Adopt and update functions from an abandoned library

src/main/java/dev/zontreck/libzontreck/edlibmc/SidedProxy.java

@@ -0,0 +1,122 @@
+/*
+ * @file SidedProxy.java
+ * @author Stefan Wilhelm (wile)
+ * @copyright (C) 2020 Stefan Wilhelm
+ * @license MIT (see https://opensource.org/licenses/MIT)
+ *
+ * General client/server sidedness selection proxy.
+ */
+package dev.zontreck.libzontreck.edlibmc;
+
+import net.minecraft.client.Minecraft;
+import net.minecraft.world.entity.player.Player;
+import net.minecraft.world.level.Level;
+import net.minecraftforge.fml.DistExecutor;
+
+import javax.annotation.Nullable;
+import java.util.Optional;
+
+public class SidedProxy {
+    @Nullable
+    public static Player getPlayerClientSide() {
+        return proxy.getPlayerClientSide();
+    }
+
+    @Nullable
+    public static Level getWorldClientSide() {
+        return proxy.getWorldClientSide();
+    }
+
+    @Nullable
+    public static Minecraft mc() {
+        return proxy.mc();
+    }
+
+    public static Optional<Boolean> isCtrlDown() {
+        return proxy.isCtrlDown();
+    }
+
+    public static Optional<Boolean> isShiftDown() {
+        return proxy.isShiftDown();
+    }
+
+    public static Optional<String> getClipboard() {
+        return proxy.getClipboard();
+    }
+
+    public static boolean setClipboard(String text) {
+        return proxy.setClipboard(text);
+    }
+
+    // --------------------------------------------------------------------------------------------------------
+
+    private static final ISidedProxy proxy = DistExecutor.unsafeRunForDist(() -> ClientProxy::new, () -> ServerProxy::new);
+
+    private interface ISidedProxy {
+        default @Nullable Player getPlayerClientSide() {
+            return null;
+        }
+
+        default @Nullable Level getWorldClientSide() {
+            return null;
+        }
+
+        default @Nullable Minecraft mc() {
+            return null;
+        }
+
+        default Optional<Boolean> isCtrlDown() {
+            return Optional.empty();
+        }
+
+        default Optional<Boolean> isShiftDown() {
+            return Optional.empty();
+        }
+
+        default Optional<String> getClipboard() {
+            return Optional.empty();
+        }
+
+        default boolean setClipboard(String text) {
+            return false;
+        }
+    }
+
+    private static final class ClientProxy implements ISidedProxy {
+        public @Nullable Player getPlayerClientSide() {
+            return Minecraft.getInstance().player;
+        }
+
+        public @Nullable Level getWorldClientSide() {
+            return Minecraft.getInstance().level;
+        }
+
+        public @Nullable Minecraft mc() {
+            return Minecraft.getInstance();
+        }
+
+        public Optional<Boolean> isCtrlDown() {
+            return Optional.of(Auxiliaries.isCtrlDown());
+        }
+
+        public Optional<Boolean> isShiftDown() {
+            return Optional.of(Auxiliaries.isShiftDown());
+        }
+
+        public Optional<String> getClipboard() {
+            return (mc() == null) ? Optional.empty() : Optional.of(net.minecraft.client.gui.font.TextFieldHelper.getClipboardContents(mc()));
+        }
+
+        public boolean setClipboard(String text) {
+            if (mc() == null) {
+                return false;
+            }
+            net.minecraft.client.gui.font.TextFieldHelper.setClipboardContents(Minecraft.getInstance(), text);
+            return true;
+        }
+    }
+
+    private static final class ServerProxy implements ISidedProxy {
+    }
+
+}