Apache OpenOffice (AOO) Bugzilla – Issue 82802
legend line samples too small to distinguish line dashes
Last modified: 2013-02-24 21:20:48 UTC
I'm working with someone who is color blind. I'm trying to make line charts where the lines are distinguishable by line style. But I find that the legends give sample lines that are too small to be able to distinguish which line is which. This is probably also a problem for people making charts for publication in print journals. I have a workaround, suggested by Frank Psotka: make the chart really big. That makes the legend really big, and allows the sample lines to be big enough to show their details. I've attached an example spreadsheet with charts. Reproduce by making a line chart with several sets of data. Make all the lines black, choose different line styles for the different lines. E.g., "Fine Dashed" versus "Continuous" and "2 dots 1 dash" versus "Fine dotted". You will find it difficult to distinguish the lines in the legend. In the attached example, I've shown the chart first with colored lines so you can see they are different (if you have a color display and aren't color challenged). Then I've used the workaround to make the chart 3x larger, and edited the chart to make everything 3x larger (the fonts, the line thicknesses, etc.) That makes the legend large enough to distinguish the line styles. Then I copy-n-pasted the chart to a Drawing, saved it as a JPG, and shrank that by a factor of 3, producing a chart (well, an image of a chart) with distinguishable lines. This is the chart I'd like to have in the first place. Below that I have the original chart with black lines, and finally I have an JPG of the black and white chart after I've blown the chart up, exported it as a JPG and then shrunk the JPG back down. I think you can still tell the lines styles apart. I shouldn't propose a solution, since you folks are the experts, but I when I was fooling around with this, I thought I would want to be able to stretch the legend horizontally, have the fonts stay as they were, but have the example line segments get longer. I hoped that way to be able to show them distinctly. But I can't change the size of the legend box. I don't know if that's the right UI solution, but it seemed to me like one way to do this. I'm actually using StarOffice 8pp5, rather than OOo2.3 directly. Hmm, now I have to figure out how to attach a file to an issue: there doesn't seem to be a place to type in a file name to be uploaded. I hope I can submit this issue and then attach the sample file.
Created attachment 49034 [details] Example charts with indistinguishable line styles, and workaround.
wrong component, changed to Chart and re-assigned Please use the latest Product Update for StarOffice 8 which is currently PU 8. This is because PU 5 did not contain the new Chart Module. Frank
Oops. I'm actually on StarOffice 8pp8, not 8pp5 as I said. That's might be crucial, since SO8pp8 has the new charting package from OO, rather than the old one.
@IHA: Maybe a idea for A11y?
->bm, please take over as you are implementing the legend. I can confirm the problem. To solve it the legend keys must somehow be so big that the different line dashes are shown completely. The problem got worse with the new chart as the lines are drawn horizontally instead of diagonal in the legend thus they are even shorter now.
Yes, for line charts, the legend key should be wider. For the workaround it suffices to make the font of the legend larger, but of course this looks not very nice. What you effectively did by enlarging and shrinking again, is to use line dashes with smaller distances. I would suggest to use different dashes as a work-around for your problem. If the list of available dashes does not suit you, you can add more user-defined one with Calc or Draw. Select a line, chose "Line" and there to "Line Styles". There you can define new ones and save them under any name. Problem is, you have to close and reopen the document to have them available in the chart. This is still an open issue, as well as being able to add line dashes directly in the chart. However, once reloaded you can use the new dashes. I'll attach an example. DevNote: The system for generating legend icons should be adapted, such that the width of a legend key may be dependent on the symbol type used. Currently all symbols have the same (bounding box) size, which is partly empty (e.g. for boxes) If I would make the keys wider, there would be more spaces wasted for boxes, so such a flexible systems seems more appropriate.
setting target
Created attachment 50086 [details] Workaround using custom dashes. See lower chart.
You are cheating! Your lower chart uses a legend with Albany 13.2 point characters. The upper one uses Albany 9.4 point characters. We already knew that using a larger font for the legend is a workaround. If you change your lower chart's legend to use 9.4 point characters, the line samples for Dist1 and Dist2 are indistinguishable: a long dash, some space (which, admittedly is different between Dist1 and Dist2 if you look really carefully), and a dot. But neither looks like a sample of the lines that are Dist1 (dash dash) or Dist2 (dash dot dot). I think you understand the problem, though, and have a fix in mind for OOo3. That's good enough for me. I'll wait patiently for the fix.
change owner
Fixed in CWS chart52. Details are specified here: http://wiki.services.openoffice.org/wiki/Chart2/Specifications/ChartLegend
Thomas, please verify in CWS chart52.
The legend key becomes 1,6cm wide, so the different dash/dot lines can be distinguished well. The legend key width becomes 60% of font size for large font sizes. You will notice it not for font sizes smaller than 76pt, because 1,6cm is the minimum width, if at least one data series has got a dash/dot line. I have tested it with the attached documents and with own documents, using Calc and Draw. So I set it to verified in CWS chart52. (I don't know, whether I should change owner back to iha.)
Thanks a lot Regina! After verification the issue is kept by the one who has verified it until the CWS is integrated into the product. After successful integration the issue can be closed. The issue is only set back to the developer if something went wrong and the fix needs to be changed. So I set this issue to you. Thomas is informed that you might take over further issues for testing. Thanks a lot again! :-)
The line in the legend item is long enough to distinguish line styles. It is correctly integrated in DEV300m101.