Map Unicode to CC's charset for char/paste events

We now convert uncode characters from "char" and "paste" events to CC's
charset[^1], rather than just leaving them unconverted. This means you
can paste in special characters like "♠" or "🮙" and they will be
converted correctly. Characters outside that range will be replaced with
"?", as before.

It would be nice to make this a bi-directional mapping, and do this for
Lua methods too (e.g. os.setComputerLabel). However, that has much wider
ramifications (and more likelyhood of breaking something), so avoiding
that for now.

 - Remove the generic "queue event" client->server message, and replace
   it with separate char/terminate/paste messages. This allows us to
   delete a chunk of code (all the NBT<->Object conversion), and makes
   server-side validation of events possible.

 - Fix os.setComputerLabel accepting the section sign — this is treated
   as special by Minecraft's formatting code. Sorry, no fun allowed.

 - Convert paste/char codepoints to CC's charset. Sadly MC's char hook
   splits the codepoint into surrogate pairs, which we *don't* attempt
   to reconstruct, so you can't currently use unicode input for block
   characters — you can paste them though!

[^1]: I'm referring this to the "terminal charset" within the code. I've
flip-flopped between "CraftOS", "terminal", "ComputerCraft", but feel
especially great.

projects/common/src/client/java/dan200/computercraft/client/gui/ClientInputHandler.java

@@ -10,10 +10,10 @@ import dan200.computercraft.shared.computer.menu.ComputerMenu;
 import dan200.computercraft.shared.network.server.ComputerActionServerMessage;
 import dan200.computercraft.shared.network.server.KeyEventServerMessage;
 import dan200.computercraft.shared.network.server.MouseEventServerMessage;
-import dan200.computercraft.shared.network.server.QueueEventServerMessage;
+import dan200.computercraft.shared.network.server.PasteEventComputerMessage;
 import net.minecraft.world.inventory.AbstractContainerMenu;
 
-import javax.annotation.Nullable;
+import java.nio.ByteBuffer;
 
 /**
  * An {@link InputHandler} for use on the client.
@@ -27,6 +27,11 @@ public final class ClientInputHandler implements InputHandler {
         this.menu = menu;
     }
 
+    @Override
+    public void terminate() {
+        ClientNetworking.sendToServer(new ComputerActionServerMessage(menu, ComputerActionServerMessage.Action.TERMINATE));
+    }
+
     @Override
     public void turnOn() {
         ClientNetworking.sendToServer(new ComputerActionServerMessage(menu, ComputerActionServerMessage.Action.TURN_ON));
@@ -42,11 +47,6 @@ public final class ClientInputHandler implements InputHandler {
         ClientNetworking.sendToServer(new ComputerActionServerMessage(menu, ComputerActionServerMessage.Action.REBOOT));
     }
 
-    @Override
-    public void queueEvent(String event, @Nullable Object[] arguments) {
-        ClientNetworking.sendToServer(new QueueEventServerMessage(menu, event, arguments));
-    }
-
     @Override
     public void keyDown(int key, boolean repeat) {
         ClientNetworking.sendToServer(new KeyEventServerMessage(menu, repeat ? KeyEventServerMessage.Action.REPEAT : KeyEventServerMessage.Action.DOWN, key));
@@ -57,6 +57,16 @@ public final class ClientInputHandler implements InputHandler {
         ClientNetworking.sendToServer(new KeyEventServerMessage(menu, KeyEventServerMessage.Action.UP, key));
     }
 
+    @Override
+    public void charTyped(byte chr) {
+        ClientNetworking.sendToServer(new KeyEventServerMessage(menu, KeyEventServerMessage.Action.CHAR, chr));
+    }
+
+    @Override
+    public void paste(ByteBuffer contents) {
+        ClientNetworking.sendToServer(new PasteEventComputerMessage(menu, contents));
+    }
+
     @Override
     public void mouseClick(int button, int x, int y) {
         ClientNetworking.sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.Action.CLICK, button, x, y));

projects/common/src/client/java/dan200/computercraft/client/gui/widgets/ComputerSidebar.java

