ParchmentMC/patches/api/0021-Add-Sidebar-Utility.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Blast-MC <cjblanton2@gmail.com>
Date: Mon, 15 Jan 2024 20:53:14 -0500
Subject: [PATCH] Add Sidebar Utility


diff --git a/src/main/java/gg/projecteden/parchment/sidebar/Sidebar.java b/src/main/java/gg/projecteden/parchment/sidebar/Sidebar.java
new file mode 100644
index 0000000000000000000000000000000000000000..b0c704387e566d76d097595c35d06d8e5cbe204f
--- /dev/null
+++ b/src/main/java/gg/projecteden/parchment/sidebar/Sidebar.java
@@ -0,0 +1,123 @@
+package gg.projecteden.parchment.sidebar;
+
+import gg.projecteden.parchment.entity.EntityData;
+import gg.projecteden.parchment.entity.EntityDataFragment;
+import gg.projecteden.parchment.entity.EntityDataKey;
+import org.bukkit.entity.Player;
+
+import java.util.Objects;
+
+public final class Sidebar extends EntityDataFragment<Player> {
+    private static final EntityDataKey<Sidebar, Player> DATA_KEY = EntityData.createKey(Sidebar::new, Player.class);
+
+    private final SidebarBuffer[] buffer = new SidebarBuffer[2];
+
+    private final StageImpl stage = new StageImpl();
+    private final Runnable layoutListener;
+
+    private SidebarLayout layout;
+
+    private boolean visible;
+    private int back;
+
+    public static Sidebar get(Player player) {
+        Objects.requireNonNull(player);
+
+        return player.getStoredEntityData().get(Sidebar.DATA_KEY);
+    }
+
+    private Sidebar() {
+        this.buffer[0] = SidebarBufferUtilSpec.IMPL_KEY.get().create("_sidebar_l");
+        this.buffer[1] = SidebarBufferUtilSpec.IMPL_KEY.get().create("_sidebar_r");
+
+        this.layoutListener = () -> {
+            this.layout.update(this.stage);
+            this.flush();
+        };
+
+        this.setPersistent(false);
+    }
+
+    public void applyLayout(SidebarLayout layout) {
+        if (this.layout != null) {
+            this.layout.unsubscribe(this.layoutListener);
+            this.buffer[this.back].clear();
+        }
+
+        this.layout = layout;
+
+        if (layout == null) {
+            this.hide();
+        } else {
+            layout.setup(this.stage);
+            this.flush();
+
+            layout.subscribe(this.layoutListener);
+        }
+    }
+
+    private void setTitle(String title) {
+        this.buffer[this.back].setTitle(title);
+    }
+
+    private void setLine(int idx, String value, String display) {
+        if (value == null) {
+            this.buffer[this.back].clearLine(idx);
+        } else {
+            this.buffer[this.back].setLine(idx, value, display);
+        }
+    }
+
+    private void flush() {
+        SidebarBuffer front = this.buffer[this.back];
+        SidebarBuffer back = this.buffer[this.back ^ 1];
+        boolean shouldShow = !this.visible;
+
+        if (front.hasDiverged(back)) {
+            front.pushChanges();
+
+            back.sync(front);
+            this.back ^= 1;
+
+            shouldShow = true;
+        }
+
+        if (shouldShow) {
+            front.setActive();
+            this.visible = true;
+        }
+    }
+
+    private void hide() {
+        SidebarBufferUtilSpec.IMPL_KEY.get().hideSidebar(this.getOwner());
+        this.visible = false;
+    }
+
+    @Override
+    protected void onOwnerChange() {
+        this.buffer[0].setOwner(this.getOwner());
+        this.buffer[1].setOwner(this.getOwner());
+
+        if (this.visible) {
+            this.buffer[this.back ^ 1].setActive();
+        }
+    }
+
+    private final class StageImpl implements SidebarStage {
+        @Override
+        public void setTitle(String title) {
+            Sidebar.this.setTitle(title);
+        }
+
+        @Override
+        public void setLine(int line, String value) {
+            this.setLine(line, value, null);
+        }
