Fixed unnecessarily complicated UI element focusing/defocusing logic.

Fixed slider bar size and positioning logic.
Ensure ListView item visibility also when pressing TAB to cycle focus.
Hide console if ESC pressed in the editor.

Bin/Data/Scripts/Editor/EditorUI.as

@@ -352,7 +352,9 @@ void HandleKeyDown(StringHash eventType, VariantMap& eventData)
     if (key == KEY_ESC)
     {
         UIElement@ front = ui.frontElement;
-        if (uiFileSelector !is null && front is uiFileSelector.window)
+        if (console.visible)
+            console.visible = false;
+        else if (uiFileSelector !is null && front is uiFileSelector.window)
             CloseFileSelector();
         else if (front is editorSettingsDialog || front is sceneWindow || front is nodeWindow)
             front.visible = false;

Engine/UI/LineEdit.cpp

@@ -123,7 +123,7 @@ void LineEdit::Update(float timeStep)
     }
    
     bool cursorVisible = false;
-    if (focus_)
+    if (HasFocus())
         cursorVisible = cursorBlinkTimer_ < 0.5f;
     cursor_->SetVisible(cursorVisible);
 }

Engine/UI/ListView.cpp

@@ -67,6 +67,7 @@ ListView::ListView(Context* context) :
     SetContentElement(container);
     
     SubscribeToEvent(E_UIMOUSECLICK, HANDLER(ListView, HandleUIMouseClick));
+    SubscribeToEvent(E_FOCUSCHANGED, HANDLER(ListView, HandleFocusChanged));
 }
 
 ListView::~ListView()
@@ -662,7 +663,7 @@ void ListView::UpdateSelectionEffect()
     {
         UIElement* item = GetItem(i);
         if (highlightMode_ != HM_NEVER && selections_.Find(i) != selections_.End())
-            item->SetSelected(focus_ || highlightMode_ == HM_ALWAYS);
+            item->SetSelected(HasFocus() || highlightMode_ == HM_ALWAYS);
         else
             item->SetSelected(false);
     }
@@ -670,7 +671,11 @@ void ListView::UpdateSelectionEffect()
 
 void ListView::EnsureItemVisibility(unsigned index)
 {
-    UIElement* item = GetItem(index);
+    EnsureItemVisibility(GetItem(index));
+}
+
+void ListView::EnsureItemVisibility(UIElement* item)
+{
     if (!item || !item->IsVisible())
         return;
     
@@ -777,3 +782,21 @@ void ListView::HandleUIMouseClick(StringHash eventType, VariantMap& eventData)
         }
     }
 }
+
+void ListView::HandleFocusChanged(StringHash eventType, VariantMap& eventData)
+{
+    using namespace FocusChanged;
+    
+    UIElement* element = static_cast<UIElement*>(eventData[P_ELEMENT].GetPtr());
+    while (element)
+    {
+        // If the focused element or its parent is in the list, scroll the list to make the item visible
+        UIElement* parent = element->GetParent();
+        if (parent == contentElement_)
+        {
+            EnsureItemVisibility(element);
+            return;
+        }
+        element = parent;
+    }
+}

Engine/UI/ListView.h

@@ -136,6 +136,8 @@ protected:
     void UpdateSelectionEffect();
     /// Ensure full visibility of the item.
     void EnsureItemVisibility(unsigned index);
+    /// Ensure full visibility of the item.
+    void EnsureItemVisibility(UIElement* item);
     
     /// Current selection.
     Set<unsigned> selections_;
@@ -157,4 +159,6 @@ protected:
 private:
     /// Handle global UI mouseclick to check for selection change.
     void HandleUIMouseClick(StringHash eventType, VariantMap& eventData);
+    /// Handle focus change to check whether an invisible item was focused.
+    void HandleFocusChanged(StringHash eventType, VariantMap& eventData);
 };

Engine/UI/Slider.cpp

@@ -104,7 +104,7 @@ void Slider::OnDragStart(const IntVector2& position, const IntVector2& screenPos
 
 void Slider::OnDragMove(const IntVector2& position, const IntVector2& screenPosition, int buttons, int qualifiers, Cursor* cursor)
 {
-    if (!dragSlider_)
+    if (!dragSlider_ || GetSize() == knob_->GetSize())
         return;
     
     float newValue = value_;
@@ -113,14 +113,14 @@ void Slider::OnDragMove(const IntVector2& position, const IntVector2& screenPosi
     if (orientation_ == O_HORIZONTAL)
     {
         int newX = Clamp(dragStartPosition_.x_ + delta.x_, 0, GetWidth() - knob_->GetWidth());
-        knob_->SetPosition(newX, dragStartPosition_.y_);
-        newValue = Clamp((float)newX * (range_ + 1.0f) / (float)GetWidth(), 0.0f, range_);
+        knob_->SetPosition(newX, 0);
+        newValue = (float)newX * range_ / (float)(GetWidth() - knob_->GetWidth());
     }
     else
     {
         int newY = Clamp(dragStartPosition_.y_ + delta.y_, 0, GetHeight() - knob_->GetHeight());
-        knob_->SetPosition(dragStartPosition_.x_, newY);
-        newValue = Clamp((float)newY * (range_ + 1.0f) / (float)GetHeight(), 0.0f, range_);
+        knob_->SetPosition(0, newY);
+        newValue = (float)newY * range_ / (float)(GetHeight() - knob_->GetHeight());
     }
     
