...

4 files changed, 140 insertions, 100 deletions

diff --git a/include/cru/common/Event.hpp b/include/cru/common/Event.hpp
index 93ab9b7a..59502527 100644
--- a/include/cru/common/Event.hpp
+++ b/include/cru/common/Event.hpp
@@ -8,12 +8,16 @@
 #include <initializer_list>
 #include <memory>
 #include <utility>
+#include <variant>
 #include <vector>
 
 namespace cru {
 class EventRevoker;
 
 namespace details {
+template <class>
+inline constexpr bool always_false_v = false;
+
 // Base class of all Event<T...>.
 // It erases event args types and provides a
 // unified form to create event revoker and
@@ -25,10 +29,8 @@ class EventBase : public SelfResolvable<EventBase> {
   using EventHandlerToken = long;
 
   EventBase() {}
-  EventBase(const EventBase& other) = delete;
-  EventBase(EventBase&& other) = delete;
-  EventBase& operator=(const EventBase& other) = delete;
-  EventBase& operator=(EventBase&& other) = delete;
+  CRU_DELETE_COPY(EventBase)
+  CRU_DEFAULT_MOVE(EventBase)
   virtual ~EventBase() = default;
 
   // Remove the handler with the given token. If the token
@@ -85,59 +87,73 @@ using DeducedEventArgs = std::conditional_t<
     std::is_lvalue_reference_v<TRaw>, TRaw,
     std::conditional_t<std::is_scalar_v<TRaw>, TRaw, const TRaw&>>;
 
+struct IBaseEvent {
+ protected:
+  IBaseEvent() = default;
+  CRU_DELETE_COPY(IBaseEvent)
+  CRU_DEFAULT_MOVE(IBaseEvent)
+  ~IBaseEvent() = default;  // Note that user can't destroy a Event via IEvent.
+                            // So destructor should be protected.
+
+  using SpyOnlyHandler = std::function<void()>;
+
+ public:
+  virtual EventRevoker AddHandler(SpyOnlyHandler handler) = 0;
+};
+
 // Provides an interface of event.
 // IEvent only allow to add handler but not to raise the event. You may
 // want to create an Event object and expose IEvent only so users won't
 // be able to emit the event.
 template <typename TEventArgs>
-struct IEvent {
+struct IEvent : virtual IBaseEvent {
  public:
   using EventArgs = DeducedEventArgs<TEventArgs>;
   using EventHandler = std::function<void(EventArgs)>;
+  using HandlerVariant = std::variant<SpyOnlyHandler, EventHandler>;
 
  protected:
   IEvent() = default;
-  IEvent(const IEvent& other) = delete;
-  IEvent(IEvent&& other) = delete;
-  IEvent& operator=(const IEvent& other) = delete;
-  IEvent& operator=(IEvent&& other) = delete;
+  CRU_DELETE_COPY(IEvent)
+  CRU_DEFAULT_MOVE(IEvent)
   ~IEvent() = default;  // Note that user can't destroy a Event via IEvent. So
                         // destructor should be protected.
 
  public:
-  virtual EventRevoker AddHandler(const EventHandler& handler) = 0;
-  virtual EventRevoker AddHandler(EventHandler&& handler) = 0;
+  virtual EventRevoker AddHandler(EventHandler handler) = 0;
 };
 
 // A non-copyable non-movable Event class.
 // It stores a list of event handlers.
 template <typename TEventArgs>
 class Event : public details::EventBase, public IEvent<TEventArgs> {
+  using typename IBaseEvent::SpyOnlyHandler;
   using typename IEvent<TEventArgs>::EventHandler;
+  using typename IEvent<TEventArgs>::HandlerVariant;
 
  private:
   struct HandlerData {
     HandlerData(EventHandlerToken token, EventHandler handler)
         : token(token), handler(handler) {}
+    HandlerData(EventHandlerToken token, SpyOnlyHandler handler)
+        : token(token), handler(handler) {}
     EventHandlerToken token;
-    EventHandler handler;
+    HandlerVariant handler;
   };
 
  public:
   Event() = default;
-  Event(const Event&) = delete;
-  Event& operator=(const Event&) = delete;
-  Event(Event&&) = delete;
-  Event& operator=(Event&&) = delete;
+  CRU_DELETE_COPY(Event)
+  CRU_DEFAULT_MOVE(Event)
   ~Event() = default;
 