@@ -55,7 +55,7 @@ public final class ComputerSidebar {
         add.accept(new DynamicImageButton(
             x, y, ICON_WIDTH, ICON_HEIGHT,
             GuiSprites.TERMINATE::get,
-            b -> input.queueEvent("terminate"),
+            b -> input.terminate(),
             new HintedMessage(
                 Component.translatable("gui.computercraft.tooltip.terminate"),
                 Component.translatable("gui.computercraft.tooltip.terminate.key")

projects/common/src/client/java/dan200/computercraft/client/gui/widgets/TerminalWidget.java

@@ -71,11 +71,8 @@ public class TerminalWidget extends AbstractWidget {
 
     @Override
     public boolean charTyped(char ch, int modifiers) {
-        if (ch >= 32 && ch <= 126 || ch >= 160 && ch <= 255) {
-            // Queue the char event for any printable chars in byte range
-            computer.queueEvent("char", new Object[]{ Character.toString(ch) });
-        }
-
+        var terminalChar = StringUtil.unicodeToTerminal(ch);
+        if (StringUtil.isTypableChar(terminalChar)) computer.charTyped(terminalChar);
         return true;
     }
 
@@ -112,8 +109,8 @@ public class TerminalWidget extends AbstractWidget {
     }
 
     private void paste() {
-        var clipboard = StringUtil.normaliseClipboardString(Minecraft.getInstance().keyboardHandler.getClipboard());
-        if (!clipboard.isEmpty()) computer.queueEvent("paste", new Object[]{ clipboard });
+        var clipboard = StringUtil.getClipboardString(Minecraft.getInstance().keyboardHandler.getClipboard());
+        if (clipboard.remaining() > 0) computer.paste(clipboard);
     }
 
     @Override
@@ -222,7 +219,7 @@ public class TerminalWidget extends AbstractWidget {
 
     public void update() {
         if (terminateTimer >= 0 && terminateTimer < TERMINATE_TIME && (terminateTimer += 0.05f) > TERMINATE_TIME) {
-            computer.queueEvent("terminate");
+            computer.terminate();
         }
 
         if (shutdownTimer >= 0 && shutdownTimer < TERMINATE_TIME && (shutdownTimer += 0.05f) > TERMINATE_TIME) {

projects/common/src/main/java/dan200/computercraft/shared/computer/core/InputHandler.java

@@ -6,7 +6,7 @@ package dan200.computercraft.shared.computer.core;
 
 import dan200.computercraft.shared.computer.menu.ServerInputHandler;
 
-import javax.annotation.Nullable;
+import java.nio.ByteBuffer;
 
 /**
  * Handles user-provided input, forwarding it to a computer. This describes the "shape" of both the client-and
@@ -16,16 +16,14 @@ import javax.annotation.Nullable;
  * @see ServerComputer
  */
 public interface InputHandler {
-    void queueEvent(String event, @Nullable Object[] arguments);
-
-    default void queueEvent(String event) {
-        queueEvent(event, null);
-    }
-
     void keyDown(int key, boolean repeat);
 
     void keyUp(int key);
 
+    void charTyped(byte chr);
+
+    void paste(ByteBuffer contents);
+
     void mouseClick(int button, int x, int y);
 
     void mouseUp(int button, int x, int y);
@@ -34,6 +32,8 @@ public interface InputHandler {
 
     void mouseScroll(int direction, int x, int y);
 
+    void terminate();
+
     void shutdown();
 
     void turnOn();

projects/common/src/main/java/dan200/computercraft/shared/computer/core/ServerComputer.java

@@ -168,7 +168,7 @@ public class ServerComputer implements ComputerEnvironment, ComputerEvents.Recei
         var server = level.getServer();
 
         for (var player : server.getPlayerList().getPlayers()) {
-            if (player.containerMenu instanceof ComputerMenu && ((ComputerMenu) player.containerMenu).getComputer() == this) {
+            if (player.containerMenu instanceof ComputerMenu menu && menu.getComputer() == this) {
                 ServerNetworking.sendToPlayer(createPacket.apply(player.containerMenu), player);
             }
         }

projects/common/src/main/java/dan200/computercraft/shared/computer/menu/ServerInputState.java

