+// ---------------------------------------------------------------------------
+// Stuff for using console from the GUI applications
+// ---------------------------------------------------------------------------
+
+#ifndef __WXWINCE__
+
+#include <wx/dynlib.h>
+
+namespace
+{
+
+/*
+ Helper class to manipulate console from a GUI app.
+
+ Notice that console output is available in the GUI app only if:
+ - AttachConsole() returns TRUE (which means it never works under pre-XP)
+ - we have a valid STD_ERROR_HANDLE
+ - command history hasn't been changed since our startup
+
+ To check if all these conditions are verified, you need to simple call
+ IsOkToUse(). It will check the first two conditions above the first time it
+ is called (and if this fails, the subsequent calls will return immediately)
+ and also recheck the last one every time it is called.
+ */
+class wxConsoleStderr
+{
+public:
+ // default ctor does nothing, call Init() before using this class
+ wxConsoleStderr()
+ {
+ m_hStderr = INVALID_HANDLE_VALUE;
+ m_historyLen =
+ m_dataLen =
+ m_dataLine = 0;
+
+ m_ok = -1;
+ }
+
+ ~wxConsoleStderr()
+ {
+ if ( m_hStderr != INVALID_HANDLE_VALUE )
+ {
+ if ( !::FreeConsole() )
+ {
+ wxLogLastError(_T("FreeConsole"));
+ }
+ }
+ }
+
+ // return true if we were successfully initialized and there had been no
+ // console activity which would interfere with our output since then
+ bool IsOkToUse() const
+ {
+ if ( m_ok == -1 )
+ {
+ wxConsoleStderr * const self = const_cast<wxConsoleStderr *>(this);
+ self->m_ok = self->DoInit();
+
+ // no need to call IsHistoryUnchanged() as we just initialized
+ // m_history anyhow
+ return m_ok == 1;
+ }
+
+ return m_ok && IsHistoryUnchanged();
+ }
+
+
+ // output the provided text on the console, return true if ok
+ bool Write(const wxString& text);
+
+private:
+ // called by Init() once only to do the real initialization
+ bool DoInit();
+
+ // retrieve the command line history into the provided buffer and return
+ // its length
+ int GetCommandHistory(wxWxCharBuffer& buf) const;
+
+ // check if the console history has changed
+ bool IsHistoryUnchanged() const;
+
+ int m_ok; // initially -1, set to true or false by Init()
+
+ wxDynamicLibrary m_dllKernel32;
+
+ HANDLE m_hStderr; // console handle, if it's valid we must call
+ // FreeConsole() (even if m_ok != 1)
+
+ wxWxCharBuffer m_history; // command history on startup
+ int m_historyLen; // length command history buffer
+
+ wxCharBuffer m_data; // data between empty line and cursor position
+ int m_dataLen; // length data buffer
+ int m_dataLine; // line offset
+
+ typedef DWORD (WINAPI *GetConsoleCommandHistory_t)(LPTSTR sCommands,
+ DWORD nBufferLength,
+ LPCTSTR sExeName);
+ typedef DWORD (WINAPI *GetConsoleCommandHistoryLength_t)(LPCTSTR sExeName);
+
+ GetConsoleCommandHistory_t m_pfnGetConsoleCommandHistory;
+ GetConsoleCommandHistoryLength_t m_pfnGetConsoleCommandHistoryLength;
+
+ DECLARE_NO_COPY_CLASS(wxConsoleStderr)
+};
+
+bool wxConsoleStderr::DoInit()
+{
+ HANDLE hStderr = ::GetStdHandle(STD_ERROR_HANDLE);
+
+ if ( hStderr == INVALID_HANDLE_VALUE || !hStderr )
+ return false;
+
+ if ( !m_dllKernel32.Load(_T("kernel32.dll")) )
+ return false;
+
+ typedef BOOL (WINAPI *AttachConsole_t)(DWORD dwProcessId);
+ AttachConsole_t wxDL_INIT_FUNC(pfn, AttachConsole, m_dllKernel32);
+
+ if ( !pfnAttachConsole || !pfnAttachConsole(ATTACH_PARENT_PROCESS) )
+ return false;
+
+ // console attached, set m_hStderr now to ensure that we free it in the
+ // dtor
+ m_hStderr = hStderr;
+
+ wxDL_INIT_FUNC_AW(m_pfn, GetConsoleCommandHistory, m_dllKernel32);
+ if ( !m_pfnGetConsoleCommandHistory )
+ return false;
+
+ wxDL_INIT_FUNC_AW(m_pfn, GetConsoleCommandHistoryLength, m_dllKernel32);
