Cleaning and some optimizations

build.gradle

@@ -1,6 +1,6 @@
 allprojects {
     group = 'haus.nightmare.j3270'
-    version = '0.1.0'
+    version = '1.2.4'
 
     repositories {
         mavenCentral()
@@ -23,6 +23,11 @@ subprojects {
         }
     }
 
+    tasks.withType(Javadoc).configureEach {
+        options.addStringOption('Xdoclint:none', '-quiet')
+        options.encoding = 'UTF-8'
+    }
+
     dependencies {
         testImplementation 'org.junit.jupiter:junit-jupiter:5.10.2'
         testRuntimeOnly 'org.junit.platform:junit-platform-launcher'

build_all.sh

@@ -91,15 +91,23 @@ if [ -d "$SCRIPT_DIR/lib3270j/src/main/resources" ]; then
     cp -r "$SCRIPT_DIR/lib3270j/src/main/resources/"* "$BUILD_DIR/lib3270j/" 2>/dev/null || true
 fi
 
-# 4. Package executable JAR
-echo "Packaging j3270.jar..."
-printf "Manifest-Version: 1.0\nMain-Class: haus.nightmare.j3270.J3270App\nImplementation-Title: j3270\nImplementation-Version: 0.1.0\nCreated-By: j3270 build_all.sh\n\n" > "$BUILD_DIR/MANIFEST.MF"
+# 4. Package JARs
+echo "Packaging lib3270j.jar (standalone library)..."
+printf "Manifest-Version: 1.0\nImplementation-Title: lib3270j\nImplementation-Version: 1.2.4\nCreated-By: j3270 build_all.sh\n\n" > "$BUILD_DIR/LIB_MANIFEST.MF"
+
+"$JAR_BIN" cvfm "$BUILD_DIR/lib3270j.jar" "$BUILD_DIR/LIB_MANIFEST.MF" \
+    -C "$BUILD_DIR/lib3270j" . > /dev/null
+
+echo "Packaging j3270.jar (standalone executable)..."
+printf "Manifest-Version: 1.0\nMain-Class: haus.nightmare.j3270.J3270App\nImplementation-Title: j3270\nImplementation-Version: 1.2.4\nCreated-By: j3270 build_all.sh\n\n" > "$BUILD_DIR/MANIFEST.MF"
 
 "$JAR_BIN" cvfm "$BUILD_DIR/j3270.jar" "$BUILD_DIR/MANIFEST.MF" \
     -C "$BUILD_DIR/lib3270j" . \
     -C "$BUILD_DIR/j3270" . > /dev/null
 
 echo "=== Build Complete ==="
+echo "Library JAR created:    $BUILD_DIR/lib3270j.jar"
+ls -lh "$BUILD_DIR/lib3270j.jar"
 echo "Executable JAR created: $BUILD_DIR/j3270.jar"
 ls -lh "$BUILD_DIR/j3270.jar"
 

gradle.properties

@@ -1,2 +1 @@
-android.useAndroidX=true
 org.gradle.jvmargs=-Xmx2048m -XX:MaxMetaspaceSize=512m

gradle/wrapper/gradle-wrapper.properties

@@ -1,7 +1,9 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-9.3.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.7.1-bin.zip
 networkTimeout=10000
+retries=0
+retryBackOffMs=500
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

gradlew

@@ -1,7 +1,7 @@
 #!/bin/sh
 
 #
-# Copyright © 2015-2021 the original authors.
+# Copyright © 2015 the original authors.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -15,10 +15,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 
 ##############################################################################
 #
-#   Gradle start up script for POSIX generated by Gradle.
+#   gradlew start up script for POSIX generated by Gradle.
 #
 #   Important for running:
 #
@@ -27,7 +29,7 @@
 #       bash, then to run this script, type that shell name before the whole
 #       command line, like:
 #
-#           ksh Gradle
+#           ksh gradlew
 #
 #       Busybox and similar reduced shells will NOT work, because this script
 #       requires all of these POSIX shell features:
@@ -55,7 +57,7 @@
 #       Darwin, MinGW, and NonStop.
 #
 #   (3) This script is generated from the Groovy template
-#       https://github.com/gradle/gradle/blob/HEAD/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       https://github.com/gradle/gradle/blob/<unknown>/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
 #       within the Gradle project.
 #
 #       You can find Gradle at https://github.com/gradle/gradle/.
@@ -84,7 +86,7 @@ done
 # shellcheck disable=SC2034
 APP_BASE_NAME=${0##*/}
 # Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
-APP_HOME=$( cd "${APP_HOME:-./}" > /dev/null && pwd -P ) || exit
+APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s\n' "$PWD" ) || exit
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD=maximum
@@ -112,7 +114,6 @@ case "$( uname )" in                #(
   NONSTOP* )        nonstop=true ;;
 esac
 
-CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
 
 
 # Determine the Java command to use to start the JVM.
@@ -170,7 +171,6 @@ fi
 # For Cygwin or MSYS, switch paths to Windows format before running java
 if "$cygwin" || "$msys" ; then
     APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
-    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
 
     JAVACMD=$( cygpath --unix "$JAVACMD" )
 
@@ -203,15 +203,14 @@ fi
 DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
 
 # Collect all arguments for the java command:
-#   * DEFAULT_JVM_OPTS, JAVA_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
 #     and any embedded shellness will be escaped.
 #   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
 #     treated as '${Hostname}' itself on the command line.
 
 set -- \
         "-Dorg.gradle.appname=$APP_BASE_NAME" \
-        -classpath "$CLASSPATH" \
-        org.gradle.wrapper.GradleWrapperMain \
+        -jar "$APP_HOME/gradle/wrapper/gradle-wrapper.jar" \
         "$@"
 
 # Stop when "xargs" is not available.

gradlew.bat

@@ -13,16 +13,18 @@
 @rem See the License for the specific language governing permissions and
 @rem limitations under the License.
 @rem
+@rem SPDX-License-Identifier: Apache-2.0
+@rem
 
 @if "%DEBUG%"=="" @echo off
 @rem ##########################################################################
 @rem
-@rem  Gradle startup script for Windows
+@rem  gradlew startup script for Windows
 @rem
 @rem ##########################################################################
 
-@rem Set local scope for the variables with windows NT shell
-if "%OS%"=="Windows_NT" setlocal
+@rem Set local scope for the variables, and ensure extensions are enabled
+setlocal EnableExtensions
 
 set DIRNAME=%~dp0
 if "%DIRNAME%"=="" set DIRNAME=.
@@ -43,13 +45,13 @@ set JAVA_EXE=java.exe
 %JAVA_EXE% -version >NUL 2>&1
 if %ERRORLEVEL% equ 0 goto execute
 
-echo.
-echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
-echo.
-echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation.
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
 
-goto fail
+"%COMSPEC%" /c exit 1
 
 :findJavaFromJavaHome
 set JAVA_HOME=%JAVA_HOME:"=%
@@ -57,36 +59,24 @@ set JAVA_EXE=%JAVA_HOME%/bin/java.exe
 
 if exist "%JAVA_EXE%" goto execute
 
-echo.
-echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
-echo.
-echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation.
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
 
-goto fail
+"%COMSPEC%" /c exit 1
 
 :execute
 @rem Setup the command line
 
-set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
 
 
-@rem Execute Gradle
-"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+@rem Execute gradlew
+@rem endlocal doesn't take effect until after the line is parsed and variables are expanded
+@rem which allows us to clear the local environment before executing the java command
+endlocal & "%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -jar "%APP_HOME%\gradle\wrapper\gradle-wrapper.jar" %* & call :exitWithErrorLevel
 
-:end
-@rem End local scope for the variables with windows NT shell
-if %ERRORLEVEL% equ 0 goto mainEnd
-
-:fail
-rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
-rem the _cmd.exe /c_ return code!
-set EXIT_CODE=%ERRORLEVEL%
-if %EXIT_CODE% equ 0 set EXIT_CODE=1
-if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
-exit /b %EXIT_CODE%
-
-:mainEnd
-if "%OS%"=="Windows_NT" endlocal
-
-:omega
+:exitWithErrorLevel
+@rem Use "%COMSPEC%" /c exit to allow operators to work properly in scripts
+"%COMSPEC%" /c exit %ERRORLEVEL%

