Link Previews

Uses Matrix's preview API to generate embedded link previews.

Only title and description for now.

![image](/uploads/2c5d632480073fe54345cdbe22ea54dc/image.png)

imports/NeoChat/Component/Timeline/LinkPreviewDelegate.qml

@@ -0,0 +1,64 @@
+// SPDX-FileCopyrightText: 2022 Bharadwaj Raju <bharadwaj.raju777@protonmail.com>
+// SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-or-later OR LicenseRef-KDE-Accepted-GPL
+
+import QtQuick 2.15
+import QtQuick.Controls 2.15
+import QtQuick.Layouts 1.15
+
+import org.kde.kirigami 2.15 as Kirigami
+
+import org.kde.neochat 1.0
+
+RowLayout {
+    id: row
+    property var links: model.display.match(/(\bhttps?:\/\/[^\s\<\>\"\']*[^\s\<\>\"\'])/g)
+        // don't show previews for room links or user mentions
+        .filter(link => !link.includes("https://matrix.to"))
+        // remove ending fullstops and commas
+        .map(link => (link.length && [".", ","].includes(link[link.length-1])) ? link.substring(0, link.length-1) : link)
+    LinkPreviewer {
+        id: lp
+        url: links[0]
+    }
+    visible: lp.loaded && lp.title
+    Rectangle {
+        Layout.fillHeight: true
+        width: Kirigami.Units.smallSpacing
+        visible: lp.loaded && lp.title
+        color: Kirigami.Theme.highlightColor
+    }
+    Image {
+        visible: lp.imageSource
+        Layout.maximumHeight: Kirigami.Units.gridUnit * 5
+        Layout.maximumWidth: Kirigami.Units.gridUnit * 5
+        source: lp.imageSource.replace("mxc://", "image://mxc/")
+        fillMode: Image.PreserveAspectFit
+    }
+    ColumnLayout {
+        id: column
+        spacing: Kirigami.Units.smallSpacing
+        Kirigami.Heading {
+            Layout.maximumWidth: messageDelegate.bubbleMaxWidth
+            Layout.fillWidth: true
+            level: 4
+            wrapMode: Text.Wrap
+            textFormat: Text.RichText
+            text: "<style>
+a {
+    text-decoration: none;
+}
+</style>
+            <a href=\"" + links[0] + "\">" + lp.title.replace("&ndash;", "—") + "</a>"
+            visible: lp.loaded
+            onLinkActivated: RoomManager.openResource(link)
+        }
+        Label {
+            text: lp.description
+            Layout.maximumWidth: messageDelegate.bubbleMaxWidth
+            Layout.fillWidth: true
+            wrapMode: Text.Wrap
+            visible: lp.loaded && lp.description
+        }
+    }
+}
+

imports/NeoChat/Component/Timeline/MessageDelegate.qml

@@ -19,9 +19,22 @@ TimelineContainer {
     onReplyClicked: ListView.view.goToEvent(eventID)
     hoverComponent: hoverActions
 
-    innerObject: RichLabel {
-        id: label
-        isEmote: messageDelegate.isEmote
-        Layout.maximumWidth: messageDelegate.bubbleMaxWidth
+    innerObject: ColumnLayout {
+        RichLabel {
+            id: label
+            isEmote: messageDelegate.isEmote
+            Layout.maximumWidth: messageDelegate.bubbleMaxWidth
+        }
+        Loader {
+            id: linkPreviewLoader
+            Layout.rightMargin: Kirigami.Units.largeSpacing
+            Layout.leftMargin: Kirigami.Units.largeSpacing
+            height: active ? item.implicitHeight : 0
+            active: !currentRoom.usesEncryption && model.display && model.display.includes("http")
+            visible: active
+            sourceComponent: LinkPreviewDelegate {
+                anchors.verticalCenter: parent.verticalCenter
+            }
+        }
     }
 }

imports/NeoChat/Component/Timeline/qmldir

@@ -12,3 +12,4 @@ EncryptedDelegate 1.0 EncryptedDelegate.qml
 EventDelegate 1.0 EventDelegate.qml
 MessageDelegate 1.0 MessageDelegate.qml
 ReadMarkerDelegate 1.0 ReadMarkerDelegate.qml
+LinkPreviewDelegate 1.0 LinkPreviewDelegate.qml

res.qrc

@@ -40,6 +40,7 @@
         <file>imports/NeoChat/Component/Timeline/SectionDelegate.qml</file>
         <file>imports/NeoChat/Component/Timeline/VideoDelegate.qml</file>
         <file>imports/NeoChat/Component/Timeline/ReactionDelegate.qml</file>
+        <file>imports/NeoChat/Component/Timeline/LinkPreviewDelegate.qml</file>
         <file>imports/NeoChat/Component/Timeline/AudioDelegate.qml</file>
         <file>imports/NeoChat/Component/Timeline/FileDelegate.qml</file>
         <file>imports/NeoChat/Component/Timeline/ImageDelegate.qml</file>

