src/Utils/MiscUI/HintCtrl.h

   1 // TortoiseGit - a Windows shell extension for easy version control
   2
   3 // Copyright (C) 2011, 2013, 2015, 2018 - TortoiseSVN
   4
   5 // This program is free software; you can redistribute it and/or
   6 // modify it under the terms of the GNU General Public License
   7 // as published by the Free Software Foundation; either version 2
   8 // of the License, or (at your option) any later version.
   9
  10 // This program is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14
  15 // You should have received a copy of the GNU General Public License
  16 // along with this program; if not, write to the Free Software Foundation,
  17 // 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 //
  19 #pragma once
  20 #include "MyMemDC.h"
  21
  22 /**
  23  * \ingroup Utils
  24  * Allows to show a hint text on a control, basically hiding the control
  25  * content. Can be used for example during lengthy operations (showing "please wait")
  26  * or to indicate why the control is empty (showing "no data available").
  27  */
  28 template <typename BaseType> class CHintCtrl : public BaseType
  29 {
  30 public:
  31         CHintCtrl() : BaseType(), m_uiFont(nullptr)
  32         {
  33                 NONCLIENTMETRICS metrics = { 0 };
  34                 metrics.cbSize = sizeof(NONCLIENTMETRICS);
  35                 SystemParametersInfo(SPI_GETNONCLIENTMETRICS, 0, &metrics, FALSE);
  36                 m_uiFont = CreateFontIndirect(&metrics.lfMessageFont);
  37         }
  38         virtual ~CHintCtrl()
  39         {
  40                 if (m_uiFont)
  41                         DeleteObject(m_uiFont);
  42         }
  43
  44         void ShowText(const CString& sText, bool forceupdate = false)
  45         {
  46                 m_sText = sText;
  47                 Invalidate();
  48                 if (forceupdate)
  49                         UpdateWindow();
  50         }
  51
  52         void ClearText()
  53         {
  54                 m_sText.Empty();
  55                 Invalidate();
  56         }
  57
  58         bool HasText() const {return !m_sText.IsEmpty();}
  59
  60         DECLARE_MESSAGE_MAP()
  61
  62 protected:
  63         afx_msg void CHintCtrl::OnPaint()
  64         {
  65                 LRESULT defres = Default();
  66                 if (!m_sText.IsEmpty())
  67                 {
  68                         COLORREF clrText = ::GetSysColor(COLOR_WINDOWTEXT);
  69                         COLORREF clrTextBk;
  70                         if (IsWindowEnabled())
  71                                 clrTextBk = ::GetSysColor(COLOR_WINDOW);
  72                         else
  73                                 clrTextBk = ::GetSysColor(COLOR_3DFACE);
  74
  75                         CRect rc;
  76                         GetClientRect(&rc);
  77                         bool bIsEmpty = false;
  78                         CListCtrl * pListCtrl = dynamic_cast<CListCtrl*>(this);
  79                         if (pListCtrl)
  80                         {
  81                                 CHeaderCtrl* pHC;
  82                                 pHC = pListCtrl->GetHeaderCtrl();
  83                                 if (pHC)
  84                                 {
  85                                         CRect rcH;
  86                                         rcH.SetRectEmpty();
  87                                         pHC->GetItemRect(0, &rcH);
  88                                         rc.top += rcH.bottom;
  89                                 }
  90                                 bIsEmpty = pListCtrl->GetItemCount() == 0;
  91                         }
  92                         CDC* pDC = GetDC();
  93                         {
  94                                 CMyMemDC memDC(pDC, &rc);
  95
  96                                 memDC.SetTextColor(clrText);
  97                                 memDC.SetBkColor(clrTextBk);
  98                                 if (bIsEmpty)
  99                                         memDC.BitBlt(rc.left, rc.top, rc.Width(), rc.Height(), pDC, rc.left, rc.top, SRCCOPY);
 100                                 else
 101                                         memDC.FillSolidRect(rc, clrTextBk);
 102                                 rc.top += 10;
 103                                 CGdiObject* oldfont = memDC.SelectObject(CGdiObject::FromHandle(m_uiFont));
 104                                 memDC.DrawText(m_sText, rc, DT_CENTER | DT_VCENTER |
 105                                         DT_WORDBREAK | DT_NOPREFIX | DT_NOCLIP);
 106                                 memDC.SelectObject(oldfont);
 107                         }
 108                         ReleaseDC(pDC);
 109                 }
 110                 if (defres)
 111                 {
 112                         // the Default() call did not process the WM_PAINT message!
 113                         // Validate the update region ourselves to avoid
 114                         // an endless loop repainting
 115                         CRect rc;
 116                         GetUpdateRect(&rc, FALSE);
 117                         if (!rc.IsRectEmpty())
 118                                 ValidateRect(rc);
 119                 }
 120         }
 121
 122 private:
 123         CString                 m_sText;
 124         HFONT                   m_uiFont;
 125 };
 126
 127 BEGIN_TEMPLATE_MESSAGE_MAP(CHintCtrl, BaseType, BaseType)
 128         ON_WM_PAINT()
 129 END_MESSAGE_MAP()
 130