Add threshold support to item and fluid covers (#785)

* Add threshold support to item and fluid covers

* Switch to storing in NBT

* Add handling for migration path

* Adjust item threshold max value

6 files changed, 496 insertions, 201 deletions

diff --git a/src/main/java/gregtech/api/metatileentity/BaseMetaPipeEntity.java b/src/main/java/gregtech/api/metatileentity/BaseMetaPipeEntity.java
index bff79743be..fc5fa64d91 100644
--- a/src/main/java/gregtech/api/metatileentity/BaseMetaPipeEntity.java
+++ b/src/main/java/gregtech/api/metatileentity/BaseMetaPipeEntity.java
@@ -176,9 +176,10 @@ public class BaseMetaPipeEntity extends BaseTileEntity implements IGregTechTileE
                     GT_CoverBehaviorBase<?> tBehavior = getCoverBehaviorAtSideNew(i);
                     if (tBehavior == null)
                         continue;
-                    mCoverData[i] = tBehavior.createDataObject();
                     if (aNBT.hasKey(COVER_DATA_NBT_KEYS[i]))
-                        mCoverData[i].loadDataFromNBT(aNBT.getTag(COVER_DATA_NBT_KEYS[i]));
+                        mCoverData[i] = tBehavior.createDataObject(aNBT.getTag(COVER_DATA_NBT_KEYS[i]));
+                    else
+                        mCoverData[i] = tBehavior.createDataObject();
                 }
             }
             if (mSidedRedstone.length != 6) mSidedRedstone = new byte[]{0, 0, 0, 0, 0, 0};
diff --git a/src/main/java/gregtech/api/util/GT_CoverBehaviorBase.java b/src/main/java/gregtech/api/util/GT_CoverBehaviorBase.java
index 50ef2632d9..c0fcc0708f 100644
--- a/src/main/java/gregtech/api/util/GT_CoverBehaviorBase.java
+++ b/src/main/java/gregtech/api/util/GT_CoverBehaviorBase.java
@@ -8,6 +8,7 @@ import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.entity.player.EntityPlayerMP;
 import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.NBTBase;
+import net.minecraft.nbt.NBTTagInt;
 import net.minecraft.world.World;
 import net.minecraftforge.fluids.Fluid;
 
@@ -31,7 +32,12 @@ public abstract class GT_CoverBehaviorBase<T extends ISerializableObject> {
 
     public abstract T createDataObject();
 
-    public T createDataObject(NBTBase aNBT) {
+    public final T createDataObject(NBTBase aNBT) {
+        // Handle legacy data (migrating from GT_CoverBehavior to GT_CoverBehaviorBase)
+        if (aNBT instanceof NBTTagInt) {
+            return createDataObject(((NBTTagInt) aNBT).func_150287_d());
+        }
+
         T ret = createDataObject();
         ret.loadDataFromNBT(aNBT);
         return ret;
diff --git a/src/main/java/gregtech/api/util/GT_LanguageManager.java b/src/main/java/gregtech/api/util/GT_LanguageManager.java
index 767c830f79..9121e41c33 100644
--- a/src/main/java/gregtech/api/util/GT_LanguageManager.java
+++ b/src/main/java/gregtech/api/util/GT_LanguageManager.java
@@ -337,6 +337,8 @@ public class GT_LanguageManager {
 		addStringLocalization("Interaction_DESCRIPTION_Index_218", "Transfer size mode. Add exactly this many items in destination input slots as long as there is room.");
 		addStringLocalization("Interaction_DESCRIPTION_Index_219", "Single recipe locking enabled. Will lock to next recipe.");
 		addStringLocalization("Interaction_DESCRIPTION_Index_220", "Single recipe locking disabled.");
+		addStringLocalization("Interaction_DESCRIPTION_Index_221", "Item threshold");
+		addStringLocalization("Interaction_DESCRIPTION_Index_222", "Fluid threshold");
 		addStringLocalization("Interaction_DESCRIPTION_Index_500", "Fitting: Loose - More Flow");
 		addStringLocalization("Interaction_DESCRIPTION_Index_501", "Fitting: Tight - More Efficiency");
 
diff --git a/src/main/java/gregtech/api/util/ISerializableObject.java b/src/main/java/gregtech/api/util/ISerializableObject.java
index 51fa40e55a..b31abaa843 100644
--- a/src/main/java/gregtech/api/util/ISerializableObject.java
+++ b/src/main/java/gregtech/api/util/ISerializableObject.java
@@ -24,6 +24,11 @@ public interface ISerializableObject {
     @Nonnull
     ISerializableObject copy();
 
+    /**
+     * If you are overriding this, you must <b>NOT</b> return {@link NBTTagInt} here! That return
+     * type is how we tell that we are loading legacy data, and only {@link LegacyCoverData} is
+     * allowed to return it. You probably want to return {@link NBTTagCompound} anyway.
+     */
     @Nonnull
     NBTBase saveDataToNBT();
 
@@ -109,7 +114,7 @@ public interface ISerializableObject {
 
         @Override
         public void loadDataFromNBT(NBTBase aNBT) {
-            mData = aNBT instanceof NBTBase.NBTPrimitive ? ((NBTBase.NBTPrimitive) aNBT).func_150287_d() : 0;
+            mData = aNBT instanceof NBTTagInt ? ((NBTTagInt) aNBT).func_150287_d() : 0;
         }
 
         @Override
diff --git a/src/main/java/gregtech/common/covers/GT_Cover_ItemMeter.java b/src/main/java/gregtech/common/covers/GT_Cover_ItemMeter.java
index a7aba3d829..718529894b 100644
--- a/src/main/java/gregtech/common/covers/GT_Cover_ItemMeter.java
+++ b/src/main/java/gregtech/common/covers/GT_Cover_ItemMeter.java
@@ -1,5 +1,6 @@
 package gregtech.common.covers;
 