+ if ( !m_pfnGetConsoleCommandHistoryLength )
+ return false;
+
+ // remember the current command history to be able to compare with it later
+ // in IsHistoryUnchanged()
+ m_historyLen = GetCommandHistory(m_history);
+ if ( !m_history )
+ return false;
+
+
+ // now find the first blank line above the current position
+ CONSOLE_SCREEN_BUFFER_INFO csbi;
+
+ if ( !::GetConsoleScreenBufferInfo(m_hStderr, &csbi) )
+ {
+ wxLogLastError(_T("GetConsoleScreenBufferInfo"));
+ return false;
+ }
+
+ COORD pos;
+ pos.X = 0;
+ pos.Y = csbi.dwCursorPosition.Y + 1;
+
+ // we decide that a line is empty if first 4 characters are spaces
+ DWORD ret;
+ char buf[4];
+ do
+ {
+ pos.Y--;
+ if ( !::ReadConsoleOutputCharacterA(m_hStderr, buf, WXSIZEOF(buf),
+ pos, &ret) )
+ {
+ wxLogLastError(_T("ReadConsoleOutputCharacterA"));
+ return false;
+ }
+ } while ( wxStrncmp(" ", buf, WXSIZEOF(buf)) != 0 );
+
+ // calculate line offset and length of data
+ m_dataLine = csbi.dwCursorPosition.Y - pos.Y;
+ m_dataLen = m_dataLine*csbi.dwMaximumWindowSize.X + csbi.dwCursorPosition.X;
+
+ if ( m_dataLen > 0 )
+ {
+ m_data.extend(m_dataLen);
+ if ( !::ReadConsoleOutputCharacterA(m_hStderr, m_data.data(), m_dataLen,
+ pos, &ret) )
+ {
+ wxLogLastError(_T("ReadConsoleOutputCharacterA"));
+ return false;
+ }
+ }
+
+ return true;
+}
+
+int wxConsoleStderr::GetCommandHistory(wxWxCharBuffer& buf) const
+{
+ // these functions are internal and may only be called by cmd.exe
+ static const wxChar *CMD_EXE = _T("cmd.exe");
+
+ const int len = m_pfnGetConsoleCommandHistoryLength(CMD_EXE);
+ if ( len )
+ {
+ buf.extend(len);
+
+ int len2 = m_pfnGetConsoleCommandHistory(buf.data(), len, CMD_EXE);
+
+#if !wxUSE_UNICODE
+ // there seems to be a bug in the GetConsoleCommandHistoryA(), it
+ // returns the length of Unicode string and not ANSI one
+ len2 /= 2;
+#endif // !wxUSE_UNICODE
+
+ if ( len2 != len )
+ {
+ wxFAIL_MSG( _T("failed getting history?") );
+ }
+ }
+
+ return len;
+}
+
+bool wxConsoleStderr::IsHistoryUnchanged() const
+{
+ wxASSERT_MSG( m_ok == 1, _T("shouldn't be called if not initialized") );
+
+ // get (possibly changed) command history
+ wxWxCharBuffer history;
+ const int historyLen = GetCommandHistory(history);
+
+ // and compare it with the original one
+ return historyLen == m_historyLen && history &&
+ memcmp(m_history, history, historyLen) == 0;
+}
+
+bool wxConsoleStderr::Write(const wxString& text)
+{
+ wxASSERT_MSG( m_hStderr != INVALID_HANDLE_VALUE,
+ _T("should only be called if Init() returned true") );
+
+ // get current position
+ CONSOLE_SCREEN_BUFFER_INFO csbi;
+ if ( !::GetConsoleScreenBufferInfo(m_hStderr, &csbi) )
+ {
+ wxLogLastError(_T("GetConsoleScreenBufferInfo"));
+ return false;
+ }
+
+ // and calculate new position (where is empty line)
+ csbi.dwCursorPosition.X = 0;
+ csbi.dwCursorPosition.Y -= m_dataLine;
+
+ if ( !::SetConsoleCursorPosition(m_hStderr, csbi.dwCursorPosition) )
+ {
+ wxLogLastError(_T("SetConsoleCursorPosition"));
+ return false;
+ }
+
+ DWORD ret;
+ if ( !::FillConsoleOutputCharacter(m_hStderr, _T(' '), m_dataLen,
+ csbi.dwCursorPosition, &ret) )
+ {
+ wxLogLastError(_T("FillConsoleOutputCharacter"));
+ return false;
+ }
+
+ if ( !::WriteConsole(m_hStderr, text.wx_str(), text.length(), &ret, NULL) )
+ {
+ wxLogLastError(_T("WriteConsole"));
+ return false;
+ }
+
+ WriteConsoleA(m_hStderr, m_data, m_dataLen, &ret, 0);
+
+ return true;
+}
+
+wxConsoleStderr s_consoleStderr;
+
+} // anonymous namespace
+
+bool wxGUIAppTraits::CanUseStderr()
+{
+ return s_consoleStderr.IsOkToUse();
+}
+
+bool wxGUIAppTraits::WriteToStderr(const wxString& text)
+{
+ return s_consoleStderr.IsOkToUse() && s_consoleStderr.Write(text);
+}
+
+#endif // !__WXWINCE__
+
projects / wxWidgets.git / blobdiff