Harden delete after free.

4 files changed, 73 insertions, 23 deletions

diff --git a/include/cru/ui/controls/Control.h b/include/cru/ui/controls/Control.h
index 684bc960..94de4cdc 100644
--- a/include/cru/ui/controls/Control.h
+++ b/include/cru/ui/controls/Control.h
@@ -1,12 +1,14 @@
 #pragma once
 #include "../Base.h"
 #include "../DeleteLater.h"
+#include "../events/KeyEventArgs.h"
+#include "../events/MouseWheelEventArgs.h"
 #include "../events/UiEvents.h"
+#include "../render/MeasureRequirement.h"
 #include "../render/RenderObject.h"
 #include "../style/StyleRuleSet.h"
-#include "cru/ui/events/KeyEventArgs.h"
-#include "cru/ui/events/MouseWheelEventArgs.h"
-#include "cru/ui/render/MeasureRequirement.h"
+
+#include <cru/base/SelfResolvable.h>
 
 namespace cru::ui::controls {
 
@@ -19,7 +21,9 @@ namespace cru::ui::controls {
  *  - RemoveChild(Control* child)
  * The last two methods are totally for convenient control tree management.
  */
-class CRU_UI_API Control : public Object, public DeleteLaterImpl {
+class CRU_UI_API Control : public Object,
+                           public DeleteLaterImpl,
+                           public SelfResolvable<Control> {
   friend class RootControl;
 
   CRU_DEFINE_CLASS_LOG_TAG("Control")
@@ -41,6 +45,7 @@ class CRU_UI_API Control : public Object, public DeleteLaterImpl {
 
   Control* GetParent() const { return parent_; }
   void SetParent(Control* parent);
+  bool HasAncestor(Control* control);
 
   virtual void ForEachChild(const std::function<void(Control*)>& predicate) = 0;
 
diff --git a/include/cru/ui/controls/Window.h b/include/cru/ui/controls/Window.h
index e25694ba..88320219 100644
--- a/include/cru/ui/controls/Window.h
+++ b/include/cru/ui/controls/Window.h
@@ -13,6 +13,8 @@ namespace cru::ui::controls {
 class CRU_UI_API Window
     : public LayoutControl<render::StackLayoutRenderObject> {
   CRU_DEFINE_CLASS_LOG_TAG("cru::ui::controls::Window")
+  friend Control;
+
  public:
   static constexpr std::string_view kControlType = "Window";
 
@@ -58,7 +60,6 @@ class CRU_UI_API Window
   void SetOverrideCursor(std::shared_ptr<platform::gui::ICursor> cursor);
 
   bool IsInEventHandling();
-  void UpdateCursor();
 
   CRU_DEFINE_EVENT(AfterLayout, std::nullptr_t)
 
@@ -104,7 +105,8 @@ class CRU_UI_API Window
     if (original_sender == nullptr || original_sender == last_receiver) return;
 
     std::string log = "Begin dispatching routed event " +
-                      (original_sender->*event_ptr)()->GetName() + ":\n\tTunnel:";
+                      (original_sender->*event_ptr)()->GetName() +
+                      ":\n\tTunnel:";
 
     Guard logging_guard([&] {
       log += "\nEnd dispatching routed event " +
@@ -112,11 +114,11 @@ class CRU_UI_API Window
       CRU_LOG_TAG_DEBUG("{}", log);
     });
 
-    std::vector<Control*> receive_list;
+    std::vector<ObjectResolver<Control>> receive_list;
 
     auto parent = original_sender;
     while (parent != last_receiver) {
-      receive_list.push_back(parent);
+      receive_list.push_back(parent->CreateResolver());
       parent = parent->GetParent();
     }
 
