Reduce font size for label (title) to 12.5 for compatibility with chartjs version

[colinl]

Description

Version 1.28.0 has the font size for the label (title in eCharts) set to 14. This gives a font size larger than in the previous chartjs version, leading to problems such as that in #1885 where the label is too long to fit the space. This PR reduces the font to 12.5 which appears to that which was used by chartjs.

Related Issue(s)

Partially fixes #1885

Checklist

• [x ] I have read the contribution guidelines
• Suitable unit/system level tests have been added and they pass
• Documentation has been updated
  • Upgrade instructions
  • Configuration details
  • Concepts
• Changes flowforge.yml?
  • Issue/PR raised on FlowFuse/helm to update ConfigMap Template
  • Issue/PR raised on FlowFuse/CloudProject to update values for Staging/Production
• Link to Changelog Entry PR, or note why one is not needed.

Labels

• Includes a DB migration? -> add the area:migration label

[Steve-Mcl]

Hi @colinl thanks very much for this. Greatly appreciated.

Where did you find that chartjs had a default 12.5 font?

[colinl]

By installing the previous version of the dashboard and measuring the length of a string in the title on screen, then experimented to find the font that gave the same size now. I don't know whether that is the default size in chartjs, but it appears to be the size that the dashboard used in the chart node.

[colinl]

I notice there is no font size spec for the radial chart. Should there be to keep the two types looking the same?

[Steve-Mcl]

By installing the previous version of the dashboard and measuring the length of a string in the title on screen, then experimented to find the font that gave the same size now.

Thanks for that. That is a reasonable enough justification for me.

[Steve-Mcl]

Approved while acknowledging this is a band aid to the real problem - but every little helps.

Thanks Colin.