:36

I must revise my description of the problem. I can fix this with
series order, but the behaviour doesn't seem to be entirely as
expected. If I plot the area contour as a psClear line, then introduce
an additional line series just to do the area contour, and poush that
new line series to the bottom of the series list, then I get what U
want.

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wp · 2015-11-16 09:46

My own tests seem to be correct (see screenshot). But maybe I still do
not understand...

Do you know that modifying the ZPosition changes the drawing order?
You have to use values > 0 to make it effective. I.e. giving the
LineSeries a value > 0 makes it (and the associated marks) being
painted after (=on top of) the area series.

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mtanner · 2015-11-16 10:06

I hadn't realised I should consider the Z-value. I was just relying on
the series order in the "Edit series" dialog.  So I'll mark this one
"SOLVED" thanks.