win32: fix form bounds for windows with multi-line main menus and/or scrollbars

lcl/interfaces/win32/win32int.pp

@@ -280,8 +280,8 @@ function AdjustWindowRectExForDpi(const lpRect: LPRECT; dwStyle: DWORD; bMenu: B
 function GetDpiForMonitor(hmonitor: HMONITOR; dpiType: TMonitorDpiType; out dpiX: UINT; out dpiY: UINT): HRESULT;
 function LoadIconWithScaleDown(hinst:HINST; pszName:LPCWStr;cx:cint;cy:cint;var phico: HICON ):HRESULT;
 
-procedure AdjustFormBounds(const AHandle: HANDLE; var ioSizeRect: TRect); overload;
+procedure AdjustFormClientToWindowSize(const AHandle: HANDLE; var ioSize: TSize); overload;
-procedure AdjustFormBounds(aHasMenu: Boolean; dwStyle, dwExStyle: DWORD; dpi: UINT; var ioSizeRect: TRect); overload;
+procedure AdjustFormClientToWindowSize(aHasMenu: Boolean; dwStyle, dwExStyle: DWORD; dpi: UINT; var ioSize: TSize); overload;
 
 implementation
 
@@ -439,44 +439,68 @@ begin
     Result := S_FALSE;
 end;
 
-procedure AdjustFormBounds(const AHandle: HANDLE; var ioSizeRect: TRect);
+procedure AdjustFormClientToWindowSize(const AHandle: HANDLE; var ioSize: TSize);
 {$IFNDEF LCLRealFormBounds}
 var
-  xClientRect, xWindowRect: TRect;
+  xClientRect, xWindowRect, xSR: TRect;
   xNonClientDPI: UINT;
-  Info: tagWINDOWINFO;
+  xInfo: tagWINDOWINFO;
+  xTopLeft: TPoint;
+  xHasMenu: Boolean;
+  xReplaceTop: LongInt;
 {$ENDIF}
 begin
   {$IFNDEF LCLRealFormBounds}
-  xClientRect := Default(TRect);
+  // convert form client size to window size
-  xWindowRect := Default(TRect);
+  //  the difference between Windows.GetClientRect(AHandle, xClientRect) and Windows.GetWindowRect(AHandle, xWindowRect)
-  if (AHandle<>0)
+  //  must not be used because it fails when the form has visible scrollbars (and can be scrolled)
-  and GetClientRect(AHandle, xClientRect) and not xClientRect.IsEmpty
-  and (GetWindowRect(AHandle, xWindowRect)<>0) and not xWindowRect.IsEmpty then
-  begin
-    Inc(ioSizeRect.Right, xWindowRect.Width-xClientRect.Width);
-    Inc(ioSizeRect.Bottom, xWindowRect.Height-xClientRect.Height);
-    Exit; // the sizes could be obtained from window-client -> exit
-  end;
 
-  // the sizes could not be obtained from window-client (e.g. the window is minimized) -> calculate default
+  if AreDpiAwarenessContextsEqual(GetThreadDpiAwarenessContext, DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2) then
-  if (AHandle<>0) and AreDpiAwarenessContextsEqual(GetThreadDpiAwarenessContext, DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2) then
     xNonClientDPI := GetDpiForWindow(AHandle)
   else
     xNonClientDPI := ScreenInfo.PixelsPerInchX;
 
-  Info := Default(tagWINDOWINFO);
+  xInfo := Default(tagWINDOWINFO);
-  Info.cbSize := SizeOf(Info);
+  xInfo.cbSize := SizeOf(xInfo);
-  if GetWindowInfo(AHandle, @Info) then
+  if GetWindowInfo(AHandle, @xInfo) then
-    AdjustWindowRectExForDpi(@ioSizeRect, Info.dwStyle, GetMenu(AHandle)<>0, Info.dwExStyle, xNonClientDPI);
+  begin
+    xHasMenu := GetMenu(AHandle)<>0;
+    xTopLeft := Point(0, 0);
+    xClientRect := Default(TRect);
+    xWindowRect := Default(TRect);
+
+    // AdjustWindowRectExForDpi calculates only 1 menu line but on Win32 the menu can have multiple lines
+    //  therefore get the top coordinate from ClientToScreen difference if possible (that is correct also when scrollbars are shown)
+    if xHasMenu
+    and Windows.GetClientRect(AHandle, xClientRect) and not xClientRect.IsEmpty // just to check that there is some client rect and ClientToScreen will return some sane results
+    and Windows.GetWindowRect(AHandle, xWindowRect) and not xWindowRect.IsEmpty
+    and Windows.ClientToScreen(AHandle, xTopLeft) then
+    begin
+      xReplaceTop := xTopLeft.Y-xWindowRect.Top;
+      xHasMenu := False;
+    end else
+      xReplaceTop := 0;
+
+    xSR := Rect(0, 0, 0, 0);
+    AdjustWindowRectExForDpi(@xSR, xInfo.dwStyle, xHasMenu, xInfo.dwExStyle, xNonClientDPI);
+    if xReplaceTop>0 then
+      xSR.Top := -xReplaceTop;
+    Inc(ioSize.cx, xSR.Width);
+    Inc(ioSize.cy, xSR.Height);
+  end;
   {$ENDIF}
 end;
 