+import com.google.common.io.ByteArrayDataInput;
 import gregtech.api.enums.GT_Values;
 import gregtech.api.gui.GT_GUICover;
 import gregtech.api.gui.widgets.GT_GuiFakeItemButton;
@@ -9,40 +10,65 @@ import gregtech.api.gui.widgets.GT_GuiIntegerTextBox;
 import gregtech.api.interfaces.metatileentity.IMetaTileEntity;
 import gregtech.api.interfaces.tileentity.ICoverable;
 import gregtech.api.interfaces.tileentity.IGregTechTileEntity;
-import gregtech.api.net.GT_Packet_TileEntityCover;
-import gregtech.api.util.GT_CoverBehavior;
+import gregtech.api.net.GT_Packet_TileEntityCoverNew;
+import gregtech.api.util.GT_CoverBehaviorBase;
 import gregtech.api.util.GT_Utility;
+import gregtech.api.util.ISerializableObject;
 import gregtech.common.tileentities.machines.GT_MetaTileEntity_Hatch_OutputBus_ME;
 import gregtech.common.tileentities.storage.GT_MetaTileEntity_DigitalChestBase;
+import io.netty.buffer.ByteBuf;
 import net.minecraft.client.gui.GuiButton;
 import net.minecraft.entity.player.EntityPlayer;
+import net.minecraft.entity.player.EntityPlayerMP;
 import net.minecraft.item.ItemStack;
+import net.minecraft.nbt.NBTBase;
+import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.tileentity.TileEntity;
+import net.minecraft.world.World;
 import net.minecraftforge.fluids.Fluid;
 
-public class GT_Cover_ItemMeter extends GT_CoverBehavior {
+import javax.annotation.Nonnull;
 
-    // format:
-    private static final int SLOT_MASK = 0x3FFFFFF; // 0 = all, 1 = 0 ...
+public class GT_Cover_ItemMeter extends GT_CoverBehaviorBase<GT_Cover_ItemMeter.ItemMeterData> {
+
+    // Legacy data format
+    private static final int SLOT_MASK = 0x3FFFFFFF; // 0 = all, 1 = 0 ...
     private static final int CONVERTED_BIT = 0x80000000;
     private static final int INVERT_BIT = 0x40000000;
 
-    @Override
-    public boolean isRedstoneSensitive(byte aSide, int aCoverID, int aCoverVariable, ICoverable aTileEntity, long aTimer) {
-        return false;
+    public GT_Cover_ItemMeter() {
+        super(ItemMeterData.class);
     }
 
     @Override
-    public int doCoverThings(byte aSide, byte aInputRedstone, int aCoverID, int aCoverVariable, ICoverable aTileEntity, long aTimer) {
+    public ItemMeterData createDataObject(int aLegacyData) {
         //Convert from ver. 5.09.33.50
-        if ((CONVERTED_BIT & aCoverVariable) == 0)
-            if (aCoverVariable == 0)
-                aCoverVariable = CONVERTED_BIT;
-            else if (aCoverVariable == 1)
-                aCoverVariable = CONVERTED_BIT | INVERT_BIT;
-            else if (aCoverVariable > 1)
-                aCoverVariable = CONVERTED_BIT | Math.min((aCoverVariable - 2), SLOT_MASK);
+        if ((CONVERTED_BIT & aLegacyData) == 0)
+            if (aLegacyData == 0)
+                aLegacyData = CONVERTED_BIT;
+            else if (aLegacyData == 1)
+                aLegacyData = CONVERTED_BIT | INVERT_BIT;
+            else if (aLegacyData > 1)
+                aLegacyData = CONVERTED_BIT | Math.min((aLegacyData - 2), SLOT_MASK);
+
+        boolean invert = (aLegacyData & INVERT_BIT) == INVERT_BIT;
+        int slot = (aLegacyData & SLOT_MASK) - 1;
+
+        return new ItemMeterData(invert, slot, 0);
+    }
+
+    @Override
+    public ItemMeterData createDataObject() {
+        return new ItemMeterData();
+    }
 
+    @Override
+    protected boolean isRedstoneSensitiveImpl(byte aSide, int aCoverID, ItemMeterData aCoverVariable, ICoverable aTileEntity, long aTimer) {
+        return false;
+    }
+
+    @Override
+    protected ItemMeterData doCoverThingsImpl(byte aSide, byte aInputRedstone, int aCoverID, ItemMeterData aCoverVariable, ICoverable aTileEntity, long aTimer) {
         long tMax = 0;
         long tUsed = 0;
         IMetaTileEntity mte = ((IGregTechTileEntity) aTileEntity).getMetaTileEntity();
@@ -58,8 +84,8 @@ public class GT_Cover_ItemMeter extends GT_CoverBehavior {
                 tUsed = 64;
             }
         } else {
-            int[] tSlots = (aCoverVariable & SLOT_MASK) > 0 ?
-                    new int[]{(aCoverVariable & SLOT_MASK) - 1} :
+            int[] tSlots = aCoverVariable.slot >= 0 ?
+                    new int[]{aCoverVariable.slot} :
                     aTileEntity.getAccessibleSlotsFromSide(aSide);
 
             for (int i : tSlots) {
@@ -72,78 +98,96 @@ public class GT_Cover_ItemMeter extends GT_CoverBehavior {
             }
         }
 
-        boolean inverted = (aCoverVariable & INVERT_BIT) == INVERT_BIT;
-        if(tUsed==0)//nothing
-            aTileEntity.setOutputRedstoneSignal(aSide, (byte)(inverted ? 15 : 0));
-        else if(tUsed >= tMax)//full
-            aTileEntity.setOutputRedstoneSignal(aSide, (byte)(inverted ? 0 : 15));
-        else//1-14 range
-            aTileEntity.setOutputRedstoneSignal(aSide, (byte)(inverted ? 14-((14*tUsed)/tMax) : 1+((14*tUsed)/tMax)) );
+        long redstoneSignal;
+        if (tUsed == 0L) {
+            // nothing
+            redstoneSignal = 0;
+        } else if (tUsed >= tMax) {
+            // full
+            redstoneSignal = 15;
+        } else {
+            // 1-14 range
+            redstoneSignal = 1 + (14 * tUsed) / tMax;
+        }
+
+        if (aCoverVariable.inverted) {
+            redstoneSignal = 15 - redstoneSignal;
+        }
+
+        if (aCoverVariable.threshold > 0) {
+            if (aCoverVariable.inverted && tUsed >= aCoverVariable.threshold) {
+                redstoneSignal = 0;
+            } else if (!aCoverVariable.inverted && tUsed < aCoverVariable.threshold) {
+                redstoneSignal = 0;
+            }
+        }
+
+        aTileEntity.setOutputRedstoneSignal(aSide, (byte) redstoneSignal);
         return aCoverVariable;
     }
 