src/CMakeLists.txt

@@ -39,6 +39,7 @@ add_library(neochat STATIC
     collapsestateproxymodel.cpp
     urlhelper.cpp
     windowcontroller.cpp
+    linkpreviewer.cpp
 )
 
 add_executable(neochat-app

src/linkpreviewer.cpp

@@ -0,0 +1,64 @@
+// SPDX-FileCopyrightText: 2022 Bharadwaj Raju <bharadwaj.raju777@protonmail.com>
+// SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-or-later OR LicenseRef-KDE-Accepted-GPL
+
+#include "linkpreviewer.h"
+
+#include "controller.h"
+
+LinkPreviewer::LinkPreviewer(QObject *parent)
+    : QObject(parent)
+    , m_loaded(false)
+{
+}
+
+bool LinkPreviewer::loaded() const
+{
+    return m_loaded;
+}
+
+QString LinkPreviewer::title() const
+{
+    return m_title;
+}
+
+QString LinkPreviewer::description() const
+{
+    return m_description;
+}
+
+QString LinkPreviewer::imageSource() const
+{
+    return m_imageSource;
+}
+
+QUrl LinkPreviewer::url() const
+{
+    return m_url;
+}
+
+void LinkPreviewer::setUrl(QUrl url)
+{
+    if (url.scheme() == QStringLiteral("https")) {
+        m_loaded = false;
+        Q_EMIT loadedChanged();
+
+        m_url = url;
+        Q_EMIT urlChanged();
+
+        auto conn = Controller::instance().activeConnection();
+
+        GetUrlPreviewJob *job = conn->callApi<GetUrlPreviewJob>(m_url.toString());
+
+        connect(job, &BaseJob::success, this, [this, job]() {
+            const auto json = job->jsonData();
+            m_title = json["og:title"].toString();
+            m_description = json["og:description"].toString();
+            m_imageSource = json["og:image"].toString();
+            m_loaded = true;
+            Q_EMIT titleChanged();
+            Q_EMIT descriptionChanged();
+            Q_EMIT imageSourceChanged();
+            Q_EMIT loadedChanged();
+        });
+    }
+}

src/linkpreviewer.h

@@ -0,0 +1,46 @@
+// SPDX-FileCopyrightText: 2022 Bharadwaj Raju <bharadwaj.raju777@protonmail.com>
+// SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-or-later OR LicenseRef-KDE-Accepted-GPL
+
+#pragma once
+
+#include <connection.h>
+#include <csapi/content-repo.h>
+
+#include <QObject>
+
+using namespace Quotient;
+
+class LinkPreviewer : public QObject
+{
+    Q_OBJECT
+    Q_PROPERTY(bool loaded READ loaded NOTIFY loadedChanged)
+    Q_PROPERTY(QString title READ title NOTIFY titleChanged)
+    Q_PROPERTY(QString description READ description NOTIFY descriptionChanged)
+    Q_PROPERTY(QString imageSource READ imageSource NOTIFY imageSourceChanged)
+    Q_PROPERTY(QUrl url READ url WRITE setUrl NOTIFY urlChanged)
+
+public:
+    explicit LinkPreviewer(QObject *parent = nullptr);
+
+    [[nodiscard]] bool loaded() const;
+    [[nodiscard]] QString title() const;
+    [[nodiscard]] QString description() const;
+    [[nodiscard]] QString imageSource() const;
+    [[nodiscard]] QUrl url() const;
+
+    void setUrl(QUrl);
+
+private:
+    bool m_loaded;
+    QString m_title;
+    QString m_description;
+    QString m_imageSource;
+    QUrl m_url;
+
+Q_SIGNALS:
+    void loadedChanged();
+    void titleChanged();
+    void descriptionChanged();
+    void imageSourceChanged();
+    void urlChanged();
+};

src/main.cpp

@@ -59,6 +59,7 @@
 #include "emojimodel.h"
 #include "filetypesingleton.h"
 #include "joinrulesevent.h"
+#include "linkpreviewer.h"
 #include "login.h"
 #include "matriximageprovider.h"
 #include "messageeventmodel.h"
@@ -213,6 +214,7 @@ int main(int argc, char *argv[])
     qmlRegisterType<SortFilterRoomListModel>("org.kde.neochat", 1, 0, "SortFilterRoomListModel");
     qmlRegisterType<SortFilterSpaceListModel>("org.kde.neochat", 1, 0, "SortFilterSpaceListModel");
     qmlRegisterType<DevicesModel>("org.kde.neochat", 1, 0, "DevicesModel");
+    qmlRegisterType<LinkPreviewer>("org.kde.neochat", 1, 0, "LinkPreviewer");
     qmlRegisterUncreatableType<RoomMessageEvent>("org.kde.neochat", 1, 0, "RoomMessageEvent", "ENUM");
     qmlRegisterUncreatableType<PushNotificationState>("org.kde.neochat", 1, 0, "PushNotificationState", "ENUM");
     qmlRegisterUncreatableType<NeoChatRoomType>("org.kde.neochat", 1, 0, "NeoChatRoomType", "ENUM");