Renders a nice cartographically pleasing curved line between the
labels and features.
Options include selecting a specific curve orientation (clockwise
or counterclockwise), or an automatic orientation option which
determines optimal orientation for each individual label. Users
also have control over the amount of curvature applied to the
callout lines.
highlight any pinned callout start or end points
This allows users to immediately see which callouts points have
been manually placed vs are automatically placed.
and destination points
Allows users to data define the starting and ending points for
label callout lines, which is useful when needing to manually
control the exact placement of individual callout lines.
This gives users control over where a callout should join to the label
text. (Previously, you only had control over where the callout would
join to the corresponding feature geometry).
Choices include:
- Closest point (previous behavior)
- Label Centroid
- Fixed corners: Top left/top right/bottom left/bottom right/etc
Data defined control over the label anchor is also possible
which controls a distance from the feature where callout lines end
Makes for visually more appealing callouts vs drawing them right
up against the edges of features
methods
While unused for now, this gives us flexibility in future to specify
additional useful contextual information about how a callout should
be rendered without breaking API (e.g. label text alignment, label
font settings, etc)
...instead of being rendered on top of some. For this callout style,
we don't want callouts overlapping labels (rather the opposite). But
leave API in place to allow other callout styles to render below
their associated labels only, as this may be wanted for some styles
(e.g. balloon style callouts)
