Add wxFileSystemHandler for "data" scheme

This notably allows embedding images directly in HTML.

Closes #24138.

Makefile.in

@@ -603,6 +603,7 @@ ALL_BASE_HEADERS =  \
 	wx/lzmastream.h \
 	wx/localedefs.h \
 	wx/uilocale.h \
+	wx/fs_data.h \
 	$(BASE_PLATFORM_HDR) \
 	wx/fs_inet.h \
 	wx/protocol/file.h \
@@ -789,6 +790,7 @@ ALL_PORTS_BASE_HEADERS =  \
 	wx/lzmastream.h \
 	wx/localedefs.h \
 	wx/uilocale.h \
+	wx/fs_data.h \
 	wx/unix/app.h \
 	wx/unix/apptbase.h \
 	wx/unix/apptrait.h \
@@ -925,6 +927,7 @@ ALL_BASE_SOURCES =  \
 	src/common/secretstore.cpp \
 	src/common/lzmastream.cpp \
 	src/common/uilocale.cpp \
+	src/common/fs_data.cpp \
 	src/common/fdiodispatcher.cpp \
 	src/common/selectdispatcher.cpp \
 	src/unix/appunix.cpp \
@@ -1130,6 +1133,7 @@ MONODLL_OBJECTS =  \
 	monodll_common_secretstore.o \
 	monodll_lzmastream.o \
 	monodll_common_uilocale.o \
+	monodll_fs_data.o \
 	$(__BASE_PLATFORM_SRC_OBJECTS) \
 	monodll_event.o \
 	monodll_fs_mem.o \
@@ -1289,6 +1293,7 @@ MONOLIB_OBJECTS =  \
 	monolib_common_secretstore.o \
 	monolib_lzmastream.o \
 	monolib_common_uilocale.o \
+	monolib_fs_data.o \
 	$(__BASE_PLATFORM_SRC_OBJECTS_1) \
 	monolib_event.o \
 	monolib_fs_mem.o \
@@ -1417,6 +1422,7 @@ BASEDLL_OBJECTS =  \
 	basedll_common_secretstore.o \
 	basedll_lzmastream.o \
 	basedll_common_uilocale.o \
+	basedll_fs_data.o \
 	$(__BASE_PLATFORM_SRC_OBJECTS_2) \
 	basedll_event.o \
 	basedll_fs_mem.o \
@@ -1527,6 +1533,7 @@ BASELIB_OBJECTS =  \
 	baselib_common_secretstore.o \
 	baselib_lzmastream.o \
 	baselib_common_uilocale.o \
+	baselib_fs_data.o \
 	$(__BASE_PLATFORM_SRC_OBJECTS_3) \
 	baselib_event.o \
 	baselib_fs_mem.o \
@@ -14966,6 +14973,9 @@ monodll_lzmastream.o: $(srcdir)/src/common/lzmastream.cpp $(MONODLL_ODEP)
 monodll_common_uilocale.o: $(srcdir)/src/common/uilocale.cpp $(MONODLL_ODEP)
 	$(CXXC) -c -o $@ $(MONODLL_CXXFLAGS) $(srcdir)/src/common/uilocale.cpp
 
+monodll_fs_data.o: $(srcdir)/src/common/fs_data.cpp $(MONODLL_ODEP)
+	$(CXXC) -c -o $@ $(MONODLL_CXXFLAGS) $(srcdir)/src/common/fs_data.cpp
+
 monodll_unix_mimetype.o: $(srcdir)/src/unix/mimetype.cpp $(MONODLL_ODEP)
 	$(CXXC) -c -o $@ $(MONODLL_CXXFLAGS) $(srcdir)/src/unix/mimetype.cpp
 
