Feat/stacked area chart example

[tomhepworth]

Description of the feature or fix

An example of how to use a line chart + masking to create a simple stacked area chart as discussed here: https://forum.lvgl.io/t/line-masking-to-create-a-stacked-area-chart/6558/6

Checkpoints

• Follow the styling guide
• Update CHANGELOG.md
• Update the documentation

[embeddedt]

@kisvegabor I think this is unrelated to the example, but there is an extra pixel being drawn at the top of each section on the right.

[embeddedt]

Thanks! It looks great; I just have a couple comments.

[tomhepworth]

@kisvegabor I think this is unrelated to the example, but there is an extra pixel being drawn at the top of each section on the right.

This is because of the x - 1 in the draw event callback. But I copied that from this example. I think in that example the point circles are covering up the extra pixel.

If I remove the x-1 in my code it looks like this - just a little bit off but perhaps preferable?

[amirgon]

@tomhepworth Any plans to add Micropython example? (lv_example_chart_8.py)

[tomhepworth]

@tomhepworth Any plans to add Micropython example? (lv_example_chart_8.py)

I have never used micropython but I can give it a go.

[amirgon]

I have never used micropython but I can give it a go.

Great!
If you don't want to build micropython locally, you can try using GitPod.

[tomhepworth]

I pushed my fixes but for some reason the PR doesn't seem to want to synchronize with my branch.

[embeddedt]

Weird, I've never seen that happen before. Perhaps try a force push? We typically squash PRs when merging anyways, so the exact commits on your branch don't matter.

[tomhepworth]

Weird, I've never seen that happen before. Perhaps try a force push? We typically squash PRs when merging anyways, so the exact commits on your branch don't matter.

I tried without success. Want me to open another PR?

Seems ok now

[lvgl-bot]

This PR is stale because it has been open 14 days with no activity. Remove stale label or comment or this will be closed in 7 days.

[kisvegabor]

Sorry for the late reply. GitHub doesn't send notifications on edits so I haven't seen the update.

Although the MicroPython version is still missing I merge it.
The MP example can be added in an other PR.

@tomhepworth thank you for adding this example.