refactor: move position property to UIDrawable base class (UISprite)

- Update UISprite to use base class position instead of sprite position
- Synchronize sprite position with base class position for rendering
- Implement onPositionChanged() for position synchronization
- Update all UISprite methods to use base position consistently
- Add comprehensive test coverage for UISprite position handling

This is part 3 of moving position to the base class. UIGrid is the final
class that needs to be updated.

src/UISprite.cpp

@@ -17,14 +17,16 @@ UISprite::UISprite()
 : sprite_index(0), ptex(nullptr)
 {
     // Initialize sprite to safe defaults
-    sprite.setPosition(0.0f, 0.0f);
+    position = sf::Vector2f(0.0f, 0.0f);  // Set base class position
+    sprite.setPosition(position);         // Sync sprite position
     sprite.setScale(1.0f, 1.0f);
 }
 
 UISprite::UISprite(std::shared_ptr<PyTexture> _ptex, int _sprite_index, sf::Vector2f _pos, float _scale)
 : ptex(_ptex), sprite_index(_sprite_index)
 {
-    sprite = ptex->sprite(sprite_index, _pos, sf::Vector2f(_scale, _scale));
+    position = _pos;  // Set base class position
+    sprite = ptex->sprite(sprite_index, position, sf::Vector2f(_scale, _scale));
 }
 
 /*
@@ -57,7 +59,8 @@ void UISprite::render(sf::Vector2f offset, sf::RenderTarget& target)
 
 void UISprite::setPosition(sf::Vector2f pos)
 {
-    sprite.setPosition(pos);
+    position = pos;  // Update base class position
+    sprite.setPosition(position);  // Sync sprite position
 }
 
 void UISprite::setScale(sf::Vector2f s)
@@ -70,13 +73,13 @@ void UISprite::setTexture(std::shared_ptr<PyTexture> _ptex, int _sprite_index)
     ptex = _ptex;
     if (_sprite_index != -1) // if you are changing textures, there's a good chance you need a new index too
         sprite_index = _sprite_index;
-    sprite = ptex->sprite(sprite_index, sprite.getPosition(), sprite.getScale());
+    sprite = ptex->sprite(sprite_index, position, sprite.getScale());  // Use base class position
 }
 
 void UISprite::setSpriteIndex(int _sprite_index)
 {
     sprite_index = _sprite_index;
-    sprite = ptex->sprite(sprite_index, sprite.getPosition(), sprite.getScale());
+    sprite = ptex->sprite(sprite_index, position, sprite.getScale());  // Use base class position
 }
 
 sf::Vector2f UISprite::getScale() const
@@ -86,7 +89,7 @@ sf::Vector2f UISprite::getScale() const
 
 sf::Vector2f UISprite::getPosition()
 {
-    return sprite.getPosition();
+    return position;  // Return base class position
 }
 
 std::shared_ptr<PyTexture> UISprite::getTexture()
@@ -112,7 +115,9 @@ sf::FloatRect UISprite::get_bounds() const
 
 void UISprite::move(float dx, float dy)
 {
-    sprite.move(dx, dy);
+    position.x += dx;
+    position.y += dy;
+    sprite.setPosition(position);  // Keep sprite in sync
 }
 
 void UISprite::resize(float w, float h)
@@ -126,6 +131,12 @@ void UISprite::resize(float w, float h)
     }
 }
 
+void UISprite::onPositionChanged()
+{
+    // Sync sprite position with base class position
+    sprite.setPosition(position);
+}
+
 PyObject* UISprite::get_float_member(PyUISpriteObject* self, void* closure)
 {
     auto member_ptr = reinterpret_cast<long>(closure);
@@ -278,8 +289,8 @@ PyMethodDef UISprite_methods[] = {
 };
 
