debug_console: Improve rendering of non-x11 clients

We'd always get "0x0: something" where the 0x0 is the xcb_window which
obviously doesn't translate.

Instead show the class name so we can easily track what kind of object
we are dealing with.
It's an easy way to show which shell it's using on Wayland, will be
useful in other cases as well.

src/debug_console.cpp

@@ -1139,14 +1139,14 @@ QVariant DebugConsoleModel::propertyData(QObject *object, const QModelIndex &ind
 }
 
 template <class T>
-QVariant DebugConsoleModel::clientData(const QModelIndex &index, int role, const QVector<T*> clients) const
+QVariant DebugConsoleModel::clientData(const QModelIndex &index, int role, const QVector<T*> clients, const std::function<QString(T*)> &toString) const
 {
     if (index.row() >= clients.count()) {
         return QVariant();
     }
     auto c = clients.at(index.row());
     if (role == Qt::DisplayRole) {
-        return QStringLiteral("0x%1: %2").arg(c->window(), 0, 16).arg(c->caption());
+        return toString(c);
     } else if (role == Qt::DecorationRole) {
         return c->icon();
     }
@@ -1193,9 +1193,11 @@ QVariant DebugConsoleModel::data(const QModelIndex &index, int role) const
         if (index.column() != 0) {
             return QVariant();
         }
+
+        auto generic = [] (AbstractClient* c) { return c->caption() + QLatin1Char(' ') + QString::fromUtf8(c->metaObject()->className()); };
         switch (index.parent().internalId()) {
         case s_x11ClientId:
-            return clientData(index, role, m_x11Clients);
+            return clientData<X11Client>(index, role, m_x11Clients, [] (X11Client* c) { return QStringLiteral("0x%1: %2").arg(c->window(), 0, 16).arg(c->caption()); });
         case s_x11UnmanagedId: {
             if (index.row() >= m_unmanageds.count()) {
                 return QVariant();
@@ -1207,9 +1209,9 @@ QVariant DebugConsoleModel::data(const QModelIndex &index, int role) const
             break;
         }
         case s_waylandClientId:
-            return clientData(index, role, m_waylandClients);
+            return clientData<WaylandClient>(index, role, m_waylandClients, generic);
         case s_workspaceInternalId:
-            return clientData(index, role, m_internalClients);
+            return clientData<InternalClient>(index, role, m_internalClients, generic);
         default:
             break;
         }

src/debug_console.h

@@ -17,6 +17,7 @@
 #include <QAbstractItemModel>
 #include <QStyledItemDelegate>
 #include <QVector>
+#include <functional>
 
 class QTextEdit;
 
@@ -62,7 +63,7 @@ private:
     int propertyCount(const QModelIndex &parent, T *(DebugConsoleModel::*filter)(const QModelIndex&) const) const;
     QVariant propertyData(QObject *object, const QModelIndex &index, int role) const;
     template <class T>
-    QVariant clientData(const QModelIndex &index, int role, const QVector<T*> clients) const;
+    QVariant clientData(const QModelIndex &index, int role, const QVector<T*> clients, const std::function<QString(T*)> &toString) const;
     template <class T>
     void add(int parentRow, QVector<T*> &clients, T *client);
     template <class T>