Combind

Combind exposes three API classes under net.pemiridosa.combind.api that let your mod register key bindings with full combo support.

Dependency Setup

Add Combind as a compile-time dependency via the Modrinth Maven repository:

// build.gradle
repositories {
    maven { url "https://api.modrinth.com/maven" }
}

dependencies {
    compileOnly "maven.modrinth:combind:VERSION"
    localRuntime "maven.modrinth:combind:VERSION" // optional: for dev runs
}

Declare the dependency in fabric.mod.json. Use depends if your mod requires Combind, or suggests if it is optional:

"depends": {
    "combind": "*"
}

API Classes

Examples

Chord — held modifier(s) + trigger key

Bind an action to Left Shift + E:

KeyMapping.Category category = KeyMapping.Category.register(
    Identifier.fromNamespaceAndPath("mymod", "mymod")
);

KeyMapping someActionMapping = KeyMappingHelper.registerKeyMapping(
    new KeyMapping("key.mymod.someaction", InputConstants.KEY_E, category)
);

// Left Shift + E
CombindKeyBinding someActionBinding = CombindKeyBinding.of(someActionMapping,
    new KeyCombo(
        InputKey.keyboard(InputConstants.KEY_E),
        new InputKey[]{ InputKey.keyboard(InputConstants.KEY_LSHIFT) }
    )
);

someActionBinding
    .onPress(ctx -> LOGGER.info("Some action PRESSED — combo: {}", ctx.combo().getDisplayName()))
    .onRelease(ctx -> LOGGER.info("Some action RELEASED — combo: {}", ctx.combo().getDisplayName()));

Chord with multiple modifiers

Bind an action to Left Control + Left Shift + E:

KeyMapping someActionMapping = KeyMappingHelper.registerKeyMapping(
    new KeyMapping("key.mymod.someaction", InputConstants.KEY_E, category)
);

// Left Control + Left Shift + E
CombindKeyBinding someActionBinding = CombindKeyBinding.of(someActionMapping,
    new KeyCombo(
        InputKey.keyboard(InputConstants.KEY_E),
        new InputKey[]{
            InputKey.keyboard(InputConstants.KEY_LCONTROL),
            InputKey.keyboard(InputConstants.KEY_LSHIFT)
        }
    )
);

someActionBinding
    .onPress(ctx -> LOGGER.info("Some action PRESSED — combo: {}", ctx.combo().getDisplayName()))
    .onRelease(ctx -> LOGGER.info("Some action RELEASED — combo: {}", ctx.combo().getDisplayName()));

Sequence — tap the same key multiple times

Bind an action to M M (double-tap) or M M M (triple-tap):

KeyMapping someActionMapping = KeyMappingHelper.registerKeyMapping(
    new KeyMapping("key.mymod.someaction", InputConstants.KEY_M, category)
);

// Double-tap M (M M)
CombindKeyBinding someActionBinding = CombindKeyBinding.of(someActionMapping,
    KeyCombo.sequence(InputKey.keyboard(InputConstants.KEY_M), 2)
);

// Triple-tap M (M M M) — even safer
CombindKeyBinding someActionBinding = CombindKeyBinding.of(someActionMapping,
    KeyCombo.sequence(InputKey.keyboard(InputConstants.KEY_M), 3)
);

someActionBinding
    .onPress(ctx -> LOGGER.info("Some action PRESSED — combo: {}", ctx.combo().getDisplayName()))
    .onRelease(ctx -> LOGGER.info("Some action RELEASED — combo: {}", ctx.combo().getDisplayName()));

Chord + sequence — hold modifier(s) while multi-tapping

Bind an action to Left Shift + Q Q (double-tap Q while holding Shift):

// Left Shift + Q Q
CombindKeyBinding binding = CombindKeyBinding.of(mapping,
    new KeyCombo(
        InputKey.keyboard(InputConstants.KEY_Q),
        new InputKey[]{ InputKey.keyboard(InputConstants.KEY_LSHIFT) },
        2
    )
);

Mouse button as trigger

Bind an action to Left Control + Left Button:

// Left Control + Left Mouse Button
CombindKeyBinding binding = CombindKeyBinding.of(mapping,
    new KeyCombo(
        InputKey.mouse(InputConstants.MOUSE_BUTTON_LEFT),
        new InputKey[]{ InputKey.keyboard(InputConstants.KEY_LCONTROL) }
    )
);

Single key (no explicit combo needed)

CombindKeyBinding.of(mapping) infers the initial combo from the KeyMapping's default key:

CombindKeyBinding binding = CombindKeyBinding.of(mapping); // defaults to the KeyMapping's key

Unbound — no key assigned by default

// Player must configure this in the Controls > Key Binds screen
CombindKeyBinding binding = CombindKeyBinding.of(mapping, KeyCombo.unbound());

Tick-Based Polling (Vanilla Style)

If you prefer the standard tick-polling pattern instead of callbacks, it works unchanged via the vanilla KeyMapping:

ClientTickEvents.END_CLIENT_TICK.register(client -> {
    while (someActionMapping.consumeClick()) {
        // handle each queued click
    }

    if (someActionMapping.isDown()) {
        // binding is currently held
    }
});

For more details, see the full implementation at src/client/java/net/pemiridosa/combind/api.