     @Override
-    public int onCoverScrewdriverclick(byte aSide, int aCoverID, int aCoverVariable, ICoverable aTileEntity, EntityPlayer aPlayer, float aX, float aY, float aZ) {
+    protected ItemMeterData onCoverScrewdriverClickImpl(byte aSide, int aCoverID, ItemMeterData aCoverVariable, ICoverable aTileEntity, EntityPlayer aPlayer, float aX, float aY, float aZ) {
         if (aPlayer.isSneaking()) {
-            if ((aCoverVariable & INVERT_BIT) == INVERT_BIT) {
-                aCoverVariable = aCoverVariable & ~INVERT_BIT;
-                GT_Utility.sendChatToPlayer(aPlayer, trans("NORMAL","Normal"));
+            if (aCoverVariable.inverted) {
+                aCoverVariable.inverted = false;
+                GT_Utility.sendChatToPlayer(aPlayer, trans("055","Normal"));
             }
             else {
-                aCoverVariable = aCoverVariable | INVERT_BIT;
-                GT_Utility.sendChatToPlayer(aPlayer, trans("INVERTED","Inverted"));
+                aCoverVariable.inverted = true;
+                GT_Utility.sendChatToPlayer(aPlayer, trans("054","Inverted"));
             }
-            return aCoverVariable;
-        }
+        } else {
+            aCoverVariable.slot++;
+            if (aCoverVariable.slot > aTileEntity.getSizeInventory())
+                aCoverVariable.slot = -1;
 
-        int slot = (aCoverVariable & SLOT_MASK) + 1;
-        if (slot > aTileEntity.getSizeInventory() || slot > SLOT_MASK)
-            slot = 0;
+            if (aCoverVariable.slot == -1)
+                GT_Utility.sendChatToPlayer(aPlayer, trans("053", "Slot: ") + trans("ALL", "All"));
+            else
+                GT_Utility.sendChatToPlayer(aPlayer, trans("053", "Slot: ") + aCoverVariable.slot);
+        }
 
-        if (slot == 0)
-            GT_Utility.sendChatToPlayer(aPlayer, trans("053", "Slot: ") + trans("ALL", "All"));
-        else
-            GT_Utility.sendChatToPlayer(aPlayer, trans("053", "Slot: ") + (slot - 1));
-        return CONVERTED_BIT | (aCoverVariable & INVERT_BIT) | slot;
+        return aCoverVariable;
     }
 
     @Override
-    public boolean letsEnergyIn(byte aSide, int aCoverID, int aCoverVariable, ICoverable aTileEntity) {
+    protected boolean letsEnergyInImpl(byte aSide, int aCoverID, ItemMeterData aCoverVariable, ICoverable aTileEntity) {
         return true;
     }
 
     @Override
-    public boolean letsEnergyOut(byte aSide, int aCoverID, int aCoverVariable, ICoverable aTileEntity) {
+    protected boolean letsEnergyOutImpl(byte aSide, int aCoverID, ItemMeterData aCoverVariable, ICoverable aTileEntity) {
         return true;
     }
 
     @Override
-    public boolean letsFluidIn(byte aSide, int aCoverID, int aCoverVariable, Fluid aFluid, ICoverable aTileEntity) {
+    protected boolean letsFluidInImpl(byte aSide, int aCoverID, ItemMeterData aCoverVariable, Fluid aFluid, ICoverable aTileEntity) {
         return true;
     }
 
     @Override
-    public boolean letsFluidOut(byte aSide, int aCoverID, int aCoverVariable, Fluid aFluid, ICoverable aTileEntity) {
+    protected boolean letsFluidOutImpl(byte aSide, int aCoverID, ItemMeterData aCoverVariable, Fluid aFluid, ICoverable aTileEntity) {
         return true;
     }
 
     @Override
-    public boolean letsItemsIn(byte aSide, int aCoverID, int aCoverVariable, int aSlot, ICoverable aTileEntity) {
+    protected boolean letsItemsInImpl(byte aSide, int aCoverID, ItemMeterData aCoverVariable, int aSlot, ICoverable aTileEntity) {
         return true;
     }
 
     @Override
-    public boolean letsItemsOut(byte aSide, int aCoverID, int aCoverVariable, int aSlot, ICoverable aTileEntity) {
+    protected boolean letsItemsOutImpl(byte aSide, int aCoverID, ItemMeterData aCoverVariable, int aSlot, ICoverable aTileEntity) {
         return true;
     }
 
     @Override
-    public boolean manipulatesSidedRedstoneOutput(byte aSide, int aCoverID, int aCoverVariable, ICoverable aTileEntity) {
+    protected boolean manipulatesSidedRedstoneOutputImpl(byte aSide, int aCoverID, ItemMeterData aCoverVariable, ICoverable aTileEntity) {
         return true;
     }
 
     @Override
-    public int getTickRate(byte aSide, int aCoverID, int aCoverVariable, ICoverable aTileEntity) {
+    protected int getTickRateImpl(byte aSide, int aCoverID, ItemMeterData aCoverVariable, ICoverable aTileEntity) {
         return 5;
     }
 
@@ -157,36 +201,97 @@ public class GT_Cover_ItemMeter extends GT_CoverBehavior {
     }
 
     @Override
-    public Object getClientGUI(byte aSide, int aCoverID, int coverData, ICoverable aTileEntity)  {
+    protected Object getClientGUIImpl(byte aSide, int aCoverID, ItemMeterData coverData, ICoverable aTileEntity, EntityPlayer aPlayer, World aWorld) {
         return new GUI(aSide, aCoverID, coverData, aTileEntity);
     }
 
