Greatly improves display of text

Makes output text configurable
Adds improved formatting and colors when displaying sign contents
Adds information about applied dye and glow status for signs
Properly cancels the default event when using the viewSign and viewSignRaw commands

src/main/java/net/knarcraft/placeholdersigns/runnable/SignUpdate.java

@@ -0,0 +1,103 @@
+package net.knarcraft.placeholdersigns.runnable;
+
+import me.clip.placeholderapi.PlaceholderAPI;
+import net.knarcraft.knarlib.property.ColorConversion;
+import net.knarcraft.knarlib.util.ColorHelper;
+import net.knarcraft.placeholdersigns.container.PlaceholderSign;
+import net.knarcraft.placeholdersigns.handler.PlaceholderSignHandler;
+import org.bukkit.Location;
+import org.bukkit.block.Sign;
+import org.bukkit.block.sign.Side;
+import org.bukkit.block.sign.SignSide;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Map;
+
+/**
+ * A runnable that updates signs
+ */
+public class SignUpdate implements Runnable {
+
+    private final @NotNull PlaceholderSignHandler signHandler;
+
+    /**
+     * Instantiates a new sign update runnable
+     *
+     * @param signHandler <p>The sign handler to get signs from</p>
+     */
+    public SignUpdate(@NotNull PlaceholderSignHandler signHandler) {
+        this.signHandler = signHandler;
+    }
+
+    @Override
+    public void run() {
+        for (PlaceholderSign placeholderSign : signHandler.getSigns()) {
+            // Ignore signs away from players
+            Location location = placeholderSign.location();
+            if (!location.getChunk().isLoaded()) {
+                continue;
+            }
+
+            // If no longer a sign, remove
+            if (!(location.getBlock().getState() instanceof Sign sign)) {
+                signHandler.unregisterSign(placeholderSign);
+                continue;
+            }
+
+            // Update placeholders
+            SignSide front = sign.getSide(Side.FRONT);
+            SignSide back = sign.getSide(Side.BACK);
+            Map<Side, Map<Integer, String>> placeholders = placeholderSign.placeholders();
+            String[] frontLines = front.getLines();
+            String[] backLines = back.getLines();
+
+            // Only update the sign if the text has changed
+            boolean updateNecessary = false;
+            if (placeholders.get(Side.FRONT) != null) {
+                updateNecessary |= updatePlaceholders(frontLines, placeholders.get(Side.FRONT), front);
+            }
+            if (placeholders.get(Side.BACK) != null) {
+                updateNecessary |= updatePlaceholders(backLines, placeholders.get(Side.BACK), back);
+            }
+            if (updateNecessary) {
+                sign.update();
+            }
+        }
+    }
+
+    /**
+     * Updates the values of placeholders on a sign
+     *
+     * @param lines        <p>The sign's current lines</p>
+     * @param placeholders <p>The sign's original placeholder lines</p>
+     * @param signSide     <p>The side of the sign to update placeholders for</p>
+     * @return <p>True if text has been changed, and the sign needs to be updated</p>
+     */
+    private boolean updatePlaceholders(@NotNull String[] lines, @NotNull Map<Integer, String> placeholders,
+                                       @NotNull SignSide signSide) {
+        boolean changed = false;
+        for (int i = 0; i < lines.length; i++) {
+            String oldText = signSide.getLine(i);
+
+            // The new text of the sign is either the same, or the original placeholder
+            String newText;
+            if (!placeholders.containsKey(i) || placeholders.get(i) == null) {
+                newText = oldText;
+            } else {
+                newText = PlaceholderAPI.setPlaceholders(null, placeholders.get(i));
+            }
+
+            // Convert color codes
+            newText = ColorHelper.translateColorCodes(newText, ColorConversion.RGB);
+
+            // Only change the line if the text has changed
+            if (!newText.equals(oldText)) {
+                signSide.setLine(i, newText);
+                changed = true;
+            }
+        }
+
+        return changed;
+    }
+
+}