Android: write appLog to file

The trick is to pick a path that is accessible from other applications.
In theory QStandardPaths::GenericDataLocation should provide that.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

3 files changed, 47 insertions, 2 deletions

diff --git a/mobile-widgets/qmlmanager.cpp b/mobile-widgets/qmlmanager.cpp
index c46832fcd..855b4918f 100644
--- a/mobile-widgets/qmlmanager.cpp
+++ b/mobile-widgets/qmlmanager.cpp
@@ -90,6 +90,18 @@ QMLManager::QMLManager() : m_locationServiceEnabled(false),
 	m_instance = this;
 	m_lastDevicePixelRatio = qApp->devicePixelRatio();
 	connect(qobject_cast<QApplication *>(QApplication::instance()), &QApplication::applicationStateChanged, this, &QMLManager::applicationStateChanged);
+
+#if defined(Q_OS_ANDROID)
+	appLogFileName = QStandardPaths::standardLocations(QStandardPaths::GenericDataLocation).first() + "/subsurface.log";
+	appLogFile.setFileName(appLogFileName);
+	if (!appLogFile.open(QIODevice::ReadWrite)) {
+		appLogFileOpen = false;
+		appendTextToLog("Failed to open logfile" + appLogFileName);
+	} else {
+		appLogFileOpen = true;
+		appendTextToLog("Successfully opened logfile" + appLogFileName);
+	}
+#endif
 	appendTextToLog("Starting " + getUserAgent());
 	appendTextToLog(QStringLiteral("build with Qt Version %1, runtime from Qt Version %2").arg(QT_VERSION_STR).arg(qVersion()));
 	setStartPageText(tr("Starting..."));
@@ -234,6 +246,10 @@ void QMLManager::finishSetup()
 
 QMLManager::~QMLManager()
 {
+#if defined(Q_OS_ANDROID)
+	if (appLogFileOpen)
+		appLogFile.close();
+#endif
 	m_instance = NULL;
 }
 
@@ -1530,6 +1546,23 @@ void QMLManager::setProgressMessage(QString text)
 
 #if defined (Q_OS_ANDROID)
 
+void writeToAppLogFile(QString logText)
+{
+	// write to storage and flush so that the data doesn't get lost
+	logText.append("\n");
+	QMLManager *self = QMLManager::instance();
+	if (self) {
+		self->writeToAppLogFile(logText);
+	}
+}
+
+void QMLManager::writeToAppLogFile(QString logText)
+{
+	if (appLogFileOpen) {
+		appLogFile.write(logText.toUtf8().data());
+		appLogFile.flush();
+	}
+}
 
 //HACK to color the system bar on Android, use qtandroidextras and call the appropriate Java methods
 //this code is based on code in the Kirigami example app for Android (under LGPL-2) Copyright 2017 Marco Martin
diff --git a/mobile-widgets/qmlmanager.h b/mobile-widgets/qmlmanager.h
index 3c450158e..d80c5f58a 100644
--- a/mobile-widgets/qmlmanager.h
+++ b/mobile-widgets/qmlmanager.h
@@ -125,6 +125,9 @@ public:
 	bool showPin() const;
 	void setShowPin(bool enable);
 	Q_INVOKABLE void setStatusbarColor(QColor color);
+#if defined(Q_OS_ANDROID)
+	void writeToAppLogFile(QString logText);
+#endif
 
 public slots:
 	void applicationStateChanged(Qt::ApplicationState state);
@@ -208,6 +211,11 @@ private:
 	bool m_showPin;
 	DCDeviceData *m_device_data;
 	QString m_progressMessage;
+#if defined(Q_OS_ANDROID)
+	QString appLogFileName;
+	QFile appLogFile;
+	bool appLogFileOpen;
+#endif
 
 signals:
 	void cloudUserNameChanged();
diff --git a/qt-models/messagehandlermodel.cpp b/qt-models/messagehandlermodel.cpp
index ec6e818c9..d783a3da6 100644
--- a/qt-models/messagehandlermodel.cpp
+++ b/qt-models/messagehandlermodel.cpp
@@ -2,11 +2,12 @@
 #include "messagehandlermodel.h"
 
 /* based on logging bits from libdivecomputer */
-#ifndef __ANDROID__
+#if !defined(Q_OS_ANDROID)
 #define INFO(fmt, ...)	fprintf(stderr, "INFO: " fmt "\n", ##__VA_ARGS__)
 #else
+extern void writeToAppLogFile(QString logText);
 #include <android/log.h>
-#define INFO(fmt, ...)	__android_log_print(ANDROID_LOG_DEBUG, __FILE__, "INFO: " fmt "\n", ##__VA_ARGS__)
+#define INFO(fmt, ...)	__android_log_print(ANDROID_LOG_DEBUG, __FILE__, "INFO: " fmt "\n", ##__VA_ARGS__);
 #endif
 
 void logMessageHandler(QtMsgType type, const QMessageLogContext &context, const QString &msg)
@@ -42,6 +43,9 @@ void MessageHandlerModel::addLog(QtMsgType type, const QString& message)
 	m_data.append({message, type});
 	endInsertRows();
 	INFO("%s", message.toUtf8().constData());
+#if defined (Q_OS_ANDROID)
+	writeToAppLogFile(message);
+#endif
 }
 
 QVariant MessageHandlerModel::data(const QModelIndex& idx, int role) const