+    public static class ItemMeterData implements ISerializableObject {
+        private boolean inverted;
+        /** The special value {@code -1} means all slots. */
+        private int slot;
+        /** The special value {@code 0} means threshold check is disabled. */
+        private int threshold;
+
+        public ItemMeterData() {
+            inverted = false;
+            slot = -1;
+            threshold = 0;
+        }
+
+        public ItemMeterData(boolean inverted, int slot, int threshold) {
+            this.inverted = inverted;
+            this.slot = slot;
+            this.threshold = threshold;
+        }
+
+        @Nonnull
+        @Override
+        public ISerializableObject copy() {
+            return new ItemMeterData(inverted, slot, threshold);
+        }
+
+        @Nonnull
+        @Override
+        public NBTBase saveDataToNBT() {
+            NBTTagCompound tag = new NBTTagCompound();
+            tag.setBoolean("invert", inverted);
+            tag.setInteger("slot", slot);
+            tag.setInteger("threshold", threshold);
+            return tag;
+        }
+
+        @Override
+        public void writeToByteBuf(ByteBuf aBuf) {
+            aBuf.writeBoolean(inverted);
+            aBuf.writeInt(slot);
+            aBuf.writeInt(threshold);
+        }
+
+        @Override
+        public void loadDataFromNBT(NBTBase aNBT) {
+            NBTTagCompound tag = (NBTTagCompound) aNBT;
+            inverted = tag.getBoolean("invert");
+            slot = tag.getInteger("slot");
+            threshold = tag.getInteger("threshold");
+        }
+
+        @Nonnull
+        @Override
+        public ISerializableObject readFromPacket(ByteArrayDataInput aBuf, EntityPlayerMP aPlayer) {
+            inverted = aBuf.readBoolean();
+            slot = aBuf.readInt();
+            threshold = aBuf.readInt();
+            return this;
+        }
+    }
+
     private class GUI extends GT_GUICover {
         private final byte side;
         private final int coverID;
-        private final GT_GuiIconCheckButton button;
+        private final GT_GuiIconCheckButton invertedButton;
         private final GT_GuiIntegerTextBox intSlot;
         private final GT_GuiFakeItemButton intSlotIcon;
-        private int coverVariable;
+        private final GT_GuiIntegerTextBox thresholdSlot;
+        private final ItemMeterData coverVariable;
+
+        private final int maxSlot;
 
         private static final int startX = 10;
         private static final int startY = 25;
         private static final int spaceX = 18;
         private static final int spaceY = 18;
 
-        private final int maxSlot;
-
         private final String ALL = trans("ALL", "All");
         private final String INVERTED = trans("INVERTED","Inverted");
         private final String NORMAL = trans("NORMAL","Normal");
 
-        public GUI(byte aSide, int aCoverID, int aCoverVariable, ICoverable aTileEntity) {
+        public GUI(byte aSide, int aCoverID, ItemMeterData aCoverVariable, ICoverable aTileEntity) {
             super(aTileEntity, 176, 107, GT_Utility.intToStack(aCoverID));
             this.side = aSide;
             this.coverID = aCoverID;
             this.coverVariable = aCoverVariable;
 
-            button = new GT_GuiIconCheckButton(this, 0, startX + spaceX*0, startY+spaceY*0, GT_GuiIcon.REDSTONE_ON, GT_GuiIcon.REDSTONE_OFF);
+            invertedButton = new GT_GuiIconCheckButton(this, 0, startX + spaceX*0, startY+spaceY*0, GT_GuiIcon.REDSTONE_ON, GT_GuiIcon.REDSTONE_OFF, INVERTED, NORMAL);
 
             intSlot = new GT_GuiIntegerTextBox(this, 1, startX + spaceX * 0, startY + spaceY * 1 + 2, spaceX * 2+5, 12);
             intSlot.setMaxStringLength(6);
@@ -202,17 +307,17 @@ public class GT_Cover_ItemMeter extends GT_CoverBehavior {
 
             if (maxSlot == -1 || tile instanceof GT_MetaTileEntity_DigitalChestBase)
                 intSlot.setEnabled(false);
+
+            thresholdSlot = new GT_GuiIntegerTextBox(this, 2, startX + spaceX * 0, startY + spaceY * 2 + 2, spaceX * 2 + 5, 12);
+            thresholdSlot.setMaxStringLength(6);
         }
 
         @Override
         public void drawExtras(int mouseX, int mouseY, float parTicks) {
             super.drawExtras(mouseX, mouseY, parTicks);
-            if (isInverted())
-                this.getFontRenderer().drawString(INVERTED,  startX + spaceX*3, 4+startY+spaceY*0, 0xFF555555);
-            else
-                this.getFontRenderer().drawString(NORMAL,  startX + spaceX*3, 4+startY+spaceY*0, 0xFF555555);
-
-            this.getFontRenderer().drawString(trans("254", "Detect slot#"),     startX + spaceX*3, 4+startY+spaceY*1, 0xFF555555);
+            this.getFontRenderer().drawString(coverVariable.inverted ? INVERTED : NORMAL, startX + spaceX*3, 4+startY+spaceY*0, 0xFF555555);
+            this.getFontRenderer().drawString(trans("254", "Detect slot#"), startX + spaceX*3, 4+startY+spaceY*1, 0xFF555555);
+            this.getFontRenderer().drawString(trans("221", "Item threshold"), startX + spaceX * 3, startY + spaceY * 2 + 4, 0xFF555555);
         }
 
         @Override
@@ -224,109 +329,130 @@ public class GT_Cover_ItemMeter extends GT_CoverBehavior {
 
         @Override
         public void buttonClicked(GuiButton btn) {
-            if (isInverted())
-                coverVariable = (coverVariable & ~INVERT_BIT);
-            else
-                coverVariable = (coverVariable | INVERT_BIT);
-
-            GT_Values.NW.sendToServer(new GT_Packet_TileEntityCover(side, coverID, coverVariable, tile));
+            coverVariable.inverted = !coverVariable.inverted;
+            GT_Values.NW.sendToServer(new GT_Packet_TileEntityCoverNew(side, coverID, coverVariable, tile));
             update();
         }
 