     SetValue(newValue);
@@ -176,24 +176,28 @@ void Slider::ChangeValue(float delta)
 
 void Slider::UpdateSlider()
 {
-    if (orientation_ == O_HORIZONTAL)
+    const IntRect& border = knob_->GetBorder();
+    
+    if (range_ > 0.0f)
     {
-        float width = (float)GetWidth();
-        if (width < M_EPSILON)
-            return;
-        float sliderLength = width / (range_ + 1.0f);
-        float sliderPos = width * value_ / (range_ + 1.0f);
-        knob_->SetSize((int)sliderLength, GetHeight());
-        knob_->SetPosition(Clamp((int)(sliderPos + 0.5f), 0, GetWidth() - knob_->GetWidth()), 0);
+        if (orientation_ == O_HORIZONTAL)
+        {
+            int sliderLength = (int)Max((float)GetWidth() / (range_ + 1.0f), (float)(border.left_ + border.right_));
+            float sliderPos = (float)(GetWidth() - sliderLength) * value_ / range_;
+            knob_->SetSize(sliderLength, GetHeight());
+            knob_->SetPosition(Clamp((int)(sliderPos + 0.5f), 0, GetWidth() - knob_->GetWidth()), 0);
+        }
+        else
+        {
+            int sliderLength = (int)Max((float)GetHeight() / (range_ + 1.0f), (float)(border.top_ + border.bottom_));
+            float sliderPos = (float)(GetHeight() - sliderLength) * value_ / range_;
+            knob_->SetSize(GetWidth(), sliderLength);
+            knob_->SetPosition(0, Clamp((int)(sliderPos + 0.5f), 0, GetHeight() - knob_->GetHeight()));
+        }
     }
     else
     {
-        float height = (float)GetHeight();
-        if (height < M_EPSILON)
-            return;
-        float sliderLength = height / (range_ + 1.0f);
-        float sliderPos = height * value_ / (range_ + 1.0f);
-        knob_->SetSize(GetWidth(), (int)sliderLength);
-        knob_->SetPosition(0, Clamp((int)(sliderPos + 0.5f), 0, GetHeight() - knob_->GetHeight()));
+        knob_->SetSize(GetSize());
+        knob_->SetPosition(0, 0);
     }
 }

Engine/UI/UI.cpp

@@ -120,8 +120,9 @@ void UI::SetFocusElement(UIElement* element)
     if (element)
     {
         // Return if already has focus
-        if (element->HasFocus())
+        if (focusElement_ == element)
             return;
+        
         // If element can not be focused, and does not reset the focus either, search toward the parent
         for (;;)
         {
@@ -134,18 +135,28 @@ void UI::SetFocusElement(UIElement* element)
         }
     }
     
-    PODVector<UIElement*> allChildren = rootElement_->GetChildren(true);
-    
-    // Go through all elements to clear the old focus
-    for (PODVector<UIElement*>::Iterator i = allChildren.Begin(); i != allChildren.End(); ++i)
+    // Remove focus from the old element
+    if (focusElement_)
     {
-        UIElement* other = *i;
-        if (other != element && other->HasFocus())
-            other->SetFocus(false);
+        UIElement* oldFocusElement = focusElement_;
+        focusElement_.Reset();
+        oldFocusElement->OnDefocus();
+        
+        VariantMap focusEventData;
+        focusEventData[Defocused::P_ELEMENT] = oldFocusElement;
+        oldFocusElement->SendEvent(E_DEFOCUSED, focusEventData);
     }
     
+    // Then set focus to the new
     if (element)
-        element->SetFocus(true);
+    {
+        focusElement_ = element;
+        element->OnFocus();
+        
+        VariantMap focusEventData;
+        focusEventData[Focused::P_ELEMENT] = element;
+        element->SendEvent(E_FOCUSED, focusEventData);
+    }
     
     eventData[P_ELEMENT] = (void*)element;
     SendEvent(E_FOCUSCHANGED, eventData);
@@ -207,15 +218,6 @@ void UI::Update(float timeStep)
             cursor_->SetShape(dragElement_ == element ? CS_ACCEPTDROP : CS_REJECTDROP);
     }
     
-    // Defocus element now if should
-    if (defocusElement_)
-    {
-        // Do nothing if the focus element changed in the meanwhile
-        if (defocusElement_ == GetFocusElement())
-            SetFocusElement(0);
-        defocusElement_.Reset();
-    }
-    
     Update(timeStep, rootElement_);
 }
 
