Make serial plotter ringbuffer size configurable

[WilhelmWiens]

[facchinm]

@ArduinoBot build this please

[ArduinoBot]

:white_check_mark: Build completed.

Please test this code using one of the following:

:arrow_down: http://downloads.arduino.cc/javaide/pull_requests/arduino-PR-7454-BUILD-747-linux32.tar.xz :arrow_down: http://downloads.arduino.cc/javaide/pull_requests/arduino-PR-7454-BUILD-747-linux64.tar.xz :arrow_down: http://downloads.arduino.cc/javaide/pull_requests/arduino-PR-7454-BUILD-747-windows.zip :arrow_down: http://downloads.arduino.cc/javaide/pull_requests/arduino-PR-7454-BUILD-747-macosx.zip :arrow_down: http://downloads.arduino.cc/javaide/pull_requests/arduino-PR-7454-BUILD-747-linuxarm.tar.xz

:information_source: The linuxarm build is still experimental and may not be always available.

[madsdyd]

Just a note for others, and to stop myself from keep opening this issue: The PR (I think this should have been in the description):

Contains code to add a spinner to the Serial Plotter GUI, that allow to change the number of retained data points from the existing fixed 500 to a user chosen value between 10 and 5000.

However, the quality check fails, because there is:

• An unused local variable legendLenght in paintComponent
• The method setNewBufferCapacity assigns a new value to its parameter.

Both of these should be trivial to fix, but are there any maintainer (person with write access) that would be willing to merge this change?

[madsdyd]

So, does arduino/Arduino#7461 actually contain all the code in this issue as well?

[WilhelmWiens]

Do not pull it yet. I have made faulty merge.

[per1234]

This partially fixes https://github.com/arduino/arduino-serial-plotter-webapp/issues/29 (and the remaining part may be wontfix)

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
2 out of 3 committers have signed the CLA.

:white_check_mark: facchinm
:white_check_mark: chromhelm
:x: Wilhelm Wiens

---

Wilhelm Wiens seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}