-procedure AdjustFormBounds(aHasMenu: Boolean; dwStyle, dwExStyle: DWORD; dpi: UINT; var ioSizeRect: TRect);
+procedure AdjustFormClientToWindowSize(aHasMenu: Boolean; dwStyle, dwExStyle: DWORD; dpi: UINT; var ioSize: TSize);
+var
+  SizeRect: TRect;
 begin
   {$IFNDEF LCLRealFormBounds}
   // no known handle -> default (1 menu line)
-  AdjustWindowRectExForDpi(@ioSizeRect, dwStyle, aHasMenu, dwExStyle, dpi);
+  SizeRect := Rect(0, 0, ioSize.Width, ioSize.Height);
+  AdjustWindowRectExForDpi(@SizeRect, dwStyle, aHasMenu, dwExStyle, dpi);
+  ioSize.Width := SizeRect.Width;
+  ioSize.Height := SizeRect.Height;
   {$ENDIF}
 end;
 

lcl/interfaces/win32/win32winapi.inc

@@ -2418,14 +2418,14 @@ function TWin32WidgetSet.GetWindowSize(Handle : hwnd;
 
   procedure ExcludeBorder(dwStyle, dwExStyle: DWORD);
   var
-    xRect: Windows.RECT;
+    xSize: Windows.SIZE;
   begin
     if (Height<>0) and (Width<>0) then
     begin
-      xRect := Rect(0, 0, 0, 0);
+      xSize := TSize.Create(0, 0);
-      AdjustFormBounds(GetMenu(Handle)<>0, dwStyle, dwExStyle, GetDpiForWindow(Handle), xRect);
+      AdjustFormClientToWindowSize(Handle, xSize);
-      Dec(Height, xRect.Height);
+      Dec(Height, xSize.Height);
-      Dec(Width, xRect.Width);
+      Dec(Width, xSize.Width);
     end;
   end;
 
@@ -2457,13 +2457,12 @@ begin
     if Result then
     begin
       // for minimized window use normal position, in other case use rcWindow of WindowInfo
-      if (WP.showCmd<>SW_MINIMIZE) and (WP.showCmd<>SW_SHOWMINIMIZED) and not Info.rcClient.IsEmpty then
+      //  DO NOT USE rcClient here because it is wrong if the form has scrollbars
-        SetWidthHeightFromRect(Info.rcClient)
+      if (WP.showCmd<>SW_MINIMIZE) and (WP.showCmd<>SW_SHOWMINIMIZED) then
+        SetWidthHeightFromRect(Info.rcWindow)
       else
-      begin
         SetWidthHeightFromRect(WP.rcNormalPosition);
-        ExcludeBorder(Info.dwStyle, Info.dwExStyle); // rcClient is not available -> get ExcludeBorder
+      ExcludeBorder(Info.dwStyle, Info.dwExStyle);
-      end;
       //WriteLn('W = ', Width, ' H = ', Height);
       Exit;
     end;

lcl/interfaces/win32/win32wsforms.pp

@@ -122,7 +122,7 @@ type
   published
   end;
 
-procedure AdjustFormBounds(const AForm: TCustomForm; var ioSizeRect: TRect); overload;
+procedure AdjustFormClientToWindowSize(const AForm: TCustomForm; var ioSize: TSize); overload;
 
 implementation
 
@@ -305,29 +305,29 @@ begin
   FlagsEx := FlagsEx or CalcBorderIconsFlagsEx(AForm);
 end;
 