j3270/src/main/java/haus/nightmare/j3270/J3270App.java

@@ -9,6 +9,7 @@ import haus.nightmare.lib3270j.screen.ScreenBuffer;
 import haus.nightmare.j3270.ui.*;
 import haus.nightmare.j3270.ft.FileTransfer;
 import haus.nightmare.j3270.ft.FileTransferDialog;
+import haus.nightmare.j3270.config.Settings;
 
 import javax.swing.*;
 import java.awt.*;
@@ -182,7 +183,7 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
         terminalPanel.setStatusBarToggleCallback(this::toggleStatusBar);
         terminalPanel.addModeChangeListener(this::syncModeMenuItems);
 
-        statusBar.setVisible(haus.nightmare.j3270.config.Settings.getStatusBarVisible());
+        statusBar.setVisible(Settings.getStatusBarVisible());
 
         getContentPane().setLayout(new BorderLayout());
         getContentPane().setBackground(Color.BLACK);
@@ -195,10 +196,10 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
         if (wordWrapItem != null) wordWrapItem.setSelected(terminalPanel.isWordWrap());
         if (aplModeItem != null) aplModeItem.setSelected(terminalPanel.isAplMode());
         if (insertModeItem != null) insertModeItem.setSelected(terminalPanel.isInsertMode());
-        if (fourColorItem != null) fourColorItem.setSelected(haus.nightmare.j3270.config.Settings.getFourColorOverride());
-        if (numLockItem != null) numLockItem.setSelected(haus.nightmare.j3270.config.Settings.getNumericFieldLock());
-        if (autoSkipItem != null) autoSkipItem.setSelected(haus.nightmare.j3270.config.Settings.getAutoSkipEnabled());
-        if (insertOffAidItem != null) insertOffAidItem.setSelected(haus.nightmare.j3270.config.Settings.getInsertOffOnAid());
+        if (fourColorItem != null) fourColorItem.setSelected(Settings.getFourColorOverride());
+        if (numLockItem != null) numLockItem.setSelected(Settings.getNumericFieldLock());
+        if (autoSkipItem != null) autoSkipItem.setSelected(Settings.getAutoSkipEnabled());
+        if (insertOffAidItem != null) insertOffAidItem.setSelected(Settings.getInsertOffOnAid());
     }
 
     private void onThemeChanged(UITheme theme) {
@@ -302,7 +303,7 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
         JRadioButtonMenuItem darkThemeItem = new JRadioButtonMenuItem("Dark Mode", ThemeManager.isDark());
         ThemeManager.styleMenuItem(darkThemeItem);
         darkThemeItem.addActionListener(e -> {
-            haus.nightmare.j3270.config.Settings.setJavaUiTheme(UITheme.DARK);
+            Settings.setJavaUiTheme(UITheme.DARK);
             ThemeManager.setTheme(UITheme.DARK);
         });
         themeGroup.add(darkThemeItem);
@@ -311,7 +312,7 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
         JRadioButtonMenuItem lightThemeItem = new JRadioButtonMenuItem("Light Mode", ThemeManager.isLight());
         ThemeManager.styleMenuItem(lightThemeItem);
         lightThemeItem.addActionListener(e -> {
-            haus.nightmare.j3270.config.Settings.setJavaUiTheme(UITheme.LIGHT);
+            Settings.setJavaUiTheme(UITheme.LIGHT);
             ThemeManager.setTheme(UITheme.LIGHT);
         });
         themeGroup.add(lightThemeItem);
@@ -320,7 +321,7 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
         viewMenu.add(themeMenu);
         viewMenu.addSeparator();
 
-        statusBarItem = new JCheckBoxMenuItem("Status Bar", statusBar != null ? statusBar.isVisible() : haus.nightmare.j3270.config.Settings.getStatusBarVisible());
+        statusBarItem = new JCheckBoxMenuItem("Status Bar", statusBar != null ? statusBar.isVisible() : Settings.getStatusBarVisible());
         ThemeManager.styleMenuItem(statusBarItem);
         statusBarItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_B, InputEvent.ALT_DOWN_MASK));
         statusBarItem.addActionListener(e -> setStatusBarVisible(statusBarItem.isSelected()));
@@ -332,7 +333,7 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
         rulerItem.addActionListener(e -> {
             boolean en = rulerItem.isSelected();
             terminalPanel.setCrosshairRulerEnabled(en);
-            haus.nightmare.j3270.config.Settings.setCrosshairRuler(en);
+            Settings.setCrosshairRuler(en);
         });
         viewMenu.add(rulerItem);
 