-        private void update() {
-            resetTextBox(intSlot);
-            button.setChecked(isInverted());
-
-            int slot = getSlot();
-            if (slot < 0) {
-                intSlotIcon.setItem(null);
-                return;
-            }
-            if (tile instanceof TileEntity && !super.tile.isDead()) {
-                if (tile.getSizeInventory() >= slot) {
-                    ItemStack item = tile.getStackInSlot(slot);
-                    intSlotIcon.setItem(item);
-                    return;
-                }
-            }
-            intSlotIcon.setItem(null);
-        }
-
         @Override
         public void onMouseWheel(int x, int y, int delta) {
-            for (GT_GuiIntegerTextBox box : textBoxes) {
-                if (box.isFocused()) {
-                    int step = Math.max(1, Math.abs(delta / 120));
-                    step = (isShiftKeyDown() ? 50 : isCtrlKeyDown() ? 5 : 1) * (delta > 0 ? step : -step);
-                    int val = parseTextBox(box);
+            if (intSlot.isFocused()) {
+                int step = Math.max(1, Math.abs(delta / 120));
+                step = (isShiftKeyDown() ? 50 : isCtrlKeyDown() ? 5 : 1) * (delta > 0 ? step : -step);
+                int val = parseTextBox(intSlot);
 
-                    if (val < 0)
-                        val = -1;
+                if (val < 0)
+                    val = -1;
 
-                    val = val + step;
+                val = val + step;
 
-                    if (val < 0)
-                        val = -1;
-                    else if (val > maxSlot )
-                        val = maxSlot;
+                if (val < 0)
+                    val = -1;
+                else if (val > maxSlot)
+                    val = maxSlot;
 
-                    box.setText(val < 0 ? ALL : String.valueOf(val));
-                    return;
+                intSlot.setText(val < 0 ? ALL : Integer.toString(val));
+            } else if (thresholdSlot.isFocused()) {
+                int val = parseTextBox(thresholdSlot);
+
+                int step = 1;
+                if (isShiftKeyDown()) {
+                    step *= 64;
+                }
+                if (isCtrlKeyDown()) {
+                    step *= 10;
                 }
+
+                val += step * Integer.signum(delta);
+
+                int upperBound = maxSlot > 0 ? maxSlot * 64 : 999_999;
+                val = GT_Utility.clamp(val, 0, upperBound);
+                thresholdSlot.setText(Integer.toString(val));
             }
         }
 
         @Override
         public void applyTextBox(GT_GuiIntegerTextBox box) {
-            int val = parseTextBox(box)+1;
-
-            if (val > SLOT_MASK)
-                val = SLOT_MASK;
-            else if (val < 0)
-                val = 0;
-
-            coverVariable = val | CONVERTED_BIT | (coverVariable & INVERT_BIT);
+            if (box == intSlot) {
+                coverVariable.slot = parseTextBox(box);
+            } else if (box == thresholdSlot) {
+                coverVariable.threshold = parseTextBox(thresholdSlot);
+            }
 
-            GT_Values.NW.sendToServer(new GT_Packet_TileEntityCover(side, coverID, coverVariable, tile));
+            GT_Values.NW.sendToServer(new GT_Packet_TileEntityCoverNew(side, coverID, coverVariable, tile));
             update();
         }
 
         @Override
         public void resetTextBox(GT_GuiIntegerTextBox box) {
-            box.setText(getSlot() < 0 ? ALL : String.valueOf(getSlot()));
+            if (box == intSlot) {
+                intSlot.setText(coverVariable.slot < 0 ? ALL : Integer.toString(coverVariable.slot));
+            } else if (box == thresholdSlot) {
+                thresholdSlot.setText(Integer.toString(coverVariable.threshold));
+            }
         }
 
-        private int parseTextBox(GT_GuiIntegerTextBox box) {
-            String text = box.getText();
-            if (text == null)
-                return -1;
-            text = text.trim();
-            if (text.startsWith(ALL))
-                text = text.substring(ALL.length());
-
-            if (text.isEmpty())
-                return -1;
-
-            int val;
-            try {
-                val = Integer.parseInt(text);
-            } catch (NumberFormatException e) {
-                return -1;
-            }
+        private void update() {
+            invertedButton.setChecked(coverVariable.inverted);
+            resetTextBox(intSlot);
+            resetTextBox(thresholdSlot);
 
-            if (val < 0)
-                return -1;
-            else if (maxSlot < val)
-                return maxSlot;
-            return val;
+            if (coverVariable.slot < 0) {
+                intSlotIcon.setItem(null);
+                return;
+            }
+            if (tile instanceof TileEntity && !super.tile.isDead()) {
+                if (tile.getSizeInventory() >= coverVariable.slot) {
+                    ItemStack item = tile.getStackInSlot(coverVariable.slot);
+                    intSlotIcon.setItem(item);
+                    return;
+                }
+            }
+            intSlotIcon.setItem(null);
         }
 
-        private boolean isInverted() {
-            return ((coverVariable & INVERT_BIT) != 0);
-        }
+        private int parseTextBox(GT_GuiIntegerTextBox box) {
+            if (box == intSlot) {
+                String text = box.getText();
+                if (text == null)
+                    return -1;
+                text = text.trim();
+                if (text.startsWith(ALL))
+                    text = text.substring(ALL.length());
+
+                if (text.isEmpty())
+                    return -1;
+
+                int val;
+                try {
+                    val = Integer.parseInt(text);
+                } catch (NumberFormatException e) {
+                    return -1;
+                }
+
+                if (val < 0)
+                    return -1;
+                else if (maxSlot < val)
+                    return maxSlot;
+                return val;
+            } else if (box == thresholdSlot) {
+                String text = box.getText();
+                if (text == null) {
+                    return 0;
+                }
+
+                int val;
+                try {
+                    val = Integer.parseInt(text.trim());
+                } catch (NumberFormatException e) {
+                    return 0;
+                }
+
+                int upperBound = maxSlot > 0 ? maxSlot * 64 : 999_999;
+                return GT_Utility.clamp(val, 0, upperBound);
+            }
 