@@ -8,6 +8,7 @@ import dan200.computercraft.core.apis.handles.ByteBufferChannel;
 import dan200.computercraft.core.apis.transfer.TransferredFile;
 import dan200.computercraft.core.apis.transfer.TransferredFiles;
 import dan200.computercraft.core.computer.ComputerEvents;
+import dan200.computercraft.core.util.StringUtil;
 import dan200.computercraft.shared.computer.upload.FileSlice;
 import dan200.computercraft.shared.computer.upload.FileUpload;
 import dan200.computercraft.shared.computer.upload.UploadResult;
@@ -22,6 +23,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import javax.annotation.Nullable;
+import java.nio.ByteBuffer;
 import java.util.List;
 import java.util.UUID;
 
@@ -49,11 +51,6 @@ public class ServerInputState<T extends AbstractContainerMenu & ComputerMenu> im
         this.owner = owner;
     }
 
-    @Override
-    public void queueEvent(String event, @Nullable Object[] arguments) {
-        owner.getComputer().queueEvent(event, arguments);
-    }
-
     @Override
     public void keyDown(int key, boolean repeat) {
         keysDown.add(key);
@@ -66,6 +63,23 @@ public class ServerInputState<T extends AbstractContainerMenu & ComputerMenu> im
         ComputerEvents.keyUp(owner.getComputer(), key);
     }
 
+    @Override
+    public void charTyped(byte chr) {
+        if (StringUtil.isTypableChar(chr)) ComputerEvents.charTyped(owner.getComputer(), chr);
+    }
+
+    @Override
+    public void paste(ByteBuffer contents) {
+        if (contents.remaining() > 0 && isValidClipboard(contents)) ComputerEvents.paste(owner.getComputer(), contents);
+    }
+
+    private static boolean isValidClipboard(ByteBuffer buffer) {
+        for (int i = buffer.remaining(), max = buffer.limit(); i < max; i++) {
+            if (!StringUtil.isTypableChar(buffer.get(i))) return false;
+        }
+        return true;
+    }
+
     @Override
     public void mouseClick(int button, int x, int y) {
         lastMouseX = x;
@@ -101,6 +115,11 @@ public class ServerInputState<T extends AbstractContainerMenu & ComputerMenu> im
         ComputerEvents.mouseScroll(owner.getComputer(), direction, x, y);
     }
 
+    @Override
+    public void terminate() {
+        owner.getComputer().queueEvent("terminate");
+    }
+
     @Override
     public void shutdown() {
         owner.getComputer().shutdown();

projects/common/src/main/java/dan200/computercraft/shared/network/NetworkMessages.java

@@ -27,9 +27,9 @@ public final class NetworkMessages {
     private static final List<MessageType<? extends NetworkMessage<ClientNetworkContext>>> clientMessages = new ArrayList<>();
 
     public static final MessageType<ComputerActionServerMessage> COMPUTER_ACTION = registerServerbound(0, "computer_action", ComputerActionServerMessage.class, ComputerActionServerMessage::new);
-    public static final MessageType<QueueEventServerMessage> QUEUE_EVENT = registerServerbound(1, "queue_event", QueueEventServerMessage.class, QueueEventServerMessage::new);
-    public static final MessageType<KeyEventServerMessage> KEY_EVENT = registerServerbound(2, "key_event", KeyEventServerMessage.class, KeyEventServerMessage::new);
-    public static final MessageType<MouseEventServerMessage> MOUSE_EVENT = registerServerbound(3, "mouse_event", MouseEventServerMessage.class, MouseEventServerMessage::new);
+    public static final MessageType<KeyEventServerMessage> KEY_EVENT = registerServerbound(1, "key_event", KeyEventServerMessage.class, KeyEventServerMessage::new);
+    public static final MessageType<MouseEventServerMessage> MOUSE_EVENT = registerServerbound(2, "mouse_event", MouseEventServerMessage.class, MouseEventServerMessage::new);
+    public static final MessageType<PasteEventComputerMessage> PASTE_EVENT = registerServerbound(3, "paste_event", PasteEventComputerMessage.class, PasteEventComputerMessage::new);
     public static final MessageType<UploadFileMessage> UPLOAD_FILE = registerServerbound(4, "upload_file", UploadFileMessage.class, UploadFileMessage::new);
 
     public static final MessageType<ChatTableClientMessage> CHAT_TABLE = registerClientbound(10, "chat_table", ChatTableClientMessage.class, ChatTableClientMessage::new);

projects/common/src/main/java/dan200/computercraft/shared/network/server/ComputerActionServerMessage.java