@@ -342,7 +343,7 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
         ThemeManager.styleMenuItem(blockCursorItem);
         blockCursorItem.addActionListener(e -> {
             terminalPanel.setCursorStyle(TerminalPanel.CursorStyle.BLOCK);
-            haus.nightmare.j3270.config.Settings.setCursorStyle("BLOCK");
+            Settings.setCursorStyle("BLOCK");
         });
         cursorGroup.add(blockCursorItem);
         cursorMenu.add(blockCursorItem);
@@ -351,7 +352,7 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
         ThemeManager.styleMenuItem(underlineCursorItem);
         underlineCursorItem.addActionListener(e -> {
             terminalPanel.setCursorStyle(TerminalPanel.CursorStyle.UNDERLINE);
-            haus.nightmare.j3270.config.Settings.setCursorStyle("UNDERLINE");
+            Settings.setCursorStyle("UNDERLINE");
         });
         cursorGroup.add(underlineCursorItem);
         cursorMenu.add(underlineCursorItem);
@@ -436,34 +437,34 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
 
         modesMenu.addSeparator();
 
-        fourColorItem = new JCheckBoxMenuItem("Base 4-Color Override", haus.nightmare.j3270.config.Settings.getFourColorOverride());
+        fourColorItem = new JCheckBoxMenuItem("Base 4-Color Override", Settings.getFourColorOverride());
         ThemeManager.styleMenuItem(fourColorItem);
         fourColorItem.addActionListener(e -> {
-            haus.nightmare.j3270.config.Settings.setFourColorOverride(fourColorItem.isSelected());
+            Settings.setFourColorOverride(fourColorItem.isSelected());
             terminalPanel.repaint();
         });
         modesMenu.add(fourColorItem);
 
-        numLockItem = new JCheckBoxMenuItem("Numeric Field Lock", haus.nightmare.j3270.config.Settings.getNumericFieldLock());
+        numLockItem = new JCheckBoxMenuItem("Numeric Field Lock", Settings.getNumericFieldLock());
         ThemeManager.styleMenuItem(numLockItem);
         numLockItem.addActionListener(e -> {
-            haus.nightmare.j3270.config.Settings.setNumericFieldLock(numLockItem.isSelected());
+            Settings.setNumericFieldLock(numLockItem.isSelected());
             terminalPanel.applyModeSettings();
         });
         modesMenu.add(numLockItem);
 
-        autoSkipItem = new JCheckBoxMenuItem("Auto-Skip Across Fields", haus.nightmare.j3270.config.Settings.getAutoSkipEnabled());
+        autoSkipItem = new JCheckBoxMenuItem("Auto-Skip Across Fields", Settings.getAutoSkipEnabled());
         ThemeManager.styleMenuItem(autoSkipItem);
         autoSkipItem.addActionListener(e -> {
-            haus.nightmare.j3270.config.Settings.setAutoSkipEnabled(autoSkipItem.isSelected());
+            Settings.setAutoSkipEnabled(autoSkipItem.isSelected());
             terminalPanel.applyModeSettings();
         });
         modesMenu.add(autoSkipItem);
 
-        insertOffAidItem = new JCheckBoxMenuItem("Reset Insert on AID Key", haus.nightmare.j3270.config.Settings.getInsertOffOnAid());
+        insertOffAidItem = new JCheckBoxMenuItem("Reset Insert on AID Key", Settings.getInsertOffOnAid());
         ThemeManager.styleMenuItem(insertOffAidItem);
         insertOffAidItem.addActionListener(e -> {
-            haus.nightmare.j3270.config.Settings.setInsertOffOnAid(insertOffAidItem.isSelected());
+            Settings.setInsertOffOnAid(insertOffAidItem.isSelected());
             terminalPanel.applyModeSettings();
         });
         modesMenu.add(insertOffAidItem);
@@ -561,13 +562,15 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
 
