Link preview messageeventmodel parameters

This move the finding of links and the creation of a `linkpreviewer` into c++.

- The links are now extracted from the text in `texthandler`
- The `messageeventmodel` now creates and stores `linkpreviewers` for events that have links in the current room.

Two new model roles have been created to let a text delegate know when the link preview should be shown (`showLinkPreview`) and pass the link previewer (`linkPreviewer`). Empty link previewer are returned where link don't exist so the qml doesn't have to have checks for whether the parameters are undefined.

autotests/texthandlertest.cpp

@@ -64,6 +64,11 @@ private Q_SLOTS:
     void receiveRichEdited_data();
     void receiveRichEdited();
     void receiveLineSeparator();
+
+    void linkPreviewsMatch_data();
+    void linkPreviewsMatch();
+    void linkPreviewsReject_data();
+    void linkPreviewsReject();
 };
 
 #ifdef QUOTIENT_07
@@ -596,5 +601,52 @@ void TextHandlerTest::receiveLineSeparator()
     QCOMPARE(textHandler.handleRecievePlainText(Qt::PlainText, true), QStringLiteral("foo bar"));
 }
 
+void TextHandlerTest::linkPreviewsMatch_data()
+{
+    QTest::addColumn<QString>("testInputString");
+    QTest::addColumn<QList<QUrl>>("testOutputLinks");
+
+    QTest::newRow("plainHttps") << QStringLiteral("https://kde.org") << QList<QUrl>({QUrl("https://kde.org")});
+    QTest::newRow("richHttps") << QStringLiteral("<a href=\"https://kde.org\">Rich Link</a>") << QList<QUrl>({QUrl("https://kde.org")});
+    QTest::newRow("plainWww") << QStringLiteral("www.example.org") << QList<QUrl>({QUrl("www.example.org")});
+    QTest::newRow("multipleHttps") << QStringLiteral("https://kde.org www.example.org")
+                                   << QList<QUrl>({
+                                          QUrl("https://kde.org"),
+                                          QUrl("www.example.org"),
+                                      });
+}
+
+void TextHandlerTest::linkPreviewsMatch()
+{
+    QFETCH(QString, testInputString);
+    QFETCH(QList<QUrl>, testOutputLinks);
+
+    TextHandler testTextHandler;
+    testTextHandler.setData(testInputString);
+
+    QCOMPARE(testTextHandler.getLinkPreviews(), testOutputLinks);
+}
+
+void TextHandlerTest::linkPreviewsReject_data()
+{
+    QTest::addColumn<QString>("testInputString");
+    QTest::addColumn<QList<QUrl>>("testOutputLinks");
+
+    QTest::newRow("mxc") << QStringLiteral("mxc://example.org/SEsfnsuifSDFSSEF") << QList<QUrl>();
+    QTest::newRow("matrixTo") << QStringLiteral("https://matrix.to/#/@alice:example.org") << QList<QUrl>();
+    QTest::newRow("noSpace") << QStringLiteral("testhttps://kde.org") << QList<QUrl>();
+}
+
+void TextHandlerTest::linkPreviewsReject()
+{
+    QFETCH(QString, testInputString);
+    QFETCH(QList<QUrl>, testOutputLinks);
+
+    TextHandler testTextHandler;
+    testTextHandler.setData(testInputString);
+
+    QCOMPARE(testTextHandler.getLinkPreviews(), testOutputLinks);
+}
+
 QTEST_GUILESS_MAIN(TextHandlerTest)
 #include "texthandlertest.moc"

src/linkpreviewer.cpp

@@ -10,24 +10,13 @@
 
 using namespace Quotient;
 
-LinkPreviewer::LinkPreviewer(QObject *parent)
+LinkPreviewer::LinkPreviewer(QObject *parent, NeoChatRoom *room, QUrl url)
     : QObject(parent)
+    , m_currentRoom(room)
     , m_loaded(false)
+    , m_url(url)
 {
-}
+    loadUrlPreview();
-
-NeoChatRoom *LinkPreviewer::room() const
-{
-    return m_currentRoom;
-}
-
-void LinkPreviewer::setRoom(NeoChatRoom *room)
-{
-    if (room == m_currentRoom) {
-        return;
-    }
-    m_currentRoom = room;
-    Q_EMIT roomChanged();
 }
 
 bool LinkPreviewer::loaded() const
@@ -57,13 +46,19 @@ QUrl LinkPreviewer::url() const
 
 void LinkPreviewer::setUrl(QUrl url)
 {
-    if (url.scheme() == QStringLiteral("https")) {
+    if (url != m_url) {
+        m_url = url;
+        urlChanged();
+        loadUrlPreview();
+    }
+}
+
+void LinkPreviewer::loadUrlPreview()
+{
+    if (m_url.scheme() == QStringLiteral("https")) {
         m_loaded = false;
         Q_EMIT loadedChanged();
 
