added explanatory comment

[wxWidgets.git] / src / common / mstream.cpp

diff --git a/src/common/mstream.cpp b/src/common/mstream.cpp
index 21cc9ee95c56ced529ec7f56a096ac453934afa7..24252d273c5e9871cf22cb19bb6d090c5d2663f2 100644 (file)
--- a/src/common/mstream.cpp
+++ b/src/common/mstream.cpp
@@ -17,23 +17,23 @@
 // headers
 // ----------------------------------------------------------------------------
 
-#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
-#pragma implementation "mstream.h"
-#endif
-
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 #ifdef __BORLANDC__
-  #pragma hdrstop
+    #pragma hdrstop
 #endif
 
 #if wxUSE_STREAMS
 
-#include <stdlib.h>
-#include "wx/stream.h"
 #include "wx/mstream.h"
 
+#ifndef   WX_PRECOMP
+    #include  "wx/stream.h"
+#endif  //WX_PRECOMP
+
+#include <stdlib.h>
+
 // ============================================================================
 // implementation
 // ============================================================================
@@ -42,6 +42,8 @@
 // wxMemoryInputStream
 // ----------------------------------------------------------------------------
 
+IMPLEMENT_ABSTRACT_CLASS(wxMemoryInputStream, wxInputStream)
+
 wxMemoryInputStream::wxMemoryInputStream(const void *data, size_t len)
 {
     m_i_streambuf = new wxStreamBuffer(wxStreamBuffer::read);
@@ -52,6 +54,56 @@ wxMemoryInputStream::wxMemoryInputStream(const void *data, size_t len)
     m_length = len;
 }
 
+wxMemoryInputStream::wxMemoryInputStream(const wxMemoryOutputStream& stream)
+{
+    const wxFileOffset lenFile = stream.GetLength();
+    if ( lenFile == wxInvalidOffset )
+    {
+        m_i_streambuf = NULL;
+        m_lasterror = wxSTREAM_EOF;
+        return;
+    }
+
+    const size_t len = wx_truncate_cast(size_t, lenFile);
+    wxASSERT_MSG( len == lenFile + size_t(0), _T("huge files not supported") );
+
+    m_i_streambuf = new wxStreamBuffer(wxStreamBuffer::read);
+    m_i_streambuf->SetBufferIO(len); // create buffer
+    stream.CopyTo(m_i_streambuf->GetBufferStart(), len);
+    m_i_streambuf->SetIntPosition(0); // seek to start pos
+    m_i_streambuf->Fixed(true);
+    m_length = len;
+}
+
+void
+wxMemoryInputStream::InitFromStream(wxInputStream& stream, wxFileOffset lenFile)
+{
+    if ( lenFile == wxInvalidOffset )
+        lenFile = stream.GetLength();
+
+    if ( lenFile == wxInvalidOffset )
+    {
+        m_i_streambuf = NULL;
+        m_lasterror = wxSTREAM_EOF;
+        return;
+    }
+
+    const size_t len = wx_truncate_cast(size_t, lenFile);
+    wxASSERT_MSG( (wxFileOffset)len == lenFile, _T("huge files not supported") );
+
+    m_i_streambuf = new wxStreamBuffer(wxStreamBuffer::read);
+    m_i_streambuf->SetBufferIO(len); // create buffer
+    stream.Read(m_i_streambuf->GetBufferStart(), len);
+    m_i_streambuf->SetIntPosition(0); // seek to start pos
+    m_i_streambuf->Fixed(true);
+    m_length = stream.LastRead();
+}
+
+bool wxMemoryInputStream::CanRead() const
+{
+    return m_i_streambuf->GetIntPosition() != m_length;
+}
+
 wxMemoryInputStream::~wxMemoryInputStream()
 {
     delete m_i_streambuf;
@@ -71,11 +123,6 @@ char wxMemoryInputStream::Peek()
     return buf[pos];
 }
 
-bool wxMemoryInputStream::Eof() const
-{
-    return !m_i_streambuf->GetBytesLeft();
-}
-
 size_t wxMemoryInputStream::OnSysRead(void *buffer, size_t nbytes)
 {
     size_t pos = m_i_streambuf->GetIntPosition();
@@ -106,6 +153,8 @@ wxFileOffset wxMemoryInputStream::OnSysTell() const
 // wxMemoryOutputStream
 // ----------------------------------------------------------------------------
 
+IMPLEMENT_DYNAMIC_CLASS(wxMemoryOutputStream, wxOutputStream)
+
 wxMemoryOutputStream::wxMemoryOutputStream(void *data, size_t len)
 {
     m_o_streambuf = new wxStreamBuffer(wxStreamBuffer::write);