@@ -19712,6 +19722,9 @@ monolib_lzmastream.o: $(srcdir)/src/common/lzmastream.cpp $(MONOLIB_ODEP)
 monolib_common_uilocale.o: $(srcdir)/src/common/uilocale.cpp $(MONOLIB_ODEP)
 	$(CXXC) -c -o $@ $(MONOLIB_CXXFLAGS) $(srcdir)/src/common/uilocale.cpp
 
+monolib_fs_data.o: $(srcdir)/src/common/fs_data.cpp $(MONOLIB_ODEP)
+	$(CXXC) -c -o $@ $(MONOLIB_CXXFLAGS) $(srcdir)/src/common/fs_data.cpp
+
 monolib_unix_mimetype.o: $(srcdir)/src/unix/mimetype.cpp $(MONOLIB_ODEP)
 	$(CXXC) -c -o $@ $(MONOLIB_CXXFLAGS) $(srcdir)/src/unix/mimetype.cpp
 
@@ -24458,6 +24471,9 @@ basedll_lzmastream.o: $(srcdir)/src/common/lzmastream.cpp $(BASEDLL_ODEP)
 basedll_common_uilocale.o: $(srcdir)/src/common/uilocale.cpp $(BASEDLL_ODEP)
 	$(CXXC) -c -o $@ $(BASEDLL_CXXFLAGS) $(srcdir)/src/common/uilocale.cpp
 
+basedll_fs_data.o: $(srcdir)/src/common/fs_data.cpp $(BASEDLL_ODEP)
+	$(CXXC) -c -o $@ $(BASEDLL_CXXFLAGS) $(srcdir)/src/common/fs_data.cpp
+
 basedll_unix_mimetype.o: $(srcdir)/src/unix/mimetype.cpp $(BASEDLL_ODEP)
 	$(CXXC) -c -o $@ $(BASEDLL_CXXFLAGS) $(srcdir)/src/unix/mimetype.cpp
 
@@ -24938,6 +24954,9 @@ baselib_lzmastream.o: $(srcdir)/src/common/lzmastream.cpp $(BASELIB_ODEP)
 baselib_common_uilocale.o: $(srcdir)/src/common/uilocale.cpp $(BASELIB_ODEP)
 	$(CXXC) -c -o $@ $(BASELIB_CXXFLAGS) $(srcdir)/src/common/uilocale.cpp
 
+baselib_fs_data.o: $(srcdir)/src/common/fs_data.cpp $(BASELIB_ODEP)
+	$(CXXC) -c -o $@ $(BASELIB_CXXFLAGS) $(srcdir)/src/common/fs_data.cpp
+
 baselib_unix_mimetype.o: $(srcdir)/src/unix/mimetype.cpp $(BASELIB_ODEP)
 	$(CXXC) -c -o $@ $(BASELIB_CXXFLAGS) $(srcdir)/src/unix/mimetype.cpp
 

build/bakefiles/files.bkl

@@ -580,6 +580,7 @@ IMPORTANT: please read docs/tech/tn0016.txt before modifying this file!
     src/common/secretstore.cpp
     src/common/lzmastream.cpp
     src/common/uilocale.cpp
+    src/common/fs_data.cpp
 </set>
 <set var="BASE_AND_GUI_CMN_SRC" hints="files">
     src/common/event.cpp
@@ -755,6 +756,7 @@ IMPORTANT: please read docs/tech/tn0016.txt before modifying this file!
     wx/lzmastream.h
     wx/localedefs.h
     wx/uilocale.h
+    wx/fs_data.h
 </set>
 
