Fix T63125: Gpencil: bones cannot be selected in weightpaint mode

Some underlying functionality was not ready for greasepencil:
- BKE_modifiers_get_virtual_modifierlist (now introduce dedicated BKE_gpencil_modifiers_get_virtual_modifierlist)
- BKE_modifiers_is_deformed_by_armature
- checks in drawing code
- checks in (pose) selection code

A couple of changes to make this work:
- `eGpencilModifierType_Armature` has to be respected (not only `eModifierType_Armature`)
- `OB_MODE_WEIGHT_GPENCIL` has to be respected (not only `OB_MODE_WEIGHT_PAINT`) --  (now use new `OB_MODE_ALL_WEIGHT_PAINT`)
- `gpencil_weightmode_toggle_exec` now shares functionality from `wpaint_mode_toggle_exec` -- moved to new `ED_object_posemode_set_for_weight_paint`

This patch will also set the context member "weight_paint_object" for greasepencil (otherwise some appropriate pose operators wont work when in weightpaint mode)

Reviewed By: campbellbarton

Maniphest Tasks: T63125

Differential Revision: https://developer.blender.org/D8483

1 files changed, 2 insertions, 44 deletions

diff --git a/source/blender/editors/sculpt_paint/paint_vertex.c b/source/blender/editors/sculpt_paint/paint_vertex.c
index e6b0c2fbd1b..3753709875b 100644
--- a/source/blender/editors/sculpt_paint/paint_vertex.c
+++ b/source/blender/editors/sculpt_paint/paint_vertex.c
@@ -1376,50 +1376,8 @@ static int wpaint_mode_toggle_exec(bContext *C, wmOperator *op)
     BKE_paint_toolslots_brush_validate(bmain, &ts->wpaint->paint);
   }
 
-  /* When locked, it's almost impossible to select the pose-object
-   * then the mesh-object to enter weight paint mode.
-   * Even when the object mode is not locked this is inconvenient - so allow in either case.
-   *
-   * In this case move our pose object in/out of pose mode.
-   * This is in fits with the convention of selecting multiple objects and entering a mode.
-   */
-  {
-    VirtualModifierData virtualModifierData;
-    ModifierData *md = BKE_modifiers_get_virtual_modifierlist(ob, &virtualModifierData);
-    if (md != NULL) {
-      /* Can be NULL. */
-      View3D *v3d = CTX_wm_view3d(C);
-      ViewLayer *view_layer = CTX_data_view_layer(C);
-      for (; md; md = md->next) {
-        if (md->type == eModifierType_Armature) {
-          ArmatureModifierData *amd = (ArmatureModifierData *)md;
-          Object *ob_arm = amd->object;
-          if (ob_arm != NULL) {
-            const Base *base_arm = BKE_view_layer_base_find(view_layer, ob_arm);
-            if (base_arm && BASE_VISIBLE(v3d, base_arm)) {
-              if (is_mode_set) {
-                if ((ob_arm->mode & OB_MODE_POSE) != 0) {
-                  ED_object_posemode_exit_ex(bmain, ob_arm);
-                }
-              }
-              else {
-                /* Only check selected status when entering weight-paint mode
-                 * because we may have multiple armature objects.
-                 * Selecting one will de-select the other, which would leave it in pose-mode
-                 * when exiting weight paint mode. While usable, this looks like inconsistent
-                 * behavior from a user perspective. */
-                if (base_arm->flag & BASE_SELECTED) {
-                  if ((ob_arm->mode & OB_MODE_POSE) == 0) {
-                    ED_object_posemode_enter_ex(bmain, ob_arm);
-                  }
-                }
-              }
-            }
-          }
-        }
-      }
-    }
-  }
+  /* Prepare armature posemode. */
+  ED_object_posemode_set_for_weight_paint(C, bmain, ob, is_mode_set);
 
   /* Weight-paint works by overriding colors in mesh,
    * so need to make sure we recalculate on enter and