@@ -33,6 +33,7 @@ public class ComputerActionServerMessage extends ComputerServerMessage {
     @Override
     protected void handle(ServerNetworkContext context, ComputerMenu container) {
         switch (action) {
+            case TERMINATE -> container.getInput().terminate();
             case TURN_ON -> container.getInput().turnOn();
             case REBOOT -> container.getInput().reboot();
             case SHUTDOWN -> container.getInput().shutdown();
@@ -45,6 +46,7 @@ public class ComputerActionServerMessage extends ComputerServerMessage {
     }
 
     public enum Action {
+        TERMINATE,
         TURN_ON,
         SHUTDOWN,
         REBOOT

projects/common/src/main/java/dan200/computercraft/shared/network/server/ComputerServerMessage.java

@@ -35,8 +35,8 @@ public abstract class ComputerServerMessage implements NetworkMessage<ServerNetw
     @Override
     public void handle(ServerNetworkContext context) {
         Player player = context.getSender();
-        if (player.containerMenu.containerId == containerId && player.containerMenu instanceof ComputerMenu) {
-            handle(context, (ComputerMenu) player.containerMenu);
+        if (player.containerMenu.containerId == containerId && player.containerMenu instanceof ComputerMenu menu) {
+            handle(context, menu);
         }
     }
 

projects/common/src/main/java/dan200/computercraft/shared/network/server/KeyEventServerMessage.java

@@ -37,10 +37,11 @@ public class KeyEventServerMessage extends ComputerServerMessage {
     @Override
     protected void handle(ServerNetworkContext context, ComputerMenu container) {
         var input = container.getInput();
-        if (type == Action.UP) {
-            input.keyUp(key);
-        } else {
-            input.keyDown(key, type == Action.REPEAT);
+        switch (type) {
+            case UP -> input.keyUp(key);
+            case DOWN -> input.keyDown(key, false);
+            case REPEAT -> input.keyDown(key, true);
+            case CHAR -> input.charTyped((byte) key);
         }
     }
 
@@ -50,6 +51,6 @@ public class KeyEventServerMessage extends ComputerServerMessage {
     }
 
     public enum Action {
-        DOWN, REPEAT, UP
+        DOWN, REPEAT, UP, CHAR
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/server/PasteEventComputerMessage.java

@@ -0,0 +1,61 @@
+// SPDX-FileCopyrightText: 2025 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.shared.network.server;
+
+import dan200.computercraft.core.util.StringUtil;
+import dan200.computercraft.shared.computer.core.ServerComputer;
+import dan200.computercraft.shared.computer.menu.ComputerMenu;
+import dan200.computercraft.shared.computer.menu.ServerInputHandler;
+import dan200.computercraft.shared.network.MessageType;
+import dan200.computercraft.shared.network.NetworkMessages;
+import io.netty.handler.codec.DecoderException;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.world.inventory.AbstractContainerMenu;
+
+import java.nio.ByteBuffer;
+
+/**
+ * Paste a string on a {@link ServerComputer}.
+ *
+ * @see ServerInputHandler#paste(ByteBuffer)
+ */
+public class PasteEventComputerMessage extends ComputerServerMessage {
+    private final ByteBuffer text;
+
+    public PasteEventComputerMessage(AbstractContainerMenu menu, ByteBuffer text) {
+        super(menu);
+        this.text = text;
+    }
+
+    public PasteEventComputerMessage(FriendlyByteBuf buf) {
+        super(buf);
+
+        var length = buf.readVarInt();
+        if (length > StringUtil.MAX_PASTE_LENGTH) {
+            throw new DecoderException("ByteArray with size " + length + " is bigger than allowed " + StringUtil.MAX_PASTE_LENGTH);
+        }
+
+        var text = new byte[length];
+        buf.readBytes(text);
+        this.text = ByteBuffer.wrap(text);
+    }
+
+    @Override
+    public void write(FriendlyByteBuf buf) {
+        super.write(buf);
+        buf.writeVarInt(text.remaining());
+        buf.writeBytes(text.duplicate());
+    }
+
+    @Override
+    protected void handle(ServerNetworkContext context, ComputerMenu container) {
+        container.getInput().paste(text);
+    }
+
+    @Override
+    public MessageType<PasteEventComputerMessage> type() {
+        return NetworkMessages.PASTE_EVENT;
+    }
+}

projects/common/src/main/java/dan200/computercraft/shared/network/server/QueueEventServerMessage.java

