Qt: Open a message box for Qt frontend errors

CHANGES

@@ -52,6 +52,7 @@ Misc:
  - GBA BIOS: Add timings for HLE BIOS math functions (fixes mgba.io/i/1396)
  - Debugger: Make tracing compatible with breakpoints/watchpoints
  - Debugger: Print breakpoint/watchpoint number when inserting
+ - Qt: Open a message box for Qt frontend errors
 
 0.7.1: (2019-02-24)
 Bugfixes:

src/platform/qt/LogController.cpp

@@ -5,11 +5,14 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "LogController.h"
 
+#include <QMessageBox>
+
 #include "ConfigController.h"
 
 using namespace QGBA;
 
 LogController LogController::s_global(mLOG_ALL);
+int LogController::s_qtCat{-1};
 
 LogController::LogController(int levels, QObject* parent)
 	: QObject(parent)
@@ -18,6 +21,7 @@ LogController::LogController(int levels, QObject* parent)
 	mLogFilterSet(&m_filter, "gba.bios", mLOG_STUB | mLOG_FATAL);
 	mLogFilterSet(&m_filter, "core.status", mLOG_ALL & ~mLOG_DEBUG);
 	m_filter.defaultLevels = levels;
+	s_qtCat = mLogCategoryById("platform.qt");
 
 	if (this != &s_global) {
 		connect(&s_global, &LogController::logPosted, this, &LogController::postLog);
@@ -65,6 +69,11 @@ void LogController::postLog(int level, int category, const QString& string) {
 			*m_logStream << line << endl;
 		}
 	}
+	if (category == s_qtCat && level == mLOG_ERROR && this == &s_global) {
+		QMessageBox* dialog = new QMessageBox(QMessageBox::Critical, tr("An error occurred"), string, QMessageBox::Ok);
+		dialog->setAttribute(Qt::WA_DeleteOnClose);
+		dialog->show();
+	}
 	emit logPosted(level, category, string);
 }
 

src/platform/qt/LogController.h

@@ -85,6 +85,7 @@ private:
 	std::unique_ptr<QTextStream> m_logStream;
 
 	static LogController s_global;
+	static int s_qtCat;
 };
 
 #define LOG(C, L) (*LogController::global())(mLOG_ ## L, _mLOG_CAT_ ## C)