Allow providing Devices as Capabilities on BlockEntities.

src/main/java/li/cil/oc2/api/bus/device/Device.java

@@ -3,6 +3,7 @@ package li.cil.oc2.api.bus.device;
 import li.cil.oc2.api.bus.DeviceBus;
 import li.cil.oc2.api.bus.DeviceBusController;
 import net.minecraft.nbt.CompoundTag;
+import net.minecraft.world.level.block.entity.BlockEntity;
 import net.minecraftforge.common.util.INBTSerializable;
 
 /**
@@ -11,6 +12,8 @@ import net.minecraftforge.common.util.INBTSerializable;
  * Which types are handled/supported by a bus depends on context of the {@link DeviceBusController}
  * managing the bus.
  * <p>
+ * May be provided as a capability on {@link BlockEntity}s.
+ * <p>
  * Note that it is strongly encouraged for implementations to provide an overloaded
  * {@link Object#equals(Object)} and {@link Object#hashCode()} so that identical devices can be
  * detected.

src/main/java/li/cil/oc2/common/bus/device/provider/Providers.java

@@ -25,6 +25,7 @@ public final class Providers {
     public static void initialize() {
         BLOCK_DEVICE_PROVIDERS.register("block", BlockStateDeviceProvider::new);
         BLOCK_DEVICE_PROVIDERS.register("block_entity", BlockEntityDeviceProvider::new);
+        BLOCK_DEVICE_PROVIDERS.register("block_entity/capability", BlockEntityCapabilityDeviceProvider::new);
 
         BLOCK_DEVICE_PROVIDERS.register("energy_storage", EnergyStorageBlockDeviceProvider::new);
         BLOCK_DEVICE_PROVIDERS.register("fluid_handler", FluidHandlerBlockDeviceProvider::new);

src/main/java/li/cil/oc2/common/bus/device/provider/block/BlockEntityCapabilityDeviceProvider.java

@@ -0,0 +1,19 @@
+package li.cil.oc2.common.bus.device.provider.block;
+
+import li.cil.oc2.api.bus.device.Device;
+import li.cil.oc2.api.bus.device.provider.BlockDeviceQuery;
+import li.cil.oc2.api.util.Invalidatable;
+import li.cil.oc2.common.bus.device.provider.util.AbstractBlockEntityCapabilityDeviceProvider;
+import li.cil.oc2.common.capabilities.Capabilities;
+import net.minecraft.world.level.block.entity.BlockEntity;
+
+public final class BlockEntityCapabilityDeviceProvider extends AbstractBlockEntityCapabilityDeviceProvider<Device, BlockEntity> {
+    public BlockEntityCapabilityDeviceProvider() {
+        super(() -> Capabilities.DEVICE);
+    }
+
+    @Override
+    protected Invalidatable<Device> getBlockDevice(final BlockDeviceQuery query, final Device device) {
+        return Invalidatable.of(device);
+    }
+}

src/main/java/li/cil/oc2/common/capabilities/Capabilities.java

@@ -1,6 +1,7 @@
 package li.cil.oc2.common.capabilities;
 
 import li.cil.oc2.api.bus.DeviceBusElement;
+import li.cil.oc2.api.bus.device.Device;
 import li.cil.oc2.api.capabilities.NetworkInterface;
 import li.cil.oc2.api.capabilities.RedstoneEmitter;
 import li.cil.oc2.api.capabilities.Robot;
@@ -20,6 +21,7 @@ public final class Capabilities {
     public static final Capability<IItemHandler> ITEM_HANDLER = CapabilityManager.get(new CapabilityToken<>() { });
 
     public static final Capability<DeviceBusElement> DEVICE_BUS_ELEMENT = CapabilityManager.get(new CapabilityToken<>() { });
+    public static final Capability<Device> DEVICE = CapabilityManager.get(new CapabilityToken<>() { });
     public static final Capability<RedstoneEmitter> REDSTONE_EMITTER = CapabilityManager.get(new CapabilityToken<>() { });
     public static final Capability<NetworkInterface> NETWORK_INTERFACE = CapabilityManager.get(new CapabilityToken<>() { });
     public static final Capability<TerminalUserProvider> TERMINAL_USER_PROVIDER = CapabilityManager.get(new CapabilityToken<>() { });
@@ -30,6 +32,7 @@ public final class Capabilities {
     @SubscribeEvent
     public static void initialize(final RegisterCapabilitiesEvent event) {
         event.register(DeviceBusElement.class);
+        event.register(Device.class);
         event.register(RedstoneEmitter.class);
         event.register(NetworkInterface.class);
         event.register(TerminalUserProvider.class);