1 files changed, 129 insertions, 0 deletions
diff --git a/src/ui/ClickDetector.cpp b/src/ui/ClickDetector.cpp
new file mode 100644
index 00000000..e873efd4
--- /dev/null
+++ b/src/ui/ClickDetector.cpp
@@ -0,0 +1,129 @@
+#include "cru/ui/ClickDetector.hpp"
+
+#include "cru/common/Logger.hpp"
+
+#include <optional>
+
+namespace cru::ui {
+ClickDetector::ClickDetector(Control* control) {
+  Expects(control);
+  control_ = control;
+
+  event_rovoker_guards_.push_back(
+      EventRevokerGuard(control->MouseEnterEvent()->Direct()->AddHandler(
+          [this](event::MouseEventArgs&) {
+            if (this->enable_) {
+              if (this->state_ == ClickState::PressInactive) {
+                if ((this->button_ & this->trigger_button_)) {
+                  this->SetState(ClickState::Press);
+                }
+              } else {
+                this->SetState(ClickState::Hover);
+              }
+            }
+          })));
+
+  event_rovoker_guards_.push_back(
+      EventRevokerGuard(control->MouseLeaveEvent()->Direct()->AddHandler(
+          [this](event::MouseEventArgs&) {
+            if (this->enable_) {
+              if (this->state_ == ClickState::Press) {
+                if ((this->button_ & this->trigger_button_)) {
+                  this->SetState(ClickState::PressInactive);
+                }
+              } else {
+                this->SetState(ClickState::None);
+              }
+            }
+          })));
+
+  event_rovoker_guards_.push_back(
+      EventRevokerGuard(control->MouseDownEvent()->Direct()->AddHandler(
+          [this](event::MouseButtonEventArgs& args) {
+            const auto button = args.GetButton();
+            if (this->enable_ && (button & this->trigger_button_) &&
+                this->state_ == ClickState::Hover) {
+              if (!this->control_->CaptureMouse()) {
+                log::Debug("Failed to capture mouse when begin click.");
+                return;
+              }
+              this->down_point_ = args.GetPoint();
+              this->button_ = button;
+              this->SetState(ClickState::Press);
+            }
+          })));
+
+  event_rovoker_guards_.push_back(
+      EventRevokerGuard(control->MouseUpEvent()->Direct()->AddHandler(
+          [this](event::MouseButtonEventArgs& args) {
+            const auto button = args.GetButton();
+            if (this->enable_ && (button & this->trigger_button_) &&
+                button == button_) {
+              if (this->state_ == ClickState::Press) {
+                this->SetState(ClickState::Hover);
+                this->event_.Raise(ClickEventArgs{this->control_,
+                                                  this->down_point_,
+                                                  args.GetPoint(), button});
+                this->control_->ReleaseMouse();
+              } else if (this->state_ == ClickState::PressInactive) {
+                this->SetState(ClickState::None);
+                this->control_->ReleaseMouse();
+              }
+            }
+          })));
+}  // namespace cru::ui
+
+void ClickDetector::SetEnabled(bool enable) {
+  if (enable == enable_) {
+    return;
+  }
+
+  enable_ = enable;
+  if (enable) {
+    SetState(control_->IsMouseOver() ? ClickState::Hover : ClickState::None);
+  } else {
+    if (state_ == ClickState::Press || state_ == ClickState::PressInactive) {
+      SetState(ClickState::None);
+      control_->ReleaseMouse();
+    } else if (state_ == ClickState::Hover) {
+      SetState(ClickState::None);
+    }
+  }
+}
+
+void ClickDetector::SetTriggerButton(MouseButton trigger_button) {
+  if (trigger_button == trigger_button_) {
+    return;
+  }
+
+  trigger_button_ = trigger_button;
+  if ((state_ == ClickState::Press || state_ == ClickState::PressInactive) &&
+      !(button_ & trigger_button)) {
+    SetState(control_->IsMouseOver() ? ClickState::Hover : ClickState::None);
+    control_->ReleaseMouse();
+  }
+}
+
+void ClickDetector::SetState(ClickState state) {
+#ifdef CRU_DEBUG
+  auto to_string = [](ClickState state) -> std::string_view {
+    switch (state) {
+      case ClickState::None:
+        return "None";
+      case ClickState::Hover:
+        return "Hover";
+      case ClickState::Press:
+        return "Press";
+      case ClickState::PressInactive:
+        return "PressInvactive";
+      default:
+        UnreachableCode();
+    }
+  };
+  log::Debug("Click state changed, new state: {}.", to_string(state));
+#endif
+
+  state_ = state;
+  state_change_event_.Raise(state);
+}
+}  // namespace cru::ui