thunder-engine · eprikazchikov · Mar 20, 2026 · Mar 17, 2026
diff --git a/engine/includes/components/transform.h b/engine/includes/components/transform.h
@@ -43,7 +43,7 @@ class ENGINE_EXPORT Transform : public Component {
     void setScale(const Vector3 &scale);
 
     Transform *parentTransform() const;
-    void setParentTransform(Transform *parent, bool force = false);
+    virtual void setParentTransform(Transform *parent, bool force = false);
 
     const Matrix4 &localTransform() const;
     const Matrix4 &worldTransform() const;

diff --git a/modules/uikit/includes/components/layout.h b/modules/uikit/includes/components/layout.h
@@ -33,7 +33,7 @@ class UIKIT_EXPORT Layout {
 
     void invalidate();
 
-    void solveItemsDimension(int availableSpace, bool horizontal);
+    void solveItemsDimension(float availableSpace, bool horizontal);
     void solveItemsPosition(float height, const Vector2 &offset);
 
 protected:

diff --git a/modules/uikit/includes/components/recttransform.h b/modules/uikit/includes/components/recttransform.h
@@ -91,6 +91,8 @@ class UIKIT_EXPORT RectTransform : public Transform {
 
     Vector4 scissorArea() const;
 
+    void setParentTransform(Transform *parent, bool force = false) override;
+
 private:
     friend class UikitSuite::RectTransformTest;
     friend class Layout;

diff --git a/modules/uikit/includes/components/splitter.h b/modules/uikit/includes/components/splitter.h
@@ -0,0 +1,50 @@
+#ifndef SPLITTER_H
+#define SPLITTER_H
+
+#include "frame.h"
+
+class UIKIT_EXPORT Splitter : public Frame {
+    A_OBJECT(Splitter, Frame, Components/UI)
+
+    A_NOPROPERTIES()
+    A_NOMETHODS()
+    A_NOENUMS()
+
+public:
+    Splitter();
+
+    int handleWidth();
+    void setHandleWidth(int width);
+
+    int orentation();
+    void setOrientation(int orientation);
+
+    void addWidget(Widget *widget);
+
+    int count();
+
+    int indexOf(Widget *widget);
+
+    void insertWidget(int index, Widget *widget);
+
+    Widget *replaceWidget(int index, Widget *widget);
+
+    Widget *widget(int index);
+
+protected:
+    void update() override;
+
+    void resizeWidget(int index, int orientation, float delta);
+
+    void childAdded(RectTransform *rect) const override;
+
+    void composeComponent() override;
+
+protected:
+    float m_savedPosition;
+
+    int m_index;
+
+};
+
+#endif // SPLITTER_H
diff --git a/modules/uikit/includes/components/widget.h b/modules/uikit/includes/components/widget.h
@@ -79,16 +79,19 @@ class UIKIT_EXPORT Widget : public NativeBehaviour {
 
     void updateStyleProperty(const TString &name, const float *v, int32_t size);
 
-private:
-    void addStyleRules(const std::map<TString, TString> &rules, uint32_t weight);
-
-    void setSystem(ObjectSystem *system) override;
+protected:
+    virtual void childAdded(RectTransform *child) const;
 
 protected:
     std::map<TString, std::pair<uint32_t, TString>> m_styleRules;
 
     std::list<Widget *> m_childWidgets;
 
+private:
+    void addStyleRules(const std::map<TString, TString> &rules, uint32_t weight);
+
+    void setSystem(ObjectSystem *system) override;
+
 private:
     friend class GuiLayer;
     friend class RectTransform;

diff --git a/modules/uikit/includes/editor/widgetcontroller.h b/modules/uikit/includes/editor/widgetcontroller.h
@@ -36,8 +36,6 @@ class WidgetController : public CameraController {
 
     UndoStack *undoRedo() const { return m_editor->undoRedo(); }
 
-    static TString findFreeObjectName(const TString &name, Object *parent);
-
 signals:
     void sceneUpdated();
     void objectsSelected(Object::ObjectList objects);

diff --git a/modules/uikit/src/components/layout.cpp b/modules/uikit/src/components/layout.cpp
@@ -195,7 +195,7 @@ void Layout::invalidate() {
 /*!
     \internal
 */
-void Layout::solveItemsDimension(int availableSpace, bool horizontal) {
+void Layout::solveItemsDimension(float availableSpace, bool horizontal) {
     if(m_orientation == Widget::Vertical) {
         if(horizontal) {
             for(auto it : m_items) {
@@ -222,15 +222,17 @@ void Layout::solveItemsDimension(int availableSpace, bool horizontal) {
         }
     }
 
-    int totalPref = 0;
+    float totalPref = 0.0f;
     int expandingCount = 0;
     int preferredCount = 0;
     int fixedCount = 0;
 
+    std::list<float> sizes;
+
     for(auto it : m_items) {
         if(it->isEnabled()) {
             RectTransform::SizePolicy policy = horizontal ? it->horizontalPolicy() : it->verticalPolicy();
-            int pref = horizontal ? it->size().x : it->size().y;
+            float pref = horizontal ? it->size().x : it->size().y;
             Vector4 margin(it->margin());
             pref += horizontal ? (margin.w + margin.y) : (margin.x + margin.z);
 