+
+        @Override
+        public void setLine(int line, String value, String display) {
+            Sidebar.this.setLine(line, value, display);
+        }
+
+    }
+}
diff --git a/src/main/java/gg/projecteden/parchment/sidebar/SidebarBuffer.java b/src/main/java/gg/projecteden/parchment/sidebar/SidebarBuffer.java
new file mode 100644
index 0000000000000000000000000000000000000000..ec13738dc625464d7fa41484ee44583ef82248fd
--- /dev/null
+++ b/src/main/java/gg/projecteden/parchment/sidebar/SidebarBuffer.java
@@ -0,0 +1,100 @@
+package gg.projecteden.parchment.sidebar;
+
+import org.bukkit.entity.Player;
+
+import java.util.Arrays;
+import java.util.Objects;
+
+public abstract class SidebarBuffer {
+
+    @SuppressWarnings("StringOperationCanBeSimplified")
+    private static final String AUTO_SPACE = new String();
+    protected final String name;
+    protected final int size;
+    protected final String[] liveLines;
+    protected final String[] stagedLines;
+    protected final String[] liveDisplays;
+    protected final String[] stagedDisplays;
+
+    protected String liveTitle = "";
+    protected String stagedTitle = "";
+
+    protected SidebarBuffer(String name, int size) {
+        this.name = name;
+        this.size = size;
+        this.liveLines = new String[size];
+        this.stagedLines = new String[size];
+        this.liveDisplays = new String[size];
+        this.stagedDisplays = new String[size];
+    }
+
+    protected abstract void setActive();
+
+    protected abstract void pushChanges();
+
+    protected abstract void setOwner(Player player);
+
+    protected abstract boolean checkTitle(String title);
+
+    protected abstract boolean checkLine(String line);
+
+    void setTitle(String title) {
+        this.stagedTitle = Objects.requireNonNullElse(title, "");
+    }
+
+    void setLine(int line, String value, String display) {
+        Objects.requireNonNull(value);
+        if (line < 0 || line > this.size - 1) {
+            throw new IndexOutOfBoundsException();
+        }
+
+        this.stagedLines[line] = value;
+        this.stagedDisplays[line] = display;
+
+        for (int i = line - 1; i >= 0; i--) {
+            if (this.stagedLines[i] == null) {
+                this.stagedLines[i] = SidebarBuffer.AUTO_SPACE;
+            } else {
+                break;
+            }
+        }
+    }
+
+    void clearLine(int line) {
+        if (line < 0 || line > this.size - 1) {
+            throw new IndexOutOfBoundsException();
+        }
+
+        this.stagedLines[line] = SidebarBuffer.AUTO_SPACE;
+
+        if (line + 1 == this.size || this.stagedLines[line + 1] == null) {
+            for (int i = line; i >= 0; i--) {
+                if (this.stagedLines[i] == SidebarBuffer.AUTO_SPACE) {
+                   this.stagedLines[i] = null;
+                } else {
+                   break;
+                }
+            }
+        }
+    }
+
+    void sync(SidebarBuffer live) {
+        this.stagedTitle = live.liveTitle;
+        System.arraycopy(live.liveLines, 0, this.stagedLines, 0, this.size);
+        System.arraycopy(live.liveDisplays, 0, this.stagedDisplays, 0, this.size);
+    }
+
+    void clear() {
+        this.stagedTitle = "";
+        Arrays.fill(this.stagedLines, null);
+        Arrays.fill(this.stagedDisplays, null);
+    }
+
+    boolean hasDiverged(SidebarBuffer live) {
+        boolean out = !Objects.equals(this.stagedTitle, live.liveTitle);
+        out = out || !Arrays.equals(this.stagedLines, live.liveLines);
+        out = out || !Arrays.equals(this.stagedDisplays, live.liveDisplays);
+
+        return out;
+    }
+}
diff --git a/src/main/java/gg/projecteden/parchment/sidebar/SidebarBufferUtilSpec.java b/src/main/java/gg/projecteden/parchment/sidebar/SidebarBufferUtilSpec.java
new file mode 100644
