patch from Wallby (https://github.com/Wallby):

correctly track the visibility of the updown control called "spin"

closes #351

src/TabBar.cpp

@@ -1,6 +1,6 @@
 // This file is part of BowPad.
 //
-// Copyright (C) 2013-2023 - Stefan Kueng
+// Copyright (C) 2013-2024 - Stefan Kueng
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -55,6 +55,7 @@ CTabBar::CTabBar(HINSTANCE hInst)
  , m_tabBarDefaultProc(nullptr)
  , m_tabBarSpinDefaultProc(nullptr)
  , m_spin(nullptr)
+ , m_bIsSpinVisible(false)
  , m_currentHoverTabItem(-1)
  , m_bIsCloseHover(false)
  , m_whichCloseClickDown(-1)
@@ -483,7 +484,7 @@ LRESULT CTabBar::RunProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
 
  DrawMainBorder(&dis);
 
- if (m_spin)
+ if (m_bIsSpinVisible)
  {
  RECT rcSpin{};
  GetWindowRect(m_spin, &rcSpin);
@@ -492,7 +493,7 @@ LRESULT CTabBar::RunProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
  dis.rcItem.right = rcSpin.left;
  }
  // paint the tabs first and then the borders
- auto count  = GetItemCount();
+ auto count = GetItemCount();
  if (!count) // no pages added
  {
  SelectObject(hDC, hOldFont);
@@ -677,7 +678,7 @@ LRESULT CTabBar::RunProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
  auto index = GetTabIndexAt(xPos, yPos);
  RECT rcItem{};
  TabCtrl_GetItemRect(*this, index, &rcItem);
- if (m_spin)
+ if (m_bIsSpinVisible)
  {
  RECT rcSpin{};
  GetWindowRect(m_spin, &rcSpin);
@@ -754,12 +755,12 @@ LRESULT CTabBar::RunProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
  RECT rPage{};
  GetClientRect(*this, &rPage);
  TabCtrl_AdjustRect(*this, FALSE, &rPage);
- if (m_spin)
+ if (m_bIsSpinVisible)
  {
  RECT rcSpin{};
  GetWindowRect(m_spin, &rcSpin);
  MapWindowPoints(nullptr, *this, reinterpret_cast<LPPOINT>(&rcSpin), 2);
- rPage.right  = rcSpin.left;
+ rPage.right = rcSpin.left;
  }
  if (m_currentHoverTabRect.left < rPage.right && m_currentHoverTabRect.right > 0)
  {
@@ -996,7 +997,7 @@ COLORREF CTabBar::GetTabColor(UINT item) const
  return clr;
 }
 
-void CTabBar::DrawMainBorder(const LPDRAWITEMSTRUCT lpdis) const
+void CTabBar::DrawMainBorder(const LPDRAWITEMSTRUCT lpdis)
 {
  GDIHelpers::FillSolidRect(lpdis->hDC, &lpdis->rcItem, CTheme::Instance().GetThemeColor(::GetSysColor(COLOR_3DFACE)));
 }
@@ -1272,10 +1273,16 @@ LRESULT CTabBar::TabBarSpin_Proc(HWND hwnd, UINT message, WPARAM wParam, LPARAM
  {
  case WM_PAINT:
  {
+ // as WM_SHOWWINDOW is only ever sent with wParam == FALSE, use WM_PAINT instead
+ // of WM_SHOWWINDOW with wParam == TRUE
+ // alternatives might be WM_NCPAINT or 1125, which also both seem to be only
+ // sent when updown control is unhidden
+ if (!pTab->m_bIsSpinVisible)
+ pTab->m_bIsSpinVisible = true;
+
  PAINTSTRUCT ps;
  BeginPaint(hwnd, &ps);
  HDC hdc = ps.hdc;
-
  RECT rcPaint{};
  GetClientRect(hwnd, &rcPaint);
  auto rcLeft = rcPaint;
@@ -1472,9 +1479,18 @@ LRESULT CTabBar::TabBarSpin_Proc(HWND hwnd, UINT message, WPARAM wParam, LPARAM
  InvalidateRect(hwnd, nullptr, false);
  }
  break;
+ case WM_SHOWWINDOW:
+ {
+ if (wParam == FALSE) //< checked and is only ever sent with wParam == FALSE
+ pTab->m_bIsSpinVisible = false;
+ else
+ pTab->m_bIsSpinVisible = true;
+ break;
+ }
  case WM_DESTROY:
  {
- pTab->m_spin = nullptr;
+ pTab->m_bIsSpinVisible = false;
+ pTab->m_spin = nullptr;
  break;
  }
  default:
@@ -1533,6 +1549,7 @@ void CTabBar::SubclassSpinBox()
 
  pThis->m_tabBarSpinDefaultProc = reinterpret_cast<WNDPROC>(::SetWindowLongPtr(hChild, GWLP_WNDPROC, reinterpret_cast<LONG_PTR>(TabBarSpin_Proc)));
  pThis->m_spin = hChild;
+ pThis->m_bIsSpinVisible = true;
  return FALSE;
  }
  return TRUE;

src/TabBar.h

@@ -1,6 +1,6 @@
 // This file is part of BowPad.
 //
-// Copyright (C) 2013-2018, 2020-2022 - Stefan Kueng
+// Copyright (C) 2013-2018, 2020-2022, 2024 - Stefan Kueng
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -117,10 +117,10 @@ class CTabBar : public CWindow
  void ExchangeItemData(POINT point);
  LRESULT RunProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam);
  COLORREF GetTabColor(UINT item) const;
- void  DrawMainBorder(LPDRAWITEMSTRUCT lpDrawItemStruct) const;
+ static void DrawMainBorder(LPDRAWITEMSTRUCT lpDrawItemStruct);
  void DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct, float fraction) const;
  void DraggingCursor(POINT screenPoint, UINT item);
- int GetTabIndexAt(const POINT &p) const { return GetTabIndexAt(p.x, p.y); }
+ int GetTabIndexAt(const POINT & p) const { return GetTabIndexAt(p.x, p.y); }
  int GetTabIndexAt(int x, int y) const;
  bool IsPointInParentZone(POINT screenPoint) const;
  void NotifyTabDelete(int tab);
@@ -145,10 +145,10 @@ class CTabBar : public CWindow
  WNDPROC m_tabBarDefaultProc;
  WNDPROC m_tabBarSpinDefaultProc;
  HWND m_spin;
+ bool m_bIsSpinVisible;
 
  RECT m_currentHoverTabRect;
  int m_currentHoverTabItem;
-
  CloseButtonZone m_closeButtonZone;
  bool m_bIsCloseHover;
  int m_whichCloseClickDown;