@@ -1,57 +0,0 @@
-// SPDX-FileCopyrightText: 2018 The CC: Tweaked Developers
-//
-// SPDX-License-Identifier: MPL-2.0
-
-package dan200.computercraft.shared.network.server;
-
-import dan200.computercraft.shared.computer.core.ServerComputer;
-import dan200.computercraft.shared.computer.menu.ComputerMenu;
-import dan200.computercraft.shared.computer.menu.ServerInputHandler;
-import dan200.computercraft.shared.network.MessageType;
-import dan200.computercraft.shared.network.NetworkMessages;
-import dan200.computercraft.shared.util.NBTUtil;
-import net.minecraft.network.FriendlyByteBuf;
-import net.minecraft.world.inventory.AbstractContainerMenu;
-
-import javax.annotation.Nullable;
-
-/**
- * Queue an event on a {@link ServerComputer}.
- *
- * @see ServerInputHandler#queueEvent(String)
- */
-public class QueueEventServerMessage extends ComputerServerMessage {
-    private final String event;
-    private final @Nullable Object[] args;
-
-    public QueueEventServerMessage(AbstractContainerMenu menu, String event, @Nullable Object[] args) {
-        super(menu);
-        this.event = event;
-        this.args = args;
-    }
-
-    public QueueEventServerMessage(FriendlyByteBuf buf) {
-        super(buf);
-        event = buf.readUtf(Short.MAX_VALUE);
-
-        var args = buf.readNbt();
-        this.args = args == null ? null : NBTUtil.decodeObjects(args);
-    }
-
-    @Override
-    public void write(FriendlyByteBuf buf) {
-        super.write(buf);
-        buf.writeUtf(event);
-        buf.writeNbt(args == null ? null : NBTUtil.encodeObjects(args));
-    }
-
-    @Override
-    protected void handle(ServerNetworkContext context, ComputerMenu container) {
-        container.getInput().queueEvent(event, args);
-    }
-
-    @Override
-    public MessageType<QueueEventServerMessage> type() {
-        return NetworkMessages.QUEUE_EVENT;
-    }
-}

projects/common/src/main/java/dan200/computercraft/shared/util/NBTUtil.java

@@ -62,125 +62,33 @@ public final class NBTUtil {
         return childTag != null && childTag.getId() == Tag.TAG_COMPOUND ? (CompoundTag) childTag : emptyTag();
     }
 
-    private static @Nullable Tag toNBTTag(@Nullable Object object) {
-        if (object == null) return null;
-        if (object instanceof Boolean) return ByteTag.valueOf((byte) ((boolean) (Boolean) object ? 1 : 0));
-        if (object instanceof Number) return DoubleTag.valueOf(((Number) object).doubleValue());
-        if (object instanceof String) return StringTag.valueOf(object.toString());
-        if (object instanceof Map<?, ?> m) {
-            var nbt = new CompoundTag();
-            var i = 0;
-            for (Map.Entry<?, ?> entry : m.entrySet()) {
-                var key = toNBTTag(entry.getKey());
-                var value = toNBTTag(entry.getKey());
-                if (key != null && value != null) {
-                    nbt.put("k" + i, key);
-                    nbt.put("v" + i, value);
-                    i++;
-                }
-            }
-            nbt.putInt("len", m.size());
-            return nbt;
-        }
-
-        return null;
-    }
-
-    public static @Nullable CompoundTag encodeObjects(@Nullable Object[] objects) {
-        if (objects == null || objects.length == 0) return null;
-
-        var nbt = new CompoundTag();
-        nbt.putInt("len", objects.length);
-        for (var i = 0; i < objects.length; i++) {
-            var child = toNBTTag(objects[i]);
-            if (child != null) nbt.put(Integer.toString(i), child);
-        }
-        return nbt;
-    }
-
-    private static @Nullable Object fromNBTTag(@Nullable Tag tag) {
-        if (tag == null) return null;
-        switch (tag.getId()) {
-            case Tag.TAG_BYTE:
-                return ((ByteTag) tag).getAsByte() > 0;
-            case Tag.TAG_DOUBLE:
-                return ((DoubleTag) tag).getAsDouble();
-            default:
-            case Tag.TAG_STRING:
-                return tag.getAsString();
-            case Tag.TAG_COMPOUND: {
-                var c = (CompoundTag) tag;
-                var len = c.getInt("len");
-                Map<Object, Object> map = new HashMap<>(len);
-                for (var i = 0; i < len; i++) {
-                    var key = fromNBTTag(c.get("k" + i));
-                    var value = fromNBTTag(c.get("v" + i));
-                    if (key != null && value != null) map.put(key, value);
-                }
-                return map;
-            }
-        }
-    }
-
     public static @Nullable Object toLua(@Nullable Tag tag) {
         if (tag == null) return null;
 
