Make 2D labels selectable

[meng@…]

The following bug report has been submitted:
Platform:        Darwin-18.7.0-x86_64-i386-64bit
ChimeraX Version: 0.91 (2019-08-30)
Description
Make 2D labels selectable.  Elaine suggested this and Scooter thinks it is a good idea.

Log:
UCSF ChimeraX version: 0.91 (2019-08-30)  
© 2016-2019 Regents of the University of California. All rights reserved.  
How to cite UCSF ChimeraX  




OpenGL version: 4.1 ATI-2.11.20
OpenGL renderer: AMD Radeon Pro Vega 20 OpenGL Engine
OpenGL vendor: ATI Technologies Inc.

[Tom Goddard]

Begin forwarded message:

From: Elaine Meng <>
Subject: Re: 2dlabels issues
Date: August 9, 2019 at 1:35:31 PM PDT
To: Tom Goddard <goddard@…>
Cc: chimera-programmers@…

I was not sure whether these kinds of models, 2D labels and eventually arrows and color keys, were supposed to be selectable. I just tried it to see if they were. If “select” can be used on those models, I’d vote for there to be a green outline and them to be selectable with the mouse as well. However, we have not discussed whether the concept of selection should apply to them in the first place.

I’m OK with them being selectable if it’s not too hard to do the outlines, etc., but haven’t developed a strong opinion one way or the other. Does anybody else care?

Elaine

[Tom Goddard]

We discussed this at group meeting and Scooter felt it would improve the user interface.

I think using selected 2d labels is going to be relatively rare and so this has much lower priority than adding a 2D label user interface panel that allows changing text, color, and font size. Currently those operations require typed commands.

If 2D labels can be selected then the user will probably expect 3D labels can be selected. That presents some problems because currently all 3D labels for a structure are represented by a single model. This differs from 2D labels where each label is a separate submodel. The reason for the difference is that it is easy to have 100 3D labels and if each was a separate model then the rendering speed becomes slow. The result is that selecting a 3D label would select all 3D labels for the same structure -- probably not expected or desirable. To allow an individual 3d label to be selected would require supporting selection for parts of the label model (like atoms can. be selected as parts of a Structure). This becomes a lot of work since the individual 3D labels will then need to be handled by the generic Objects class.

[Tom Goddard]

Currently 2D labels can be selected by command or Model Panel but do not show selection outlines, because the drawing code does not render outlines for overlay models. Also 3D labels don't show selection outlines because models drawn on top of all other models were not drawing outlines (bug).

I've fixed those two problems so now 2D and 3D labels show selection outlines. But neither can be selected with the mouse. 3D labels deliberately set a flag saying they are not selectable with the mouse, and 2D labels are overlays which and overlays do not have mouse selection support.

[Elaine Meng]

(1) There is a reasonably strong argument for making 2D labels but not
3D labels independently selectable, or even that making 3D labels
independently selectable would be detrimental. Currently 3D labels
(like cartoons and molecular surface) are specified by the items they
label, and we do not want to decouple (spatially or conceptually) these
annotations/representations from the associated 3D items. Some commands
(cartoon, surface, label) act only on that type of annotation/representation,
whereas others (color, show) use a "target" argument to distinguish among them.
Cartoons/mol surf are selectable but automatically select the associated atoms.
In my opinion, it would be a mistake to treat 3D labels differently and make
them independently selectable (without selecting associated atoms) because
that would layer another paradigm on top of the one we already have, and add
complexity to command interpretations (infer target from contents of "sel").
Making them selectable at all, even if associated atoms were automatically
also selected, seems not to add much utility.

(2) However, if 2D labels are only going to be "selectable, sort of" (not
with mouse, no green outline), it may be confusing. I.e. if those two
aspects are "wontfix" for overlays, it might be better if they weren't
selectable at all. In that case, the Model Panel select buttons should be
omitted or grayed out for those models.

[goddard@…]

Yesterday’s changes make 2d and 3d labels show green selection outlines.

Currently all models are selectable in chimerax although some do not select with the mouse (labels and volume image models).

[Elaine Meng]

My impression from the discussion was that selection with the mouse was one of the main reasons to make 2D labels selectable…. otherwise, it defeats the purpose of not having to look up the model numbers (or use the Model Panel).  In the Model Panel, you can only select one at a time.  Cumulative selection requires using the “select add” command, which most users will not figure out.

Bugettes?
(1) If I have two 2D labels #2.1 and #2.2, checking the selection box for #2 checks the submodel selection boxes too (so far so good) but does not show any selection outlines.
(2) with #2 selected as above, command “select clear” does not clear the checkboxes although based on trying “hide sel” the selection is actually cleared.  Don’t have this problem with atomic models.
(3) if I open an atomic model #1 and show a 3D label on something, then select #1 (which does show an outline on the label as well as everything else), then choose “hide sel models” it hides only the label even though the entire model #1 and all its submodels are selected.

Another problem mentioned before is that if you select labels only, using a command that excludes labels as the default target  on “sel” is confusing.  E.g. “color sel red” does nothing.  If only label(s) are selected maybe it should infer target is labels.  However, if the selection includes a bunch of different items, only some of which are labels, it may not be good to infer the target includes labels.  (“close sel” and hide/show works so maybe it’s only “color sel” that is potentially confusing)

We may be in agreement about some of this, as Scooter was the strongest proponent of making all models selectable.  Just setting down thoughts in case we need them for further discussion.