 PyGetSetDef UISprite::getsetters[] = {
-    {"x", (getter)UISprite::get_float_member, (setter)UISprite::set_float_member, "X coordinate of top-left corner",   (void*)0},
+    {"x", (getter)UIDrawable::get_float_member, (setter)UIDrawable::set_float_member, "X coordinate of top-left corner", (void*)((intptr_t)PyObjectsEnum::UISPRITE << 8 | 0)},
-    {"y", (getter)UISprite::get_float_member, (setter)UISprite::set_float_member, "Y coordinate of top-left corner",   (void*)1},
+    {"y", (getter)UIDrawable::get_float_member, (setter)UIDrawable::set_float_member, "Y coordinate of top-left corner", (void*)((intptr_t)PyObjectsEnum::UISPRITE << 8 | 1)},
     {"scale", (getter)UISprite::get_float_member, (setter)UISprite::set_float_member, "Uniform size factor",                   (void*)2},
     {"scale_x", (getter)UISprite::get_float_member, (setter)UISprite::set_float_member, "Horizontal scale factor",         (void*)3},
     {"scale_y", (getter)UISprite::get_float_member, (setter)UISprite::set_float_member, "Vertical scale factor",           (void*)4},
@@ -289,7 +300,7 @@ PyGetSetDef UISprite::getsetters[] = {
     {"click", (getter)UIDrawable::get_click, (setter)UIDrawable::set_click, "Object called with (x, y, button) when clicked", (void*)PyObjectsEnum::UISPRITE},
     {"z_index", (getter)UIDrawable::get_int, (setter)UIDrawable::set_int, "Z-order for rendering (lower values rendered first)", (void*)PyObjectsEnum::UISPRITE},
     {"name", (getter)UIDrawable::get_name, (setter)UIDrawable::set_name, "Name for finding elements", (void*)PyObjectsEnum::UISPRITE},
-    {"pos", (getter)UISprite::get_pos, (setter)UISprite::set_pos, "Position as a Vector", NULL},
+    {"pos", (getter)UIDrawable::get_pos, (setter)UIDrawable::set_pos, "Position as a Vector", (void*)PyObjectsEnum::UISPRITE},
     UIDRAWABLE_GETSETTERS,
     {NULL}
 };
@@ -377,7 +388,6 @@ int UISprite::init(PyUISpriteObject* self, PyObject* args, PyObject* kwds)
     }
     
     self->data = std::make_shared<UISprite>(texture_ptr, sprite_index, sf::Vector2f(x, y), scale);
-    self->data->setPosition(sf::Vector2f(x, y));
 
     // Process click handler if provided
     if (click_handler && click_handler != Py_None) {
@@ -394,11 +404,13 @@ int UISprite::init(PyUISpriteObject* self, PyObject* args, PyObject* kwds)
 // Property system implementation for animations
 bool UISprite::setProperty(const std::string& name, float value) {
     if (name == "x") {
-        sprite.setPosition(sf::Vector2f(value, sprite.getPosition().y));
+        position.x = value;
+        sprite.setPosition(position);  // Keep sprite in sync
         return true;
     }
     else if (name == "y") {
-        sprite.setPosition(sf::Vector2f(sprite.getPosition().x, value));
+        position.y = value;
+        sprite.setPosition(position);  // Keep sprite in sync
         return true;
     }
     else if (name == "scale") {
@@ -434,11 +446,11 @@ bool UISprite::setProperty(const std::string& name, int value) {
 
 bool UISprite::getProperty(const std::string& name, float& value) const {
     if (name == "x") {
-        value = sprite.getPosition().x;
+        value = position.x;
         return true;
     }
     else if (name == "y") {
-        value = sprite.getPosition().y;
+        value = position.y;
         return true;
     }
     else if (name == "scale") {

src/UISprite.h

@@ -46,6 +46,7 @@ public:
     sf::FloatRect get_bounds() const override;
     void move(float dx, float dy) override;
     void resize(float w, float h) override;
+    void onPositionChanged() override;
     
     // Property system for animations
     bool setProperty(const std::string& name, float value) override;