Graphs should support Unicode characters & other improvements

[matt]

Here is the current list of requests to improve ImageGraph plugin (#1721)

• Fatter line on graphs

Maybe add 2 pixels to make it more visible in all devices?

• Graph line has too many vertical lines in the background

The standard piwik displays the grey vertical line in the background every 5 label.  see screenshot.

Also, the horizontal grey line in this screenshot is too thick, can we make it slightly smaller (1 pixel?)?

• Show more labels on X Axis
  • Example with 2 vertical bars 148.png, only one label is shown. When there are only 2 elements to plot we should display both labels on X Axis. Then it would stop the legend text after half of the axis. Important in case for example the Keyword for the first plot has a very long string, should not overlap but cut.
  • Also when there are 5 values, only the first is displayed in Screenshot_150. However on screenshot 151 all labels are displayed, which then looks amazing!! In the algorithm that decides how often you plot, could you also truncate the text after 15 characters for example, then we can safely plot one label every two plots.

What are your thoughts guys?

• Pie graph % display

Can we display the % of visits next to the label next to the pie slice legend?

• Support for all fonts (chinese, arabic, japanese, etc.)

I thought we could use the PDF fonts, but they are in a raw format (see  http://dev.piwik.org/trac/browser/trunk/libs/tcpdf/fonts)

however the graph library pcharts is using GD freetype imagettf functions which require a .ttf file (currently tahoma.ttf at  http://dev.piwik.org/trac/browser/trunk/libs/pChart.1.27d/Fonts

Is there a way we can reuse the tcpdf fonts on the graphs, to automatically handle all languages? Or should we bundle extra .ttf to support all existing languages (potentially adding a lot of bytes to the Piwik download since these fonts are heavy...)

Would anyone know how to solve this problem? :)

[matt]

See also #2706 Support graphs in Email reports

[vipsoft]

Trunk has a license conflict. From  http://dev.piwik.org/trac/ticket/1721#comment:13:

The pChart library contains Microsoft fonts (i.e., tahoma.ttf in pChart 1.27d and verdana.ttf in pChart 2) that don't allow for this form of redistribution. The font should be removed from the package. (The user can be instructed to install the missing font, if required.)

[vipsoft]

If the tahoma font is required, please see if the LGPL tahoma.ttf font from the Wine project works as a replacement. (Supposedly has similar/same kerning to Microsoft's.)

 http://source.winehq.org/git/wine.git/tree/HEAD:/fonts

[vipsoft]

Take a look at GNU Unifont:  http://unifoundry.com/unifont.html -- it's a pan-unicode font with lots of coverage and is included with Debian.

It's supposedly GPL v2 or higher, but there's an unanswered question in the Debian bugs database.  http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=584672

[matt]

Looks interesting, but very big font, as expected :)

Is there a TTF version?

[matt]

PDF Reports with graphs, showing that the legends is not frequent enough

[matt]

When we create the PDF reports with all reports as vertical bar graph, unfortunately the report is not useful because the graphs do not show enough legends. We should, for the Keywords, Countries, Referrers, Pages, etc. show the X legend for EACH data point. The legends text would have to be vertical or diagonal to fit, and we could display maybe 10-15 maximum?

This is I believe the most urgent item to tackle to improve the Graphs :)

[JulienM]

I'm currently investigating the comment:9 legend issue.

[JulienM]

The best way to go forward with comment:9 is to introduce a new type of graph: horizontal bars.

I'm currently refactoring the whole ImageGraph Plugin code.

[JulienM]

Per Anthon's suggestions, I'd like to:

• remove licensed font
• select fonts according to locale (like in the PDFReport plugin)

However,

• the fonts from the tcpdf plugin doesn't seem to be in the same format as the ones from the pChart library
• the pChart library doesn't have the fonts we need to be consistent with the PDFReport plugin
• pChart 2 doesn't have the font that is currently in use by the ImageGraph plugin (tahoma)

How do you suggest we deal with this ?

[arni]

Maybe we should write the chart drawing on our own. If you also think so, I could start with this task...

[JulienM]

I've actually almost finished updating the ImageGraph plugin to use pChart 2.1.3.

