Implemented #856: Always select next node upon deletion of the selected node

Author: joachimmarder

Source/VirtualTrees.BaseTree.pas

@@ -1423,7 +1423,7 @@   TBaseVirtualTree = class abstract(TVTBaseAncestor)
     function EndEditNode: Boolean;
     procedure EndSynch;
     procedure EndUpdate; virtual;
-    procedure EnsureNodeSelected(); virtual;
+    procedure EnsureNodeSelected(pAfterDeletion: Boolean); virtual;
     function ExecuteAction(Action: TBasicAction): Boolean; override;
     procedure FinishCutOrCopy;
     procedure FlushClipboard;
@@ -10205,7 +10205,7 @@ procedure TBaseVirtualTree.DoCollapsed(Node: PVirtualNode);
     end;//if
     //if there is (still) no selected node, then use FNextNodeToSelect to select one
     if SelectedCount = 0 then
-      EnsureNodeSelected();
+      EnsureNodeSelected(False);
   end;//if
 end;
 
@@ -10550,7 +10550,7 @@ procedure TBaseVirtualTree.DoEndOperation(OperationKind: TVTOperationKind);
 procedure TBaseVirtualTree.DoEnter();
 begin
   inherited;
-  EnsureNodeSelected();
+  EnsureNodeSelected(False);
 end;
 
 //----------------------------------------------------------------------------------------------------------------------
@@ -10672,7 +10672,7 @@ procedure TBaseVirtualTree.DoFreeNode(Node: PVirtualNode);
 
   FreeMem(Node);
   if Self.UpdateCount = 0 then
-    EnsureNodeSelected();
+    EnsureNodeSelected(True);
 end;
 
 //----------------------------------------------------------------------------------------------------------------------
@@ -12083,9 +12083,11 @@ procedure TBaseVirtualTree.EnsureNodeFocused();
 
 //----------------------------------------------------------------------------------------------------------------------
 
-procedure TBaseVirtualTree.EnsureNodeSelected();
+procedure TBaseVirtualTree.EnsureNodeSelected(pAfterDeletion: Boolean);
 begin
-  if (toAlwaysSelectNode in TreeOptions.SelectionOptions) and not IsEmpty then
+  if IsEmpty then
+    exit; // Nothing to do
+  if (toAlwaysSelectNode in TreeOptions.SelectionOptions) or (pAfterDeletion and (toSelectNextNodeOnRemoval in TreeOptions.SelectionOptions)) then
   begin
     if (SelectedCount = 0) and not SelectionLocked then
     begin
@@ -15259,7 +15261,7 @@ procedure TBaseVirtualTree.UpdateNextNodeToSelect(Node: PVirtualNode);
 // selected one gets deleted.
 
 begin
-  if not (toAlwaysSelectNode in TreeOptions.SelectionOptions) then
+  if ([toAlwaysSelectNode, toSelectNextNodeOnRemoval] * TreeOptions.SelectionOptions) = [] then
     Exit;
   if GetNextSibling(Node) <> nil then
     FNextNodeToSelect := GetNextSibling(Node)
@@ -16938,7 +16940,7 @@ procedure TBaseVirtualTree.DeleteChildren(Node: PVirtualNode; ResetHasChildren:
         InvalidateToBottom(Node);
       if tsChangePending in FStates then begin
         DoChange(FLastChangedNode);
-        EnsureNodeSelected();
+        EnsureNodeSelected(True);
       end;
     end;
     StructureChange(Node, crChildDeleted);
@@ -17205,7 +17207,7 @@ procedure TBaseVirtualTree.EndUpdate;
       NotifyAccessibilityCollapsed(); // See issue #1174
 
       DoUpdating(usEnd);
-      EnsureNodeSelected();
+      EnsureNodeSelected(False);
     end
     else
       DoUpdating(usUpdate);

Source/VirtualTrees.Types.pas

@@ -359,9 +359,10 @@   TSortDirectionHelper = record helper for VirtualTrees.Types.TSortDirection
     toRestoreSelection,              // Set to true if upon refill the previously selected nodes should be selected again.
                                      // The nodes will be identified by its caption (text in MainColumn)
                                      // You may use TVTHeader.RestoreSelectiuonColumnIndex to define an other column that should be used for indentification.
-    toSyncCheckboxesWithSelection    // If checkboxes are shown, they follow the change in selections. When checkboxes are
+    toSyncCheckboxesWithSelection,   // If checkboxes are shown, they follow the change in selections. When checkboxes are
                                      // changed, the selections follow them and vice-versa.
                                      // **Only supported for ctCheckBox type checkboxes.
+    toSelectNextNodeOnRemoval        // If the selected node gets deleted, automatically select the next node.
     );
   TVTSelectionOptions = set of TVTSelectionOption;
 
@@ -768,7 +769,7 @@   TChunkHeader = record
   DefaultPaintOptions     = [toShowButtons, toShowDropmark, toShowTreeLines, toShowRoot, toThemeAware, toUseBlendedImages];
   DefaultAnimationOptions = [];
   DefaultAutoOptions      = [toAutoDropExpand, toAutoTristateTracking, toAutoScrollOnExpand, toAutoDeleteMovedNodes, toAutoChangeScale, toAutoSort, toAutoHideButtons];
-  DefaultSelectionOptions = [];
+  DefaultSelectionOptions = [toSelectNextNodeOnRemoval];
   DefaultMiscOptions      = [toAcceptOLEDrop, toFullRepaintOnResize, toInitOnSave, toToggleOnDblClick, toWheelPanning, toEditOnClick];
 
   DefaultStringOptions    = [toSaveCaptions, toAutoAcceptEditChange];