Tree Model 2 Electric Boogaloo

This draws heavily on what @carlschwan did in network/neochat!1579 but I found it easier to start again and grab the bits as I needed them plus some other copying from what I did in the Space tree model.

From my current limited testing this seems to work nicely try and break it.

src/models/roomtreeitem.cpp

@@ -0,0 +1,100 @@
+// SPDX-FileCopyrightText: 2024 Carl Schwan <carl@carlschwan.eu>
+// SPDX-FileCopyrightText: 2024 James Graham <james.h.graham@protonmail.com>
+// SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only OR LicenseRef-KDE-Accepted-GPL
+
+#include "roomtreeitem.h"
+
+RoomTreeItem::RoomTreeItem(TreeData data, RoomTreeItem *parent)
+    : m_parentItem(parent)
+    , m_data(data)
+{
+}
+
+bool RoomTreeItem::operator==(const RoomTreeItem &other) const
+{
+    if (std::holds_alternative<NeoChatRoomType::Types>(m_data) && std::holds_alternative<NeoChatRoomType::Types>(other.data())) {
+        return std::get<NeoChatRoomType::Types>(m_data) == std::get<NeoChatRoomType::Types>(m_data);
+    }
+    if (std::holds_alternative<NeoChatRoom *>(m_data) && std::holds_alternative<NeoChatRoom *>(other.data())) {
+        return std::get<NeoChatRoom *>(m_data)->id() == std::get<NeoChatRoom *>(m_data)->id();
+    }
+    return false;
+}
+
+RoomTreeItem *RoomTreeItem::child(int row)
+{
+    return row >= 0 && row < childCount() ? m_children.at(row).get() : nullptr;
+}
+
+int RoomTreeItem::childCount() const
+{
+    return int(m_children.size());
+}
+
+bool RoomTreeItem::insertChild(std::unique_ptr<RoomTreeItem> newChild)
+{
+    if (newChild == nullptr) {
+        return false;
+    }
+
+    for (auto it = m_children.begin(), end = m_children.end(); it != end; ++it) {
+        if (*it == newChild) {
+            *it = std::move(newChild);
+            return true;
+        }
+    }
+
+    m_children.push_back(std::move(newChild));
+    return true;
+}
+
+bool RoomTreeItem::removeChild(int row)
+{
+    if (row < 0 || row >= childCount()) {
+        return false;
+    }
+    m_children.erase(m_children.begin() + row);
+    return true;
+}
+
+int RoomTreeItem::row() const
+{
+    if (m_parentItem == nullptr) {
+        return 0;
+    }
+
+    const auto it = std::find_if(m_parentItem->m_children.cbegin(), m_parentItem->m_children.cend(), [this](const std::unique_ptr<RoomTreeItem> &treeItem) {
+        return treeItem.get() == this;
+    });
+
+    if (it != m_parentItem->m_children.cend()) {
+        return std::distance(m_parentItem->m_children.cbegin(), it);
+    }
+    Q_ASSERT(false); // should not happen
+    return -1;
+}
+
+RoomTreeItem *RoomTreeItem::parentItem() const
+{
+    return m_parentItem;
+}
+
+RoomTreeItem::TreeData RoomTreeItem::data() const
+{
+    return m_data;
+}
+
+std::optional<int> RoomTreeItem::rowForRoom(Quotient::Room *room) const
+{
+    Q_ASSERT_X(std::holds_alternative<NeoChatRoomType::Types>(m_data), __FUNCTION__, "rowForRoom only works items for rooms not categories");
+
+    int i = 0;
+    for (const auto &child : m_children) {
+        if (std::get<NeoChatRoom *>(child->data()) == room) {
+            return i;
+        }
+        i++;
+    }
+
+    return std::nullopt;
+}