AnnotatedUrl: add QNdefFilter support

Update the example to show the usage of QNdefFilter.

Task-number: QTBUG-94033
Pick-to: 6.2
Change-Id: I41b463bcf41bd3f4cb5b60981d9e3a89f7622531
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

7 files changed, 72 insertions, 7 deletions

diff --git a/examples/nfc/annotatedurl/annotatedurl.cpp b/examples/nfc/annotatedurl/annotatedurl.cpp
index c1945083..9c9ef351 100644
--- a/examples/nfc/annotatedurl/annotatedurl.cpp
+++ b/examples/nfc/annotatedurl/annotatedurl.cpp
@@ -74,6 +74,13 @@ AnnotatedUrl::AnnotatedUrl(QObject *parent)
             this, &AnnotatedUrl::targetLost);
     connect(manager, &QNearFieldManager::adapterStateChanged,
             this, &AnnotatedUrl::handleAdapterStateChange);
+
+//! [populateFilter]
+    messageFilter.setOrderMatch(false);
+    messageFilter.appendRecord<QNdefNfcTextRecord>(1, 100);
+    messageFilter.appendRecord<QNdefNfcUriRecord>(1, 1);
+    messageFilter.appendRecord(QNdefRecord::Mime, "", 0, 1);
+//! [populateFilter]
 }
 
 AnnotatedUrl::~AnnotatedUrl()
@@ -100,6 +107,8 @@ void AnnotatedUrl::targetDetected(QNearFieldTarget *target)
 
     connect(target, &QNearFieldTarget::ndefMessageRead,
             this, &AnnotatedUrl::handlePolledNdefMessage);
+    connect(target, &QNearFieldTarget::error, this,
+            [this]() { emit tagError("Tag read error"); });
     target->readNdefMessages();
 }
 
@@ -133,6 +142,13 @@ void AnnotatedUrl::handleMessage(const QNdefMessage &message, QNearFieldTarget *
 //! [handleMessage 1]
     Q_UNUSED(target);
 
+//! [handleMessage 2]
+    if (!messageFilter.match(message)) {
+        emit tagError("Invalid message format");
+        return;
+    }
+//! [handleMessage 2]
+
     enum {
         MatchedNone,
         MatchedFirst,
@@ -147,14 +163,14 @@ void AnnotatedUrl::handleMessage(const QNdefMessage &message, QNearFieldTarget *
     QUrl url;
     QPixmap pixmap;
 
-//! [handleMessage 2]
+//! [handleMessage 3]
     for (const QNdefRecord &record : message) {
         if (record.isRecordType<QNdefNfcTextRecord>()) {
             QNdefNfcTextRecord textRecord(record);
 
             title = textRecord.text();
             QLocale locale(textRecord.locale());
-//! [handleMessage 2]
+//! [handleMessage 3]
             // already found best match
             if (bestMatch == MatchedLanguageAndCountry) {
                 // do nothing
@@ -168,7 +184,7 @@ void AnnotatedUrl::handleMessage(const QNdefMessage &message, QNearFieldTarget *
             } else if (bestMatch == MatchedNone) {
                 bestMatch = MatchedFirst;
             }
-//! [handleMessage 3]
+//! [handleMessage 4]
         } else if (record.isRecordType<QNdefNfcUriRecord>()) {
             QNdefNfcUriRecord uriRecord(record);
 
@@ -177,10 +193,10 @@ void AnnotatedUrl::handleMessage(const QNdefMessage &message, QNearFieldTarget *
                    record.type().startsWith("image/")) {
             pixmap = QPixmap::fromImage(QImage::fromData(record.payload()));
         }
-//! [handleMessage 3]
 //! [handleMessage 4]
+//! [handleMessage 5]
     }
 
     emit annotatedUrl(url, title, pixmap);
 }
-//! [handleMessage 4]
+//! [handleMessage 5]
diff --git a/examples/nfc/annotatedurl/annotatedurl.h b/examples/nfc/annotatedurl/annotatedurl.h
index 4c0bdbe0..3e823f3e 100644
--- a/examples/nfc/annotatedurl/annotatedurl.h
+++ b/examples/nfc/annotatedurl/annotatedurl.h
@@ -53,6 +53,7 @@
 
 #include <QtNfc/QNdefMessage>
 #include <QtNfc/QNearFieldManager>
+#include <QtNfc/QNdefFilter>
 
 #include <QtCore/QObject>
 #include <QtCore/QUrl>
@@ -74,6 +75,7 @@ public:
 signals:
     void annotatedUrl(const QUrl &url, const QString &title, const QPixmap &pixmap);
     void nfcStateChanged(bool enabled);
+    void tagError(const QString &error);
 
 public slots:
     void targetDetected(QNearFieldTarget *target);
@@ -84,6 +86,7 @@ public slots:
 
 private:
     QNearFieldManager *manager;
+    QNdefFilter messageFilter;
 };
 //! [0]
 
diff --git a/examples/nfc/annotatedurl/doc/images/annotatedurl3.png b/examples/nfc/annotatedurl/doc/images/annotatedurl3.png
new file mode 100644
index 00000000..363b7687
--- /dev/null
+++ b/examples/nfc/annotatedurl/doc/images/annotatedurl3.png
diff --git a/examples/nfc/annotatedurl/doc/src/annotatedurl.qdoc b/examples/nfc/annotatedurl/doc/src/annotatedurl.qdoc
index b2004839..fc229d14 100644
--- a/examples/nfc/annotatedurl/doc/src/annotatedurl.qdoc
+++ b/examples/nfc/annotatedurl/doc/src/annotatedurl.qdoc
@@ -63,6 +63,31 @@ is touched. Such usecase is currently supported on Android.
 