     // ========== Dialog Openers ==========
 
-    private void showFindDialog() {
+    public void showFindDialog() {
         if (client == null) {
             JOptionPane.showMessageDialog(this, "Connect to a host before using Find.", "Not Connected", JOptionPane.WARNING_MESSAGE);
             return;
         }
         if (findDialog == null) {
             findDialog = new FindDialog(this, client, terminalPanel);
+        } else {
+            findDialog.setClient(client);
         }
         findDialog.setVisible(true);
     }
@@ -620,13 +623,15 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
         }
     }
 
-    private void showScriptDialog() {
+    public void showScriptDialog() {
         if (client == null) {
             JOptionPane.showMessageDialog(this, "Connect to a host before running scripts.", "Not Connected", JOptionPane.WARNING_MESSAGE);
             return;
         }
         if (scriptDialog == null) {
             scriptDialog = new ScriptDialog(this, client, terminalPanel);
+        } else {
+            scriptDialog.setClient(client);
         }
         scriptDialog.setVisible(true);
     }
@@ -707,7 +712,7 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
             terminalPanel.refreshScreen();
             statusBar.updateStatus();
         }
-        haus.nightmare.j3270.config.Settings.setCodePage(cpId);
+        Settings.setCodePage(cpId);
     }
 
     private void changeGraphicsMode(GraphicsMode mode) {
@@ -715,7 +720,7 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
             client.getDataStreamProcessor().getQueryReplyBuilder().setGraphicsMode(mode);
             terminalPanel.repaint();
         }
-        haus.nightmare.j3270.config.Settings.setGraphicsMode(mode);
+        Settings.setGraphicsMode(mode);
     }
 
     private void printScreen() {
@@ -814,15 +819,15 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
         }
 
         ConnectDialog dialog = new ConnectDialog(this);
-        String initialHost = lastHost != null && !lastHost.isEmpty() ? lastHost : haus.nightmare.j3270.config.Settings.getAutoConnectHost();
-        int initialPort = lastPort > 0 ? lastPort : haus.nightmare.j3270.config.Settings.getAutoConnectPort();
+        String initialHost = lastHost != null && !lastHost.isEmpty() ? lastHost : Settings.getAutoConnectHost();
+        int initialPort = lastPort > 0 ? lastPort : Settings.getAutoConnectPort();
         dialog.setInitialHost(initialHost);
         dialog.setInitialPort(initialPort);
-        dialog.setInitialTls(haus.nightmare.j3270.config.Settings.getAutoConnectTls());
-        dialog.setInitialVerifyCert(haus.nightmare.j3270.config.Settings.getAutoConnectVerifyCert());
-        dialog.setInitialCodePage(haus.nightmare.j3270.config.Settings.getCodePage());
-        dialog.setInitialGraphicsMode(haus.nightmare.j3270.config.Settings.getGraphicsMode());
-        dialog.setInitialHostType(haus.nightmare.j3270.config.Settings.getDefaultHostType());
+        dialog.setInitialTls(Settings.getAutoConnectTls());
+        dialog.setInitialVerifyCert(Settings.getAutoConnectVerifyCert());
+        dialog.setInitialCodePage(Settings.getCodePage());
+        dialog.setInitialGraphicsMode(Settings.getGraphicsMode());
+        dialog.setInitialHostType(Settings.getDefaultHostType());
         dialog.setVisible(true);
 
         if (dialog.isConfirmed()) {
@@ -835,7 +840,7 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
 