-        switch (tag.getId()) {
-            case Tag.TAG_BYTE:
-            case Tag.TAG_SHORT:
-            case Tag.TAG_INT:
-            case Tag.TAG_LONG:
-                return ((NumericTag) tag).getAsLong();
-            case Tag.TAG_FLOAT:
-            case Tag.TAG_DOUBLE:
-                return ((NumericTag) tag).getAsDouble();
-            case Tag.TAG_STRING: // String
-                return tag.getAsString();
-            case Tag.TAG_COMPOUND: { // Compound
+        return switch (tag.getId()) {
+            case Tag.TAG_BYTE, Tag.TAG_SHORT, Tag.TAG_INT, Tag.TAG_LONG -> ((NumericTag) tag).getAsLong();
+            case Tag.TAG_FLOAT, Tag.TAG_DOUBLE -> ((NumericTag) tag).getAsDouble();
+            case Tag.TAG_STRING -> tag.getAsString();
+            case Tag.TAG_COMPOUND -> {
                 var compound = (CompoundTag) tag;
                 Map<String, Object> map = new HashMap<>(compound.size());
                 for (var key : compound.getAllKeys()) {
                     var value = toLua(compound.get(key));
                     if (value != null) map.put(key, value);
                 }
-                return map;
+                yield map;
             }
-            case Tag.TAG_LIST: {
-                var list = (ListTag) tag;
-                List<Object> map = new ArrayList<>(list.size());
-                for (var value : list) map.add(toLua(value));
-                return map;
-            }
-            case Tag.TAG_BYTE_ARRAY: {
+            case Tag.TAG_LIST -> ((ListTag) tag).stream().map(NBTUtil::toLua).toList();
+            case Tag.TAG_BYTE_ARRAY -> {
                 var array = ((ByteArrayTag) tag).getAsByteArray();
                 List<Byte> map = new ArrayList<>(array.length);
                 for (var b : array) map.add(b);
-                return map;
+                yield map;
             }
-            case Tag.TAG_INT_ARRAY: {
-                var array = ((IntArrayTag) tag).getAsIntArray();
-                List<Integer> map = new ArrayList<>(array.length);
-                for (var j : array) map.add(j);
-                return map;
-            }
-
-            default:
-                return null;
-        }
-    }
-
-    public static @Nullable Object[] decodeObjects(CompoundTag tag) {
-        var len = tag.getInt("len");
-        if (len <= 0) return null;
-
-        var objects = new Object[len];
-        for (var i = 0; i < len; i++) {
-            var key = Integer.toString(i);
-            if (tag.contains(key)) {
-                objects[i] = fromNBTTag(tag.get(key));
-            }
-        }
-        return objects;
+            case Tag.TAG_INT_ARRAY -> Arrays.stream(((IntArrayTag) tag).getAsIntArray()).boxed().toList();
+            case Tag.TAG_LONG_ARRAY -> Arrays.stream(((LongArrayTag) tag).getAsLongArray()).boxed().toList();
+            default -> null;
+        };
     }
 
     @Nullable

projects/core/src/main/java/dan200/computercraft/core/computer/ComputerEvents.java

@@ -4,7 +4,10 @@
 
 package dan200.computercraft.core.computer;
 
