fpicker/source/win32/filepicker/PreviewCtrl.hxx

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  27
  28 #ifndef _PREVIEWCTRL_HXX_
  29 #define _PREVIEWCTRL_HXX_
  30
  31 //------------------------------------------------------------------------
  32 // includes
  33 //------------------------------------------------------------------------
  34
  35 #include <sal/types.h>
  36 #include <rtl/ustring.hxx>
  37
  38 #include <comdef.h>
  39
  40 #include <memory>
  41
  42 //---------------------------------------------
  43 // declaration
  44 //---------------------------------------------
  45
  46 class CDimension
  47 {
  48 public:
  49     CDimension( ) :
  50         m_cx( 0 ),
  51         m_cy( 0 )
  52     {
  53     }
  54
  55     CDimension( sal_Int32 cx, sal_Int32 cy ) :
  56         m_cx( cx ),
  57         m_cy( cy )
  58     {
  59     }
  60
  61     sal_Int32 m_cx;
  62     sal_Int32 m_cy;
  63 };
  64
  65 //--------------------------------------------------
  66 // we use OleInitialize here because we are calling
  67 // some Ole functions to realize the picture preview
  68 // and we expect to be called from the main thread
  69 // so that there will be no problem calling
  70 // OleInitialize (the main thread should be an STA)
  71 // When OleInitialize should fail at worst the
  72 // preview doesn't work
  73 //--------------------------------------------------
  74
  75 class CAutoOleInit
  76 {
  77 public:
  78
  79     // used to communicate ole
  80     // initialzation failures
  81     class COleInitException { };
  82
  83     CAutoOleInit( )
  84     {
  85         HRESULT hr = OleInitialize( NULL );
  86         if ( FAILED( hr ) )
  87             throw COleInitException( );
  88     }
  89
  90     ~CAutoOleInit( )
  91     {
  92         OleUninitialize( );
  93     }
  94 };
  95
  96 //---------------------------------------------
  97 // A simple file preview class to preview some
  98 // common picture formats like *.gif, *jpg, etc.
  99 // This class is not thread-safe and is
 100 // implmented as singleton, because the class
 101 // has only one static member to reconnect
 102 // from callback functions
 103 // we use a singleton-destroyer to get rid off
 104 // the singleton instance, but this happens
 105 // only on shutdown (unloading of the dll) -
 106 // it's a question of taste (other solutions
 107 // are possible)
 108 //---------------------------------------------
 109
 110 class CFilePreview
 111 {
 112 public:
 113     // to ensure only one instance (singleton)
 114     static CFilePreview* createInstance(
 115         HWND aParent,
 116         POINT ulCorner,
 117         const CDimension& aSize,
 118         HINSTANCE hInstance,
 119         sal_Bool bShow = sal_True,
 120         sal_Bool bEnabled = sal_True );
 121
 122     // sets the size of the preview window
 123     sal_Bool SAL_CALL setSize( const CDimension& aSize );
 124
 125     // returns the CDimension of the preview
 126     sal_Bool SAL_CALL getSize( CDimension& theSize ) const;
 127
 128     // sets the position of the upper left corner
 129     // of the preview window relative to the
 130     // upper left corner of the parent window
 131     sal_Bool SAL_CALL setPos( POINT ulCorner );
 132
 133     // returns the current position of the preview
 134     // relative to the upper left corner of the
 135     // parent window
 136     sal_Bool SAL_CALL getPos( POINT& ulCorner ) const;
 137
 138     // enables or disables the preview window
 139     // bEnable - true the window is enabled and updates its
 140     // view when update is called
 141     // bEnable - false the window shows itself in disabled
 142     // mode and does not update its view when update is
 143     // called
 144     void SAL_CALL enable( sal_Bool bEnable );
 145
 146     // shows the preview window
 147     // possible values see SHOW_STATE
 148     sal_Bool SAL_CALL show( sal_Bool bShow );
 149
 150
 151     // if the preview is shown and enabled
 152     // preview of the given file will be shown
 153     // returns true on success or false if an error
 154     // occured (the file in not there or not accessible etc.)
 155     virtual sal_Bool SAL_CALL update( const rtl::OUString& aFileName );
 156
 157 protected:
 158     // clients can create instances only through the static create method
 159     CFilePreview(
 160         HWND aParent,
 161         POINT ulCorner,
 162         const CDimension& aSize,
 163         HINSTANCE hInstance,
 164         sal_Bool bShow = sal_True,
 165         sal_Bool bEnabled = sal_True );
 166
 167     // only the singleton destroyer class is allowed to delete the
 168     // singleton instance of this class
 169     virtual ~CFilePreview( );
 170
 171     // we use the stl auto_ptr class as singleton destroyer
 172     typedef std::auto_ptr< CFilePreview > FILEPREVIEW_SINGLETON_DESTROYER_T;
 173
 174 protected:
 175     virtual void SAL_CALL onPaint( HWND hWnd, HDC hDC );
 176
 177     sal_Bool loadFile( const rtl::OUString& aFileName );
 178
 179 private:
 180     CAutoOleInit m_autoOleInit;
 181     POINT        m_pt;
 182     CDimension   m_dim;
 183     HWND         m_hwnd;
 184     sal_Bool     m_bEnabled;
 185     IPicturePtr  m_IPicture;
 186     ATOM         m_atomPrevWndClass;
 187     HINSTANCE    m_hInstance;
 188
 189     static LRESULT CALLBACK WndProc( HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam );
 190
 191     static CFilePreview* s_FilePreviewInst;
 192     static FILEPREVIEW_SINGLETON_DESTROYER_T s_SingletonDestroyer;
 193
 194 private:
 195     friend FILEPREVIEW_SINGLETON_DESTROYER_T;
 196 };
 197
 198
 199 #endif