-        m_url = url;
-        Q_EMIT urlChanged();
-
         auto conn = m_currentRoom->connection();
         GetUrlPreviewJob *job = conn->callApi<GetUrlPreviewJob>(m_url.toString());
 

src/linkpreviewer.h

@@ -19,12 +19,6 @@ class NeoChatRoom;
 class LinkPreviewer : public QObject
 {
     Q_OBJECT
-
-    /**
-     * @brief The current room that the URL is from.
-     */
-    Q_PROPERTY(NeoChatRoom *room READ room WRITE setRoom NOTIFY roomChanged)
-
     /**
      * @brief The URL to get the preview for.
      */
@@ -51,10 +45,7 @@ class LinkPreviewer : public QObject
     Q_PROPERTY(QUrl imageSource READ imageSource NOTIFY imageSourceChanged)
 
 public:
-    explicit LinkPreviewer(QObject *parent = nullptr);
+    explicit LinkPreviewer(QObject *parent = nullptr, NeoChatRoom *room = nullptr, QUrl url = {});
-
-    [[nodiscard]] NeoChatRoom *room() const;
-    void setRoom(NeoChatRoom *room);
 
     [[nodiscard]] QUrl url() const;
     void setUrl(QUrl);
@@ -67,16 +58,18 @@ private:
     NeoChatRoom *m_currentRoom = nullptr;
 
     bool m_loaded;
-    QString m_title;
+    QString m_title = QString();
-    QString m_description;
+    QString m_description = QString();
-    QUrl m_imageSource;
+    QUrl m_imageSource = QUrl();
     QUrl m_url;
 
+    void loadUrlPreview();
+
 Q_SIGNALS:
-    void roomChanged();
     void loadedChanged();
     void titleChanged();
     void descriptionChanged();
     void imageSourceChanged();
     void urlChanged();
 };
+Q_DECLARE_METATYPE(LinkPreviewer *)

src/models/messageeventmodel.cpp

@@ -28,6 +28,7 @@
 #include <KLocalizedString>
 
 #include "neochatuser.h"
+#include "texthandler.h"
 
 using namespace Quotient;
 
@@ -45,6 +46,8 @@ QHash<int, QByteArray> MessageEventModel::roleNames() const
     roles[SpecialMarksRole] = "marks";
     roles[LongOperationRole] = "progressInfo";
     roles[EventResolvedTypeRole] = "eventResolvedType";
+    roles[ShowLinkPreviewRole] = "showLinkPreview";
+    roles[LinkPreviewRole] = "linkPreview";
     roles[MediaInfoRole] = "mediaInfo";
     roles[IsReplyRole] = "isReply";
     roles[ReplyAuthor] = "replyAuthor";
@@ -101,12 +104,20 @@ void MessageEventModel::setRoom(NeoChatRoom *room)
     beginResetModel();
     if (m_currentRoom) {
         m_currentRoom->disconnect(this);
+        m_linkPreviewers.clear();
     }
 
     m_currentRoom = room;
     if (room) {
         m_lastReadEventIndex = QPersistentModelIndex(QModelIndex());
         room->setDisplayed();
+
+        for (auto event = m_currentRoom->messageEvents().begin(); event != m_currentRoom->messageEvents().end(); ++event) {
+            if (auto e = &*event->viewAs<RoomMessageEvent>()) {
+                createLinkPreviewerForEvent(e);
+            }
+        }
+
         if (m_currentRoom->timelineSize() < 10 && !room->allHistoryLoaded()) {
             room->getPreviousContent(50);
         }
@@ -118,10 +129,12 @@ void MessageEventModel::setRoom(NeoChatRoom *room)
 
