This patch implements the navigating while transforming feature as an experimental (See image):

In addition to the experimental navigation while transforming feature, a considerable part of this patch is the implementation of two temporary operators:

• TRANSFORM_OT_modalkeymap_update
• TRANSFORM_OT_modalkeymap_restore

These operators are for modifying the keymap to remove conflicts with navigation shortcuts. (More details of these conflicts at the end below.)

The main solution in the patch was to create the bool ED_view3d_navigation_do(...); utility that can be used for any operator.

Navigating while transforming is not a new idea:

• https://rightclickselect.com/p/ui/Tqbbbc/allow-navigating-while-transforming (See comments);
• D1583: Allow no modal transform.

This feature allows us to be more freedom in transforming an object in closed spaces.

And with D9415: Transform: add feature to edit the 'Snap Base' navigating while transform becomes necessary because:

• we are incapable of choosing the occluded snap origin point while transforming

• Currently only 3 navigation operators are supported (more may be added over time):
  • VIEW3D_OT_zoom,
  • VIEW3D_OT_rotate,
  • VIEW3D_OT_move

• This patch affects the modal transform operators in 3D View. They are:
  • Translation,
  • Rotation,
  • Resize,
  • Skin Resize,
  • To Sphere,
  • Shear,
  • Bend,
  • Shrink/Fatten,
  • Tilt,
  • Trackball,
  • Push/Pull,
  • Crease,
  • Bone Size,
  • Bone Envelope,
  • Bone Envelope Distance,
  • Curve Shrink/Fatten,
  • Grease Pencil Shrink/Fatten,
  • Bone Roll,
  • Bevel Weight,
  • Align,
  • Edge Slide,
  • Sequence Slide,
  • Grease Pencil Opacity
• Navigation is not available when transforming with Release Confirm
• Default modal keymaps need to be edited to avoid conflict (in the patch a temporary operator was implemented to automatically update keymaps)