-        private int getSlot() {
-            return (coverVariable & SLOT_MASK) - 1;
+            throw new UnsupportedOperationException("Unknown text box: " + box);
         }
     }
 }
diff --git a/src/main/java/gregtech/common/covers/GT_Cover_LiquidMeter.java b/src/main/java/gregtech/common/covers/GT_Cover_LiquidMeter.java
index ed75bca967..f3b0ad5b23 100644
--- a/src/main/java/gregtech/common/covers/GT_Cover_LiquidMeter.java
+++ b/src/main/java/gregtech/common/covers/GT_Cover_LiquidMeter.java
@@ -1,29 +1,55 @@
 package gregtech.common.covers;
 
+import com.google.common.io.ByteArrayDataInput;
 import gregtech.api.enums.GT_Values;
 import gregtech.api.gui.GT_GUICover;
 import gregtech.api.gui.widgets.GT_GuiIcon;
 import gregtech.api.gui.widgets.GT_GuiIconCheckButton;
+import gregtech.api.gui.widgets.GT_GuiIntegerTextBox;
 import gregtech.api.interfaces.tileentity.ICoverable;
-import gregtech.api.net.GT_Packet_TileEntityCover;
-import gregtech.api.util.GT_CoverBehavior;
+import gregtech.api.net.GT_Packet_TileEntityCoverNew;
+import gregtech.api.util.GT_CoverBehaviorBase;
 import gregtech.api.util.GT_Utility;
+import gregtech.api.util.ISerializableObject;
+import io.netty.buffer.ByteBuf;
 import net.minecraft.client.gui.GuiButton;
 import net.minecraft.entity.player.EntityPlayer;
+import net.minecraft.entity.player.EntityPlayerMP;
+import net.minecraft.nbt.NBTBase;
+import net.minecraft.nbt.NBTTagCompound;
+import net.minecraft.world.World;
 import net.minecraftforge.common.util.ForgeDirection;
 import net.minecraftforge.fluids.Fluid;
 import net.minecraftforge.fluids.FluidStack;
 import net.minecraftforge.fluids.FluidTankInfo;
 import net.minecraftforge.fluids.IFluidHandler;
 
-public class GT_Cover_LiquidMeter extends GT_CoverBehavior {
+import javax.annotation.Nonnull;
+import java.util.Arrays;
+
+public class GT_Cover_LiquidMeter extends GT_CoverBehaviorBase<GT_Cover_LiquidMeter.LiquidMeterData> {
+
+    public GT_Cover_LiquidMeter() {
+        super(LiquidMeterData.class);
+    }
+
+    @Override
+    public LiquidMeterData createDataObject(int aLegacyData) {
+        return new LiquidMeterData(aLegacyData == 0, 0);
+    }
+
+    @Override
+    public LiquidMeterData createDataObject() {
+        return new LiquidMeterData();
+    }
+
     @Override
-    public boolean isRedstoneSensitive(byte aSide, int aCoverID, int aCoverVariable, ICoverable aTileEntity, long aTimer) {
+    protected boolean isRedstoneSensitiveImpl(byte aSide, int aCoverID, LiquidMeterData aCoverVariable, ICoverable aTileEntity, long aTimer) {
         return false;
     }
 
     @Override
-    public int doCoverThings(byte aSide, byte aInputRedstone, int aCoverID, int aCoverVariable, ICoverable aTileEntity, long aTimer) {
+    protected LiquidMeterData doCoverThingsImpl(byte aSide, byte aInputRedstone, int aCoverID, LiquidMeterData aCoverVariable, ICoverable aTileEntity, long aTimer) {
         if ((aTileEntity instanceof IFluidHandler)) {
             FluidTankInfo[] tTanks = ((IFluidHandler) aTileEntity).getTankInfo(ForgeDirection.UNKNOWN);
             long tMax = 0;
@@ -39,12 +65,32 @@ public class GT_Cover_LiquidMeter extends GT_CoverBehavior {
                     }
                 }
             }
-            if(tUsed==0L)//nothing
-                aTileEntity.setOutputRedstoneSignal(aSide, (byte)(aCoverVariable == 0 ? 15 : 0));
-            else if(tUsed >= tMax)//full
-                aTileEntity.setOutputRedstoneSignal(aSide, (byte)(aCoverVariable == 0 ? 0 : 15));
-            else//1-14 range
-                aTileEntity.setOutputRedstoneSignal(aSide, (byte)(aCoverVariable == 0 ? 14-((14*tUsed)/tMax) : 1+((14*tUsed)/tMax)) );
+
+            long redstoneSignal;
+            if (tUsed == 0L) {
+                // nothing
+                redstoneSignal = 0;
+            } else if (tUsed >= tMax) {
+                // full
+                redstoneSignal = 15;
+            } else {
+                // 1-14 range
+                redstoneSignal = 1 + (14 * tUsed) / tMax;
+            }
+
+            if (aCoverVariable.inverted) {
+                redstoneSignal = 15 - redstoneSignal;
+            }
+
+            if (aCoverVariable.threshold > 0) {
+                if (aCoverVariable.inverted && tUsed >= aCoverVariable.threshold) {
+                    redstoneSignal = 0;
+                } else if (!aCoverVariable.inverted && tUsed < aCoverVariable.threshold) {
+                    redstoneSignal = 0;
+                }
+            }
+
+            aTileEntity.setOutputRedstoneSignal(aSide, (byte) redstoneSignal);
         } else {
             aTileEntity.setOutputRedstoneSignal(aSide, (byte)0);
         }
@@ -52,52 +98,54 @@ public class GT_Cover_LiquidMeter extends GT_CoverBehavior {
     }
 
