[ci skip] move log4j plugin into proper location

purpur-server/src/log4jPlugins/java/org/purpurmc/purpur/gui/util/HighlightErrorConverter.java

@@ -0,0 +1,85 @@
+package org.purpurmc.purpur.gui.util;
+
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.core.LogEvent;
+import org.apache.logging.log4j.core.config.Configuration;
+import org.apache.logging.log4j.core.config.plugins.Plugin;
+import org.apache.logging.log4j.core.layout.PatternLayout;
+import org.apache.logging.log4j.core.pattern.ConverterKeys;
+import org.apache.logging.log4j.core.pattern.LogEventPatternConverter;
+import org.apache.logging.log4j.core.pattern.PatternConverter;
+import org.apache.logging.log4j.core.pattern.PatternFormatter;
+import org.apache.logging.log4j.core.pattern.PatternParser;
+import org.apache.logging.log4j.util.PerformanceSensitive;
+
+import java.util.List;
+
+@Plugin(name = "highlightGUIError", category = PatternConverter.CATEGORY)
+@ConverterKeys({"highlightGUIError"})
+@PerformanceSensitive("allocation")
+public final class HighlightErrorConverter extends LogEventPatternConverter {
+    private static final String ERROR = "\u00A74\u00A7l"; // Bold Red
+    private static final String WARN = "\u00A7e\u00A7l"; // Bold Yellow
+
+    private final List<PatternFormatter> formatters;
+
+    private HighlightErrorConverter(List<PatternFormatter> formatters) {
+        super("highlightGUIError", null);
+        this.formatters = formatters;
+    }
+
+    @Override
+    public void format(LogEvent event, StringBuilder toAppendTo) {
+        Level level = event.getLevel();
+        if (level.isMoreSpecificThan(Level.ERROR)) {
+            format(ERROR, event, toAppendTo);
+            return;
+        } else if (level.isMoreSpecificThan(Level.WARN)) {
+            format(WARN, event, toAppendTo);
+            return;
+        }
+        for (PatternFormatter formatter : formatters) {
+            formatter.format(event, toAppendTo);
+        }
+    }
+
+    private void format(String style, LogEvent event, StringBuilder toAppendTo) {
+        int start = toAppendTo.length();
+        toAppendTo.append(style);
+        int end = toAppendTo.length();
+
+        for (PatternFormatter formatter : formatters) {
+            formatter.format(event, toAppendTo);
+        }
+
+        if (toAppendTo.length() == end) {
+            toAppendTo.setLength(start);
+        }
+    }
+
+    @Override
+    public boolean handlesThrowable() {
+        for (final PatternFormatter formatter : formatters) {
+            if (formatter.handlesThrowable()) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public static HighlightErrorConverter newInstance(Configuration config, String[] options) {
+        if (options.length != 1) {
+            LOGGER.error("Incorrect number of options on highlightGUIError. Expected 1 received " + options.length);
+            return null;
+        }
+
+        if (options[0] == null) {
+            LOGGER.error("No pattern supplied on highlightGUIError");
+            return null;
+        }
+
+        PatternParser parser = PatternLayout.createPatternParser(config);
+        List<PatternFormatter> formatters = parser.parse(options[0]);
+        return new HighlightErrorConverter(formatters);
+    }
+}