 

build/cmake/files.cmake

@@ -492,6 +492,7 @@ set(BASE_CMN_SRC
     src/generic/fswatcherg.cpp
     src/common/lzmastream.cpp
     src/common/uilocale.cpp
+    src/common/fs_data.cpp
 )
 
 set(BASE_AND_GUI_CMN_SRC
@@ -669,6 +670,7 @@ set(BASE_CMN_HDR
     wx/lzmastream.h
     wx/localedefs.h
     wx/uilocale.h
+    wx/fs_data.h
 )
 
 set(NET_UNIX_SRC

build/files

@@ -455,6 +455,7 @@ BASE_CMN_SRC =
     src/common/filtfind.cpp
     src/common/fmapbase.cpp
     src/common/fs_arc.cpp
+    src/common/fs_data.cpp
     src/common/fs_filter.cpp
     src/common/hash.cpp
     src/common/hashmap.cpp
@@ -571,6 +572,7 @@ BASE_CMN_HDR =
     wx/fontenc.h
     wx/fontmap.h
     wx/fs_arc.h
+    wx/fs_data.h
     wx/fs_filter.h
     wx/fs_mem.h
     wx/fs_zip.h

build/msw/makefile.gcc

@@ -498,6 +498,7 @@ MONODLL_OBJECTS =  \
 	$(OBJS)\monodll_common_secretstore.o \
 	$(OBJS)\monodll_lzmastream.o \
 	$(OBJS)\monodll_common_uilocale.o \
+	$(OBJS)\monodll_fs_data.o \
 	$(OBJS)\monodll_basemsw.o \
 	$(OBJS)\monodll_crashrpt.o \
 	$(OBJS)\monodll_debughlp.o \
@@ -659,6 +660,7 @@ MONOLIB_OBJECTS =  \
 	$(OBJS)\monolib_common_secretstore.o \
 	$(OBJS)\monolib_lzmastream.o \
 	$(OBJS)\monolib_common_uilocale.o \
+	$(OBJS)\monolib_fs_data.o \
 	$(OBJS)\monolib_basemsw.o \
 	$(OBJS)\monolib_crashrpt.o \
 	$(OBJS)\monolib_debughlp.o \
@@ -808,6 +810,7 @@ BASEDLL_OBJECTS =  \
 	$(OBJS)\basedll_common_secretstore.o \
 	$(OBJS)\basedll_lzmastream.o \
 	$(OBJS)\basedll_common_uilocale.o \
+	$(OBJS)\basedll_fs_data.o \
 	$(OBJS)\basedll_basemsw.o \
 	$(OBJS)\basedll_crashrpt.o \
 	$(OBJS)\basedll_debughlp.o \
@@ -938,6 +941,7 @@ BASELIB_OBJECTS =  \
 	$(OBJS)\baselib_common_secretstore.o \
 	$(OBJS)\baselib_lzmastream.o \
 	$(OBJS)\baselib_common_uilocale.o \
+	$(OBJS)\baselib_fs_data.o \
 	$(OBJS)\baselib_basemsw.o \
 	$(OBJS)\baselib_crashrpt.o \
 	$(OBJS)\baselib_debughlp.o \
@@ -7235,6 +7239,9 @@ $(OBJS)\monodll_lzmastream.o: ../../src/common/lzmastream.cpp
 $(OBJS)\monodll_common_uilocale.o: ../../src/common/uilocale.cpp
 	$(CXX) -c -o $@ $(MONODLL_CXXFLAGS) $(CPPDEPS) $<
 
+$(OBJS)\monodll_fs_data.o: ../../src/common/fs_data.cpp
+	$(CXX) -c -o $@ $(MONODLL_CXXFLAGS) $(CPPDEPS) $<
+
 $(OBJS)\monodll_basemsw.o: ../../src/msw/basemsw.cpp
 	$(CXX) -c -o $@ $(MONODLL_CXXFLAGS) $(CPPDEPS) $<
 
@@ -9826,6 +9833,9 @@ $(OBJS)\monolib_lzmastream.o: ../../src/common/lzmastream.cpp
 $(OBJS)\monolib_common_uilocale.o: ../../src/common/uilocale.cpp
 	$(CXX) -c -o $@ $(MONOLIB_CXXFLAGS) $(CPPDEPS) $<
 
