core, handle multiple downloads at the same time. Progress bar no more flickering

src/core/Bar.qml

@@ -280,7 +280,7 @@ Item {
         target: DownloadManager
 
         onDownloadStarted: content.value |= content.download
-        onDownloadFinished: content.value &= ~content.download
+        onAllDownloadsFinished: content.value &= ~content.download
         onError: content.value &= ~content.download
     }
 

src/core/DownloadDialog.qml

@@ -180,7 +180,7 @@ Item {
             wrapMode: TextEdit.WordWrap
             z: 2
             height: 60 * ApplicationInfo.ratio
-            text: qsTr("Downloading ...")
+            text: qsTr("Downloading...")
         }
 
         Rectangle {
@@ -293,8 +293,8 @@ Item {
             downloadDialogProgress.value = 0;
         }
 
-        onDownloadFinished: {
-            //console.log("dialog: DM reports finished: " + code);
+        onAllDownloadsFinished: {
+            //console.log("dialog: DM all reports finished");
             downloadDialog.finished();
             if (downloadDialog.reportSuccess
                     && code != 1) // note: errors will be reported by the onError handler
@@ -318,6 +318,10 @@ Item {
             } else if (downloadDialog.autohide)
                 downloadDialog.shutdown();
         }
+
+        onDownloadFinished: {
+            //console.log("dialog: DM reports finished: " + code);
+        }
     }
 
 }

src/core/DownloadManager.cpp

@@ -87,7 +87,7 @@ void DownloadManager::abortDownloads()
         QMutableListIterator<DownloadJob*> iter(activeJobs);
         while (iter.hasNext()) {
             DownloadJob *job = iter.next();
-            if (job->reply != nullptr) {
+            if (!job->downloadFinished && job->reply != nullptr) {
                 disconnect(job->reply, SIGNAL(finished()), this, SLOT(downloadFinished()));
                 disconnect(job->reply, SIGNAL(error(QNetworkReply::NetworkError)),
                         this, SLOT(handleError(QNetworkReply::NetworkError)));
@@ -99,6 +99,7 @@ void DownloadManager::abortDownloads()
                 }
                 job->reply->deleteLater();
             }
+            delete job;
             iter.remove();
         }
         locker.unlock();
@@ -244,7 +245,7 @@ bool DownloadManager::download(DownloadJob* job)
             this, SLOT(handleError(QNetworkReply::NetworkError)));
     if (job->url.fileName() != contentsFilename) {
         connect(reply, &QNetworkReply::downloadProgress,
-                this, &DownloadManager::downloadProgress);
+                this, &DownloadManager::downloadInProgress);
         emit downloadStarted(job->url.toString().remove(0, serverUrl.toString().length()));
     }
 
@@ -467,11 +468,33 @@ bool DownloadManager::areVoicesRegistered() const
     return isDataRegistered(resource);
 }
 
+void DownloadManager::downloadInProgress(qint64 bytesReceived, qint64 bytesTotal) {
+    QNetworkReply *reply = dynamic_cast<QNetworkReply*>(sender());
+    DownloadJob *job = nullptr;
+    // don't call getJobByReply to not cause deadlock with mutex
+    for (auto activeJob : activeJobs) {
+        if (activeJob->reply == reply) {
+            job = activeJob;
+            break;
+        }
+    }
+    job->bytesReceived = bytesReceived;
+    job->bytesTotal = bytesTotal;
+    qint64 allJobsBytesReceived = 0;
+    qint64 allJobsBytesTotal = 0;
+    for (auto activeJob : activeJobs) {
+        allJobsBytesReceived += activeJob->bytesReceived;
+        allJobsBytesTotal += activeJob->bytesTotal;
+    }
+    emit downloadProgress(allJobsBytesReceived, allJobsBytesTotal);
+}
+
 void DownloadManager::downloadFinished()
 {
     QNetworkReply* reply = dynamic_cast<QNetworkReply*>(sender());
     DownloadFinishedCode code = Success;
     DownloadJob *job = getJobByReply(reply);
+    bool allFinished = false;
     if (job->file.isOpen()) {
         job->file.flush();  // note: important, or checksums might be wrong!
         job->file.close();
@@ -570,15 +593,27 @@ void DownloadManager::downloadFinished()
         }
 
     // none left, DownloadJob finished
+    job->downloadFinished = true;
+    job->downloadResult = code;
     if (job->file.isOpen())
         job->file.close();
-    { // note: must remove before signalling downloadFinished(), otherwise race condition for the Qt.quit() case
-        QMutexLocker locker(&jobsMutex);
-        activeJobs.removeOne(job);
-    }
     emit downloadFinished(code);
     reply->deleteLater();
-    delete job;
+
+    allFinished = std::all_of(activeJobs.constBegin(), activeJobs.constEnd(),
+                              [](const DownloadJob* job) { return job->downloadFinished;});
+    if(allFinished) {
+        QMutexLocker locker(&jobsMutex);
+        DownloadFinishedCode allCode = Success;
+        std::for_each(activeJobs.constBegin(), activeJobs.constEnd(),
+                      [&allCode] (const DownloadJob *job) {
+                          if(job->downloadResult == Error)
+                              allCode = Error;
+                          delete job;
+                      });
+        activeJobs.clear();
+        emit allDownloadsFinished(allCode);
+    }
     return;
 
   outError:

src/core/DownloadManager.h

@@ -97,8 +97,16 @@ private:
         QMap<QString,QString> contents;  ///< checksum map for download verification
         QList<QUrl> knownContentsUrls;   ///< store already tried upstream Contents files (for infinite loop protection)
 
+        qint64 bytesReceived;
+        qint64 bytesTotal;
+        bool downloadFinished;
+        int downloadResult;
         DownloadJob(const QUrl &u = QUrl()) : url(u), file(), reply(0),
-                queue(QList<QUrl>()) {}
+                                              queue(QList<QUrl>()),
+                                              bytesReceived(0),
+                                              bytesTotal(0),
+                                              downloadFinished(false),
+                                              downloadResult(0) {}
     } DownloadJob;
 
     QList<DownloadJob*> activeJobs;  ///< track active jobs to allow for parallel downloads
@@ -281,6 +289,15 @@ public:
 
 public slots:
 
+    /** Emitted when a download in progressing.
+     *
+     * Job is retrieved using sender() method.
+     *
+     * @param bytesReceived Downloaded bytes for this job.
+     * @param bytesTotal Total bytes to download for this job.
+     */
+    void downloadInProgress(qint64 bytesReceived, qint64 bytesTotal);
+
     /**
      * Updates a resource @p path from the upstream server unless prohibited
      * by the settings and registers it if possible.
@@ -364,6 +381,13 @@ signals:
      */
     void downloadFinished(int code);
 
+    /** Emitted when all downloads have finished.
+     *
+     * If all downloads are successful, code is Success.
+     * Else if at least one download is in error, code is Error.
+     */
+    void allDownloadsFinished(int code);
+
     /** Emitted when a resource has been registered.
      *
      * @param resource Relative resource path of the registered resource.