1 files changed, 30 insertions, 0 deletions
diff --git a/src/main/java/gregtech/api/interfaces/covers/IControlsWorkCover.java b/src/main/java/gregtech/api/interfaces/covers/IControlsWorkCover.java
new file mode 100644
index 0000000000..d4cd1e9ec2
--- /dev/null
+++ b/src/main/java/gregtech/api/interfaces/covers/IControlsWorkCover.java
@@ -0,0 +1,30 @@
+package gregtech.api.interfaces.covers;
+
+import net.minecraftforge.common.util.ForgeDirection;
+
+import gregtech.api.interfaces.tileentity.ICoverable;
+import gregtech.api.interfaces.tileentity.IMachineProgress;
+
+/**
+ * Marker interface for covers that might control whether the work can start on a {@link IMachineProgress}.
+ */
+public interface IControlsWorkCover {
+
+    /**
+     * Make sure there is only one GT_Cover_ControlsWork on the aTileEntity TODO this is a migration thing. Remove this
+     * after 2.3.0 is released.
+     *
+     * @return true if the cover is the first (side) one
+     **/
+    static boolean makeSureOnlyOne(ForgeDirection aMySide, ICoverable aTileEntity) {
+        for (final ForgeDirection side : ForgeDirection.VALID_DIRECTIONS) {
+            if (aTileEntity.getCoverBehaviorAtSideNew(side) instanceof IControlsWorkCover
+                && side.ordinal() < aMySide.ordinal()) {
+                aTileEntity.dropCover(side, side, true);
+                aTileEntity.markDirty();
+                return false;
+            }
+        }
+        return true;
+    }
+}