+$(OBJS)\monolib_fs_data.o: ../../src/common/fs_data.cpp
+	$(CXX) -c -o $@ $(MONOLIB_CXXFLAGS) $(CPPDEPS) $<
+
 $(OBJS)\monolib_basemsw.o: ../../src/msw/basemsw.cpp
 	$(CXX) -c -o $@ $(MONOLIB_CXXFLAGS) $(CPPDEPS) $<
 
@@ -12417,6 +12427,9 @@ $(OBJS)\basedll_lzmastream.o: ../../src/common/lzmastream.cpp
 $(OBJS)\basedll_common_uilocale.o: ../../src/common/uilocale.cpp
 	$(CXX) -c -o $@ $(BASEDLL_CXXFLAGS) $(CPPDEPS) $<
 
+$(OBJS)\basedll_fs_data.o: ../../src/common/fs_data.cpp
+	$(CXX) -c -o $@ $(BASEDLL_CXXFLAGS) $(CPPDEPS) $<
+
 $(OBJS)\basedll_basemsw.o: ../../src/msw/basemsw.cpp
 	$(CXX) -c -o $@ $(BASEDLL_CXXFLAGS) $(CPPDEPS) $<
 
@@ -12759,6 +12772,9 @@ $(OBJS)\baselib_lzmastream.o: ../../src/common/lzmastream.cpp
 $(OBJS)\baselib_common_uilocale.o: ../../src/common/uilocale.cpp
 	$(CXX) -c -o $@ $(BASELIB_CXXFLAGS) $(CPPDEPS) $<
 
+$(OBJS)\baselib_fs_data.o: ../../src/common/fs_data.cpp
+	$(CXX) -c -o $@ $(BASELIB_CXXFLAGS) $(CPPDEPS) $<
+
 $(OBJS)\baselib_basemsw.o: ../../src/msw/basemsw.cpp
 	$(CXX) -c -o $@ $(BASELIB_CXXFLAGS) $(CPPDEPS) $<
 

build/msw/makefile.vc

@@ -534,6 +534,7 @@ MONODLL_OBJECTS =  \
 	$(OBJS)\monodll_common_secretstore.obj \
 	$(OBJS)\monodll_lzmastream.obj \
 	$(OBJS)\monodll_common_uilocale.obj \
+	$(OBJS)\monodll_fs_data.obj \
 	$(OBJS)\monodll_basemsw.obj \
 	$(OBJS)\monodll_crashrpt.obj \
 	$(OBJS)\monodll_debughlp.obj \
@@ -704,6 +705,7 @@ MONOLIB_OBJECTS =  \
 	$(OBJS)\monolib_common_secretstore.obj \
 	$(OBJS)\monolib_lzmastream.obj \
 	$(OBJS)\monolib_common_uilocale.obj \
+	$(OBJS)\monolib_fs_data.obj \
 	$(OBJS)\monolib_basemsw.obj \
 	$(OBJS)\monolib_crashrpt.obj \
 	$(OBJS)\monolib_debughlp.obj \
@@ -862,6 +864,7 @@ BASEDLL_OBJECTS =  \
 	$(OBJS)\basedll_common_secretstore.obj \
 	$(OBJS)\basedll_lzmastream.obj \
 	$(OBJS)\basedll_common_uilocale.obj \
+	$(OBJS)\basedll_fs_data.obj \
 	$(OBJS)\basedll_basemsw.obj \
 	$(OBJS)\basedll_crashrpt.obj \
 	$(OBJS)\basedll_debughlp.obj \
@@ -1002,6 +1005,7 @@ BASELIB_OBJECTS =  \
 	$(OBJS)\baselib_common_secretstore.obj \
 	$(OBJS)\baselib_lzmastream.obj \
 	$(OBJS)\baselib_common_uilocale.obj \
+	$(OBJS)\baselib_fs_data.obj \
 	$(OBJS)\baselib_basemsw.obj \
 	$(OBJS)\baselib_crashrpt.obj \
 	$(OBJS)\baselib_debughlp.obj \
@@ -7692,6 +7696,9 @@ $(OBJS)\monodll_lzmastream.obj: ..\..\src\common\lzmastream.cpp
 $(OBJS)\monodll_common_uilocale.obj: ..\..\src\common\uilocale.cpp
 	$(CXX) /c /nologo /TP /Fo$@ $(MONODLL_CXXFLAGS) ..\..\src\common\uilocale.cpp
 
