diff --git a/lcl/extctrls.pp b/lcl/extctrls.pp
index 72e0ba7efd..9fc9c0fe49 100644
--- a/lcl/extctrls.pp
+++ b/lcl/extctrls.pp
@@ -498,6 +498,8 @@ type
     rsUpdate    // draw nothing, update splitter position during moving
   );
 
+  TCanOffsetEvent = procedure(Sender: TObject; var NewOffset: Integer;
+    var Accept: Boolean) of object;
   TCanResizeEvent = procedure(Sender: TObject; var NewSize: Integer;
     var Accept: Boolean) of object;
   { TCustomSplitter is a control to interactively resize another control.
@@ -515,6 +517,7 @@ type
     FBeveled: boolean;
     FMinSize: integer;
     FMouseInControl: Boolean;
+    FOnCanOffset: TCanOffsetEvent;
     FOnCanResize: TCanResizeEvent;
     FOnMoved: TNotifyEvent;
     FResizeAnchor: TAnchorKind;
@@ -529,7 +532,9 @@ type
   protected
     class procedure WSRegisterClass; override;
     procedure CheckAlignment;
-    function CheckNewSize(var NewSize: integer): boolean; virtual;
+    function CheckNewSize(var NewSize: Integer): Boolean; virtual;
+    function CheckOffset(var NewOffset: Integer): Boolean; virtual;
+
     function FindAlignControl: TControl;
     function FindAlignOtherControl: TControl;
 
@@ -560,6 +565,7 @@ type
     property Beveled: boolean read FBeveled write SetBeveled default false;
     property Cursor default crHSplit;
     property MinSize: integer read FMinSize write SetMinSize default 30;
+    property OnCanOffset: TCanOffsetEvent read FOnCanOffset write FOnCanOffset;
     property OnCanResize: TCanResizeEvent read FOnCanResize write FOnCanResize;
     property OnMoved: TNotifyEvent read FOnMoved write FOnMoved;
     property ResizeAnchor: TAnchorKind read FResizeAnchor write SetResizeAnchor default akLeft;
@@ -580,6 +586,7 @@ type
     property Cursor;
     property Height;
     property MinSize;
+    property OnCanOffset;
     property OnCanResize;
     property OnChangeBounds;
     property OnMoved;
diff --git a/lcl/include/customsplitter.inc b/lcl/include/customsplitter.inc
index 6bf3e660c8..26fbb1be51 100644
--- a/lcl/include/customsplitter.inc
+++ b/lcl/include/customsplitter.inc
@@ -401,7 +401,7 @@ begin
     NewSize := CalcNewSize(StartSize, EndSize, Offset);
 
     // OnCanResize event
-    if CheckNewSize(NewSize) then
+    if CheckOffset(Offset) and CheckNewSize(NewSize) then
       if not FSplitDragging or (ResizeStyle = rsUpdate) then
         SetAlignControlSize(NewSize)
       else
@@ -463,25 +463,28 @@ begin
     //DebugLn(['TCustomSplitter.MoveSplitter Offset=',Offset,' OffsetMaxLower=',OffsetMaxLower,' OffsetMaxUpper=',OffsetMaxUpper]);
 
     // move splitter
-    if not FSplitDragging or (ResizeStyle = rsUpdate) then
+    if CheckOffset(Offset) then
     begin
-      if ResizeAnchor in [akLeft, akRight] then
-        Left := Left + Offset
+      if not FSplitDragging or (ResizeStyle = rsUpdate) then
+      begin
+        if ResizeAnchor in [akLeft, akRight] then
+          Left := Left + Offset
+        else
+          Top := Top + Offset;
+      end
       else
-        Top := Top + Offset;
-    end
-    else
-    begin
-      // get the splitter position
-      NewRect := BoundsRect;
-      NewRect.TopLeft := Parent.ClientToScreen(NewRect.TopLeft);
-      NewRect.BottomRight := Parent.ClientToScreen(NewRect.BottomRight);
+      begin
+        // get the splitter position
+        NewRect := BoundsRect;
+        NewRect.TopLeft := Parent.ClientToScreen(NewRect.TopLeft);
+        NewRect.BottomRight := Parent.ClientToScreen(NewRect.BottomRight);
 
-      if ResizeAnchor in [akLeft, akRight] then
-        OffsetRect(NewRect, Offset, 0)
-      else
-        OffsetRect(NewRect, 0, Offset);
-      SetRubberBandRect(FSplitterWindow, NewRect);
+        if ResizeAnchor in [akLeft, akRight] then
+          OffsetRect(NewRect, Offset, 0)
+        else
+          OffsetRect(NewRect, 0, Offset);
+        SetRubberBandRect(FSplitterWindow, NewRect);
+      end;
     end;
   end;
 end;
@@ -821,6 +824,13 @@ begin
     OnCanResize(Self, NewSize, Result);
 end;
 
+function TCustomSplitter.CheckOffset(var NewOffset: Integer): Boolean;
+begin
+  Result := True;
+  if Assigned(OnCanOffset) then
+    OnCanOffset(Self, NewOffset, Result);
+end;
+
 procedure TCustomSplitter.Paint;
   procedure DrawThemedPattern(ARect: TRect);
   const