mobile: enable switching BT on/off during session.

This commit implements possible switching BT on and off during a session,
so not needing a restart of the app when the user forgot to switch
it on when starting the app.

For this, the following needed to be done: 1) create a handler that
reacts on local BT device status changes. 2) repopulate the connection
list in the download screen when a BT status change is detected.

Notice the subtile change of the Q_INVOKABLE btEnabled() function
to a Q_PROPERTY. This gives a nice dynamic behaviour when
switching BT on/off with the app open.

Fixes: #556

Signed-off-by: Jan Mulder <jlmulder@xs4all.nl>

core/btdiscovery.cpp

@@ -60,6 +60,12 @@ BTDiscovery::BTDiscovery(QObject *parent)
 	}
 	m_instance = this;
 #if defined(BT_SUPPORT)
+	BTDiscoveryReDiscover();
+#endif
+}
+
+void BTDiscovery::BTDiscoveryReDiscover()
+{
 #if !defined(Q_OS_IOS)
 	if (localBtDevice.isValid() &&
 	    localBtDevice.hostMode() == QBluetoothLocalDevice::HostConnectable) {
@@ -100,7 +106,6 @@ BTDiscovery::BTDiscovery(QObject *parent)
 		m_btValid = false;
 	}
 #endif
-#endif
 }
 
 BTDiscovery::~BTDiscovery()

core/btdiscovery.h

@@ -46,6 +46,8 @@ public:
 	void getBluetoothDevices();
 #endif
 	QList<btVendorProduct> getBtDcs();
+	QBluetoothLocalDevice localBtDevice;
+	void BTDiscoveryReDiscover();
 
 private:
 	static BTDiscovery *m_instance;
@@ -59,7 +61,6 @@ private:
 #endif
 
 	QList<struct btPairedDevice> btPairedDevices;
-	QBluetoothLocalDevice localBtDevice;
 	QBluetoothDeviceDiscoveryAgent *discoveryAgent;
 
 signals:

mobile-widgets/qml/DownloadFromDiveComputer.qml

@@ -17,8 +17,8 @@ Kirigami.Page {
 
 	property alias dcImportModel: importModel
 	property bool divesDownloaded: false
-	property bool btEnabled: manager.btEnabled()
+	property bool btEnabled: manager.btEnabled
-	property string btMessage: manager.btEnabled() ? "" : qsTr("Bluetooth is not enabled")
+	property string btMessage: manager.btEnabled ? "" : qsTr("Bluetooth is not enabled")
 
 	DCDownloadThread {
 		id: downloadThread

mobile-widgets/qmlmanager.cpp

@@ -12,6 +12,7 @@
 #include <QElapsedTimer>
 #include <QTimer>
 #include <QDateTime>
+#include <QBluetoothLocalDevice>
 
 #include "qt-models/divelistmodel.h"
 #include "qt-models/gpslistmodel.h"
@@ -77,6 +78,23 @@ extern "C" int gitProgressCB(const char *text)
 	return 0;
 }
 
+void QMLManager::btHostModeChange(QBluetoothLocalDevice::HostMode state)
+{
+	BTDiscovery *btDiscovery = BTDiscovery::instance();
+
+	qDebug() << "btHostModeChange to " << state;
+	if (state != QBluetoothLocalDevice::HostPoweredOff) {
+		connectionListModel.removeAllAddresses();
+		btDiscovery->BTDiscoveryReDiscover();
+		m_btEnabled = btDiscovery->btAvailable();
+	} else {
+		connectionListModel.removeAllAddresses();
+		set_non_bt_addresses();
+		m_btEnabled = false;
+	}
+	emit btEnabledChanged();
+}
+
 QMLManager::QMLManager() : m_locationServiceEnabled(false),
 	m_verboseEnabled(false),
 	reply(0),
@@ -117,6 +135,8 @@ QMLManager::QMLManager() : m_locationServiceEnabled(false),
 	// to QML, but that doesn't seem to always work
 	BTDiscovery *btDiscovery = BTDiscovery::instance();
 	m_btEnabled = btDiscovery->btAvailable();
+	connect(&btDiscovery->localBtDevice, &QBluetoothLocalDevice::hostModeStateChanged,
+		this, &QMLManager::btHostModeChange);
 #else
 	m_btEnabled = false;
 #endif
@@ -1659,6 +1679,11 @@ bool QMLManager::btEnabled() const
 	return m_btEnabled;
 }
 
+void QMLManager::setBtEnabled(bool value)
+{
+	m_btEnabled = value;
+}
+
 #if defined (Q_OS_ANDROID)
 
 void writeToAppLogFile(QString logText)

mobile-widgets/qmlmanager.h

@@ -45,6 +45,7 @@ class QMLManager : public QObject {
 	Q_PROPERTY(QString progressMessage READ progressMessage WRITE setProgressMessage NOTIFY progressMessageChanged)
 	Q_PROPERTY(bool libdcLog READ libdcLog WRITE setLibdcLog NOTIFY libdcLogChanged)
 	Q_PROPERTY(bool developer READ developer WRITE setDeveloper NOTIFY developerChanged)
+	Q_PROPERTY(bool btEnabled READ btEnabled WRITE setBtEnabled NOTIFY btEnabledChanged)
 
 public:
 	QMLManager();
@@ -124,6 +125,9 @@ public:
 	bool developer() const;
 	void setDeveloper(bool value);
 
+	bool btEnabled() const;
+	void setBtEnabled(bool value);
+
 	typedef void (QMLManager::*execute_function_type)();
 	DiveListSortModel *dlSortModel;
 
@@ -134,7 +138,7 @@ public:
 	bool showPin() const;
 	void setShowPin(bool enable);
 	Q_INVOKABLE void setStatusbarColor(QColor color);
-	Q_INVOKABLE bool btEnabled() const;
+	void btHostModeChange(QBluetoothLocalDevice::HostMode state);
 
 #if defined(Q_OS_ANDROID)
 	void writeToAppLogFile(QString logText);
@@ -258,6 +262,7 @@ signals:
 	void progressMessageChanged();
 	void libdcLogChanged();
 	void developerChanged();
+	void btEnabledChanged();
 };
 
 #endif