Text Leaders

[Josh-Schifter]

Related to Issue: TextBox

Summary:

Propose to add leaders as an optional feature of TextAnnotation2d/3d elements. This proposal aims to avoid the problems we had with MicroStation 'Notes' which were made of multiple related elements.

Detailed proposal:

• Add a new property to TextAnnotation2d/3d 'Leaders' to store properties related to array of leaders.
• Each member of the array would store information describing a leader (see below)
• Store leader styling information in Text Style.
• TextAnnotation2d/3d geometry stream should include the leader geometry

For each leader, need to store:

• Attachment point stored as a string (ex. "MiddleRight"). This will be related to the shape of the Text Frame.
• Target point stored as Point3d.
• Overrides for styling properties such as color, terminator shape and size, curve type (ex. line, curve, etc.)
• ElementDrivesElement relationship to the target element.

The Drawing Production team would like to do the implementation.

@pmconne, @jffmarker, @claudiaareneee , @SheetalNair , @Alfonso-Martello

[Josh-Schifter]

How I see the pros and cons of this proposal vs. the alternative.

Option 1 (this proposal): A single element combining text, frame, and leaders:

Pro	Con
Geometry generation is centralized Easier to implement manipulation dynamics Only need relationship to ‘driving’ elements, not between leader and text Clear relationship between leader and Text Style	One text element ‘driven’ by N other elements Text element has to store more information [leader attachment point, association info, additional data for multisegment leaders] All code changes for leaders have to be done in core packages.

Option 2 (alternative to this proposal): A new element for just a single leader:

Pro	Con
Each leader only has two relationships (no more) Decoupled	Heavier reliance on relationships When user deletes text we must delete all leaders Need to prevent move, rotate tool for leader element

[pmconne]

Attachment point stored as a string (ex. "MiddleRight"). This will be related to the shape of the Text Frame.

So users can't choose any point on the frame shape / bounding box - they are restricted to a small set of options?
How does it work for non-rectangular frames (clouds, ovals, pentagons, triangles)? e.g., what do "top-left" and "top-right" mean for a triangular frame like 🔺 ?

Could something like specifying the attachment point as the fraction along the curve representing the frame better support arbitrary attachment points and various frame shapes?

[pmconne]

I lean toward Option 1. It can make sense for a text annotation to be a BIS object. It doesn't make much sense for a leader to be a BIS object.

[Josh-Schifter]

I think the available options for attachment point might vary per frame. I'm not sure of the details. Compared to MicroStation, I'd like to consider adding one new attachment point called "nearest".