-  EventRevoker AddHandler(const EventHandler& handler) override {
+  EventRevoker AddHandler(SpyOnlyHandler handler) override {
     const auto token = current_token_++;
-    this->handler_data_list_.emplace_back(token, handler);
+    this->handler_data_list_.emplace_back(token, std::move(handler));
     return CreateRevoker(token);
   }
 
-  EventRevoker AddHandler(EventHandler&& handler) override {
+  EventRevoker AddHandler(EventHandler handler) override {
     const auto token = current_token_++;
     this->handler_data_list_.emplace_back(token, std::move(handler));
     return CreateRevoker(token);
@@ -150,13 +166,25 @@ class Event : public details::EventBase, public IEvent<TEventArgs> {
   // is called, so even if you delete a handler during this period, all handlers
   // in the snapshot will be executed.
   void Raise(typename IEvent<TEventArgs>::EventArgs args) {
-    std::vector<EventHandler> handlers;
+    std::vector<HandlerVariant> handlers;
     handlers.reserve(this->handler_data_list_.size());
     for (const auto& data : this->handler_data_list_) {
       handlers.push_back(data.handler);
     }
-    for (const auto& handler : handlers) {
-      handler(args);
+    for (const auto& handler_variant : handlers) {
+      std::visit(
+          [&args](auto&& handler) {
+            using T = std::decay_t<decltype(handler)>;
+            if constexpr (std::is_same_v<T, SpyOnlyHandler>) {
+              handler();
+            } else if constexpr (std::is_same_v<T, EventHandler>) {
+              handler(args);
+            } else {
+              static_assert(details::always_false_v<T>,
+                            "non-exhaustive visitor!");
+            }
+          },
+          handler_variant);
     }
   }
 
diff --git a/include/cru/common/SelfResolvable.hpp b/include/cru/common/SelfResolvable.hpp
index 94f3ae87..eaa4ce34 100644
--- a/include/cru/common/SelfResolvable.hpp
+++ b/include/cru/common/SelfResolvable.hpp
@@ -39,9 +39,27 @@ class SelfResolvable {
   SelfResolvable() : resolver_(new T*(static_cast<T*>(this))) {}
   SelfResolvable(const SelfResolvable&) = delete;
   SelfResolvable& operator=(const SelfResolvable&) = delete;
-  SelfResolvable(SelfResolvable&&) = delete;
-  SelfResolvable& operator=(SelfResolvable&&) = delete;
-  virtual ~SelfResolvable() { (*resolver_) = nullptr; }
+
+  // Resolvers to old object will resolve to new object.
+  SelfResolvable(SelfResolvable&& other)
+      : resolver_(std::move(other.resolver_)) {
+    (*resolver_) = static_cast<T*>(this);
+  }
+
+  // Old resolvers for this object will resolve to nullptr.
+  // Other's resolvers will now resolve to this.
+  SelfResolvable& operator=(SelfResolvable&& other) {
+    if (this != &other) {
+      (*resolver_) = nullptr;
+      resolver_ = std::move(other.resolver_);
+      (*resolver_) = static_cast<T*>(this);
+    }
+    return *this;
+  }
+
+  virtual ~SelfResolvable() {
+    if (resolver_ != nullptr) (*resolver_) = nullptr;
+  }
 
