Code Samples

Counter

private final MutableIntState counterState = mutableState(0);

@Override
public void onInit(ViewConfigBuilder config) {
    config.title("Counter")
        .cancelOnClick()
        .layout("  - # +  ");
}

@Override
public void onFirstRender(RenderContext render) {
    // Current count item
    render.layoutSlot('#')
        // The `watch` here updates the item when `counterState` updates
        .watch(counterState)
        .renderWith(() -> new ItemStack(
                /* type = */ Material.GOLD_INGOT,
                /* amount = */ counterState.get(render)
        ));

    // Decrement button
    render.layoutSlot('-', new ItemStack(Material.ARROW))
        .onClick(counterState::decrement);

    // Increment button
    render.layoutSlot('+', new ItemStack(Material.ARROW))
        .onClick(counterState::increment);
}