     @Override
-    public int onCoverScrewdriverclick(byte aSide, int aCoverID, int aCoverVariable, ICoverable aTileEntity, EntityPlayer aPlayer, float aX, float aY, float aZ) {
-        if (aCoverVariable == 0) {
-            GT_Utility.sendChatToPlayer(aPlayer, trans("055", "Normal"));
+    protected LiquidMeterData onCoverScrewdriverClickImpl(byte aSide, int aCoverID, LiquidMeterData aCoverVariable, ICoverable aTileEntity, EntityPlayer aPlayer, float aX, float aY, float aZ) {
+        if (aCoverVariable.inverted) {
+            aCoverVariable.inverted = false;
+            GT_Utility.sendChatToPlayer(aPlayer, trans("055","Normal"));
         } else {
-            GT_Utility.sendChatToPlayer(aPlayer, trans("054", "Inverted"));
+            aCoverVariable.inverted = true;
+            GT_Utility.sendChatToPlayer(aPlayer, trans("054","Inverted"));
         }
-        return aCoverVariable == 0 ? 1 : 0;
+        return aCoverVariable;
     }
 
     @Override
-    public boolean letsEnergyIn(byte aSide, int aCoverID, int aCoverVariable, ICoverable aTileEntity) {
+    protected boolean letsEnergyInImpl(byte aSide, int aCoverID, LiquidMeterData aCoverVariable, ICoverable aTileEntity) {
         return true;
     }
 
     @Override
-    public boolean letsEnergyOut(byte aSide, int aCoverID, int aCoverVariable, ICoverable aTileEntity) {
+    protected boolean letsEnergyOutImpl(byte aSide, int aCoverID, LiquidMeterData aCoverVariable, ICoverable aTileEntity) {
         return true;
     }
 
     @Override
-    public boolean letsFluidIn(byte aSide, int aCoverID, int aCoverVariable, Fluid aFluid, ICoverable aTileEntity) {
+    protected boolean letsFluidInImpl(byte aSide, int aCoverID, LiquidMeterData aCoverVariable, Fluid aFluid, ICoverable aTileEntity) {
         return true;
     }
 
     @Override
-    public boolean letsFluidOut(byte aSide, int aCoverID, int aCoverVariable, Fluid aFluid, ICoverable aTileEntity) {
+    protected boolean letsFluidOutImpl(byte aSide, int aCoverID, LiquidMeterData aCoverVariable, Fluid aFluid, ICoverable aTileEntity) {
         return true;
     }
 
     @Override
-    public boolean letsItemsIn(byte aSide, int aCoverID, int aCoverVariable, int aSlot, ICoverable aTileEntity) {
+    protected boolean letsItemsInImpl(byte aSide, int aCoverID, LiquidMeterData aCoverVariable, int aSlot, ICoverable aTileEntity) {
         return true;
     }
 
     @Override
-    public boolean letsItemsOut(byte aSide, int aCoverID, int aCoverVariable, int aSlot, ICoverable aTileEntity) {
+    protected boolean letsItemsOutImpl(byte aSide, int aCoverID, LiquidMeterData aCoverVariable, int aSlot, ICoverable aTileEntity) {
         return true;
     }
 
     @Override
-    public boolean manipulatesSidedRedstoneOutput(byte aSide, int aCoverID, int aCoverVariable, ICoverable aTileEntity) {
+    protected boolean manipulatesSidedRedstoneOutputImpl(byte aSide, int aCoverID, LiquidMeterData aCoverVariable, ICoverable aTileEntity) {
         return true;
     }
 
     @Override
-    public int getTickRate(byte aSide, int aCoverID, int aCoverVariable, ICoverable aTileEntity) {
+    protected int getTickRateImpl(byte aSide, int aCoverID, LiquidMeterData aCoverVariable, ICoverable aTileEntity) {
         return 5;
     }
     /**
@@ -110,73 +158,180 @@ public class GT_Cover_LiquidMeter extends GT_CoverBehavior {
     }
 
     @Override
-    public Object getClientGUI(byte aSide, int aCoverID, int coverData, ICoverable aTileEntity)  {
+    public Object getClientGUIImpl(byte aSide, int aCoverID, LiquidMeterData coverData, ICoverable aTileEntity, EntityPlayer aPlayer, World aWorld) {
         return new GUI(aSide, aCoverID, coverData, aTileEntity);
     }
 
+    public static class LiquidMeterData implements ISerializableObject {
+        private boolean inverted;
+        /** The special value {@code 0} means threshold check is disabled. */
+        private int threshold;
+
+        public LiquidMeterData() {
+            inverted = false;
+            threshold = 0;
+        }
+
+        public LiquidMeterData(boolean inverted, int threshold) {
+            this.inverted = inverted;
+            this.threshold = threshold;
+        }
+
+        @Nonnull
+        @Override
+        public ISerializableObject copy() {
+            return new LiquidMeterData(inverted, threshold);
+        }
+
+        @Nonnull
+        @Override
+        public NBTBase saveDataToNBT() {
+            NBTTagCompound tag = new NBTTagCompound();
+            tag.setBoolean("invert", inverted);
+            tag.setInteger("threshold", threshold);
+            return tag;
+        }
+
+        @Override
+        public void writeToByteBuf(ByteBuf aBuf) {
+            aBuf.writeBoolean(inverted);
+            aBuf.writeInt(threshold);
+        }
+
+        @Override
+        public void loadDataFromNBT(NBTBase aNBT) {
+            NBTTagCompound tag = (NBTTagCompound) aNBT;
+            inverted = tag.getBoolean("invert");
+            threshold = tag.getInteger("threshold");
+        }
+
+        @Nonnull
+        @Override
+        public ISerializableObject readFromPacket(ByteArrayDataInput aBuf, EntityPlayerMP aPlayer) {
+            inverted = aBuf.readBoolean();
+            threshold = aBuf.readInt();
+            return this;
+        }
+    }
+
     private class GUI extends GT_GUICover {
         private final byte side;
         private final int coverID;
-        private int coverVariable;
+        private final GT_GuiIconCheckButton invertedButton;
+        private final GT_GuiIntegerTextBox thresholdSlot;
+        private final LiquidMeterData coverVariable;
+
+        private final int maxCapacity;
 
         private static final int startX = 10;
         private static final int startY = 25;
         private static final int spaceX = 18;
         private static final int spaceY = 18;
 
