Centralize legacy history bridge

src/legacy_history_services.cpp

@@ -0,0 +1,58 @@
+#include "pch.h"
+
+#include "legacy_history_services.h"
+
+#include "action.h"
+
+#include <limits>
+
+namespace pp::panopainter {
+namespace {
+
+[[nodiscard]] int saturated_history_metric(size_t value) noexcept
+{
+    constexpr auto max_int = static_cast<size_t>(std::numeric_limits<int>::max());
+    return value > max_int ? std::numeric_limits<int>::max() : static_cast<int>(value);
+}
+
+class LegacyHistoryUiServices final : public pp::app::HistoryUiServices {
+public:
+    void invoke_undo() override
+    {
+        ActionManager::undo();
+    }
+
+    void invoke_redo() override
+    {
+        ActionManager::redo();
+    }
+
+    void clear_history() override
+    {
+        ActionManager::clear();
+    }
+};
+
+} // namespace
+
+LegacyHistorySnapshot legacy_history_snapshot() noexcept
+{
+    return LegacyHistorySnapshot {
+        .undo_count = saturated_history_metric(ActionManager::I.m_actions.size()),
+        .redo_count = saturated_history_metric(ActionManager::I.m_redos.size()),
+        .memory_bytes = saturated_history_metric(ActionManager::I.m_memory),
+    };
+}
+
+pp::foundation::Status execute_legacy_history_plan(const pp::app::HistoryUiPlan& plan)
+{
+    LegacyHistoryUiServices services;
+    return pp::app::execute_history_ui_plan(plan, services);
+}
+
+void clear_legacy_history() noexcept
+{
+    ActionManager::clear();
+}
+
+} // namespace pp::panopainter