Fix the keyboard input related crash, that mostly happened on comms.

src/gui/gui2_canvas.cpp

@@ -88,3 +88,11 @@ void GuiCanvas::onClick(sf::Vector2f mouse_position)
 void GuiCanvas::onKey(sf::Keyboard::Key key, int unicode)
 {
 }
+
+void GuiCanvas::unfocusElement(GuiElement* element)
+{
+    if (focus_element == element)
+        focus_element = nullptr;
+    if (click_element == element)
+        click_element = nullptr;
+}

src/gui/gui2_canvas.h

@@ -23,6 +23,9 @@ class GuiCanvas : public Renderable, public GuiContainer, public InputEventHandl
 
     virtual void onClick(sf::Vector2f mouse_position);
     virtual void onKey(sf::Keyboard::Key key, int unicode);
+
+    //Called when an element is destroyed in this tree.
+    void unfocusElement(GuiElement* element);
 };
 
 #endif//GUI2_CANVAS_H

src/gui/gui2_element.cpp

@@ -1,4 +1,5 @@
 #include "gui2_element.h"
+#include "gui2_canvas.h"
 #include "main.h"
 
 GuiElement::GuiElement(GuiContainer* owner, string id)
@@ -10,7 +11,15 @@ GuiElement::GuiElement(GuiContainer* owner, string id)
 GuiElement::~GuiElement()
 {
     if (owner)
+    {
         owner->elements.remove(this);
+        //Find the owning cancas, as we need to remove ourselves if we are the focus or click element.
+        GuiCanvas* canvas = dynamic_cast<GuiCanvas*>(getTopLevelContainer());
+        if (canvas)
+        {
+            canvas->unfocusElement(this);
+        }
+    }
 }
 
 bool GuiElement::onMouseDown(sf::Vector2f position)
@@ -174,6 +183,14 @@ GuiContainer* GuiElement::getOwner()
     return owner;
 }
 
+GuiContainer* GuiElement::getTopLevelContainer()
+{
+    GuiContainer* top_level = owner;
+    while(dynamic_cast<GuiElement*>(top_level) != nullptr)
+        top_level = dynamic_cast<GuiElement*>(top_level)->getOwner();
+    return top_level;
+}
+
 void GuiElement::updateRect(sf::FloatRect window_rect)
 {
     sf::Vector2f local_size = size;

src/gui/gui2_element.h

@@ -77,6 +77,7 @@ class GuiElement : public GuiContainer
     sf::Vector2f getCenterPoint();
 
     GuiContainer* getOwner();
+    GuiContainer* getTopLevelContainer();
 
     friend class GuiContainer;
     friend class GuiCanvas;

src/gui/gui2_selector.cpp

@@ -26,10 +26,7 @@ GuiSelector::GuiSelector(GuiContainer* owner, string id, func_t func)
     });
     right->setPosition(0, 0, ATopRight)->setSize(GuiSizeMatchHeight, GuiSizeMax);
 
-    GuiContainer* top_level = owner;
-    while(dynamic_cast<GuiElement*>(top_level) != nullptr)
-        top_level = dynamic_cast<GuiElement*>(top_level)->getOwner();
-    popup = new GuiPanel(top_level, "");
+    popup = new GuiPanel(getTopLevelContainer(), "");
     popup->hide();
 }