         using namespace Quotient;
         connect(m_currentRoom, &Room::aboutToAddNewMessages, this, [this](RoomEventsRange events) {
-            if (NeoChatConfig::self()->showFancyEffects()) {
+            for (auto &&event : events) {
-                for (auto &event : events) {
+                const RoomMessageEvent *message = dynamic_cast<RoomMessageEvent *>(event.get());
-                    RoomMessageEvent *message = dynamic_cast<RoomMessageEvent *>(event.get());
+                if (message != nullptr) {
-                    if (message) {
+                    createLinkPreviewerForEvent(message);
+
+                    if (NeoChatConfig::self()->showFancyEffects()) {
                         QString planBody = message->plainBody();
                         // snowflake
                         const QString snowlakeEmoji = QString::fromUtf8("\xE2\x9D\x84");
@@ -155,6 +168,12 @@ void MessageEventModel::setRoom(NeoChatRoom *room)
             beginInsertRows({}, timelineBaseIndex(), timelineBaseIndex() + int(events.size()) - 1);
         });
         connect(m_currentRoom, &Room::aboutToAddHistoricalMessages, this, [this](RoomEventsRange events) {
+            for (auto &event : events) {
+                RoomMessageEvent *message = dynamic_cast<RoomMessageEvent *>(event.get());
+                if (message) {
+                    createLinkPreviewerForEvent(message);
+                }
+            }
             if (rowCount() > 0) {
                 rowBelowInserted = rowCount() - 1; // See #312
             }
@@ -455,6 +474,8 @@ inline QVariantMap userInContext(NeoChatUser *user, NeoChatRoom *room)
     };
 }
 
+static LinkPreviewer *emptyLinkPreview = new LinkPreviewer;
+
 QVariant MessageEventModel::data(const QModelIndex &idx, int role) const
 {
     const auto row = idx.row();
@@ -684,6 +705,18 @@ QVariant MessageEventModel::data(const QModelIndex &idx, int role) const
         return role == TimeRole ? QVariant(ts) : renderDate(ts);
     }
 
+    if (role == ShowLinkPreviewRole) {
+        return m_linkPreviewers.contains(evt.id());
+    }
+
+    if (role == LinkPreviewRole) {
+        if (m_linkPreviewers.contains(evt.id())) {
+            return QVariant::fromValue<LinkPreviewer *>(m_linkPreviewers[evt.id()]);
+        } else {
+            return QVariant::fromValue<LinkPreviewer *>(emptyLinkPreview);
+        }
+    }
+
     if (role == MediaInfoRole) {
         return getMediaInfoForEvent(evt);
     }
@@ -1197,3 +1230,29 @@ QVariantMap MessageEventModel::getMediaInfoFromFileInfo(const EventContent::File
 
     return mediaInfo;
 }
+
+void MessageEventModel::createLinkPreviewerForEvent(const Quotient::RoomMessageEvent *event)
+{
+    if (m_linkPreviewers.contains(event->id())) {
+        return;
+    } else {
+        QString text;
+        if (event->hasTextContent()) {
+            auto textContent = static_cast<const EventContent::TextContent *>(event->content());
+            if (textContent) {
+                text = textContent->body;
+            } else {
+                text = event->plainBody();
+            }
+        } else {
+            text = event->plainBody();
+        }
+        TextHandler textHandler;
+        textHandler.setData(text);
+
+        QList<QUrl> links = textHandler.getLinkPreviews();
+        if (links.size() > 0) {
+            m_linkPreviewers[event->id()] = new LinkPreviewer(nullptr, m_currentRoom, links.size() > 0 ? links[0] : QUrl());
+        }
+    }
+}

src/models/messageeventmodel.h

@@ -5,6 +5,7 @@
 
 #include <QAbstractListModel>
 
+#include "linkpreviewer.h"
 #include "neochatroom.h"
 
 /**
@@ -70,6 +71,9 @@ public:
         FormattedBodyRole, /**< The formatted body of a rich message. */
         GenericDisplayRole, /**< A generic string based upon the message type. */
 
+        ShowLinkPreviewRole, /**< Whether a link preview should be shown. */
+        LinkPreviewRole, /**< The link preview details. */
+
         MediaInfoRole, /**< The media info for the event. */
         MimeTypeRole, /**< The mime type of the message's file or media. */
 
