Feature Requst: Object tree is too small for MMU/object manipulation

[Area5142]

Version

PrusaSlicer-2.3.0-alpha3 and previous alphas

Operating system type + version

I use Linux Mint 19.3 x64 but all platforms is affected.

3D printer brand / version + firmware version (if known)

All

Behavior

When assigning colors to MMU print or manipulation modifiers I use the object tree list in the side panel. The working area of this list has decreased in size for every release of PrusaSlicer as the sidebar functionality has grown:

Working with this small list is very annoying as it changes size whenever there is a change (background processing on) and the element in focus often disappears outside the visible window.

I find no alternative to object extruder assignment besides this list. When the model has many parts or the build plate has many parts it is easy to loose the overview and spend a lot of time trying to find the correct object to change. Using long names forces the horizontal scroll bar to be used as the sidebar has a max width, further complicating navigation.

Suggested solutions

Best solution would be to make the sidebar tabbed with the object-tree in one of the tabs.

A smaller change to the current sidebar could be optimizing it, giving more space for the individual elements:

1. Make section: Print Settings, Filament, Printer+Support+Infill, Group Manipulation, Object-tree and Sliced Info into collapsible sections. This would make space for all the non-collapsed elements. Make the setting persistent between sessions.
2. Make Object-tree user sizable, but without auto sizing as today. This would make the list easier to work with, not jumping around in size.
3. Move Inches checkbox to its rightful place in settings making more space. Normally a user works in either Imperial or Metric system.

Is this a new feature request? Yes

Project File (.3MF) where problem occurs

No project/gcode needed

[bubnikv]

The object list has been extended in PrusaSlicer 2.3.0-beta3.

[lukasmatena]

After complains that the object list is now too large (#5462), we reduced (8849aa77dc5fe4eacaafd29c274dcbdacc638aef) the height again so the minimum is now larger than originally but not as high as after the first change. We will likely fix this eventually by changing the clamping limits dynamically based on the number of items, but not for 2.3.0 release.

[Area5142]

When no objects is selected, the tree view has a usable size, but when an object is selected the Instance manipulation panel pops up and and "steals" the space. Unfortunately it is not possible to change an object without selecting it, like when changing extruder/color.

If somehow the Instance manipulation panel could collapse or hide it would provide the necessary space for a bigger tree view. It could be as simple as clicking the heading label Instance manipulation and toggle it on/off. It already has the code to hide when no object is selected.