Added wxCriticalSection::TryEnter() method.

[wxWidgets.git] / include / wx / animdecod.h

diff --git a/include/wx/animdecod.h b/include/wx/animdecod.h
index ee0e21ab48620037481a698f09404cd89ef20ba5..876c802520099430dab4c3ab33cb79aec36fb2cd 100644 (file)
--- a/include/wx/animdecod.h
+++ b/include/wx/animdecod.h
@@ -16,8 +16,9 @@
 
 #include "wx/colour.h"
 #include "wx/gdicmn.h"
 
 #include "wx/colour.h"
 #include "wx/gdicmn.h"

+#include "wx/log.h"
+#include "wx/stream.h"

 
 

-class WXDLLIMPEXP_FWD_BASE wxInputStream;

 class WXDLLIMPEXP_FWD_CORE wxImage;
 
 /*
 class WXDLLIMPEXP_FWD_CORE wxImage;
 
 /*


@@ -30,15 +31,15 @@ class WXDLLIMPEXP_FWD_CORE wxImage;
     wxAnimationDecoders always load an input stream using some optimized format
     to store it which is format-depedent. This allows to store a (possibly big)
     animation using a format which is a good compromise between required memory
     wxAnimationDecoders always load an input stream using some optimized format
     to store it which is format-depedent. This allows to store a (possibly big)
     animation using a format which is a good compromise between required memory

-    and time required to blit in on the screen.
+    and time required to blit it on the screen.

 
 

- 2) wxAnimationDecoders contain the animation data in some internal var.
+ 2) wxAnimationDecoders contain the animation data in some internal variable.

     That's why they derive from wxObjectRefData: they are data which can be shared.
 
  3) wxAnimationDecoders can be used by a wxImageHandler to retrieve a frame
     in wxImage format; the viceversa cannot be done.
 
     That's why they derive from wxObjectRefData: they are data which can be shared.
 
  3) wxAnimationDecoders can be used by a wxImageHandler to retrieve a frame
     in wxImage format; the viceversa cannot be done.
 

- 4) wxAnimationDecoders are decoders only, thus do not support save features.
+ 4) wxAnimationDecoders are decoders only, thus they do not support save features.

 
  5) wxAnimationDecoders are directly used by wxAnimation (generic implementation)
     as wxObjectRefData while they need to be 'wrapped' by a wxImageHandler for
 
  5) wxAnimationDecoders are directly used by wxAnimation (generic implementation)
     as wxObjectRefData while they need to be 'wrapped' by a wxImageHandler for


@@ -61,11 +62,11 @@ enum wxAnimationDisposal
     // Do not dispose. The graphic is to be left in place.
     wxANIM_DONOTREMOVE = 0,
 
     // Do not dispose. The graphic is to be left in place.
     wxANIM_DONOTREMOVE = 0,
 

-    // Restore to background color. The area used by the graphic must be 
+    // Restore to background color. The area used by the graphic must be

     // restored to the background color.
     wxANIM_TOBACKGROUND = 1,
 
     // restored to the background color.
     wxANIM_TOBACKGROUND = 1,
 

-    // Restore to previous. The decoder is required to restore the area 
+    // Restore to previous. The decoder is required to restore the area

     // overwritten by the graphic with what was there prior to rendering the graphic.
     wxANIM_TOPREVIOUS = 2
 };
     // overwritten by the graphic with what was there prior to rendering the graphic.
     wxANIM_TOPREVIOUS = 2
 };


@@ -84,19 +85,37 @@ enum wxAnimationType
 // wxAnimationDecoder class
 // --------------------------------------------------------------------------
 
 // wxAnimationDecoder class
 // --------------------------------------------------------------------------
 

-class WXDLLIMPEXP_ADV wxAnimationDecoder : public wxObjectRefData
+class WXDLLIMPEXP_CORE wxAnimationDecoder : public wxObjectRefData

 {
 public:
     wxAnimationDecoder()
     {
 {
 public:
     wxAnimationDecoder()
     {

-        m_background = wxNullColour;

         m_nFrames = 0;
     }
         m_nFrames = 0;
     }

-    virtual ~wxAnimationDecoder() { }
-

 
     virtual bool Load( wxInputStream& stream ) = 0;
 
     virtual bool Load( wxInputStream& stream ) = 0;

-    virtual bool CanRead( wxInputStream& stream ) const = 0;
+
+    bool CanRead( wxInputStream& stream ) const
+    {
+        // NOTE: this code is the same of wxImageHandler::CallDoCanRead
+
+        if ( !stream.IsSeekable() )
+            return false;        // can't test unseekable stream
+
+        wxFileOffset posOld = stream.TellI();
+        bool ok = DoCanRead(stream);
+
+        // restore the old position to be able to test other formats and so on
+        if ( stream.SeekI(posOld) == wxInvalidOffset )
+        {
+            wxLogDebug(wxT("Failed to rewind the stream in wxAnimationDecoder!"));
+
+            // reading would fail anyhow as we're not at the right position
+            return false;
+        }
+
+        return ok;
+    }

 
     virtual wxAnimationDecoder *Clone() const = 0;
     virtual wxAnimationType GetType() const = 0;
 
     virtual wxAnimationDecoder *Clone() const = 0;
     virtual wxAnimationType GetType() const = 0;


@@ -132,6 +151,12 @@ public:
     unsigned int GetFrameCount() const { return m_nFrames; }
 
 protected:
     unsigned int GetFrameCount() const { return m_nFrames; }
 
 protected:

+    // checks the signature of the data in the given stream and returns true if it
+    // appears to be a valid animation format recognized by the animation decoder;
+    // this function should modify the stream current position without taking care
+    // of restoring it since CanRead() will do it.
+    virtual bool DoCanRead(wxInputStream& stream) const = 0;
+

     wxSize m_szAnimation;
     unsigned int m_nFrames;
 
     wxSize m_szAnimation;
     unsigned int m_nFrames;
 


@@ -140,7 +165,7 @@ protected:
     wxColour m_background;
 };
 
     wxColour m_background;
 };
 

-

 #endif  // wxUSE_STREAMS
 #endif  // wxUSE_STREAMS

+

 #endif  // _WX_ANIMDECOD_H
 
 #endif  // _WX_ANIMDECOD_H