From 79faa46da0b8da1d346a2eaf34a07889312021a5 Mon Sep 17 00:00:00 2001
From: Martchus <martchus@gmx.net>
Date: Tue, 1 Sep 2015 20:05:38 +0200
Subject: [PATCH] added method to activate stdout/stderr for GUI app on Windows

---
 application/argumentparser.cpp   |  6 ++++-
 application/commandlineutils.cpp | 44 +++++++++++++++++++++++++++++++-
 application/commandlineutils.h   |  7 +++++
 3 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/application/argumentparser.cpp b/application/argumentparser.cpp
index 8776a90..222ffe6 100644
--- a/application/argumentparser.cpp
+++ b/application/argumentparser.cpp
@@ -1,4 +1,5 @@
 #include "argumentparser.h"
+#include "commandlineutils.h"
 #include "failure.h"
 
 #include "../conversion/stringconversion.h"
@@ -652,7 +653,10 @@ void ArgumentParser::parseArgs(int argc, char *argv[])
 HelpArgument::HelpArgument(ArgumentParser &parser) :
     Argument("help", "h", "shows this information")
 {
-    setCallback([&parser] (const StringVector &) {parser.printHelp(cout);});
+    setCallback([&parser] (const StringVector &) {
+        CMD_UTILS_START_CONSOLE;
+        parser.printHelp(cout);
+    });
 }
 
 }
diff --git a/application/commandlineutils.cpp b/application/commandlineutils.cpp
index c883778..dbcd0f9 100644
--- a/application/commandlineutils.cpp
+++ b/application/commandlineutils.cpp
@@ -3,10 +3,18 @@
 #include <string>
 #include <iostream>
 
+#ifdef PLATFORM_WINDOWS
+#include <windows.h>
+#include <fcntl.h>
+#endif
+
 using namespace std;
 
 namespace ApplicationUtilities {
 
+/*!
+ * \brief Prompts for confirmation displaying the specified \a message.
+ */
 bool confirmPrompt(const char *message, Response defaultResponse)
 {
     cout << message;
@@ -28,5 +36,39 @@ bool confirmPrompt(const char *message, Response defaultResponse)
     }
 }
 
-} // namespace ApplicationUtilities
+/*!
+ * \brief Starts the console.
+ * \remarks This method is only available on Windows and used to start
+ *          a console from a GUI application.
+ */
+void startConsole()
+{
+    AttachConsole(ATTACH_PARENT_PROCESS);
+    CONSOLE_SCREEN_BUFFER_INFO coninfo;
+    GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &coninfo);
+    coninfo.dwSize.X = 200;
+    coninfo.dwSize.Y = 500;
+    SetConsoleScreenBufferSize(GetStdHandle(STD_OUTPUT_HANDLE), coninfo.dwSize);
+    // redirect stdout
+    auto stdHandle = reinterpret_cast<intptr_t>(GetStdHandle(STD_OUTPUT_HANDLE));
+    auto conHandle = _open_osfhandle(stdHandle, _O_TEXT);
+    auto fp = _fdopen(conHandle, "w");
+    *stdout = *fp;
+    setvbuf(stdout, NULL, _IONBF, 0);
+    // redirect stdin
+    stdHandle = reinterpret_cast<intptr_t>(GetStdHandle(STD_INPUT_HANDLE));
+    conHandle = _open_osfhandle(stdHandle, _O_TEXT);
+    fp = _fdopen(conHandle, "r");
+    *stdin = *fp;
+    setvbuf(stdin, NULL, _IONBF, 0);
+    // redirect stderr
+    stdHandle = reinterpret_cast<intptr_t>(GetStdHandle(STD_ERROR_HANDLE));
+    conHandle = _open_osfhandle(stdHandle, _O_TEXT);
+    fp = _fdopen(conHandle, "w");
+    *stderr = *fp;
+    setvbuf(stderr, NULL, _IONBF, 0);
+    // sync
+    ios::sync_with_stdio(true);
+}
 
+} // namespace ApplicationUtilities
diff --git a/application/commandlineutils.h b/application/commandlineutils.h
index ec23009..71b50c5 100644
--- a/application/commandlineutils.h
+++ b/application/commandlineutils.h
@@ -14,6 +14,13 @@ enum class Response
 
 bool LIB_EXPORT confirmPrompt(const char *message, Response defaultResponse = Response::None);
 
+#ifdef PLATFORM_WINDOWS
+void LIB_EXPORT startConsole();
+#define CMD_UTILS_START_CONSOLE ::ApplicationUtilities::startConsole();
+#else
+#define CMD_UTILS_START_CONSOLE
+#endif
+
 } // namespace ApplicationUtilities
 
 #endif // APPLICATIONUTILITIES_COMMANDLINEUTILS_H