UI-System.md

UI System Documentation

The UI System provides functionality for creating and managing user interface elements in the game engine.

Main Components

UISystem Class

The UISystem class is the central manager for all UI elements. It handles:

• Creation of UI elements (factory methods)
• Event handling (mouse clicks, movement, dragging)
• Managing element states (hover, focus, drag)
• Rendering delegation

// Create a UISystem instance
UISystem uiSystem = new UISystem(gameWindow, ecsInstance);

// Register with a scene
uiSystem.setCurrentRegistrar(sceneRegistrar);

Available UI Elements

Button

Buttons can be clicked to trigger actions.

// Create a button
Entity button = uiSystem.createButton("Click Me", 100, 100, 150, 40);

// Add click handler
Button buttonComponent = button.get(UIComponent.class).getUi();
buttonComponent.setOnClick(() -> System.out.println("Button clicked!"));

Label

Labels display static text.

// Create a label
Entity label = uiSystem.createLabel("Hello World", 100, 100);

Panel

Panels are container elements that can hold other UI elements.

// Create a panel
Entity panel = uiSystem.createPanel(50, 50, 300, 200);

// Add elements to the panel
Entity button = uiSystem.createButton("Panel Button", 10, 10, 100, 30);
uiSystem.addToPanel(panel, button);

Slider

Sliders allow the user to select a value from a range.

// Create a slider
Entity slider = uiSystem.createSlider("Volume", 100, 150, 200, 30, 0.0f, 1.0f, 0.5f);

// Add value change callback
uiSystem.setSliderCallback(slider, value -> System.out.println("New value: " + value));

Debug Overlay

Debug overlays display performance metrics and debug information.

// Create a debug overlay
Entity debugOverlay = uiSystem.createDebugOverlay(10, 10);

Event Handling

The UISystem automatically handles mouse events for all UI elements. This includes:

• Hover effects for buttons
• Focus management
• Slider dragging
• Click events

Advanced Usage

Custom UI Elements

You can create custom UI elements by extending AbstractUIElement and implementing the required methods.

public class CustomElement extends AbstractUIElement {
    public CustomElement(float x, float y, float width, float height) {
        super(x, y, width, height);
    }

    @Override
    public void render(Graphics2D g) {
        // Custom rendering code
    }

    @Override
    public void update(double deltaTime) {
        // Custom update logic
    }
}