   ObjectResolver<T> CreateResolver() { return ObjectResolver<T>(resolver_); }
 
diff --git a/include/cru/ui/style/Condition.hpp b/include/cru/ui/style/Condition.hpp
new file mode 100644
index 00000000..b88a338f
--- /dev/null
+++ b/include/cru/ui/style/Condition.hpp
@@ -0,0 +1,69 @@
+#pragma once
+#include "../Base.hpp"
+#include "cru/common/Base.hpp"
+#include "cru/common/Event.hpp"
+#include "cru/ui/controls/IClickableControl.hpp"
+#include "cru/ui/helper/ClickDetector.hpp"
+
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+namespace cru::ui::style {
+class Condition {
+ public:
+  virtual ~Condition() = default;
+
+  virtual std::vector<IBaseEvent*> ChangeOn(
+      controls::Control* control) const = 0;
+  virtual bool Judge(controls::Control* control) const = 0;
+};
+
+class CompoundCondition : public Condition {
+ public:
+  explicit CompoundCondition(std::vector<Condition*> conditions);
+
+  const std::vector<Condition*>& GetConditions() const { return conditions_; }
+
+  std::vector<IBaseEvent*> ChangeOn(controls::Control* control) const override;
+
+ private:
+  std::vector<Condition*> conditions_;
+};
+
+class AndCondition : public CompoundCondition {
+ public:
+  using CompoundCondition::CompoundCondition;
+
+  bool Judge(controls::Control* control) const override;
+};
+
+class OrCondition : public CompoundCondition {
+ public:
+  using CompoundCondition::CompoundCondition;
+
+  bool Judge(controls::Control* control) const override;
+};
+
+class FocusCondition : public Condition {
+ public:
+  explicit FocusCondition(bool has_focus);
+
+  std::vector<IBaseEvent*> ChangeOn(controls::Control* control) const override;
+  bool Judge(controls::Control* control) const override;
+
+ private:
+  bool has_focus_;
+};
+
+class ClickStateCondition : public Condition {
+ public:
+  explicit ClickStateCondition(helper::ClickState click_state);
+
+  std::vector<IBaseEvent*> ChangeOn(controls::Control* control) const override;
+  bool Judge(controls::Control* control) const override;
+
+ private:
+  helper::ClickState click_state_;
+};
+}  // namespace cru::ui::style
diff --git a/include/cru/ui/style/Trigger.hpp b/include/cru/ui/style/Trigger.hpp
deleted file mode 100644
index ab012a3e..00000000
--- a/include/cru/ui/style/Trigger.hpp
+++ /dev/null
@@ -1,75 +0,0 @@
-#pragma once
-#include "../Base.hpp"
-#include "cru/common/Base.hpp"
-#include "cru/common/Event.hpp"
-#include "cru/ui/controls/IClickableControl.hpp"
-#include "cru/ui/helper/ClickDetector.hpp"
-
-#include <utility>
-#include <vector>
-
-namespace cru::ui::style {
-class Trigger {
- public:
-  virtual ~Trigger() = default;
-
-  bool GetState() const { return current_; }
-  IEvent<bool>* ChangeEvent() { return &change_event_; }
-
- protected:
-  void Raise(bool value);
-
- private:
-  bool current_ = false;
-  Event<bool> change_event_;
-
- protected:
-  EventRevokerListGuard guard_;
-};
-
-class CompoundTrigger : public Trigger {
- public:
-  explicit CompoundTrigger(std::vector<Trigger*> triggers);
-
-  const std::vector<Trigger*>& GetTriggers() const { return triggers_; }
-
- protected:
-  virtual bool CalculateState(const std::vector<Trigger*>& triggers) const = 0;
-
- private:
-  std::vector<Trigger*> triggers_;
-};
-
-class AndTrigger : public CompoundTrigger {
- public:
-  using CompoundTrigger::CompoundTrigger;
-
- protected:
-  bool CalculateState(const std::vector<Trigger*>& triggers) const override;
-};
-
-class OrTrigger : public CompoundTrigger {
- public:
-  using CompoundTrigger::CompoundTrigger;
-
- protected:
-  bool CalculateState(const std::vector<Trigger*>& triggers) const override;
-};
-
-class FocusTrigger : public Trigger {
- public:
-  FocusTrigger(controls::Control* control, bool has_focus);
-
- private:
-  bool has_focus_;
-};
-
-class ClickStateTrigger : public Trigger {
- public:
-  ClickStateTrigger(controls::IClickableControl* control,
-                    helper::ClickState click_state);
-
- private:
-  helper::ClickState click_state_;
-};
-}  // namespace cru::ui::style