+$(OBJS)\monodll_fs_data.obj: ..\..\src\common\fs_data.cpp
+	$(CXX) /c /nologo /TP /Fo$@ $(MONODLL_CXXFLAGS) ..\..\src\common\fs_data.cpp
+
 $(OBJS)\monodll_basemsw.obj: ..\..\src\msw\basemsw.cpp
 	$(CXX) /c /nologo /TP /Fo$@ $(MONODLL_CXXFLAGS) ..\..\src\msw\basemsw.cpp
 
@@ -10283,6 +10290,9 @@ $(OBJS)\monolib_lzmastream.obj: ..\..\src\common\lzmastream.cpp
 $(OBJS)\monolib_common_uilocale.obj: ..\..\src\common\uilocale.cpp
 	$(CXX) /c /nologo /TP /Fo$@ $(MONOLIB_CXXFLAGS) ..\..\src\common\uilocale.cpp
 
+$(OBJS)\monolib_fs_data.obj: ..\..\src\common\fs_data.cpp
+	$(CXX) /c /nologo /TP /Fo$@ $(MONOLIB_CXXFLAGS) ..\..\src\common\fs_data.cpp
+
 $(OBJS)\monolib_basemsw.obj: ..\..\src\msw\basemsw.cpp
 	$(CXX) /c /nologo /TP /Fo$@ $(MONOLIB_CXXFLAGS) ..\..\src\msw\basemsw.cpp
 
@@ -12874,6 +12884,9 @@ $(OBJS)\basedll_lzmastream.obj: ..\..\src\common\lzmastream.cpp
 $(OBJS)\basedll_common_uilocale.obj: ..\..\src\common\uilocale.cpp
 	$(CXX) /c /nologo /TP /Fo$@ $(BASEDLL_CXXFLAGS) ..\..\src\common\uilocale.cpp
 
+$(OBJS)\basedll_fs_data.obj: ..\..\src\common\fs_data.cpp
+	$(CXX) /c /nologo /TP /Fo$@ $(BASEDLL_CXXFLAGS) ..\..\src\common\fs_data.cpp
+
 $(OBJS)\basedll_basemsw.obj: ..\..\src\msw\basemsw.cpp
 	$(CXX) /c /nologo /TP /Fo$@ $(BASEDLL_CXXFLAGS) ..\..\src\msw\basemsw.cpp
 
@@ -13216,6 +13229,9 @@ $(OBJS)\baselib_lzmastream.obj: ..\..\src\common\lzmastream.cpp
 $(OBJS)\baselib_common_uilocale.obj: ..\..\src\common\uilocale.cpp
 	$(CXX) /c /nologo /TP /Fo$@ $(BASELIB_CXXFLAGS) ..\..\src\common\uilocale.cpp
 
+$(OBJS)\baselib_fs_data.obj: ..\..\src\common\fs_data.cpp
+	$(CXX) /c /nologo /TP /Fo$@ $(BASELIB_CXXFLAGS) ..\..\src\common\fs_data.cpp
+
 $(OBJS)\baselib_basemsw.obj: ..\..\src\msw\basemsw.cpp
 	$(CXX) /c /nologo /TP /Fo$@ $(BASELIB_CXXFLAGS) ..\..\src\msw\basemsw.cpp
 