index 0000000000000000000000000000000000000000..22239d7ea5d632f306caba0d139fe1576e85a7dc
--- /dev/null
+++ b/src/main/java/gg/projecteden/parchment/sidebar/SidebarBufferUtilSpec.java
@@ -0,0 +1,12 @@
+package gg.projecteden.parchment.sidebar;
+
+import gg.projecteden.parchment.entity.EntityDataServiceKey;
+import org.bukkit.entity.Player;
+
+public interface SidebarBufferUtilSpec {
+    EntityDataServiceKey<SidebarBufferUtilSpec> IMPL_KEY = new EntityDataServiceKey<>(SidebarBufferUtilSpec.class);
+
+    SidebarBuffer create(String bufferName);
+
+    void hideSidebar(Player player);
+}
diff --git a/src/main/java/gg/projecteden/parchment/sidebar/SidebarLayout.java b/src/main/java/gg/projecteden/parchment/sidebar/SidebarLayout.java
new file mode 100644
index 0000000000000000000000000000000000000000..238d2c1338aee95b24fd31c9643e0f966fe0b79f
--- /dev/null
+++ b/src/main/java/gg/projecteden/parchment/sidebar/SidebarLayout.java
@@ -0,0 +1,58 @@
+package gg.projecteden.parchment.sidebar;
+
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * A sidebar layout. Subclasses can describe custom layouts by using the
+ * {@link #setup(SidebarStage)} and {@link #update(SidebarStage)} hooks.
+ */
+public abstract class SidebarLayout {
+    private final Set<Runnable> subscribers = new HashSet<>();
+
+    /**
+     * Pushes an update to all subscribers.
+     */
+    public final void refresh() {
+        synchronized (this.subscribers) {
+            for (Runnable s : this.subscribers) {
+                s.run();
+            }
+        }
+    }
+
+    /**
+     * Runs when the layout is first applied.
+     *
+     * <p> The provided sidebar stage may be used to create the first
+     * frame of sidebar data, which will be pushed to the client upon
+     * exit of this method.
+     *
+     * @param stage The sidebar stage. Using it outside this method will
+     *              result in undefined behavior.
+     */
+    protected void setup(SidebarStage stage) {
+    }
+
+    /**
+     * Runs when a refresh is requested.
+     *
+     * <p> The provided sidebar stage may be used to update the existing
+     * sidebar data, which will be pushed to the client upon exit of
+     * this method. Sidebar data from previous hook calls will stay the
+     * same unless explicitly changed here.
+     *
+     * @param stage The sidebar stage. Using it outside this method will
+     *              result in undefined behavior.
+     */
+    protected void update(SidebarStage stage) {
+    }
+
+    final void subscribe(Runnable listener) {
+        this.subscribers.add(listener);
+    }
+
+    final void unsubscribe(Runnable listener) {
+        this.subscribers.remove(listener);
+    }
+}
diff --git a/src/main/java/gg/projecteden/parchment/sidebar/SidebarStage.java b/src/main/java/gg/projecteden/parchment/sidebar/SidebarStage.java
new file mode 100644
index 0000000000000000000000000000000000000000..9e604d3b8183abe342ef5c055069f1c4b16df55c
--- /dev/null
+++ b/src/main/java/gg/projecteden/parchment/sidebar/SidebarStage.java
@@ -0,0 +1,32 @@
+package gg.projecteden.parchment.sidebar;
+
+/**
+ * An abstracted sidebar stage.
+ */
+public interface SidebarStage {
+    /**
+     * Stages a new title.
+     *
+     * @param title The new title.
+     */
+    void setTitle(String title);
+
+    /**
+     * Stages a new line at the provided index.
+     *
+     * @param line  The line index.
+     * @param value The new line.
+     */
+    void setLine(int line, String value);
+
+    /**
+     * Stages a new line at the provided index
+     * Uses the display as the right aligned text
+     *
+     * @param line The line index
+     * @param value The new line
+     * @param display The right aligned text
+     */
+    void setLine(int line, String value, String display);
+
+}