Add RTF support to wxMSW wxTextCtrl too

Make IsRTFSupported() non-static function as RTF is only supported by
some (rich), but not all, wxTextCtrls under Windows.

Closes #24718.

include/wx/msw/textctrl.h

@@ -40,6 +40,12 @@ public:
     virtual wxString GetValue() const override;
     virtual wxString GetRange(long from, long to) const override;
 
+#if wxUSE_RICHEDIT
+    virtual wxString GetRTFValue() const override;
+    virtual void SetRTFValue(const wxString& val) override;
+    virtual bool IsRTFSupported() override { return IsRich(); }
+#endif // wxUSE_RICHEDIT
+
     virtual bool IsEmpty() const;
 
     virtual void WriteText(const wxString& text) override;

include/wx/osx/core/private.h

@@ -718,6 +718,8 @@ public :
     virtual bool CanClipMaxLength() const { return false; }
     virtual void SetMaxLength(unsigned long WXUNUSED(len)) {}
 
+    virtual bool IsRTFSupported() { return false; }
+
     virtual bool CanForceUpper() { return false; }
     virtual void ForceUpper() {}
 

include/wx/osx/textctrl.h

@@ -111,6 +111,7 @@ public:
 
     virtual wxString GetRTFValue() const override;
     virtual void SetRTFValue(const wxString& val) override;
+    virtual bool IsRTFSupported() override { return IsMultiLine(); }
 
     // callbacks
     void OnDropFiles(wxDropFilesEvent& event);

include/wx/textctrl.h

@@ -103,10 +103,10 @@ const wxTextCoord wxInvalidTextCoord    = -2;
 // wxTextCtrl file types
 // ----------------------------------------------------------------------------
 
-// For now only wxOSX supports RTF in wxTextCtrl.
-#ifdef __WXOSX__
+// wxOSX and wxMSW support RTF in wxTextCtrl.
+#if defined(__WXOSX__) || (defined(__WXMSW__) && wxUSE_RICHEDIT)
     #define wxHAS_TEXTCTRL_RTF
-#endif // __WXOSX__
+#endif
 
 enum wxTextCtrlFileType
 {
@@ -691,7 +691,7 @@ public:
     virtual void SetValue(const wxString& value) = 0;
 
     // Returns whether the RTF-related functions below can be used.
-    static bool IsRTFSupported();
+    virtual bool IsRTFSupported() { return false; }
 
     // Base class implementations simply assert, if IsRTFSupported() returns
     // true, the port must override these functions to really implement them.

interface/wx/textctrl.h

@@ -76,7 +76,7 @@ enum wxTextCtrlFileType
     /**
         Rich Text Format.
 
-        This format is only supported under macOS currently.
+        This format is only supported under macOS and MSW.
 
         @since 3.3.0
     */
@@ -1659,14 +1659,15 @@ public:
         Returns @c true if text controls support reading and writing RTF (Rich
         Text Format).
 
-        Currently this function only returns true in wxOSX, which is the only
-        port implementing RTF support in wxTextCtrl.
+        This function only returns @true in wxOSX (for multiline contrls) and
+        wxMSW (for rich controls), which are the only ports implementing
+        RTF support in wxTextCtrl.
 
         @since 3.3.0
 
         @see GetRTFValue(), SetRTFValue()
     */
-    static bool IsRTFSupported();
+    bool IsRTFSupported();
 
     /**
         Returns the content of a multiline text control as RTF (Rich Text

samples/text/text.cpp

@@ -479,13 +479,12 @@ bool MyApp::OnInit()
     file_menu->Append(TEXT_LOAD, "&Load file\tCtrl-O",
                       "Load the sample file into text control");
 
-    if ( wxTextCtrl::IsRTFSupported() )
-    {
+#ifdef wxHAS_TEXTCTRL_RTF
         file_menu->Append(TEXT_SAVE_RTF, "&Save file as RTF",
             "Save the text control contents to file");
         file_menu->Append(TEXT_LOAD_RTF, "&Load RTF file",
             "Load the sample file into text control");
-    }
+#endif
 
     file_menu->AppendSeparator();
     file_menu->Append(TEXT_RICH_TEXT_TEST, "Show Rich Text Editor");
@@ -534,11 +533,10 @@ bool MyApp::OnInit()
     menuText->Append(TEXT_SELECT, "&Select characters 4 to 8\tCtrl-I");
     menuText->Append(TEXT_SET, "&Set the first text zone value\tCtrl-E");
     menuText->Append(TEXT_CHANGE, "&Change the first text zone value\tShift-Ctrl-E");
-    if ( wxTextCtrl::IsRTFSupported() )
-    {
+#ifdef wxHAS_TEXTCTRL_RTF
         menuText->AppendSeparator();
         menuText->Append(TEXT_SET_RTF, "Set the rich text zone value from rich text formatted content");
-    }
+#endif
     menuText->AppendSeparator();
     menuText->Append(TEXT_MOVE_ENDTEXT, "Move cursor to the end of &text");
     menuText->Append(TEXT_MOVE_ENDENTRY, "Move cursor to the end of &entry");

src/common/textcmn.cpp

@@ -931,16 +931,6 @@ bool wxTextCtrlBase::SetDefaultStyle(const wxTextAttr& style)
     return true;
 }
 