@@ -124,8 +126,12 @@ class CRU_UI_API Window
 
     // tunnel
     for (auto i = receive_list.crbegin(); i != receive_list.crend(); ++i) {
-      auto control = *i;
+      auto control = i->Resolve();
       log += " ";
+      if (!control) {
+        log += "(deleted)";
+        continue;
+      }
       log += control->GetDebugId();
       EventArgs event_args(control, original_sender,
                            std::forward<Args>(args)...);
@@ -140,8 +146,13 @@ class CRU_UI_API Window
     // bubble
     if (!handled) {
       log += "\n\tBubble:";
-      for (auto control : receive_list) {
+      for (auto resolver : receive_list) {
+        auto control = resolver.Resolve();
         log += " ";
+        if (!control) {
+          log += "(deleted)";
+          continue;
+        }
         log += control->GetDebugId();
         EventArgs event_args(control, original_sender,
                              std::forward<Args>(args)...);
@@ -155,8 +166,13 @@ class CRU_UI_API Window
 
     log += "\n\tDirect:";
     // direct
-    for (auto control : receive_list) {
+    for (auto resolver : receive_list) {
+      auto control = resolver.Resolve();
       log += " ";
+      if (!control) {
+        log += "(deleted)";
+        continue;
+      }
       log += control->GetDebugId();
       EventArgs event_args(control, original_sender,
                            std::forward<Args>(args)...);
@@ -164,6 +180,9 @@ class CRU_UI_API Window
     }
   }
 
+  void UpdateCursor();
+  void NotifyControlDestroyed(Control* control);
+
  private:
   int event_handling_count_;
 
diff --git a/src/ui/controls/Control.cpp b/src/ui/controls/Control.cpp
index e903b5b3..9c0fc537 100644
--- a/src/ui/controls/Control.cpp
+++ b/src/ui/controls/Control.cpp
@@ -1,4 +1,5 @@
 #include "cru/ui/controls/Control.h"
+#include "cru/base/log/Logger.h"
 #include "cru/ui/controls/Window.h"
 
 #include "cru/platform/gui/Cursor.h"
@@ -27,11 +28,14 @@ Control::Control() {
 Control::~Control() {
   if (auto window = GetWindow()) {
     if (window->IsInEventHandling()) {
-      // Don't delete control during event handling. Use DeleteLater.
-      std::terminate();
+      CRU_LOG_TAG_WARN(
+          "Better use delete later to delete control during event handling.");
     }
   }
 
+  if (auto window = GetWindow()) {
+    window->NotifyControlDestroyed(this);
+  }
   RemoveFromParent();
 }
 
@@ -58,6 +62,15 @@ void Control::SetParent(Control* parent) {
   OnParentChanged(old_parent, parent);
 }
 
+bool Control::HasAncestor(Control* control) {
+  auto parent = this;
+  while (parent) {
+    if (parent == control) return true;
+    parent = parent->GetParent();
+  }
+  return false;
+}
+
 void Control::RemoveFromParent() {
   if (parent_) {
     parent_->RemoveChild(this);
diff --git a/src/ui/controls/Window.cpp b/src/ui/controls/Window.cpp
index e6abc48d..c82b2485 100644
--- a/src/ui/controls/Window.cpp
+++ b/src/ui/controls/Window.cpp
@@ -265,16 +265,6 @@ void Window::SetOverrideCursor(std::shared_ptr<platform::gui::ICursor> cursor) {
 
 bool Window::IsInEventHandling() { return event_handling_count_; }
 
-void Window::UpdateCursor() {
-  if (override_cursor_) {
-    native_window_->SetCursor(override_cursor_);
-  } else {
-    const auto capture = GetMouseCaptureControl();
-    native_window_->SetCursor(
-        (capture ? capture : GetMouseHoverControl())->GetInheritedCursor());
-  }
-}
-
 void Window::OnNativeDestroy(platform::gui::INativeWindow* window,
                              std::nullptr_t) {
   CRU_UNUSED(window)
@@ -428,4 +418,27 @@ void Window::DispatchMouseHoverControlChangeEvent(Control* old_control,
   }
 }
 
+void Window::UpdateCursor() {
+  if (override_cursor_) {
+    native_window_->SetCursor(override_cursor_);
+  } else {
+    const auto capture = GetMouseCaptureControl();
+    native_window_->SetCursor(
+        (capture ? capture : GetMouseHoverControl())->GetInheritedCursor());
+  }
+}
+
+void Window::NotifyControlDestroyed(Control* control) {
+  if (focus_control_->HasAncestor(control)) {
+    focus_control_ = control->GetParent();
+  }
+
+  if (mouse_captured_control_->HasAncestor(control)) {
+    mouse_captured_control_ = control->GetParent();
+  }
+
+  if (mouse_hover_control_->HasAncestor(control)) {
+    mouse_hover_control_ = control->GetParent();
+  }
+}
 }  // namespace cru::ui::controls