Make it more obvious what tags the NFC poster example expects.

Task-number: QTBUG-53616
Change-Id: Ie3a87abc61100ac8fe0a5b671725f54ae28e1501
Reviewed-by: Martin Smith <martin.smith@theqtcompany.com>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>

3 files changed, 33 insertions, 2 deletions

diff --git a/examples/nfc/poster/doc/images/qml-poster-example.png b/examples/nfc/poster/doc/images/qml-poster-example.png
index d3ead72e..8ed2292c 100644
--- a/examples/nfc/poster/doc/images/qml-poster-example.png
+++ b/examples/nfc/poster/doc/images/qml-poster-example.png
diff --git a/examples/nfc/poster/doc/src/poster.qdoc b/examples/nfc/poster/doc/src/poster.qdoc
index a569f47a..26320f56 100644
--- a/examples/nfc/poster/doc/src/poster.qdoc
+++ b/examples/nfc/poster/doc/src/poster.qdoc
@@ -31,7 +31,7 @@
 \brief A QML example about reading and displaying NFC Data Exchange Format (NDEF) messages.
 
 The QML Poster example displays the contents of specifically formatted NFC Data
-Exchange Format (NDEF) messages read from an NFC Tag. The NDEF message should
+Exchange Format (NDEF) messages read from an NFC Tag. The NDEF message must
 contain a URI record, an optional \c image/* MIME record, and one or more
 localized Text records.
 
@@ -39,5 +39,24 @@ localized Text records.
 
 \include examples-run.qdocinc
 
+\section1 Applying NDEF Filters
+
+The example is designed to display the content of a very specific type of NFC tag.
+The tag must contain at least one URI record and one text record. If those two
+record types do not exist, nothing will happen. Such filtering is applied via the
+\l NearField type's filter property. The property accepts a list of \l NdefFilter objects.
+
+\snippet poster/poster.qml QML NDEF filtering
+
+\section1 Processing Found NDEF Messages
+
+Once an appropriate tag is found, the \l NearField::messageRecords property reflects the content.
+It transports the list of found NDEF records. The QML snippet below
+demonstrates how these records can be accessed:
+
+\snippet poster/poster.qml messageRecordsChanged 1
+\snippet poster/poster.qml messageRecordsChanged 2
+\snippet poster/poster.qml messageRecordsChanged 3
+
 \sa {Qt NFC}
 */
diff --git a/examples/nfc/poster/poster.qml b/examples/nfc/poster/poster.qml
index a70a998b..d57ed5d9 100644
--- a/examples/nfc/poster/poster.qml
+++ b/examples/nfc/poster/poster.qml
@@ -62,13 +62,18 @@ Rectangle {
             }
         }
 
+        //! [QML NDEF filtering]
         filter: [
             NdefFilter { type: "U"; typeNameFormat: NdefRecord.NfcRtd; maximum: 1 },
             NdefFilter { type: "T"; typeNameFormat: NdefRecord.NfcRtd },
             NdefFilter { typeNameFormat: NdefRecord.Mime; minimum: 0; maximum: 1 }
         ]
 
+        //! [QML NDEF filtering]
+
+        //! [messageRecordsChanged 1]
         onMessageRecordsChanged: {
+        //! [messageRecordsChanged 1]
             posterText.text = "";
             posterImage.source = "";
             posterUrl.text = "";
@@ -76,6 +81,7 @@ Rectangle {
             var currentLocaleMatch = NdefTextRecord.LocaleMatchedNone;
             var i;
             var found = false;
+        //! [messageRecordsChanged 2]
             for (i = 0; i < messageRecords.length; ++i) {
                 switch (messageRecords[i].typeNameFormat) {
                 case NdefRecord.NfcRtd:
@@ -102,18 +108,24 @@ Rectangle {
                 if (!found)
                     console.warn("Unknown NFC tag detected. Cannot display content.")
             }
+             //! [messageRecordsChanged 2]
 
             root.state = "show";
+        //! [messageRecordsChanged 3]
         }
+        //! [messageRecordsChanged 3]
     }
 
     Text {
         id: touchText
         anchors.horizontalCenter: parent.horizontalCenter
         anchors.verticalCenter: parent.verticalCenter
-        text: "Touch an NFC tag"
+        text: "Touch an NFC tag with at least one Text and one URI record."
         font.bold: true
         font.pointSize: 18
+        wrapMode: Text.WordWrap
+        width: root.width*0.75
+        horizontalAlignment: Text.AlignHCenter
     }
 
     Image {