-        public GUI(byte aSide, int aCoverID, int aCoverVariable, ICoverable aTileEntity) {
+        private final String INVERTED = trans("INVERTED", "Inverted");
+        private final String NORMAL = trans("NORMAL", "Normal");
+
+        public GUI(byte aSide, int aCoverID, LiquidMeterData aCoverVariable, ICoverable aTileEntity) {
             super(aTileEntity, 176, 107, GT_Utility.intToStack(aCoverID));
             this.side = aSide;
             this.coverID = aCoverID;
             this.coverVariable = aCoverVariable;
-            new GT_GuiIconCheckButton(this, 0, startX + spaceX*0, startY+spaceY*0, GT_GuiIcon.REDSTONE_ON, GT_GuiIcon.REDSTONE_OFF);
+
+            invertedButton = new GT_GuiIconCheckButton(this, 0, startX + spaceX * 0, startY + spaceY * 0, GT_GuiIcon.REDSTONE_ON, GT_GuiIcon.REDSTONE_OFF, INVERTED, NORMAL);
+            thresholdSlot = new GT_GuiIntegerTextBox(this, 2, startX + spaceX * 0, startY + spaceY * 1 + 2, spaceX * 4 + 5, 12);
+
+            if (tile instanceof IFluidHandler) {
+                FluidTankInfo[] tanks = ((IFluidHandler) tile).getTankInfo(ForgeDirection.UNKNOWN);
+                maxCapacity =
+                        Arrays.stream(tanks)
+                                .mapToInt(tank -> tank.capacity)
+                                .sum();
+            } else {
+                maxCapacity = -1;
+            }
         }
 
         @Override
         public void drawExtras(int mouseX, int mouseY, float parTicks) {
             super.drawExtras(mouseX, mouseY, parTicks);
-            String s2;
-            if (coverVariable == 0)
-                s2 = trans("INVERTED","Inverted");
-            else
-                s2 = trans("NORMAL","Normal");
-
-            this.fontRendererObj.drawString(s2,  startX + spaceX*1, 4+startY+spaceY*0, 0xFF555555);
+            this.fontRendererObj.drawString(coverVariable.inverted ? INVERTED : NORMAL, startX + spaceX * 1, 4 + startY + spaceY * 0, 0xFF555555);
+            this.getFontRenderer().drawString(trans("222", "Fluid threshold"), startX + spaceX * 5 - 10, startY + spaceY * 1 + 4, 0xFF555555);
         }
 
         @Override
         protected void onInitGui(int guiLeft, int guiTop, int gui_width, int gui_height) {
-            updateButtons();
+            update();
+            thresholdSlot.setFocused(true);
+        }
+
+        @Override
+        public void buttonClicked(GuiButton btn) {
+            coverVariable.inverted = !coverVariable.inverted;
+            GT_Values.NW.sendToServer(new GT_Packet_TileEntityCoverNew(side, coverID, coverVariable, tile));
+            update();
+        }
+
+        @Override
+        public void onMouseWheel(int x, int y, int delta) {
+            if (thresholdSlot.isFocused()) {
+                int val = parseTextBox(thresholdSlot);
+
+                int step = 1000;
+                if (isShiftKeyDown()) {
+                    step *= 100;
+                }
+                if (isCtrlKeyDown()) {
+                    step /= 10;
+                }
+
+                val += step * Integer.signum(delta);
+                int upperBound = maxCapacity > 0 ? maxCapacity : Integer.MAX_VALUE;
+                val = GT_Utility.clamp(val, 0, upperBound);
+                thresholdSlot.setText(Integer.toString(val));
+            }
         }
 
         @Override
-        public void buttonClicked(GuiButton btn){
-            boolean state = false;
-            if (btn.id == 0)
-                state = ((GT_GuiIconCheckButton) btn).isChecked();
-
-            coverVariable = getNewCoverVariable(btn.id, state);
-            GT_Values.NW.sendToServer(new GT_Packet_TileEntityCover(side, coverID, coverVariable, tile));
-            updateButtons();
-        }
-
-        private void updateButtons(){
-            GuiButton b;
-            for (Object o : buttonList) {
-                b = (GuiButton) o;
-                if(b.id == 0)
-                    ((GT_GuiIconCheckButton) b).setChecked(coverVariable == 0);
+        public void applyTextBox(GT_GuiIntegerTextBox box) {
+            if (box == thresholdSlot) {
+                coverVariable.threshold = parseTextBox(thresholdSlot);
             }
+
+            GT_Values.NW.sendToServer(new GT_Packet_TileEntityCoverNew(side, coverID, coverVariable, tile));
+            update();
         }
 
-        private int getNewCoverVariable(int id, boolean buttonState) {
-            if (id == 0) {
-                if (buttonState)
-                    return coverVariable | 0x1;
-                else
-                    return coverVariable & ~0x1;
+        @Override
+        public void resetTextBox(GT_GuiIntegerTextBox box) {
+            if (box == thresholdSlot) {
+                thresholdSlot.setText(Integer.toString(coverVariable.threshold));
             }
-            return coverVariable;
+        }
+
+        private void update() {
+            invertedButton.setChecked(coverVariable.inverted);
+            resetTextBox(thresholdSlot);
+        }
+
+        private int parseTextBox(GT_GuiIntegerTextBox box) {
+            if (box == thresholdSlot) {
+                String text = box.getText();
+                if (text == null) {
+                    return 0;
+                }
+
+                int val;
+                try {
+                    val = Integer.parseInt(text.trim());
+                } catch (NumberFormatException e) {
+                    return 0;
+                }
+
+                int upperBound = maxCapacity > 0 ? maxCapacity : Integer.MAX_VALUE;
+                return GT_Utility.clamp(val, 0, upperBound);
+            }
+
+            throw new UnsupportedOperationException("Unknown text box: " + box);
         }
     }
 }