+import dan200.computercraft.core.util.StringUtil;
+
 import javax.annotation.Nullable;
+import java.nio.ByteBuffer;
 
 /**
  * Built-in events that can be queued on a computer.
@@ -21,6 +24,28 @@ public final class ComputerEvents {
         receiver.queueEvent("key_up", new Object[]{ key });
     }
 
+    /**
+     * Type a character on the computer.
+     *
+     * @param receiver The computer to queue the event on.
+     * @param chr      The character to type.
+     * @see StringUtil#isTypableChar(byte)
+     */
+    public static void charTyped(Receiver receiver, byte chr) {
+        receiver.queueEvent("char", new Object[]{ new byte[]{ chr } });
+    }
+
+    /**
+     * Paste a string.
+     *
+     * @param receiver The computer to queue the event on.
+     * @param contents The string to paste.
+     * @see StringUtil#getClipboardString(String)
+     */
+    public static void paste(Receiver receiver, ByteBuffer contents) {
+        receiver.queueEvent("paste", new Object[]{ contents });
+    }
+
     public static void mouseClick(Receiver receiver, int button, int x, int y) {
         receiver.queueEvent("mouse_click", new Object[]{ button, x, y });
     }

projects/core/src/main/java/dan200/computercraft/core/util/StringUtil.java

@@ -4,52 +4,116 @@
 
 package dan200.computercraft.core.util;
 
+import dan200.computercraft.core.computer.ComputerEvents;
+
+import java.nio.ByteBuffer;
+
 public final class StringUtil {
+    public static final int MAX_PASTE_LENGTH = 512;
+
     private StringUtil() {
     }
 
-    private static boolean isAllowed(char c) {
-        return (c >= ' ' && c <= '~') || (c >= 161 && c <= 172) || (c >= 174 && c <= 255);
+    /**
+     * Convert a Unicode character to a terminal one.
+     *
+     * @param chr The Unicode character.
+     * @return The terminal character.
+     */
+    public static byte unicodeToTerminal(int chr) {
+        // ASCII and latin1 map to themselves
+        if (chr == 0 || chr == '\t' || chr == '\n' || chr == '\r' || (chr >= ' ' && chr <= '~') || (chr >= 160 && chr <= 255)) {
+            return (byte) chr;
         }
 
-    private static String removeSpecialCharacters(String text, int length) {
-        var builder = new StringBuilder(length);
-        for (var i = 0; i < length; i++) {
-            var c = text.charAt(i);
-            builder.append(isAllowed(c) ? c : '?');
+        // Teletext block mosaics are *fairly* contiguous.
+        if (chr >= 0x1FB00 && chr <= 0x1FB13) return (byte) (chr + (129 - 0x1fb00));
+        if (chr >= 0x1FB14 && chr <= 0x1FB1D) return (byte) (chr + (150 - 0x1fb14));
+
+        // Everything else is just a manual lookup. For now, we just use a big switch statement, which we spin into a
+        // separate function to hopefully avoid inlining it here.
+        return unicodeToCraftOsFallback(chr);
     }
 
-        return builder.toString();
-    }
-
-    public static String normaliseLabel(String text) {
-        return removeSpecialCharacters(text, Math.min(32, text.length()));
+    private static byte unicodeToCraftOsFallback(int c) {
+        return switch (c) {
+            case 0x263A -> 1;
+            case 0x263B -> 2;
+            case 0x2665 -> 3;
+            case 0x2666 -> 4;
+            case 0x2663 -> 5;
+            case 0x2660 -> 6;
+            case 0x2022 -> 7;
+            case 0x25D8 -> 8;
+            case 0x2642 -> 11;
+            case 0x2640 -> 12;
+            case 0x266A -> 14;
+            case 0x266B -> 15;
+            case 0x25BA -> 16;
+            case 0x25C4 -> 17;
+            case 0x2195 -> 18;
+            case 0x203C -> 19;
+            case 0x25AC -> 22;
+            case 0x21A8 -> 23;
+            case 0x2191 -> 24;
+            case 0x2193 -> 25;
+            case 0x2192 -> 26;
+            case 0x2190 -> 27;
+            case 0x221F -> 28;
+            case 0x2194 -> 29;
+            case 0x25B2 -> 30;
+            case 0x25BC -> 31;
+            case 0x1FB99 -> 127;
+            case 0x258C -> (byte) 149;
+            default -> '?';
+        };
     }
 