build/msw/wx_base.vcxproj

@@ -622,6 +622,7 @@
       <ObjectFileName Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">$(IntDir)common_%(Filename).obj</ObjectFileName>
       <ObjectFileName Condition="'$(Configuration)|$(Platform)'=='Release|x64'">$(IntDir)common_%(Filename).obj</ObjectFileName>
     </ClCompile>
+    <ClCompile Include="..\..\src\common\fs_data.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ResourceCompile Include="..\..\src\msw\version.rc">
@@ -841,6 +842,7 @@
     <ClInclude Include="..\..\include\wx\lzmastream.h" />
     <ClInclude Include="..\..\include\wx\localedefs.h" />
     <ClInclude Include="..\..\include\wx\uilocale.h" />
+    <ClInclude Include="..\..\include\wx\fs_data.h" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">

build/msw/wx_base.vcxproj.filters

@@ -123,6 +123,9 @@
     <ClCompile Include="..\..\src\common\fs_arc.cpp">
       <Filter>Common Sources</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\src\common\fs_data.cpp">
+      <Filter>Common Sources</Filter>
+    </ClCompile>
     <ClCompile Include="..\..\src\common\fs_filter.cpp">
       <Filter>Common Sources</Filter>
     </ClCompile>
@@ -535,6 +538,9 @@
     <ClInclude Include="..\..\include\wx\fs_arc.h">
       <Filter>Common Headers</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\include\wx\fs_data.h">
+      <Filter>Common Headers</Filter>
+    </ClInclude>
     <ClInclude Include="..\..\include\wx\fs_filter.h">
       <Filter>Common Headers</Filter>
     </ClInclude>

docs/doxygen/overviews/filesystem.h

@@ -73,6 +73,10 @@ The following virtual file system handlers are part of wxWidgets so far:
     A handler for archives such as zip
     and tar. Include file is wx/fs_arc.h. URLs examples:
     "archive.zip#zip:filename", "archive.tar.gz#gzip:#tar:filename".
+@li @b wxDataSchemeFSHandler:
+    A handler for accessing data inlined in URI according to RFC 2397.
+    URI example: "data:text/plain;base64,d3hXaWRnZXRzIGV4YW1wbGU=".
+    Include file is wx/fs_data.h.
 @li @b wxFilterFSHandler:
     A handler for compression schemes such
     as gzip. Header is wx/fs_filter.h. URLs are in the form, e.g.:

include/wx/fs_data.h

@@ -0,0 +1,31 @@
+/////////////////////////////////////////////////////////////////////////////
+// Name:        wx/fs_data.h
+// Purpose:     DATA scheme file system.
+// Author:      Vyacheslav Lisovski
+// Copyright:   (c) 2023 Vyacheslav Lisovski
+// Licence:     wxWindows licence
+/////////////////////////////////////////////////////////////////////////////
+
+#ifndef _WX_FS_DATA_H_
+#define _WX_FS_DATA_H_
+
+#include "wx/defs.h"
+
+#if wxUSE_FILESYSTEM
+
+#include "wx/filesys.h"
+
+// ----------------------------------------------------------------------------
+// wxDataSchemeFSHandler
+// ----------------------------------------------------------------------------
+
+class WXDLLIMPEXP_BASE wxDataSchemeFSHandler : public wxFileSystemHandler
+{
+public:
+    virtual bool CanOpen(const wxString& location) override;
+    virtual wxFSFile* OpenFile(wxFileSystem& fs, const wxString& location) override;
+};
+
+#endif // wxUSE_FILESYSTEM
+
+#endif // _WX_FS_DATA_H_

