feat: axis with break

[Ovilia]

Brief Information

This pull request is in the type of:

• bug fixing
• new feature
• others

What does this PR do?

Provide a way to make break axes that may range too wide.

This is also helpful for expressing the lunch break (11:30-13:00) on intraday stock trading charts.

This PR also changes indicesOfNearest from DataStore to Series so that when in axisPointer, we can compare the data in the view coordinate rather ran data value, so that the nearest data is more intuitive since it's nearer to the mouse position.

Fixed issues

Document Info

One of the following should be checked.

• This PR doesn't relate to document changes
• The document should be updated later
• The document changes have been made in apache/echarts-doc#xxx

Misc

ZRender Changes

• This PR depends on ZRender changes (ecomfe/zrender#xxx).

Related test cases or examples to use the new APIs

When doing visual tests agains v6 branches, there are 4 diffs:

• axis-break: This is the new test file for this feature so it's expected to be different
• tooltip-axisPointer-snap: This is the new test file for indicesOfNearest and it checks if axisPointer snaps to the nearest data in view coord instead of data value so it's expected to be different
• area-large: Due to the change of indicesOfNearest, it's now always get the nearest data. But before, some position may don't show tooltip (probably due to large data filtering). So it's expected to be different.
• pie-label-extreme: After adding the logic to hiding label elements with zero width and height, the pie labelLines with no label text (due to truncation) will not be displayed. This is a more reasonable presentation because it seems to be not expected to show labelLine when there is not label displayed.

See the full test report:

report.html.zip

Others

Merging options

• Please squash the commits into a single one when merging.

Other information

[echarts-bot]

Thanks for your contribution!
The community will review it ASAP. In the meanwhile, please checkout the coding standard and Wiki about How to make a pull request.

The pull request is marked to be PR: author is committer because you are a committer of this project.

⚠️ MISSING DOCUMENT INFO: Please make sure one of the document options are checked in this PR's description. Search "Document Info" in the description of this PR. This should be done either by the author or the reviewers of the PR.

[Ovilia]

Discussion: Should this feature be called "axis breaking" or "axis collapsing"? This may probably depend on if I can implement break folding/unfolding feature.

I think the HighCharts implementation is quite tricky for the users. Although we can provide similar APIs with graphic.elements to enable developers do similar things, I'd prefer implementing such design as default axis broken style so that it won't be misleading to viewers if developers aren't very experienced in dataviz and don't know how to (or why should) let viewers understand this is an axis skipped some ranges.

[github-actions]

The changes brought by this PR can be previewed at: https://echarts.apache.org/examples/editor?version=PR-19459@85c56b9

[echarts-bot]

Document changes are required in this PR. Please also make a PR to apache/echarts-doc for document changes and update the issue id in the PR description. When the doc PR is merged, the maintainers will remove the PR: awaiting doc label.