fpicker/source/win32/filepicker/PreviewCtrl.hxx

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  30
  31 #ifndef _PREVIEWCTRL_HXX_
  32 #define _PREVIEWCTRL_HXX_
  33
  34 //------------------------------------------------------------------------
  35 // includes
  36 //------------------------------------------------------------------------
  37
  38 #include <sal/types.h>
  39 #include <rtl/ustring.hxx>
  40
  41 #include <comdef.h>
  42
  43 #include <memory>
  44
  45 //---------------------------------------------
  46 // declaration
  47 //---------------------------------------------
  48
  49 class CDimension
  50 {
  51 public:
  52     CDimension( ) :
  53         m_cx( 0 ),
  54         m_cy( 0 )
  55     {
  56     }
  57
  58     CDimension( sal_Int32 cx, sal_Int32 cy ) :
  59         m_cx( cx ),
  60         m_cy( cy )
  61     {
  62     }
  63
  64     sal_Int32 m_cx;
  65     sal_Int32 m_cy;
  66 };
  67
  68 //--------------------------------------------------
  69 // we use OleInitialize here because we are calling
  70 // some Ole functions to realize the picture preview
  71 // and we expect to be called from the main thread
  72 // so that there will be no problem calling
  73 // OleInitialize (the main thread should be an STA)
  74 // When OleInitialize should fail at worst the
  75 // preview doesn't work
  76 //--------------------------------------------------
  77
  78 class CAutoOleInit
  79 {
  80 public:
  81
  82     // used to communicate ole
  83     // initialzation failures
  84     class COleInitException { };
  85
  86     CAutoOleInit( )
  87     {
  88         HRESULT hr = OleInitialize( NULL );
  89         if ( FAILED( hr ) )
  90             throw COleInitException( );
  91     }
  92
  93     ~CAutoOleInit( )
  94     {
  95         OleUninitialize( );
  96     }
  97 };
  98
  99 //---------------------------------------------
 100 // A simple file preview class to preview some
 101 // common picture formats like *.gif, *jpg, etc.
 102 // This class is not thread-safe and is
 103 // implmented as singleton, because the class
 104 // has only one static member to reconnect
 105 // from callback functions
 106 // we use a singleton-destroyer to get rid off
 107 // the singleton instance, but this happens
 108 // only on shutdown (unloading of the dll) -
 109 // it's a question of taste (other solutions
 110 // are possible)
 111 //---------------------------------------------
 112
 113 class CFilePreview
 114 {
 115 public:
 116     // to ensure only one instance (singleton)
 117     static CFilePreview* createInstance(
 118         HWND aParent,
 119         POINT ulCorner,
 120         const CDimension& aSize,
 121         HINSTANCE hInstance,
 122         sal_Bool bShow = sal_True,
 123         sal_Bool bEnabled = sal_True );
 124
 125     // sets the size of the preview window
 126     sal_Bool SAL_CALL setSize( const CDimension& aSize );
 127
 128     // returns the CDimension of the preview
 129     sal_Bool SAL_CALL getSize( CDimension& theSize ) const;
 130
 131     // sets the position of the upper left corner
 132     // of the preview window relative to the
 133     // upper left corner of the parent window
 134     sal_Bool SAL_CALL setPos( POINT ulCorner );
 135
 136     // returns the current position of the preview
 137     // relative to the upper left corner of the
 138     // parent window
 139     sal_Bool SAL_CALL getPos( POINT& ulCorner ) const;
 140
 141     // enables or disables the preview window
 142     // bEnable - true the window is enabled and updates its
 143     // view when update is called
 144     // bEnable - false the window shows itself in disabled
 145     // mode and does not update its view when update is
 146     // called
 147     void SAL_CALL enable( sal_Bool bEnable );
 148
 149     // shows the preview window
 150     // possible values see SHOW_STATE
 151     sal_Bool SAL_CALL show( sal_Bool bShow );
 152
 153
 154     // if the preview is shown and enabled
 155     // preview of the given file will be shown
 156     // returns true on success or false if an error
 157     // occured (the file in not there or not accessible etc.)
 158     virtual sal_Bool SAL_CALL update( const rtl::OUString& aFileName );
 159
 160 protected:
 161     // clients can create instances only through the static create method
 162     CFilePreview(
 163         HWND aParent,
 164         POINT ulCorner,
 165         const CDimension& aSize,
 166         HINSTANCE hInstance,
 167         sal_Bool bShow = sal_True,
 168         sal_Bool bEnabled = sal_True );
 169
 170     // only the singleton destroyer class is allowed to delete the
 171     // singleton instance of this class
 172     virtual ~CFilePreview( );
 173
 174     // we use the stl auto_ptr class as singleton destroyer
 175     typedef std::auto_ptr< CFilePreview > FILEPREVIEW_SINGLETON_DESTROYER_T;
 176
 177 protected:
 178     virtual void SAL_CALL onPaint( HWND hWnd, HDC hDC );
 179
 180     sal_Bool loadFile( const rtl::OUString& aFileName );
 181
 182 private:
 183     CAutoOleInit m_autoOleInit;
 184     POINT                m_pt;
 185     CDimension   m_dim;
 186     HWND                 m_hwnd;
 187     sal_Bool     m_bEnabled;
 188     IPicturePtr  m_IPicture;
 189     ATOM                 m_atomPrevWndClass;
 190     HINSTANCE    m_hInstance;
 191
 192     static LRESULT CALLBACK WndProc( HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam );
 193
 194     static CFilePreview* s_FilePreviewInst;
 195     static FILEPREVIEW_SINGLETON_DESTROYER_T s_SingletonDestroyer;
 196
 197 private:
 198     friend FILEPREVIEW_SINGLETON_DESTROYER_T;
 199 };
 200
 201
 202 #endif