interface/wx/fs_data.h

@@ -0,0 +1,31 @@
+/////////////////////////////////////////////////////////////////////////////
+// Name:        wx/fs_data.h
+// Purpose:     DATA scheme file system
+// Author:      Vyacheslav Lisovski
+// Copyright:   (c) 2023 Vyacheslav Lisovski
+// Licence:     wxWindows licence
+/////////////////////////////////////////////////////////////////////////////
+
+/**
+    @class wxDataSchemeFSHandler
+
+    File system handler for "data" URI scheme (RFC 2397).
+    URI syntax: @c "data:[<mediatype>][;base64],<data>".
+
+    The handler makes the data, included (encoded) into URI, available for
+    components that use the wxFileSystem infrastructure.
+
+    To make available for usage it should be registered somewhere within an
+    initialization procedure:
+    @code
+    wxFileSystem::AddHandler(new wxDataSchemeFSHandler);
+    @endcode
+
+    @since 3.3.0
+*/
+
+class wxDataSchemeFSHandler : public wxFileSystemHandler
+{
+public:
+    wxDataSchemeFSHandler();
+};

src/common/fs_data.cpp

@@ -0,0 +1,126 @@
+/////////////////////////////////////////////////////////////////////////////
+// Name:        src/common/fs_data.cpp
+// Purpose:     DATA scheme file system
+// Author:      Vyacheslav Lisovski
+// Copyright:   (c) 2023 Vyacheslav Lisovski
+// Licence:     wxWindows licence
+/////////////////////////////////////////////////////////////////////////////
+
+#include "wx/wxprec.h"
+
+#if wxUSE_FILESYSTEM
+
+#include "wx/fs_data.h"
+
+#include "wx/base64.h"
+#include "wx/filesys.h"
+#include "wx/mstream.h"
+#include "wx/sstream.h"
+#include "wx/uri.h"
+
+namespace
+{
+
+// This stream holds the buffer and deletes when destroyed
+class wxBufferedMemoryInputStream : public wxMemoryInputStream
+{
+public:
+    wxBufferedMemoryInputStream(const wxMemoryBuffer& buffer) :
+        wxMemoryInputStream(buffer.GetData(), buffer.GetDataLen()),
+        m_buffer{buffer}
+    {
+    }
+
+private:
+    wxMemoryBuffer m_buffer;
+};
+
+// URL syntax: data:[<mediatype>][;base64],<data>
+int GetMetadata(const wxString& location, wxString& mediatype, bool& isBase64)
+{
+    int dataPos = location.Find(',');
+    if (dataPos > 0)
+    {
+        const int hdrPos = location.Find(':');
+        if (hdrPos > 0)
+        {
+            wxString metadata(location, hdrPos + 1, dataPos - hdrPos - 1);
+
+            int encPos = metadata.Find(';', true);
+
+            if (encPos > 0)
+            {
+                auto encoding = metadata.Right(metadata.Len() - encPos - 1);
+                if (encoding.IsSameAs("base64", false))
+                {
+                    isBase64 = true;
+                }
+                else
+                {
+                    encPos = metadata.Len();
+                }
+            }
+            else
+                encPos = metadata.Len();
+
+            mediatype = metadata.Left(encPos);
+        }
+        ++dataPos;
+    }
+    return dataPos;
+}
+
+} // anonymous namespace
+
+// ----------------------------------------------------------------------------
+// wxDataSchemeFSHandler
+// ----------------------------------------------------------------------------
+
+bool wxDataSchemeFSHandler::CanOpen(const wxString& location)
+{
+    return GetProtocol(location).IsSameAs("data", false);
+}
+
+wxFSFile* wxDataSchemeFSHandler::OpenFile(wxFileSystem& WXUNUSED(fs),
+                                          const wxString& location)
+{
+    wxString mediatype;
+    bool isBase64 = false;
+    int dataPos = GetMetadata(location, mediatype, isBase64);
+
+    if (dataPos < 0)
+        return nullptr;
+
+    if (mediatype.IsEmpty())
+        mediatype = "text/plain";
+
+    wxInputStream* stream = nullptr;
+    if (isBase64)
+    {
+#if wxUSE_BASE64
+        stream = new wxBufferedMemoryInputStream(
+            wxBase64Decode(location.Right(location.Len() - dataPos)));
+#endif // wxUSE_BASE64
+    }
+    else
+    {
+        stream = new wxStringInputStream(
+            wxURI::Unescape(location.Right(location.Len() - dataPos)));
+    }
+
+    if (stream)
+    {
+        return new wxFSFile(stream,
+                            "",
+                            mediatype,
+                            ""
+#if wxUSE_DATETIME
+                            , wxDateTime::Now()
+#endif // wxUSE_DATETIME
+                    );
+    }
+
+    return nullptr;
+}
+
+#endif // wxUSE_FILESYSTEM