@@ -180,6 +184,8 @@ private:
     int rowBelowInserted = -1;
     bool movingEvent = false;
 
+    QMap<QString, LinkPreviewer *> m_linkPreviewers;
+
     [[nodiscard]] int timelineBaseIndex() const;
     [[nodiscard]] QDateTime makeMessageTimestamp(const Quotient::Room::rev_iter_t &baseIt) const;
     [[nodiscard]] static QString renderDate(const QDateTime &timestamp);
@@ -195,6 +201,7 @@ private:
     const Quotient::RoomEvent *getReplyForEvent(const Quotient::RoomEvent &event) const;
     QVariantMap getMediaInfoForEvent(const Quotient::RoomEvent &event) const;
     QVariantMap getMediaInfoFromFileInfo(const Quotient::EventContent::FileInfo *fileInfo, const QString &eventId, bool isThumbnail = false) const;
+    void createLinkPreviewerForEvent(const Quotient::RoomMessageEvent *event);
 
     std::vector<Quotient::event_ptr_tt<Quotient::RoomEvent>> m_extraEvents;
     // Hack to ensure that we don't call endInsertRows when we haven't called beginInsertRows

src/qml/Component/Timeline/LinkPreviewDelegate.qml

@@ -14,33 +14,16 @@ Loader {
     id: root
 
     /**
-     * @brief The room that the component is created in.
+     * @brief The link preview properties.
-     */
-    property var room
-
-    /**
-     * @brief Get a list of hyperlinks in the text.
      *
-     * User links i.e. anything starting with https://matrix.to are ignored.
+     * This is a list or object containing the following:
+     *  - url - The URL being previewed.
+     *  - loaded - Whether the URL preview has been loaded.
+     *  - title - the title of the URL preview.
+     *  - description - the description of the URL preview.
+     *  - imageSource - a source URL for the preview image.
      */
-    property var links: {
+    property var linkPreviewer
-        let matches = model.display.match(/\bhttps?:\/\/[^\s\<\>\"\']+/g)
-        if (matches && matches.length > 0) {
-            // don't show previews for room links or user mentions or custom emojis
-            return matches.filter(link => !(
-                link.includes("https://matrix.to") || link.includes("/_matrix/media/r0/download/")
-            ))
-            // remove ending fullstops and commas
-            .map(link => (link.length && [".", ","].includes(link[link.length-1])) ? link.substring(0, link.length-1) : link)
-        }
-        return []
-
-    }
-    LinkPreviewer {
-        id: linkPreviewer
-        room: root.room
-        url: root.links && root.links.length > 0 ? root.links[0] : ""
-    }
 
     /**
      * @brief Standard height for the link preview.
@@ -55,8 +38,7 @@ Loader {
      */
     property bool indicatorEnabled: false
 
-    active: !currentRoom.usesEncryption && model.display && links && links.length > 0 && currentRoom.urlPreviewEnabled
+    visible: active
-    visible: Config.showLinkPreview && active
     sourceComponent: linkPreviewer.loaded ? linkPreviewComponent : loadingComponent
 
     Component {
@@ -95,16 +77,16 @@ Loader {
                         wrapMode: Text.Wrap
                         textFormat: Text.RichText
                         text: "<style>
-    a {
+                            a {
-        text-decoration: none;
+                                text-decoration: none;
-    }
+                            }
-    </style>
+                            </style>
-                        <a href=\"" + root.links[0] + "\">" + (maximizeButton.checked ? linkPreviewer.title : titleTextMetrics.elidedText).replace("&ndash;", "—") + "</a>"
+                            <a href=\"" + root.linkPreviewer.url + "\">" + (maximizeButton.checked ? root.linkPreviewer.title : titleTextMetrics.elidedText).replace("&ndash;", "—") + "</a>"
                         onLinkActivated: RoomManager.openResource(link)
 