@@ -239,7 +241,7 @@ void Layout::solveItemsDimension(int availableSpace, bool horizontal) {
             switch(policy) {
                 case RectTransform::Fixed: fixedCount++; break;
                 case RectTransform::Preferred: preferredCount++; break;
-                case RectTransform::Expanding: expandingCount++; break;
+                case RectTransform::Expanding: expandingCount++; sizes.push_back(pref); break;
                 default: break;
             }
         }
@@ -249,17 +251,29 @@ void Layout::solveItemsDimension(int availableSpace, bool horizontal) {
 
     totalPref += spacesCount * m_spacing;
 
+    auto size = sizes.begin();
+    std::list<float> weights;
+    for(auto it : m_items) {
+        if(it->isEnabled()) {
+            RectTransform::SizePolicy policy = horizontal ? it->horizontalPolicy() : it->verticalPolicy();
+            if(policy == RectTransform::Expanding) {
+                float weight = (*size) / totalPref;
+                weights.push_back(weight);
+                ++size;
+            }
+        }
+    }
+
     if(availableSpace <= totalPref) { // Need to reduce size of widgets
-        int remainingSpace = availableSpace;
+        float remainingSpace = availableSpace;
 
         for(auto it : m_items) {
             if(it->isEnabled()) {
                 RectTransform::SizePolicy policy = horizontal ? it->horizontalPolicy() : it->verticalPolicy();
-                if(policy == RectTransform::Fixed) {
-                    int pref = horizontal ? it->size().x : it->size().y;
+                if(policy == RectTransform::Fixed || policy == RectTransform::Preferred) {
+                    float pref = horizontal ? it->size().x : it->size().y;
                     Vector4 margin(it->margin());
                     pref += horizontal ? (margin.w + margin.y) : (margin.x + margin.z);
-
                     remainingSpace -= pref;
                 }
             }
@@ -268,46 +282,42 @@ void Layout::solveItemsDimension(int availableSpace, bool horizontal) {
         remainingSpace -= spacesCount * m_spacing;
 
         if(expandingCount > 0 && remainingSpace > 0) {
-            int spacePerFlexible = remainingSpace / expandingCount;
-
+            auto weight = weights.begin();
             for(auto it : m_items) {
                 if(it->isEnabled()) {
                     RectTransform::SizePolicy policy = horizontal ? it->horizontalPolicy() : it->verticalPolicy();
                     if(policy == RectTransform::Expanding) {
                         Vector4 margin(it->margin());
                         Vector2 size(it->size());
                         if(horizontal) {
-                            size.x = spacePerFlexible - (margin.w + margin.y);
+                            size.x = remainingSpace * (*weight) - (margin.w + margin.y);
                         } else {
-                            size.y = spacePerFlexible - (margin.x + margin.z);
+                            size.y = remainingSpace * (*weight) - (margin.x + margin.z);
                         }
                         it->setSize(size);
+                        ++weight;
                     }
                 }
             }
         }
     } else { // Need to expand widgets
-        int extra = availableSpace - totalPref;
-
+        float extra = availableSpace - totalPref;
+        auto weight = weights.begin();
         for(auto it : m_items) {
             if(it->isEnabled()) {
                 RectTransform::SizePolicy policy = horizontal ? it->horizontalPolicy() : it->verticalPolicy();
-
-                float extraSize = 0;
-                if(expandingCount > 0) {
-                    if(policy == RectTransform::Expanding) {
-                        extraSize = extra / static_cast<float>(expandingCount);
-                    }
-                }
-
-                if(extraSize != 0) {
-                    Vector2 size(it->size());
-                    if(horizontal) {
-                        size.x += extraSize;
-                    } else {
-                        size.y += extraSize;
+                if(policy == RectTransform::Expanding) {
+                    float extraSize = extra * (*weight);
+                    if(extraSize != 0) {
+                        Vector2 size(it->size());
+                        if(horizontal) {
+                            size.x += extraSize;
+                        } else {
+                            size.y += extraSize;
+                        }
+                        it->setSize(size);
                     }
-                    it->setSize(size);
+                    ++weight;
                 }
             }
         }
@@ -335,7 +345,7 @@ void Layout::solveItemsPosition(float height, const Vector2 &offset) {
             } else {
                 shift += size.x * pivot.x + margin.w;
                 it->m_position.x = shift;
-                it->m_position.y = offset.y - size.y * pivot.y - margin.z;
+                it->m_position.y = offset.y - size.y * (1.0f - pivot.y) - margin.z;
                 shift += size.x * (1.0f - pivot.x) + margin.y;
             }
             it->setDirty();

diff --git a/modules/uikit/src/components/recttransform.cpp b/modules/uikit/src/components/recttransform.cpp
@@ -296,7 +296,7 @@ void RectTransform::setPadding(const Vector4 &padding) {
         if(!isSignalsBlocked()) {
             Widget *widget = RectTransform::widget();
             if(widget) {
-                widget->updateStyleProperty(gCssPadding, m_border.v, 4);
+                widget->updateStyleProperty(gCssPadding, m_padding.v, 4);
             }
         }
 #endif
@@ -638,6 +638,19 @@ Vector4 RectTransform::scissorArea() const {
 /*!
     \internal
 */
+void RectTransform::setParentTransform(Transform *parent, bool force) {
+    Transform::setParentTransform(parent, force);
+
+    RectTransform *rect = dynamic_cast<RectTransform *>(parent);
+    if(rect) {
+        for(auto it : rect->m_subscribers) {
+            it->childAdded(this);
+        }
+    }
+}
+/*!
+    \internal
+*/
 void RectTransform::applyStyle() {
     Widget *widget = RectTransform::widget();