tests/allheaders.h

@@ -152,6 +152,7 @@
 #include <wx/fontutil.h>
 #include <wx/frame.h>
 #include <wx/fs_arc.h>
+#include <wx/fs_data.h>
 #include <wx/fs_filter.h>
 #include <wx/fs_inet.h>
 #include <wx/fs_mem.h>

tests/filesys/filesystest.cpp

@@ -1,7 +1,7 @@
 ///////////////////////////////////////////////////////////////////////////////
 // Name:        tests/filesys/filesys.cpp
 // Purpose:     wxFileSystem unit test
-// Author:      Vaclav Slavik
+// Author:      Vaclav Slavik, Vyacheslav Lisovski
 // Created:     2004-03-28
 // Copyright:   (c) 2004 Vaclav Slavik
 ///////////////////////////////////////////////////////////////////////////////
@@ -21,7 +21,9 @@
 
 #if wxUSE_FILESYSTEM
 
+#include "wx/fs_data.h"
 #include "wx/fs_mem.h"
+#include "wx/sstream.h"
 
 #include <memory>
 
@@ -177,6 +179,51 @@ TEST_CASE("wxFileSystem::UnicodeFileNameToUrlConversion", "[filesys][url][filena
     CHECK( filename.SameAs(wxFileName::URLToFileName(url)) );
 }
 
+TEST_CASE("wxFileSystem::DataSchemeFSHandler", "[filesys][dataschemefshandler][openfile]")
+{
+    // Install wxDataSchemeFSHandler just for the duration of this test.
+    class AutoDataSchemeFSHandler
+    {
+    public:
+        AutoDataSchemeFSHandler() : m_handler(new wxDataSchemeFSHandler())
+        {
+            wxFileSystem::AddHandler(m_handler.get());
+        }
+        ~AutoDataSchemeFSHandler()
+        {
+            wxFileSystem::RemoveHandler(m_handler.get());
+        }
+    private:
+        std::unique_ptr<wxDataSchemeFSHandler> const m_handler;
+    } autoDataSchemeFSHandler;
+
+    wxFileSystem fs;
+
+    const struct wxTestCaseData
+    {
+        const char *info, *input, *result1, *result2;
+    } testData[] =
+    {
+        { "Testing minimal URI with data",
+            "data:,the%20data", "text/plain", "the data" },
+        { "Testing base64 encoded",
+            "data:x-t1/x-s1;base64,SGVsbG8sIFdvcmxkIQ==", "x-t1/x-s1", "Hello, World!" },
+        { "Testing complex media type",
+            "data:image/svg+xml;utf8,<svg width='10'... </svg>", "image/svg+xml;utf8", "<svg width='10'... </svg>" }
+    };
+
+    for ( const auto& dataItem : testData )
+    {
+        INFO(dataItem.info);
+        std::unique_ptr<wxFSFile> file(fs.OpenFile(dataItem.input));
+        CHECK(file->GetMimeType() == dataItem.result1);
+
+        wxStringOutputStream sos;
+        sos.Write(*file->GetStream());
+        CHECK(sos.GetString () == dataItem.result2);
+    }
+}
+
 // Test that using FindFirst() after removing a previously found URL works:
 // this used to be broken, see https://github.com/wxWidgets/wxWidgets/issues/18744
 TEST_CASE("wxFileSystem::MemoryFSHandler", "[filesys][memoryfshandler][find]")