-// static
-bool wxTextAreaBase::IsRTFSupported()
-{
-#ifdef wxHAS_TEXTCTRL_RTF
-    return true;
-#else
-    return false;
-#endif
-}
-
 wxString wxTextAreaBase::GetRTFValue() const
 {
     wxFAIL_MSG("Not implemented for the current platform.");

src/msw/textctrl.cpp

@@ -1114,6 +1114,92 @@ void wxTextCtrl::DoSetValue(const wxString& value, int flags)
     }
 }
 
+#if wxUSE_RICHEDIT
+
+DWORD wxCALLBACK MSWEditStreamOutCallback(DWORD_PTR dwCookie, LPBYTE pbBuff,
+    LONG cb, LONG* pcb)
+{
+    // write the text
+    std::string* psEntry = reinterpret_cast<std::string*>(dwCookie);
+    psEntry->append(reinterpret_cast<const char*>(pbBuff), cb);
+    *pcb = cb;
+
+    return 0;
+}
+
+wxString wxTextCtrl::GetRTFValue() const
+{
+    if ( !IsRich() )
+    {
+        wxFAIL_MSG("RTF support is only available for rich controls!");
+        return wxEmptyString;
+    }
+
+    // The Rich Edit control must write to a char buffer,
+    // which we will later convert to a Unicode wxString using the current code page.
+    //
+    // We will reserve enough space assuming that the RTF will be twice as large
+    // as the unencoded content.
+    std::string buffer;
+    buffer.reserve(GetLastPosition() * 2);
+
+    // Use a EDITSTREAMCALLBACK to stream text out from the control.
+    EDITSTREAM es{ 0 };
+    es.dwError = 0;
+    es.pfnCallback = MSWEditStreamOutCallback;
+    // our callback will write to a char buffer (i.e., std::string)
+    es.dwCookie = reinterpret_cast<DWORD_PTR>(&buffer);
+
+    // Do NOT call with "(CP_UTF8 << 16) | SF_USECODEPAGE", as this will format the
+    // output RTF to UTF-8 with a "urtf1" header (note the 'u').
+    // Although this is a more modern format, few programs
+    // (including Microsoft Wordpad) recognize it.
+    //
+    // Instead, write the content to an ANSI string using the current code page
+    // (which will use a "rtf1" header). The control will encode any Unicode values
+    // outside of the current code page with "\'[0-9A-F][0-9A-F]" syntax that most
+    // parsers would support.
+    //
+    // Finally, use SFF_PLAINRTF so that the generated RTF is more portable between
+    // RTF readers.
+    ::SendMessage(GetHwnd(), EM_STREAMOUT,
+        (WPARAM)(SF_RTF | SFF_PLAINRTF), (LPARAM)&es);
+
+    // Valid RTF is supposed to consist of 7-bit ASCII characters only,
+    // anything else is escaped.
+    return wxString::FromAscii(buffer.c_str(), buffer.length());
+}
+
+void wxTextCtrl::SetRTFValue(const wxString& val)
+{
+    wxCHECK_RET(IsRich(), "RTF support is only available for rich controls!");
+
+    SETTEXTEX textInfo{ 0 };
+    textInfo.flags = ST_DEFAULT | ST_UNICODE;
+    textInfo.codepage = 1200;
+
+    // Setting from Unicode will fail if control is read-only
+    // (this is an undocumented "feature"), so we need to toggle that temporarily.
+    const bool
+        isReadOnly = (::GetWindowLong(GetHwnd(), GWL_STYLE) & ES_READONLY) != 0;
+    if ( isReadOnly )
+    {
+        ::SendMessage(GetHwnd(), EM_SETREADONLY, FALSE, 0);
+    }
+
+    ::SendMessage(GetHwnd(), EM_SETTEXTEX, (WPARAM)&textInfo,
+        (LPARAM)static_cast<const wchar_t*>(val.wc_str()));
+
+    if ( isReadOnly )
+    {
+        ::SendMessage(GetHwnd(), EM_SETREADONLY, TRUE, 0);
+    }
+
+    SetInsertionPoint(0);
+}
+
+#endif // wxUSE_RICHEDIT
+
 void wxTextCtrl::WriteText(const wxString& value)
 {
     DoWriteText(value);