Add support for copying & deleting multiple messages at once

BUG: 496458

src/app/qml/RoomPage.qml

@@ -229,6 +229,58 @@ Kirigami.Page {
             Layout.fillWidth: true
         }
 
+        Kirigami.InlineMessage {
+            id: selectedMessagesControl
+
+            Layout.fillWidth: true
+
+            showCloseButton: false
+            visible: root.currentRoom?.selectedMessageCount > 0
+            position: Kirigami.InlineMessage.Position.Header
+            type: Kirigami.MessageType.Positive
+            icon.name: "edit-select-all-symbolic"
+
+            text: i18nc("@info", "Selected Messages: %1", root.currentRoom?.selectedMessageCount)
+
+            actions: [
+                Kirigami.Action {
+                    text: i18nc("@action:button", "Copy Conversation")
+                    icon.name: "edit-copy"
+                    onTriggered: {
+                        Clipboard.saveText(root.currentRoom.getFormattedSelectedMessages())
+                        showPassiveNotification(i18nc("@info", "Conversation copied to clipboard"));
+                    }
+                },
+                Kirigami.Action {
+                    text: i18nc("@action:button", "Delete Messages")
+                    icon.name: "trash-empty-symbolic"
+                    icon.color: Kirigami.Theme.negativeTextColor
+                    enabled: root.currentRoom?.canDeleteSelectedMessages
+                    onTriggered: {
+                        let dialog = pageStack.pushDialogLayer(Qt.createComponent('org.kde.neochat', 'ReasonDialog'), {
+                            title: i18nc("@title:dialog", "Remove Messages"),
+                            placeholder: i18nc("@info:placeholder", "Optionally give a reason for removing these messages"),
+                            actionText: i18nc("@action:button 'Remove' as in 'Remove these messages'", "Remove"),
+                            icon: "delete",
+                            reporting: false,
+                            connection: root.currentRoom.connection,
+                        }, {
+                            title: i18nc("@title:dialog", "Remove Messages"),
+                            width: Kirigami.Units.gridUnit * 25
+                        }) as ReasonDialog;
+                        dialog.accepted.connect(reason => {
+                            root.currentRoom.deleteSelectedMessages(reason);
+                        });
+                    }
+                },
+                Kirigami.Action {
+                    icon.name: "dialog-close"
+                    icon.color: Kirigami.Theme.negativeTextColor
+                    onTriggered: root.currentRoom.clearSelectedMessages()
+                }
+            ]
+        }
+
         Kirigami.InlineMessage {
             id: banner
 

src/app/roommanager.cpp

@@ -604,6 +604,7 @@ QString RoomManager::findSpaceIdForCurrentRoom() const
 void RoomManager::setCurrentRoom(const QString &roomId)
 {
     if (m_currentRoom != nullptr) {
+        m_currentRoom->clearSelectedMessages();
         m_currentRoom->disconnect(this);
     }