Noticed working on #5596 and #5708 a few issue when pset template is changing the prop types.
E.g. prop had string data type and now template suggests that it should be a float.
Previously, it might error trying to cast a string to a float. Now it will show a float until user will set it to null, then next time it will be loaded from the template data type.
Another example - prop was a string and now it's a boolean. Previously, it would be cast to boolean implicitly. E.g. "test" -> bool("test") -> True. And if user wouldn't be paying attention then enabling pset editing and saving it would make them lose "test" value.
Now - https://imgchest.com/p/na7ke99wb78
Before - https://imgchest.com/p/5xy23rr3z4l
Basically it won't allow setting values below 0 by accident (especially important for representation item props as it may lead to a crash).
1) IfcPositiveLengthMeasure will affect bunch of props like Depth in IfcExtrudedAreaSolid.
2) IfcNonNegativeLengthMeasure will affect MaterialLayer and some profiles attributes.
As it's the quicker way to select it than searching it in outliner - https://i.imgur.com/p2NVcdR.png
Couldn't find a simpler a way to do it in UI and had to create bunch of columns. Tried to use splits but they end up readjusting the buttons.
1) Fixed non-existent tool.Blender.get_screen
2) ui.py - remove try/except for the case when tabs are not loaded yet as it's covered by BIMTabProperties
3) removed previous_tab, alt_tab props never used in ui
4) general method for getting area properties that includes BIMTabProperties automatically
I guess by accident in d443c5e I've made this method too strict and it broke get_references using it for IfcPropertySets. Maybe it's a good idea to make it more strict in the future, for now just restoring the previous behaviour.
Basically now all length ifc attributes should be displayed in UI as Blender length properties - they display the units and allow math, typing different units, etc.
Example - https://imgchest.com/p/dl7p93gz64o
Andrej730
