Show a room preview in the join confirmation dialog

Requires MSC3266

Fixes #1129

src/ui/RoomSummary.cpp

@@ -0,0 +1,54 @@
+// SPDX-FileCopyrightText: 2022 Nheko Contributors
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "RoomSummary.h"
+
+#include <QMetaType>
+
+#include "ChatPage.h"
+#include "MatrixClient.h"
+
+RoomSummary::RoomSummary(std::string roomIdOrAlias_,
+                         std::vector<std::string> vias_,
+                         QString r_,
+                         QObject *p)
+  : QObject(p)
+  , roomIdOrAlias(std::move(roomIdOrAlias_))
+  , vias(std::move(vias_))
+  , reason_(std::move(r_))
+{
+    auto ctx = std::make_shared<RoomSummaryProxy>();
+
+    connect(ctx.get(), &RoomSummaryProxy::failed, this, [this]() {
+        loaded_ = true;
+        emit loaded();
+    });
+    connect(
+      ctx.get(), &RoomSummaryProxy::loaded, this, [this](const mtx::responses::PublicRoom &resp) {
+          loaded_ = true;
+          room    = resp;
+          emit loaded();
+      });
+
+    http::client()->get_summary(
+      roomIdOrAlias,
+      [proxy = std::move(ctx)](const mtx::responses::PublicRoom &room, mtx::http::RequestErr e) {
+          if (e) {
+              emit proxy->failed();
+          } else {
+              emit proxy->loaded(room);
+          }
+      },
+      vias);
+}
+
+void
+RoomSummary::join()
+{
+    if (isKnockOnly())
+        ChatPage::instance()->knockRoom(
+          QString::fromStdString(roomIdOrAlias), vias, reason_, false, false);
+    else
+        ChatPage::instance()->joinRoomVia(roomIdOrAlias, vias, false, reason_);
+}