@@ -367,17 +369,7 @@ UIElement* UI::GetElementAt(int x, int y, bool activeOnly)
 
 UIElement* UI::GetFocusElement() const
 {
-    if (!rootElement_)
-        return 0;
-    
-    PODVector<UIElement*> allChildren = rootElement_->GetChildren(true);
-    for (PODVector<UIElement*>::Iterator i = allChildren.Begin(); i != allChildren.End(); ++i)
-    {
-        if ((*i)->HasFocus())
-            return *i;
-    }
-    
-    return 0;
+    return focusElement_;
 }
 
 UIElement* UI::GetFrontElement() const
@@ -671,8 +663,8 @@ void UI::HandleMouseButtonDown(StringHash eventType, VariantMap& eventData)
         }
         else
         {
-            // If clicked over no element, or a disabled element, try to lose focus
-            defocusElement_ = GetFocusElement();
+            // If clicked over no element, or a disabled element, lose focus
+            SetFocusElement(0);
         }
         
         using namespace UIMouseClick;
@@ -790,7 +782,7 @@ void UI::HandleKeyDown(StringHash eventType, VariantMap& eventData)
         }
         // Defocus the element
         else if (key == KEY_ESC && element->GetFocusMode() == FM_FOCUSABLE_DEFOCUSABLE)
-            defocusElement_ = element;
+            element->SetFocus(false);
         // If none of the special keys, pass the key to the focused element
         else
             element->OnKey(key, mouseButtons_, qualifiers_);

Engine/UI/UI.h

@@ -131,8 +131,8 @@ private:
     SharedPtr<Cursor> cursor_;
     /// UI element being dragged.
     WeakPtr<UIElement> dragElement_;
-    /// Element to defocus on the next update.
-    WeakPtr<UIElement> defocusElement_;
+    /// Currently focused element
+    WeakPtr<UIElement> focusElement_;
     /// UI rendering batches.
     PODVector<UIBatch> batches_;
     /// UI rendering quads.

Engine/UI/UIElement.cpp

@@ -25,6 +25,7 @@
 #include "Context.h"
 #include "ResourceCache.h"
 #include "StringUtils.h"
+#include "UI.h"
 #include "UIElement.h"
 #include "UIEvents.h"
 
@@ -77,7 +78,6 @@ UIElement::UIElement(Context* context) :
     clipChildren_(false),
     active_(false),
     focusMode_(FM_NOTFOCUSABLE),
-    focus_(false),
     selected_(false),
     visible_(true),
     hovering_(false),
@@ -526,20 +526,19 @@ void UIElement::SetFocus(bool enable)
     if (focusMode_ < FM_FOCUSABLE)
         enable = false;
     
-    if (enable != focus_)
+    UI* ui = GetSubsystem<UI>();
+    if (!ui)
+        return;
+    
+    if (enable)
     {
-        focus_ = enable;
-        
-        if (enable)
-            OnFocus();
-        else
-            OnDefocus();
-        
-        using namespace Focused;
-        
-        VariantMap eventData;
-        eventData[P_ELEMENT] = (void*)this;
-        SendEvent(focus_ ? E_FOCUSED : E_DEFOCUSED, eventData);
+        if (ui->GetFocusElement() != this)
+            ui->SetFocusElement(this);
+    }
+    else
+    {
+        if (ui->GetFocusElement() == this)
+            ui->SetFocusElement(0);
     }
 }
 
@@ -906,6 +905,15 @@ float UIElement::GetDerivedOpacity()
     return derivedOpacity_;
 }
 
+bool UIElement::HasFocus() const
+{
+    UI* ui = GetSubsystem<UI>();
+    if (!ui)
+        return false;
+    else
+        return ui->GetFocusElement() == this;
+}
+
 PODVector<UIElement*> UIElement::GetChildren(bool recursive) const
 {
     if (!recursive)

Engine/UI/UIElement.h

@@ -207,7 +207,7 @@ public:
     void SetClipChildren(bool enable);
     /// %Set whether reacts to input.
     void SetActive(bool enable);
-    /// %Set whether is focused. Usually called by UI. If called manually, other elements should be defocused.
+    /// %Set whether is focused. Only one element can be focused at a time.
     void SetFocus(bool enable);
     /// %Set selected mode. Actual meaning is element dependent, for example constant hover or pressed effect.
     void SetSelected(bool enable);
@@ -297,7 +297,7 @@ public:
     /// Return whether should clip child elements.
     bool GetClipChildren() const { return clipChildren_; }
     /// Return whether has focus.
-    bool HasFocus() const { return focus_; }
+    bool HasFocus() const;
     /// Return whether reacts to input.
     bool IsActive() const { return active_; }
     /// Return whether is selected. Actual meaning is element dependent.
@@ -381,8 +381,6 @@ protected:
     bool bringToBack_;
     /// Clip children flag.
     bool clipChildren_;
-    /// Focused flag.
-    bool focus_;
     /// Input enabled flag.
     bool active_;
     /// Selected flag.