[Bf-blender-cvs] [c3e13d5a2b8] blender-v2.93-release: GPencil: fix separate points/strokes freezing with empty selection

[Philipp Oeser]

Commit: c3e13d5a2b8e9ada467850b4629dc4f228a2b2b8
Author: Philipp Oeser
Date:   Fri May 14 13:21:10 2021 +0200
Branches: blender-v2.93-release
https://developer.blender.org/rBc3e13d5a2b8e9ada467850b4629dc4f228a2b2b8

GPencil: fix separate points/strokes freezing with empty selection

Code would still create an object (without setting up materials), code
for removing unused material slots would then freeze.

Now return/cancel early in case of empty selection.

This came up in T88269 [which is still not fully fixed, transforming
curve edit points clear their GP_STROKE_SELECT flag which now results in
the early exit, should be looked at separately]

Maniphest Tasks: T88269

Differential Revision: https://developer.blender.org/D11252

===================================================================

M	source/blender/editors/gpencil/gpencil_edit.c
M	source/blender/editors/gpencil/gpencil_utils.c
M	source/blender/editors/include/ED_gpencil.h

===================================================================

diff --git a/source/blender/editors/gpencil/gpencil_edit.c b/source/blender/editors/gpencil/gpencil_edit.c
index d388e11dc8c..66d50e2fd12 100644
--- a/source/blender/editors/gpencil/gpencil_edit.c
+++ b/source/blender/editors/gpencil/gpencil_edit.c
@@ -4520,6 +4520,9 @@ static int gpencil_stroke_separate_exec(bContext *C, wmOperator *op)
 
   eGP_SeparateModes mode = RNA_enum_get(op->ptr, "mode");
 
+  const bool is_multiedit = (bool)GPENCIL_MULTIEDIT_SESSIONS_ON(gpd_src);
+  const bool is_curve_edit = (bool)GPENCIL_CURVE_EDIT_SESSIONS_ON(gpd_src);
+
   /* sanity checks */
   if (ELEM(NULL, gpd_src)) {
     return OPERATOR_CANCELLED;
@@ -4530,8 +4533,22 @@ static int gpencil_stroke_separate_exec(bContext *C, wmOperator *op)
     return OPERATOR_CANCELLED;
   }
 
-  const bool is_multiedit = (bool)GPENCIL_MULTIEDIT_SESSIONS_ON(gpd_src);
-  const bool is_curve_edit = (bool)GPENCIL_CURVE_EDIT_SESSIONS_ON(gpd_src);
+  /* Cancel if nothing selected. */
+  if (ELEM(mode, GP_SEPARATE_POINT, GP_SEPARATE_STROKE)) {
+    bool has_selected = false;
+    CTX_DATA_BEGIN (C, bGPDlayer *, gpl, editable_gpencil_layers) {
+      if (ED_gpencil_layer_has_selected_stroke(gpl, is_multiedit)) {
+        has_selected = true;
+        break;
+      }
+    }
+    CTX_DATA_END;
+
+    if (!has_selected) {
+      BKE_report(op->reports, RPT_ERROR, "Nothing selected");
+      return OPERATOR_CANCELLED;
+    }
+  }
 
   /* Create a new object. */
   /* Take into account user preferences for duplicating actions. */
diff --git a/source/blender/editors/gpencil/gpencil_utils.c b/source/blender/editors/gpencil/gpencil_utils.c
index 8d42024a518..9fba2ce5902 100644
--- a/source/blender/editors/gpencil/gpencil_utils.c
+++ b/source/blender/editors/gpencil/gpencil_utils.c
@@ -542,6 +542,38 @@ bool gpencil_stroke_inside_circle(const float mval[2], int rad, int x0, int y0,
   return false;
 }
 
+/* ******************************************************** */
+/* Selection Validity Testing */
+
+bool ED_gpencil_frame_has_selected_stroke(const bGPDframe *gpf)
+{
+  LISTBASE_FOREACH (bGPDstroke *, gps, &gpf->strokes) {
+    if (gps->flag & GP_STROKE_SELECT) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+bool ED_gpencil_layer_has_selected_stroke(const bGPDlayer *gpl, const bool is_multiedit)
+{
+  bGPDframe *init_gpf = (is_multiedit) ? gpl->frames.first : gpl->actframe;
+  for (bGPDframe *gpf = init_gpf; gpf; gpf = gpf->next) {
+    if ((gpf == gpl->actframe) || ((gpf->flag & GP_FRAME_SELECT) && (is_multiedit))) {
+      if (ED_gpencil_frame_has_selected_stroke(gpf)) {
+        return true;
+      }
+    }
+    /* If not multiedit, exit loop. */
+    if (!is_multiedit) {
+      break;
+    }
+  }
+
+  return false;
+}
+
 /* ******************************************************** */
 /* Stroke Validity Testing */
 
diff --git a/source/blender/editors/include/ED_gpencil.h b/source/blender/editors/include/ED_gpencil.h
index e9ac21f60cf..d4ff374dc38 100644
--- a/source/blender/editors/include/ED_gpencil.h
+++ b/source/blender/editors/include/ED_gpencil.h
@@ -144,6 +144,8 @@ bool ED_gpencil_data_owner_is_annotation(struct PointerRNA *owner_ptr);
 bool ED_gpencil_has_keyframe_v3d(struct Scene *scene, struct Object *ob, int cfra);
 
 /* ----------- Stroke Editing Utilities ---------------- */
+bool ED_gpencil_frame_has_selected_stroke(const struct bGPDframe *gpf);
+bool ED_gpencil_layer_has_selected_stroke(const struct bGPDlayer *gpl, const bool is_multiedit);
 
 bool ED_gpencil_stroke_can_use_direct(const struct ScrArea *area, const struct bGPDstroke *gps);
 bool ED_gpencil_stroke_can_use(const struct bContext *C, const struct bGPDstroke *gps);