I don't think writing our own charting library is wise considering pChart has almost all we need.

[matt]

Re: Fonts. Yes this is a known problem, see ticket description. Fonts from tcpdf seem to not be reusable for graphs (since not in ttf format)...

You can plug the free tahoma font in the imagegraph plugin, sure, it should just work like the other tahoma.

good luck, looking forward to seeing the result!

[vipsoft]

Wine's tahoma font has the same kerning as Microsoft's, but doesn't lacks many anti-aliasing hints, so it looks kind of ugly.

Unifont is a ttf, but font width and kerning is different.

[JulienM]

unifont demo

[JulienM]

tahoma demo

[JulienM]

unifont demo

[JulienM]

tahoma demo (png seems to be better for comparison, maybe there is an even better format?)

[JulienM]

Please discard all the tahoma examples. I used the Microsoft file.

I'm close to fixing this ticket and the two related ones (#2788 #2706).

What's stalling the progress is that we may need to modify pChart 2 source code to fix the following issue :  http://sourceforge.net/tracker/?func=detail&aid=3443890&group_id=227755&atid=1071632

Also, I have yet to find a way to display icons and percentages as specified in  http://dev.piwik.org/trac/attachment/ticket/2704/Wishlist%20graphs%20horizontal%20bars.jpg

[matt]

I have contacted pCharts dev by email - not sure what is the best way to get things moving faster?

Did you take a shot yourself, maybe the bug can be cracked in a few minutes ;-)

Icons & percentages, probably not possible now, would require new features in the lib. If not easy, it will be no problem committing without it!

[JulienM]

I'll try and fix it.

Concerning LEGALNOTICE, does the wine font belong to section THIRD-PARTY CONTENT ?

Also, the pChart 2 readme mention the font files we decided to remove :

  The provided font files are licensed under their own terms :

   │
   ├─ dvent_light.ttf	Copyright Andreas K. inde
   ├─ Bedizen.ttf	Copyright Tepid Monkey Fonts
   ├─ calibri.ttf	Copyright Microsoft
   ├─ Forgotte.ttf	Copyright Ray Larabie
   ├─ GeosansLight.ttf	Copyright Manfred Klein
   ├─ MankSans.ttf	Copyright Manfred  Klein
   ├─ pf_arma_five.ttf	Copyright Yusuke Kamiyamane
   ├─ Silkscreen.ttf	Copyright Jason Aleksandr Kottke
   └─ verdana.ttf	Copyright Microsoft

Do we leave it that way ?

[vipsoft]

THIRD-PARTY CONTENT: yes, that's the appropriate section for non-code.

Leave pChart's readme as is. Just add a note to piwik/libs/README_LIBS mentioning the font removal.

[matt]

(In [5549]) Refs #2704 Restoring _GET parameters to original values, even when an exception is thrown. This might fix some bugs in scheduled reports when 1) reports contains several graphs 2) one or several graphs have "no data" 3) the following graph wouldn't start with the correct value of _GET causing maybe problems?

[JulienM]

New graph type Horizontal Bar requirement moved to #2828 for changelog clarity.

[JulienM]

Percentage values in static graphs deferred to #2829

[JulienM]

(In [5582]) * fixes #2706, #2828, #2704, refs #1721, #2637, #2711, #2318, #71 : horizontal static graph implemented

• fixes #2788, refs #2670, #1721, #2637, #2711 : default graph type logic moved to ImageGraph API, improved date/period logic, new parameter graphs_default_period_to_plot_when_period_range
• fixes #2704, #2804, refs #1721 : pChart updated to 2.1.3, pChart code removed from Piwik code, OOP refactoring, support for unifont.ttf if present in ImageGraph/fonts, testAllSizes now uses report metadata ImageGraphUrl
• refs #71 : space between report title and report table reduced to avoid page overflow
• refs #2829 : TODO display percentages
• r5544, r5547, r5549 merged

[JulienM]

New FAQs concerning unicode support in ImageGraph :

http://piwik.org/faq/how-to-install/#faq_142

http://piwik.org/faq/troubleshooting/#faq_143

[matt]

(In [5736]) Refs #2704 svn clean up unused directories