Add new release detection code (not very user-visible yet)

src/aptmanager.cpp

@@ -144,6 +144,22 @@ void AptManager::handleUpdateProcessBuffer()
                     conffileList.append(confLine);
                 }
             }
+        } else if (line == "Lubuntu Update !!! NEW LTS RELEASE") {
+            // Same busy-wait technique, but here we're just getting one extra line, the model code.
+            while (!aptProcess->canReadLine()) {
+                QThread::msleep(20);
+            }
+            aptProcess->readLine(lineBuf, 2048);
+            QString ltsReleaseCode = QString(lineBuf);
+            emit newLtsRelease(ltsReleaseCode);
+        } else if (line == "Lubuntu Update !!! NEW STABLE RELEASE") {
+            // Ditto
+            while (!aptProcess->canReadLine()) {
+                QThread::msleep(20);
+            }
+            aptProcess->readLine(lineBuf, 2048);
+            QString stableReleaseCode = QString(lineBuf);
+            emit newStableRelease(stableReleaseCode);
         }
 
         double percentageDone = (static_cast<double>(internalUpdateProgress) / (((internalUpdateInfo[0].count() + internalUpdateInfo[1].count()) * 4) + internalUpdateInfo[2].count())) * 100;

src/aptmanager.h

@@ -28,6 +28,8 @@ signals:
     void progressUpdated(int progress);
     void logLineReady(QString logLine);
     void conffileListReady(QStringList conffileList);
+    void newLtsRelease(QString code);
+    void newStableRelease(QString code);
 
 private slots:
     void handleUpdateProcessBuffer();

src/lubuntu-update-backend

@@ -4,6 +4,43 @@
 set -e
 export LC_ALL='C'
 
+# Returns 0 if the release is supported, 1 if unsupported, 2 if if didn't exist at all, and 3 if something went wrong.
+isReleaseSupported () {
+	releaseYear="${1:-}";
+	releaseMonth="${2:-}";
+	metaReleaseStr="${3:-}";
+
+	if [ -z "$releaseYear" ]; then
+		echo '! ! ! releaseYear is blank';
+		return 3;
+	elif [ -z "$releaseMonth" ]; then
+		echo '! ! ! releaseMonth is blank';
+		return 3;
+	elif [ -z "$metaReleaseStr" ]; then
+		echo '! ! ! metaReleaseStr is blank';
+		return 3;
+	fi
+
+	releaseCode="$releaseYear.$releaseMonth";
+	scanForSupported='n';
+
+	while IFS= read -r line || [[ -n $line ]]; do
+		if [[ "$line" =~ $releaseCode ]]; then
+			scanForSupported='y';
+		fi
+		if [ "$scanForSupported" = 'y' ]; then
+			if [[ "$line" =~ Supported ]]; then
+				if [ "$(echo "$line" | cut -d':' -f2 | tail -c+2)" = '0' ]; then
+					return 1;
+				else
+					return 0;
+				fi
+			fi
+		fi
+	done < <(printf '%s' "$metaReleaseStr")
+	return 2;
+}
+
 if [ "$1" = 'pkgver' ]; then
 	shift
 	while [ "$1" != '' ]; do
@@ -90,5 +127,42 @@ elif [ "$1" = 'doupdate' ]; then
 		fi
 	done
 
+	echo 'Checking release status...'
+
+	releaseCode="$(cat /etc/lsb-release | grep "DISTRIB_RELEASE" | cut -d'=' -f2)";
+	releaseYear="$(cut -d'.' -f1 <<< "$releaseCode")";
+	releaseMonth="$(cut -d'.' -f2 <<< "$releaseCode")";
+	metaReleaseData="$(curl https://changelogs.ubuntu.com/meta-release)";
+	nextReleaseMonth='';
+	nextReleaseYear='';
+	nextLTSReleaseMonth='';
+	nextLTSReleaseYear='';
+
+	if ((releaseMonth == 4)); then
+		nextReleaseMonth=((releaseMonth + 6));
+		nextReleaseYear="$releaseYear";
+		if (((releaseYear % 2) == 0)); then
+			nextLTSReleaseMonth='04';
+			nextLTSReleaseYear=((releaseYear + 2));
+		fi
+	else
+		nextReleaseMonth="$releaseMonth";
+		nextReleaseYear=((releaseYear + 1));
+	fi
+
+	if [ -n "$nextLTSReleaseYear" ]; then
+		if isReleaseSupported "$nextLTSReleaseYear" "$nextLTSReleaseMonth" "$metaReleaseData"; then
+			echo 'Lubuntu Update !!! NEW LTS RELEASE';
+			echo "$nextLTSReleaseYear.$nextLTSReleaseMonth";
+		fi
+	fi
+
+	if ! (((nextReleaseYear == nextLTSReleaseYear) && (nextReleaseMonth == nextLTSReleaseMonth))); then
+		if isReleaseSupported "$nextReleaseYear" "$nextReleaseMonth" "$metaReleaseData"; then
+			echo 'Lubuntu Update !!! NEW STABLE RELEASE';
+			echo "$nextReleaseYear.$nextReleaseMonth";
+		fi
+	fi
+
 	echo 'Update installation complete.'
 fi

src/mainwindow.cpp

@@ -25,6 +25,8 @@ MainWindow::MainWindow(QWidget *parent)
     connect(aptManager, &AptManager::progressUpdated, this, &MainWindow::onProgressUpdate);
     connect(aptManager, &AptManager::logLineReady, this, &MainWindow::onLogLineReady);
     connect(aptManager, &AptManager::conffileListReady, this, &MainWindow::onConffileListReady);
+    connect(aptManager, &AptManager::newLtsRelease, this, &MainWindow::onNewLtsRelease);
+    connect(aptManager, &AptManager::newStableRelease, this, &MainWindow::onNewStableRelease);
 }
 
 MainWindow::~MainWindow()
@@ -143,6 +145,7 @@ void MainWindow::onUpdateCompleted()
     ui->progressBar->setVisible(false);
     ui->statLabel->setText(tr("Update installation complete."));
     emit updatesInstalled(); // this tells the orchestrator to hide the tray icon
+    handleNewReleases();
 }
 
 void MainWindow::onCheckUpdatesCompleted()
@@ -175,3 +178,20 @@ void MainWindow::onConffileListReady(QStringList conffileList)
     }
     aptManager->doneWithConffiles();
 }
+
+void MainWindow::onNewLtsRelease(QString code)
+{
+    newLtsReleaseAvailable = true;
+}
+
+void MainWindow::onNewStableRelease(QString code)
+{
+    newStableReleaseAvailable = true;
+}
+
+void MainWindow::handleNewReleases()
+{
+    // TODO: Write code that informs the user when a new release is available here
+    newLtsReleaseAvailable = false;
+    newStableReleaseAvailable = false;
+}

src/mainwindow.h

@@ -39,9 +39,15 @@ private slots:
     void onProgressUpdate(int progress);
     void onLogLineReady(QString logLine);
     void onConffileListReady(QStringList conffileList);
+    void onNewLtsRelease(QString code);
+    void onNewStableRelease(QString code);
 
 private:
     Ui::MainWindow *ui;
     AptManager *aptManager;
+    bool newLtsReleaseAvailable = false;
+    bool newStableReleaseAvailable = false;
+
+    void handleNewReleases();
 };
 #endif // MAINWINDOW_H