Change for #832: Turn TVirtualNode.NodeHeight into a readonly property

Source/VirtualTrees.BaseTree.pas

@@ -4330,7 +4330,7 @@ procedure TBaseVirtualTree.InitRootNode(OldSize: Cardinal = 0);
     States := [vsInitialized, vsExpanded, vsHasChildren, vsVisible];
     TotalHeight := FDefaultNodeHeight;
     TotalCount := 1;
-    NodeHeight := FDefaultNodeHeight;
+    SetNodeHeight(FDefaultNodeHeight);
     Align := 50;
   end;
 end;
@@ -4414,7 +4414,7 @@ function TBaseVirtualTree.MakeNewNode: PVirtualNode;
   begin
     TotalCount := 1;
     TotalHeight := FDefaultNodeHeight;
-    NodeHeight := FDefaultNodeHeight;
+    SetNodeHeight(FDefaultNodeHeight);
     States := [vsVisible];
     Align := 50;
   end;
@@ -5180,7 +5180,7 @@ procedure TBaseVirtualTree.SetDefaultNodeHeight(Value: TDimension);
   if FDefaultNodeHeight <> Value then
   begin
     Inc(FRoot.TotalHeight, Value - FDefaultNodeHeight);
-    Inc(FRoot.NodeHeight, Value - FDefaultNodeHeight);
+    FRoot.SetNodeHeight(FRoot.NodeHeight + Value - FDefaultNodeHeight);
     FDefaultNodeHeight := Value;
     InvalidateCache;
     if (FUpdateCount = 0) and HandleAllocated and not (csLoading in ComponentState) then
@@ -5599,7 +5599,7 @@ procedure TBaseVirtualTree.SetNodeHeight(Node: PVirtualNode; Value: TDimension);
   if (Node.NodeHeight <> Value) then
   begin
     Difference := Value - Node.NodeHeight;
-    Node.NodeHeight := Value;
+    Node.SetNodeHeight(Value);
 
     // If the node is effectively filtered out, nothing else has to be done, as it is not visible anyway.
     if not IsEffectivelyFiltered[Node] then
@@ -9027,7 +9027,7 @@ procedure TBaseVirtualTree.ScaleNodeHeights(M, D: Integer);
         SetNodeHeight(Run, MulDiv(Run.NodeHeight, M, D))
       else // prevent initialization of non-initialzed nodes
       begin
-        Run.NodeHeight := MulDiv(Run.NodeHeight, M, D);
+        Run.SetNodeHeight(MulDiv(Run.NodeHeight, M, D));
         // The next three lines fix issue #1000
         lNewNodeTotalHeight := MulDiv(Run.TotalHeight, M, D);
         FRoot.TotalHeight := Cardinal(Int64(FRoot.TotalHeight) + Int64(lNewNodeTotalHeight) - Int64(Run.TotalHeight)); // Avoiding EIntOverflow exception.
@@ -15122,7 +15122,7 @@ function TBaseVirtualTree.ReadChunk(Stream: TStream; Version: Integer; Node: PVi
         begin
           // Set states first, in case the node is invisible.
           States := ChunkBody.States;
-          NodeHeight := ChunkBody.NodeHeight;
+          SetNodeHeight(ChunkBody.NodeHeight);
           TotalHeight := NodeHeight;
           Align := ChunkBody.Align;
           CheckState := ChunkBody.CheckState;

Source/VirtualTrees.Types.pas

@@ -887,8 +887,8 @@   TScrollBarOptions = class(TPersistent)
   private
     fIndex: Cardinal;         // index of node with regard to its parent
     fChildCount: Cardinal;    // number of child nodes
+    fNodeHeight: TDimension;  // height in pixels
   public
-    NodeHeight: TDimension;  // height in pixels
     States: TVirtualNodeStates; // states describing various properties of the node (expanded, initialized etc.)
     Align: Byte;             // line/button alignment
     CheckState: TCheckState; // indicates the current check state (e.g. checked, pressed etc.)
@@ -917,12 +917,14 @@   TScrollBarOptions = class(TPersistent)
     procedure SetLastChild(const pLastChild: PVirtualNode); inline; //internal method, do not call directly
     procedure SetIndex(const pIndex: Cardinal); inline;       //internal method, do not call directly.
     procedure SetChildCount(const pCount: Cardinal); inline; //internal method, do not call directly.
+    procedure SetNodeHeight(const pNodeHeight: TDimension); inline; //internal method, do not call directly.
     property Index: Cardinal read fIndex;
     property ChildCount: Cardinal read fChildCount;
     property Parent: PVirtualNode read fParent;
     property PrevSibling: PVirtualNode read fPrevSibling;
     property NextSibling: PVirtualNode read fNextSibling;
     property LastChild: PVirtualNode read fLastChild;
+    property NodeHeight: TDimension read fNodeHeight;
   private
     Data: record end;        // this is a placeholder, each node gets extra data determined by NodeDataSize
   public
@@ -1149,6 +1151,11 @@ function TVirtualNode.IsAssigned: Boolean;
   Exit(@Self <> nil);
 end;
 
+procedure TVirtualNode.SetNodeHeight(const pNodeHeight: TDimension);
+begin
+  fNodeHeight := pNodeHeight;
+end;
+
 //----------------------------------------------------------------------------------------------------------------------
 
 procedure TVirtualNode.SetData(pUserData: Pointer);