-procedure AdjustFormBounds(const AForm: TCustomForm; var ioSizeRect: TRect); overload;
+procedure AdjustFormClientToWindowSize(const AForm: TCustomForm; var ioSize: TSize);
 var
   xNonClientDPI: LCLType.UINT;
 begin
   if AForm.HandleAllocated then
-    AdjustFormBounds(AForm.Handle, ioSizeRect)
+    AdjustFormClientToWindowSize(AForm.Handle, ioSize)
   else // default handling
-    AdjustFormBounds(AForm.Menu<>nil,
+    AdjustFormClientToWindowSize(AForm.Menu<>nil,
       CalcBorderStyleFlags(AForm) or CalcBorderIconsFlags(AForm),
       CalcBorderStyleFlagsEx(AForm) or CalcBorderIconsFlagsEx(AForm),
-      ScreenInfo.PixelsPerInchX, ioSizeRect);
+      ScreenInfo.PixelsPerInchX, ioSize);
 end;
 
 function CustomFormWndProc(Window: HWnd; Msg: UInt; WParam: Windows.WParam; LParam: Windows.LParam): LResult; stdcall;
 
   procedure LCLFormSizeToWin32Size(AForm: TCustomForm; var AWidth, AHeight: Integer);
   var
-    SizeRect: Windows.RECT;
+    Size: TSize;
   begin
-    SizeRect := Classes.Rect(0, 0, AWidth, AHeight);
+    Size := TSize.Create(AWidth, AHeight);
-    AdjustFormBounds(AForm, SizeRect);
+    AdjustFormClientToWindowSize(AForm, Size);
-    AWidth := SizeRect.Width;
+    AWidth := Size.Width;
-    AHeight := SizeRect.Height;
+    AHeight := Size.Height;
   end;
 
   procedure SetMinMaxInfo(WinControl: TWinControl; var MinMaxInfo: TMINMAXINFO);
@@ -420,6 +420,7 @@ var
   Bounds: TRect;
   SystemMenu: HMenu;
   MaximizeForm: Boolean = False;
+  lSize: TSize;
 begin
   // general initialization of Params
   PrepareCreateWindow(AWinControl, AParams, Params);
@@ -471,7 +472,9 @@ begin
     pClassName := @ClsName[0];
     WindowTitle := StrCaption;
     Bounds := lForm.BoundsRect;
-    AdjustFormBounds(lForm, Bounds);
+    lSize := Bounds.Size;
+    AdjustFormClientToWindowSize(lForm, lSize);
+    Bounds.Size := lSize;
     if (lForm.Position in [poDefault, poDefaultPosOnly]) and not (csDesigning in lForm.ComponentState) then
     begin
       Left := CW_USEDEFAULT;
@@ -643,18 +646,26 @@ class procedure TWin32WSCustomForm.SetBounds(const AWinControl: TWinControl;
 var
   AForm: TCustomForm absolute AWinControl;
   CurRect: Windows.RECT = (Left: 0; Top: 0; Right: 0; Bottom: 0);
-  SizeRect: Windows.RECT;
+  lSize: Windows.SIZE;
   L, T, W, H: Integer;
+  Attempt: 0..1; // 2 attempts
+begin
+  // Problem:
+  //   When setting the ClientRect, the main menu may change height (the menu lines may change).
+  //   After the first attempt to set bounds, they can be wrong because the number of the lines changed and
+  //     it is not possible to determine the menu line count for the target rectangle/
+  //   Therefore a second attempt is needed to get the correct height.
+  for Attempt := Low(Attempt) to High(Attempt) do
   begin
     // the LCL defines the size of a form without border, win32 with.
     // -> adjust size according to BorderStyle
-  SizeRect := Bounds(ALeft, ATop, AWidth, AHeight);
+    lSize := TSize.Create(AWidth, AHeight);
 
-  AdjustFormBounds(AForm, SizeRect);
+    AdjustFormClientToWindowSize(AForm, lSize);
     L := ALeft;
     T := ATop;
-  W := SizeRect.Right - SizeRect.Left;
+    W := lSize.Width;
-  H := SizeRect.Bottom - SizeRect.Top;
+    H := lSize.Height;
 
     // we are calling setbounds in TWinControl.Initialize
     // if position is default it will be changed to designed. We do not want this.
@@ -678,6 +689,11 @@ begin
 
     // rect adjusted, pass to inherited to do real work
     TWin32WSWinControl.SetBounds(AWinControl, L, T, W, H);
+    if (Attempt=High(Attempt)) // last one, no need to call GetClientRect
+    or not GetClientRect(AWinControl, CurRect) // not available
+    or ((CurRect.Width=AWidth) and (CurRect.Height=AHeight)) then // or correct size -> break
+      break;
+  end;
 end;
 
 class procedure TWin32WSCustomForm.SetIcon(const AForm: TCustomForm; const Small, Big: HICON);