TEXTOUT.H

//==========================================================================; 
// 
//  THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY 
//  KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE 
//  IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR 
//  PURPOSE. 
// 
//  Copyright (c) 1992 - 1997  Microsoft Corporation.  All Rights Reserved. 
// 
//--------------------------------------------------------------------------; 
 
// You MUST change this when adapting this sample! 
// Run uuidgen.exe from any SDK to get a new GUID 
 
DEFINE_GUID(CLSID_PlainText, 
0x48025242, 0x2d39, 0x11ce, 0x87, 0x5d, 0x0, 0x60, 0x8c, 0xb7, 0x80, 0x66); 
 
class CTextOutFilter; 
class CTextOutWindow; 
 
// These are our video window styles 
 
const LPTSTR TextClassName = TEXT("TextRendererBaseClass"); 
const DWORD TextClassStyles = (CS_HREDRAW | CS_VREDRAW | CS_BYTEALIGNCLIENT); 
const DWORD TextWindowStyles = (WS_OVERLAPPEDWINDOW | WS_CLIPCHILDREN); 
 
// Derived class handling window interactions. We did have the main renderer 
// object inheriting from CBaseControlWindow so that we didn't have to have 
// a separate class but that means there are two many classes derived from 
// CUnknown, so when in the final text out filter class you call something 
// like GetOwner it gets really confusing to know who is actually going to 
// be called. So in the end we made it a separate class for the window. We 
// have to specialise the base class to provide the PURE virtual method that 
// returns the class and window information (GetClassWindowStyles). We are 
// also interested in certain window messages like WM_PAINT and WM_NCHITTEST 
 
class CTextOutWindow : public CBaseControlWindow 
{ 
    CTextOutFilter *m_pRenderer; 
 
public: 
 
    CTextOutWindow(TCHAR *pName,                 // Object description 
                   LPUNKNOWN pUnk,               // Normal COM ownership 
                   HRESULT *phr,                 // OLE failure code 
                   CCritSec *pLock,              // Our interface Lock 
                   CTextOutFilter *pRenderer);   // Delegates locking to 
 
    ~CTextOutWindow(); 
    BOOL OnClose(); 
 
    LRESULT OnReceiveMessage(HWND hwnd,             // Window handle 
                             UINT uMsg,             // Message ID 
                             WPARAM wParam,         // First parameter 
                             LPARAM lParam);        // Other parameter 
 
    LPTSTR GetClassWindowStyles(DWORD *pClassStyles, 
                                DWORD *pWindowStyles, 
                                DWORD *pWindowStylesEx); 
 
}; // CTextOutWindow 
 
// Overall filter object for the text renderer. We have to provide our own 
// version of NonDelegatingQueryInterface so that we can expose not only the 
// interfaces supported by the base renderer but also pass on queries for 
// IVideoWindow to our window handling class (m_TextWindow). The rest of the 
// methods we override are pretty dull, dealing with type checking and so on 
 
class CTextOutFilter : public CBaseRenderer 
{ 
    CTextOutWindow m_TextWindow; 
 
public: 
 
    static CUnknown * WINAPI CreateInstance(LPUNKNOWN pUnk, HRESULT *phr); 
 
    CTextOutFilter(LPUNKNOWN pUnk,HRESULT *phr); 
    ~CTextOutFilter(); 
    STDMETHODIMP NonDelegatingQueryInterface(REFIID, void **); 
 
    STDMETHODIMP Pause(); 
    HRESULT BreakConnect(); 
    HRESULT CheckMediaType(const CMediaType *pmt); 
    BOOL OnPaint(COLORREF WindowColour); 
    HRESULT DoRenderSample(IMediaSample *pMediaSample); 
    void OnReceiveFirstSample(IMediaSample *pMediaSample); 
    void DrawText(IMediaSample *pMediaSample); 
 
}; // CTextOutFilter