Fix multi-item and group deletion

simplexui/interfaceModel.py

@@ -168,7 +168,7 @@ def coerceIndexToRoots(indexes):
         The coerced list
     """
     indexes = [i for i in indexes if i.column() == 0]
-    indexes = sorted(indexes, key=lambda x: x.model().itemFromIndex(x), reverse=True)
+    indexes = sorted(indexes, key=lambda x: x.model().itemFromIndex(x).classDepth, reverse=True)
     # Check each item to see if any of it's ancestors
     # are in the selection list.  If not, it's a root
     roots = []

simplexui/items/group.py

@@ -260,12 +260,14 @@ def delete(self):
 
         mgrs = [model.removeItemManager(self) for model in self.models]
         with nested(*mgrs):
-            gList.remove(self)
+            # Delete the children first
             # Gotta iterate over copies of the lists
             # as .delete removes the items from the list
             for item in self.items[:]:
                 item.delete()
 
+            gList.remove(self)
+
     @stackable
     def take(self, things):
         """Remove some items from their current groups and put them in this one

simplexui/simplexDialog.py

@@ -673,13 +673,13 @@ def sliderTreeDelete(self):
         idxs = self.uiSliderTREE.getSelectedIndexes()
         roots = coerceIndexToRoots(idxs)
         if not roots:
-            QMessageBox.warning(self, "Warning", "Nothing Selected")
+            QMessageBox.warning(self, "Warning", "Nothing Selected in Slider tree")
             return
         roots = makeUnique([i.model().itemFromIndex(i) for i in roots])
         for r in roots:
             if isinstance(r, Simplex):
                 QMessageBox.warning(
-                    self, "Warning", "Cannot delete a simplex system this way (for now)"
+                    self, "Warning", "Cannot delete a simplex system this way"
                 )
                 return
 
@@ -692,7 +692,17 @@ def comboTreeDelete(self):
         """Delete some objects in the Combo tree"""
         idxs = self.uiComboTREE.getSelectedIndexes()
         roots = coerceIndexToRoots(idxs)
+        if not roots:
+            QMessageBox.warning(self, "Warning", "Nothing Selected in Combo tree")
+            return
         roots = makeUnique([i.model().itemFromIndex(i) for i in roots])
+        for r in roots:
+            if isinstance(r, Simplex):
+                QMessageBox.warning(
+                    self, "Warning", "Cannot delete a simplex system this way"
+                )
+                return
+
         for r in roots:
             r.delete()
         self.uiComboTREE.model().invalidateFilter()