Use QNetworkInformation to queue QFieldCloud pushes offline and resume when back online

src/core/qfieldcloud/qfieldcloudconnection.cpp

@@ -60,6 +60,78 @@ QFieldCloudConnection::QFieldCloudConnection()
     mTokenConfigId.clear();
     QSettings().remove( "/QFieldCloud/tokenConfigId" );
   }
+
+  QNetworkInformation::loadBackendByFeatures( QNetworkInformation::Feature::Reachability );
+  mNetworkInfo = QNetworkInformation::instance();
+
+  if ( mNetworkInfo )
+  {
+    connect( mNetworkInfo, &QNetworkInformation::reachabilityChanged, this,
+             [this]( QNetworkInformation::Reachability ) {
+               emit reachabilityToCloudChanged();
+               tryFlushQueuedProjectPushes();
+             } );
+  }
+}
+
+
+void QFieldCloudConnection::queueProjectPush( const QString &projectId, const bool shouldDownloadUpdates )
+{
+  if ( projectId.isEmpty() )
+    return;
+
+  // merge flag so "true" wins
+  mQueuedProjectPushes[projectId] = mQueuedProjectPushes.value( projectId, false ) || shouldDownloadUpdates;
+
+  tryFlushQueuedProjectPushes();
+}
+
+void QFieldCloudConnection::tryFlushQueuedProjectPushes()
+{
+  if ( mIsFlushingQueuedProjectPushes )
+    return;
+
+  if ( mQueuedProjectPushes.isEmpty() )
+    return;
+
+  if ( status() != ConnectionStatus::LoggedIn )
+    return;
+
+  if ( !isReachableToCloud() )
+    return;
+
+  mIsFlushingQueuedProjectPushes = true;
+
+  const auto queued = mQueuedProjectPushes;
+  mQueuedProjectPushes.clear();
+
+  for ( auto it = queued.cbegin(); it != queued.cend(); ++it )
+    emit queuedProjectPush( it.key(), it.value() );
+
+  mIsFlushingQueuedProjectPushes = false;
+}
+
+bool QFieldCloudConnection::isReachableToCloud() const
+{
+  if ( !mNetworkInfo || !mNetworkInfo->supports( QNetworkInformation::Feature::Reachability ) )
+  {
+    // No backend or no reachability support, dont change behaviour
+    return true;
+  }
+
+  switch ( mNetworkInfo->reachability() )
+  {
+    case QNetworkInformation::Reachability::Online:
+    case QNetworkInformation::Reachability::Unknown:
+      return true;
+
+    case QNetworkInformation::Reachability::Disconnected:
+    case QNetworkInformation::Reachability::Local:
+    case QNetworkInformation::Reachability::Site:
+      return false;
+  }
+
+  return true;
 }
 
 QMap<QString, QString> QFieldCloudConnection::sErrors = QMap<QString, QString>(
@@ -155,6 +227,7 @@ void QFieldCloudConnection::setUsername( const QString &username )
   if ( mUsername == username )
     return;
 
+  mQueuedProjectPushes.clear();
   mUsername = username;
 
   if ( mStatus != ConnectionStatus::Disconnected )
@@ -603,6 +676,7 @@ void QFieldCloudConnection::setToken( const QByteArray &token )
 
 void QFieldCloudConnection::invalidateToken()
 {
+  mQueuedProjectPushes.clear();
   if ( mToken.isNull() )
     return;
 

src/core/qfieldcloud/qfieldcloudconnection.h

@@ -20,7 +20,9 @@
 #include "networkreply.h"
 #include "qfieldcloudutils.h"
 
+#include <QHash>
 #include <QJsonDocument>
+#include <QNetworkInformation>
 #include <QObject>
 #include <QVariantMap>
 
@@ -218,6 +220,10 @@ class QFieldCloudConnection : public QObject
      */
     qsizetype uploadPendingAttachments();
 
+    bool isReachableToCloud() const;
+    void queueProjectPush( const QString &projectId, const bool shouldDownloadUpdates );
+    void tryFlushQueuedProjectPushes();
+
   signals:
     void providerChanged();
     void usernameChanged();
@@ -240,6 +246,9 @@ class QFieldCloudConnection : public QObject
     void availableProvidersChanged();
     void isFetchingAvailableProvidersChanged();
 
