OP-1119 Added cancel functionality on download. Added soem more gui update logic.

ground/openpilotgcs/src/plugins/flightlog/FlightLogDialog.qml

@@ -146,7 +146,7 @@ Rectangle {
             height: 40
             Button {
                 id: exportButton
-                enabled: !logManager.disableControls
+                enabled: !logManager.disableControls && !logManager.disableExport
                 text: qsTr("Export...")
                 activeFocusOnPress: true
                 onClicked: logManager.exportLogs()
@@ -161,10 +161,18 @@ Rectangle {
             Rectangle {
                 Layout.fillWidth: true
             }
+            Button {
+                id: cancelButton
+                enabled: logManager.disableControls
+                text: qsTr("Cancel")
+                activeFocusOnPress: true
+                onClicked: logManager.cancelExportLogs()
+            }
             Button {
                 id: okButton
                 enabled: !logManager.disableControls
                 text: qsTr("OK")
+                isDefault: true
                 activeFocusOnPress: true
                 onClicked: dialog.close()
             }

ground/openpilotgcs/src/plugins/flightlog/flightlogmanager.cpp

@@ -37,7 +37,7 @@
 #include "utils/logfile.h"
 
 FlightLogManager::FlightLogManager(QObject *parent) :
-    QObject(parent), m_disableControls(false)
+    QObject(parent), m_disableControls(false), m_cancelDownload(false)
 {
     ExtensionSystem::PluginManager *pm = ExtensionSystem::PluginManager::instance();
 
@@ -121,6 +121,7 @@ void FlightLogManager::clearLogList()
     m_logEntries.clear();
 
     emit logEntriesChanged();
+    setDisableExport(true);
 
     while (!tmpList.isEmpty()) {
         delete tmpList.takeFirst();
@@ -131,7 +132,7 @@ void FlightLogManager::retrieveLogs(int flightToRetrieve)
 {
     setDisableControls(true);
     QApplication::setOverrideCursor(Qt::WaitCursor);
-
+    m_cancelDownload = false;
     UAVObjectUpdaterHelper updateHelper;
     UAVObjectRequestHelper requestHelper;
 
@@ -169,16 +170,30 @@ void FlightLogManager::retrieveLogs(int flightToRetrieve)
                 // We failed for some reason
                 break;
             }
+            if (m_cancelDownload) {
+                break;
+            }
+        }
+        if (m_cancelDownload) {
+            break;
         }
     }
+
+    if (m_cancelDownload) {
+        clearLogList();
+        m_cancelDownload = false;
+    }
+
     emit logEntriesChanged();
+    setDisableExport(m_logEntries.count() == 0);
+
     QApplication::restoreOverrideCursor();
     setDisableControls(false);
 }
 
 void FlightLogManager::exportLogs()
 {
-    if(m_flightEntries.isEmpty()) {
+    if(m_logEntries.isEmpty()) {
         return;
     }
 
@@ -231,6 +246,11 @@ void FlightLogManager::exportLogs()
     setDisableControls(false);
 }
 
+void FlightLogManager::cancelExportLogs()
+{
+    m_cancelDownload = true;
+}
+
 void FlightLogManager::updateFlightEntries(quint16 currentFlight)
 {
     Q_UNUSED(currentFlight);

ground/openpilotgcs/src/plugins/flightlog/flightlogmanager.h

@@ -71,6 +71,7 @@ class FlightLogManager : public QObject {
     Q_PROPERTY(QQmlListProperty<ExtendedDebugLogEntry> logEntries READ logEntries NOTIFY logEntriesChanged)
     Q_PROPERTY(QStringList flightEntries READ flightEntries NOTIFY flightEntriesChanged)
     Q_PROPERTY(bool disableControls READ disableControls WRITE setDisableControls NOTIFY disableControlsChanged)
+    Q_PROPERTY(bool disableExport READ disableExport WRITE setDisableExport NOTIFY disableExportChanged)
 
 public:
     explicit FlightLogManager(QObject *parent = 0);
@@ -89,18 +90,24 @@ public:
         return m_disableControls;
     }
 
+    bool disableExport() const
+    {
+        return m_disableExport;
+    }
+
     void clearLogList();
 
 signals:
     void logEntriesChanged();
     void flightEntriesChanged();
     void disableControlsChanged(bool arg);
-
+    void disableExportChanged(bool arg);
 
 public slots:
     void clearAllLogs();
     void retrieveLogs(int flightToRetrieve = -1);
     void exportLogs();
+    void cancelExportLogs();
 
     void setDisableControls(bool arg)
     {
@@ -110,6 +117,14 @@ public slots:
         }
     }
 
+    void setDisableExport(bool arg)
+    {
+        if (m_disableExport != arg) {
+            m_disableExport = arg;
+            emit disableExportChanged(arg);
+        }
+    }
+
 private slots:
     void updateFlightEntries(quint16 currentFlight);
 
@@ -123,6 +138,8 @@ private:
 
     static const int UAVTALK_TIMEOUT = 4000;
     bool m_disableControls;
+    bool m_disableExport;
+    bool m_cancelDownload;
 };
 
 #endif // FLIGHTLOGMANAGER_H