                         TextMetrics {
                             id: titleTextMetrics
-                            text: linkPreviewer.title
+                            text: root.linkPreviewer.title
                             font: linkPreviewTitle.font
                             elide: Text.ElideRight
                             elideWidth: (linkPreviewTitle.width - Kirigami.Units.largeSpacing * 2.5) * 3

src/qml/Component/Timeline/MessageDelegate.qml

@@ -35,7 +35,8 @@ TimelineContainer {
         }
         LinkPreviewDelegate {
             Layout.fillWidth: true
-            room: currentRoom
+            active: !currentRoom.usesEncryption && currentRoom.urlPreviewEnabled && Config.showLinkPreview && model.showLinkPreview
+            linkPreviewer: model.linkPreview
             indicatorEnabled: messageDelegate.isVisibleInTimeline()
         }
     }

src/texthandler.cpp

@@ -430,7 +430,21 @@ QString TextHandler::unescapeHtml(QString stringIn)
 QString TextHandler::linkifyUrls(QString stringIn)
 {
     stringIn = stringIn.replace(TextRegex::mxId, QStringLiteral(R"(\1<a href="https://matrix.to/#/\2">\2</a>)"));
-    stringIn.replace(TextRegex::fullUrl, QStringLiteral(R"(<a href="\1">\1</a>)"));
+    stringIn.replace(TextRegex::plainUrl, QStringLiteral(R"(<a href="\1">\1</a>)"));
     stringIn = stringIn.replace(TextRegex::emailAddress, QStringLiteral(R"(<a href="mailto:\2">\1\2</a>)"));
     return stringIn;
 }
+
+QList<QUrl> TextHandler::getLinkPreviews()
+{
+    auto data = m_data.remove(TextRegex::removeRichReply);
+    auto linksMatch = TextRegex::url.globalMatch(data);
+    QList<QUrl> links;
+    while (linksMatch.hasNext()) {
+        auto link = linksMatch.next().captured();
+        if (!link.contains(QStringLiteral("matrix.to"))) {
+            links += QUrl(link);
+        }
+    }
+    return links;
+}

src/texthandler.h

@@ -21,10 +21,13 @@ static const QRegularExpression codePill{QStringLiteral("<pre><code[^>]*>(.*?)</
 static const QRegularExpression userPill{QStringLiteral("(<a href=\"https://matrix.to/#/@.*?:.*?\">.*?</a>)"), QRegularExpression::DotMatchesEverythingOption};
 static const QRegularExpression strikethrough{QStringLiteral("<del>(.*?)</del>"), QRegularExpression::DotMatchesEverythingOption};
 static const QRegularExpression mxcImage{QStringLiteral(R"AAA(<img(.*?)src="mxc:\/\/(.*?)\/(.*?)"(.*?)>)AAA")};
-static const QRegularExpression fullUrl(
+static const QRegularExpression plainUrl(
     QStringLiteral(
         R"(<a.*?<\/a>(*SKIP)(*F)|\b((www\.(?!\.)(?!(\w|\.|-)+@)|(https?|ftp):(//)?\w|(magnet|matrix):)(&(?![lg]t;)|[^&\s<>'"])+(&(?![lg]t;)|[^&!,.\s<>'"\]):])))"),
     QRegularExpression::CaseInsensitiveOption | QRegularExpression::UseUnicodePropertiesOption);
+static const QRegularExpression
+    url(QStringLiteral(R"(\b((www\.(?!\.)(?!(\w|\.|-)+@)|https?:(//)?\w)(&(?![lg]t;)|[^&\s<>'"])+(&(?![lg]t;)|[^&!,.\s<>'"\]):])))"),
+        QRegularExpression::CaseInsensitiveOption | QRegularExpression::UseUnicodePropertiesOption);
 static const QRegularExpression emailAddress(QStringLiteral(R"(<a.*?<\/a>(*SKIP)(*F)|\b(mailto:)?((\w|\.|-)+@(\w|\.|-)+\.\w+\b))"),
                                              QRegularExpression::CaseInsensitiveOption | QRegularExpression::UseUnicodePropertiesOption);
 static const QRegularExpression mxId(QStringLiteral(R"((^|[][[:space:](){}`'";])([!#@][-a-z0-9_=#/.]{1,252}:\w(?:\w|\.|-)*\.\w+(?::\d{1,5})?))"),
@@ -109,6 +112,14 @@ public:
      */
     QString handleRecievePlainText(Qt::TextFormat inputFormat = Qt::PlainText, const bool &stripNewlines = false);
 
+    /**
+     * @brief Return a list of links that can be previewed.
+     *
+     * This function is designed to give only links that should be previewed so
+     * http, https or something starting with www.
+     */
+    QList<QUrl> getLinkPreviews();
+
 private:
     QString m_data;