+    void reachabilityToCloudChanged();
+    void queuedProjectPush( const QString &projectId, const bool shouldDownloadUpdates );
+
   private:
     void setStatus( ConnectionStatus status );
     void setState( ConnectionState state );
@@ -271,6 +280,11 @@ class QFieldCloudConnection : public QObject
     qsizetype mUploadFailingCount = 0;
 
     void setClientHeaders( QNetworkRequest &request );
+
+    QHash<QString, bool> mQueuedProjectPushes;
+    bool mIsFlushingQueuedProjectPushes = false;
+
+    const QNetworkInformation *mNetworkInfo = nullptr;
 };
 
 #endif // QFIELDCLOUDCONNECTION_H

src/core/qfieldcloud/qfieldcloudprojectsmodel.cpp

@@ -40,14 +40,16 @@
 QFieldCloudProjectsModel::QFieldCloudProjectsModel()
 {
   // TODO all of these connects are a bit too much, and I guess not very precise, should be refactored!
-
   connect( this, &QFieldCloudProjectsModel::dataChanged, this, [this]( const QModelIndex &topLeft, const QModelIndex &bottomRight, const QVector<int> &roles ) {
     Q_UNUSED( bottomRight )
     Q_UNUSED( roles )
 
     if ( roles.isEmpty() || roles.contains( StatusRole ) )
     {
       emit busyProjectIdsChanged();
+
+      if ( mCloudConnection )
+        mCloudConnection->tryFlushQueuedProjectPushes();
     }
   } );
 }
@@ -67,6 +69,7 @@ void QFieldCloudProjectsModel::setCloudConnection( QFieldCloudConnection *cloudC
     disconnect( mCloudConnection, &QFieldCloudConnection::statusChanged, this, &QFieldCloudProjectsModel::connectionStatusChanged );
     disconnect( mCloudConnection, &QFieldCloudConnection::usernameChanged, this, &QFieldCloudProjectsModel::usernameChanged );
     disconnect( mCloudConnection, &QFieldCloudConnection::urlChanged, this, &QFieldCloudProjectsModel::urlChanged );
+    disconnect( mCloudConnection, &QFieldCloudConnection::queuedProjectPush, this, &QFieldCloudProjectsModel::projectPush );
   }
 
   mCloudConnection = cloudConnection;
@@ -76,10 +79,12 @@ void QFieldCloudProjectsModel::setCloudConnection( QFieldCloudConnection *cloudC
     connect( mCloudConnection, &QFieldCloudConnection::statusChanged, this, &QFieldCloudProjectsModel::connectionStatusChanged );
     connect( mCloudConnection, &QFieldCloudConnection::usernameChanged, this, &QFieldCloudProjectsModel::usernameChanged );
     connect( mCloudConnection, &QFieldCloudConnection::urlChanged, this, &QFieldCloudProjectsModel::urlChanged );
+    connect( mCloudConnection, &QFieldCloudConnection::queuedProjectPush, this, &QFieldCloudProjectsModel::projectPush );
 
     mUsername = mCloudConnection->username();
     mUrl = mCloudConnection->url();
     resetProjects();
+    mCloudConnection->tryFlushQueuedProjectPushes();
   }
 
   emit cloudConnectionChanged();
@@ -323,9 +328,26 @@ void QFieldCloudProjectsModel::projectPush( const QString &projectId, const bool
     return;
 
   QFieldCloudProject *project = mProjects[projectIndex.row()];
+  if ( !project )
+    return;
+
+  // If the network is not active, queue the push and warn the user.
+  if ( !mCloudConnection || !mCloudConnection->isReachableToCloud() )
+  {
+    if ( mCloudConnection )
+      mCloudConnection->queueProjectPush( projectId, shouldDownloadUpdates );
 
-  if ( !( project->status() == QFieldCloudProject::ProjectStatus::Idle ) )
+    emit warning( tr( "Network is not currently active. "
+                      "We will push the changes automatically once you are back online." ) );
     return;
+  }
+
+  if ( project->status() != QFieldCloudProject::ProjectStatus::Idle )
+  {
+    // if user requested push while busy, schedule it
+    mCloudConnection->queueProjectPush( projectId, shouldDownloadUpdates );
+    return;
+  }
 
   project->push( shouldDownloadUpdates );
 }

src/core/qfieldcloud/qfieldcloudprojectsmodel.h

@@ -20,6 +20,7 @@
 #include "qgsgpkgflusher.h"
 
 #include <QAbstractListModel>
+#include <QHash>
 #include <QJsonArray>
 #include <QNetworkReply>
 #include <QPointer>