 \snippet annotatedurl/main.cpp 0
 
+\section1 Message Filtering
+
+As it is mentioned above, the application supports the NDEF messages of a
+specific format. A correct message should contain the following fields:
+
+\list
+    \li \e {At least one} NDEF Text record, which will be used as a header.
+    \li \e {Exactly one} NDEF URI record.
+    \li \e {An optional} MIME record with an icon.
+\endlist
+
+The order of the records is not strictly specified.
+
+An instance of \l QNdefFilter is used to validate the NDEF message. The filter
+is populated as follows:
+
+\snippet annotatedurl/annotatedurl.cpp populateFilter
+
+If the incoming message does not match the filter, an error message is shown:
+
+\image annotatedurl3.png
+
+\note The \l {ndefeditor}{NDEF Editor} example application can be used to create
+the tags with correct or incorrect message structure.
+
 \section1 AnnotatedUrl Handler Implementation
 
 NFC messages read by the \l QNearFieldManager are forwarded to
@@ -70,17 +95,23 @@ NFC messages read by the \l QNearFieldManager are forwarded to
 
 \snippet annotatedurl/annotatedurl.cpp handleMessage 1
 
+At first the messages are validated using the \l QNdefFilter::match() method:
+
+\snippet annotatedurl/annotatedurl.cpp handleMessage 2
+
+If the messages have the correct format, the parsing continues.
+
 Because NFC messages are composed of several NDEF records, looping
 through all of the records allows the extraction of the 3 parameters
 to be displayed in the UI: the Uri, the Title and the Pixmap:
 
-\snippet annotatedurl/annotatedurl.cpp handleMessage 2
 \snippet annotatedurl/annotatedurl.cpp handleMessage 3
+\snippet annotatedurl/annotatedurl.cpp handleMessage 4
 
 Finally after having extracted the parameters of the NFC message the
 corresponding signal is emitted so that the UI can handle it.
 
-\snippet annotatedurl/annotatedurl.cpp handleMessage 4
+\snippet annotatedurl/annotatedurl.cpp handleMessage 5
 
 \section1 Adapter State Handling
 
diff --git a/examples/nfc/annotatedurl/main.cpp b/examples/nfc/annotatedurl/main.cpp
index 8134b002..52cb40aa 100644
--- a/examples/nfc/annotatedurl/main.cpp
+++ b/examples/nfc/annotatedurl/main.cpp
@@ -68,6 +68,8 @@ int main(int argc, char *argv[])
                      &mainWindow, &MainWindow::displayAnnotatedUrl);
     QObject::connect(&annotatedUrl, &AnnotatedUrl::nfcStateChanged,
                      &mainWindow, &MainWindow::nfcStateChanged);
+    QObject::connect(&annotatedUrl, &AnnotatedUrl::tagError,
+                     &mainWindow, &MainWindow::showTagError);
 
     annotatedUrl.startDetection();
     mainWindow.show();
diff --git a/examples/nfc/annotatedurl/mainwindow.cpp b/examples/nfc/annotatedurl/mainwindow.cpp
index e9863d03..6cac65c7 100644
--- a/examples/nfc/annotatedurl/mainwindow.cpp
+++ b/examples/nfc/annotatedurl/mainwindow.cpp
@@ -111,6 +111,18 @@ void MainWindow::nfcStateChanged(bool enabled)
     m_infoLabel->setText(text);
 }
 
+void MainWindow::showTagError(const QString &message)
+{
+    m_uriLabel->clear();
+    m_titleLabel->clear();
+    m_pixmap = QPixmap();
+    m_landscapeIconLabel->setVisible(false);
+    m_portraitIconLabel->setVisible(false);
+
+    m_infoLabel->setHidden(false);
+    m_infoLabel->setText(message);
+}
+
 void MainWindow::mouseReleaseEvent(QMouseEvent * /*event*/)
 {
     QDesktopServices::openUrl(QUrl(m_uriLabel->text()));
diff --git a/examples/nfc/annotatedurl/mainwindow.h b/examples/nfc/annotatedurl/mainwindow.h
index 1770c39f..c5e80cb5 100644
--- a/examples/nfc/annotatedurl/mainwindow.h
+++ b/examples/nfc/annotatedurl/mainwindow.h
@@ -71,6 +71,7 @@ public:
 public slots:
     void displayAnnotatedUrl(const QUrl &url, const QString &title, const QPixmap &pixmap);
     void nfcStateChanged(bool enabled);
+    void showTagError(const QString &message);
 
 protected:
     void mouseReleaseEvent(QMouseEvent *event) override;