// TortoiseSVN - a Windows shell extension for easy version control

// Copyright (C) 2011, 2013, 2015, 2017-2018, 2020-2021 - TortoiseSVN

// 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 the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software Foundation,
// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
//
#pragma once
#include "MyMemDC.h"
#include "Theme.h"

/**
 * \ingroup Utils
 * Allows to show a hint text on a control, basically hiding the control
 * content. Can be used for example during lengthy operations (showing "please wait")
 * or to indicate why the control is empty (showing "no data available").
 */
template <typename BaseType>
class CHintCtrl : public BaseType
{
public:
    CHintCtrl()
        : BaseType()
        , m_uiFont(nullptr)
    {
        NONCLIENTMETRICS metrics = {0};
        metrics.cbSize           = sizeof(NONCLIENTMETRICS);
        SystemParametersInfo(SPI_GETNONCLIENTMETRICS, 0, &metrics, FALSE);
        m_uiFont = CreateFontIndirect(&metrics.lfMessageFont);
    }
    virtual ~CHintCtrl()
    {
        if (m_uiFont)
            DeleteObject(m_uiFont);
    }

    virtual ULONG GetGestureStatus(CPoint /*ptTouch*/) override
    {
        return 0;
    }

    void ShowText(const CString& sText, bool forceupdate = false)
    {
        m_sText = sText;
        BaseType::Invalidate();
        if (forceupdate)
            BaseType::UpdateWindow();
    }

    void ClearText()
    {
        m_sText.Empty();
        BaseType::Invalidate();
    }

    bool HasText() const { return !m_sText.IsEmpty(); }

    DECLARE_MESSAGE_MAP()

protected:
    afx_msg void OnPaint()
    {
        LRESULT defRes = BaseType::Default();
        if (!m_sText.IsEmpty())
        {
            COLORREF clrText = CTheme::Instance().IsDarkTheme() ? CTheme::darkTextColor : ::GetSysColor(COLOR_WINDOWTEXT);
            COLORREF clrTextBk;
            if (BaseType::IsWindowEnabled())
                clrTextBk = CTheme::Instance().IsDarkTheme() ? CTheme::darkBkColor : ::GetSysColor(COLOR_WINDOW);
            else
                clrTextBk = CTheme::Instance().GetThemeColor(::GetSysColor(COLOR_3DFACE));

            CRect rc;
            BaseType::GetClientRect(&rc);
            bool       bIsEmpty  = false;
            CListCtrl* pListCtrl = dynamic_cast<CListCtrl*>(this);
            if (pListCtrl)
            {
                CHeaderCtrl* pHC = pListCtrl->GetHeaderCtrl();
                if (pHC != nullptr)
                {
                    CRect rcH;
                    rcH.SetRectEmpty();
                    pHC->GetItemRect(0, &rcH);
                    rc.top += rcH.bottom;
                }
                bIsEmpty = pListCtrl->GetItemCount() == 0;
            }
            CDC* pDC = BaseType::GetDC();
            {
                pDC->SetBkMode(TRANSPARENT);
                pDC->SetTextColor(clrText);
                pDC->SetBkColor(clrTextBk);
                CMyMemDC memDC(pDC, &rc);

                memDC.SetTextColor(clrText);
                memDC.SetBkColor(clrTextBk);
                memDC.SetBkMode(TRANSPARENT);
                if (bIsEmpty)
                    memDC.BitBlt(rc.left, rc.top, rc.Width(), rc.Height(), pDC, rc.left, rc.top, SRCCOPY);
                else
                    memDC.FillSolidRect(rc, clrTextBk);
                rc.top += 10;
                CGdiObject* oldfont = memDC.SelectObject(CGdiObject::FromHandle(m_uiFont));
                memDC.DrawText(m_sText, rc, DT_CENTER | DT_VCENTER | DT_WORDBREAK | DT_NOPREFIX | DT_NOCLIP);
                memDC.SelectObject(oldfont);
            }
            BaseType::ReleaseDC(pDC);
        }
        if (defRes)
        {
            // the Default() call did not process the WM_PAINT message!
            // Validate the update region ourselves to avoid
            // an endless loop repainting
            CRect rc;
            BaseType::GetUpdateRect(&rc, FALSE);
            if (!rc.IsRectEmpty())
                BaseType::ValidateRect(rc);
        }
    }

private:
    CString m_sText;
    HFONT   m_uiFont;
};

BEGIN_TEMPLATE_MESSAGE_MAP(CHintCtrl, BaseType, BaseType)
ON_WM_PAINT()
END_MESSAGE_MAP
()