     /**
-     * Normalise a string from the clipboard, suitable for pasting into a computer.
+     * Check if a character is capable of being input and passed to a {@linkplain ComputerEvents#charTyped(ComputerEvents.Receiver, byte)
+     * "char" event}.
+     *
+     * @param chr The character to check.
+     * @return Whether this character can be typed.
+     */
+    public static boolean isTypableChar(byte chr) {
+        return chr != 0 && chr != '\r' && chr != '\n';
+    }
+
+    private static boolean isAllowedInLabel(char c) {
+        // Limit to ASCII and latin1, excluding '§' (Minecraft's formatting character).
+        return (c >= ' ' && c <= '~') || (c >= 161 && c <= 255 && c != 167);
+    }
+
+    public static String normaliseLabel(String text) {
+        var length = Math.min(32, text.length());
+        var builder = new StringBuilder(length);
+        for (var i = 0; i < length; i++) {
+            var c = text.charAt(i);
+            builder.append(isAllowedInLabel(c) ? c : '?');
+        }
+        return builder.toString();
+    }
+
+    /**
+     * Convert a Java string to a Lua one (using the terminal charset), suitable for pasting into a computer.
      * <p>
      * This removes special characters and strips to the first line of text.
      *
      * @param clipboard The text from the clipboard.
-     * @return The normalised clipboard text.
+     * @return The encoded clipboard text.
      */
-    public static String normaliseClipboardString(String clipboard) {
-        // Clip to the first occurrence of \r or \n
-        var newLineIndex1 = clipboard.indexOf('\r');
-        var newLineIndex2 = clipboard.indexOf('\n');
+    public static ByteBuffer getClipboardString(String clipboard) {
+        var output = new byte[Math.min(MAX_PASTE_LENGTH, clipboard.length())];
+        var idx = 0;
 
-        int length;
-        if (newLineIndex1 >= 0 && newLineIndex2 >= 0) {
-            length = Math.min(newLineIndex1, newLineIndex2);
-        } else if (newLineIndex1 >= 0) {
-            length = newLineIndex1;
-        } else if (newLineIndex2 >= 0) {
-            length = newLineIndex2;
-        } else {
-            length = clipboard.length();
+        var iterator = clipboard.codePoints().iterator();
+        while (iterator.hasNext() && idx <= output.length) {
+            var chr = unicodeToTerminal(iterator.next());
+            if (!isTypableChar(chr)) break;
+            output[idx++] = chr;
         }
 
-        return removeSpecialCharacters(clipboard, Math.min(length, 512));
+        return ByteBuffer.wrap(output, 0, idx).asReadOnlyBuffer();
     }
 }

projects/standalone/src/main/java/cc/tweaked/standalone/InputState.java

@@ -50,10 +50,8 @@ public class InputState {
     }
 
     public void onCharEvent(int codepoint) {
-        if (codepoint >= 32 && codepoint <= 126 || codepoint >= 160 && codepoint <= 255) {
-            // Queue the char event for any printable chars in byte range
-            computer.queueEvent("char", new Object[]{ Character.toString(codepoint) });
-        }
+        var terminalChar = StringUtil.unicodeToTerminal(codepoint);
+        if (StringUtil.isTypableChar(terminalChar)) ComputerEvents.charTyped(computer, terminalChar);
     }
 
     public void onKeyEvent(long window, int key, int action, int modifiers) {
@@ -69,8 +67,8 @@ public class InputState {
         if (key == GLFW.GLFW_KEY_V && modifiers == GLFW.GLFW_MOD_CONTROL) {
             var string = GLFW.glfwGetClipboardString(window);
             if (string != null) {
-                var clipboard = StringUtil.normaliseClipboardString(string);
-                if (!clipboard.isEmpty()) computer.queueEvent("paste", new Object[]{ clipboard });
+                var clipboard = StringUtil.getClipboardString(string);
+                if (clipboard.remaining() > 0) ComputerEvents.paste(computer, clipboard);
             }
             return;
         }