UIManager

Class

Source: UIManager.h

Description

Registry of touch UI elements for event routing (non-owning pointers).

The scene (or another owner) constructs widgets and registers them with addElement. clear/removeElement only unregister pointers — they never destroy objects.

Lifetime Contract

UIManager holds NON-OWNING pointers to UITouchElement instances. The widget lifetime is managed exclusively by the caller (Scene, game code, arena allocator).

Ownership Rules

• UIManager does NOT delete widgets
• Widgets must call removeElement() BEFORE being destroyed
• Failure to unregister results in dangling pointers and potential crashes

Safe Destruction Sequence

// CORRECTO: Desregistrar antes de destruir
uiManager.removeElement(myButton.get());
myButton.reset();  // or delete myButton;

// INCORRECTO: Destruir sin desregistrar
myButton.reset();  // Widget destruido
// UIManager::capturedWidget o hoverWidget ahora son dangling!

Captured Widget Safety UIManager automatically clears capturedWidget when removeElement() is called. However, if a widget is deleted directly without removeElement(), the caller MUST call uiManager.releaseCapture() to avoid use-after-free.

Methods

bool addElement(UITouchElement* element)

Description:

Register an element for touch hit-testing and processEvents.

Parameters:

• element: Non-null; must outlive registration (or until remove/clear).

Returns: false if full, duplicate pointer, or element is null

bool removeElement(uint8_t id)

bool removeElement(UITouchWidget* widget)

UITouchElement* getElement(uint8_t id) const

UITouchElement* getElementAt(uint8_t index) const

uint8_t getElementCount() const

uint8_t getMaxElements() const

bool isFull() const

void clear()

uint8_t processEvents(pixelroot32::input::TouchEvent* events, uint8_t count)

bool processEvent(pixelroot32::input::TouchEvent& event)

UITouchWidget* getActiveWidget() const

UITouchWidget* getHoverWidget() const

UITouchElement** getElements()

UITouchElement* const* getElements() const

void updateHover(int16_t x, int16_t y)

void clearConsumeFlags()

UITouchWidget* getCapturedWidget() const

void releaseCapture()

void update(unsigned long deltaTime)

void draw(pixelroot32::graphics::Renderer& renderer)