     public void setConnectionHostType(haus.nightmare.lib3270j.ft.FTConfig.HostType ht) {
         if (ht == null) return;
-        haus.nightmare.j3270.config.Settings.setDefaultHostType(ht.name());
+        Settings.setDefaultHostType(ht.name());
         if (client != null && client.getConfig() != null) {
             client.getConfig().setFtHostType(ht);
             String profileId = client.getConfig().getSavedProfileId();
@@ -857,7 +862,7 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
         if (client != null && client.getConfig() != null) {
             currentHt = client.getConfig().getFtHostType();
         } else {
-            String def = haus.nightmare.j3270.config.Settings.getDefaultHostType();
+            String def = Settings.getDefaultHostType();
             try {
                 if (def != null) currentHt = haus.nightmare.lib3270j.ft.FTConfig.HostType.valueOf(def.trim().toUpperCase());
             } catch (Exception ignored) {}
@@ -905,6 +910,18 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
         if (refreshTimer != null) {
             refreshTimer.stop();
         }
+        if (findDialog != null) {
+            findDialog.dispose();
+            findDialog = null;
+        }
+        if (scriptDialog != null) {
+            scriptDialog.dispose();
+            scriptDialog = null;
+        }
+        if (fieldInspectorDialog != null) {
+            fieldInspectorDialog.dispose();
+            fieldInspectorDialog = null;
+        }
         if (printerSessionDialog != null) {
             printerSessionDialog.dispose();
         }
@@ -985,6 +1002,18 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
         return statusBar;
     }
 
+    public FindDialog getFindDialog() {
+        return findDialog;
+    }
+
+    public ScriptDialog getScriptDialog() {
+        return scriptDialog;
+    }
+
+    public FieldInspectorDialog getFieldInspectorDialog() {
+        return fieldInspectorDialog;
+    }
+
     public void connect(ConnectionConfig config) {
         connect(config, true);
     }
@@ -1004,19 +1033,19 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
         lastHost = config.getHost();
         lastPort = config.getPort();
 
-        haus.nightmare.j3270.config.Settings.setAutoConnectHost(config.getHost());
-        haus.nightmare.j3270.config.Settings.setAutoConnectPort(config.getPort());
-        haus.nightmare.j3270.config.Settings.setAutoConnectTls(config.isUseTls());
-        haus.nightmare.j3270.config.Settings.setAutoConnectVerifyCert(config.isTlsVerifyCert());
-        haus.nightmare.j3270.config.Settings.setCodePage(config.getCodePage());
+        Settings.setAutoConnectHost(config.getHost());
+        Settings.setAutoConnectPort(config.getPort());
+        Settings.setAutoConnectTls(config.isUseTls());
+        Settings.setAutoConnectVerifyCert(config.isTlsVerifyCert());
+        Settings.setCodePage(config.getCodePage());
         if (config.getHostType() != null) {
-            haus.nightmare.j3270.config.Settings.setDefaultHostType(config.getHostType());
+            Settings.setDefaultHostType(config.getHostType());
         }
         if (FileTransferDialog.getLastTransferState() != null && config.isSavedConnection()) {
             FileTransferDialog.getLastTransferState().hostType = config.getFtHostType();
         }
         if (config.getGraphicsMode() != null) {
-            haus.nightmare.j3270.config.Settings.setGraphicsMode(config.getGraphicsMode());
+            Settings.setGraphicsMode(config.getGraphicsMode());
         }
 
         Telnet3270Client oldClient = client;
@@ -1045,6 +1074,15 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
 
         terminalPanel.setClient(client);
         statusBar.setClient(client, terminalPanel);
+        if (findDialog != null) {
+            findDialog.setClient(client);
+        }
+        if (scriptDialog != null) {
+            scriptDialog.setClient(client);
+        }
+        if (fieldInspectorDialog != null) {
+            fieldInspectorDialog.setClient(client);
+        }
 
         String tlsIndicator = config.isUseTls() ? (config.isTlsVerifyCert() ? " [TLS]" : " [TLS/Unverified]") : "";
         setTitle("j3270 — " + config.getHost() + ":" + config.getPort() + tlsIndicator);
@@ -1101,6 +1139,15 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
             client = null;
             c.removeConnectionListener(this);
             c.removeScreenUpdateListener(this);
+            if (findDialog != null) {
+                findDialog.setClient(null);
+            }
+            if (scriptDialog != null) {
+                scriptDialog.setClient(null);
+            }
+            if (fieldInspectorDialog != null) {
+                fieldInspectorDialog.setClient(null);
+            }
 
             new Thread(() -> {
                 try {
@@ -1142,7 +1189,7 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
         if (statusBar != null) {
             statusBar.setVisible(visible);
         }
-        haus.nightmare.j3270.config.Settings.setStatusBarVisible(visible);
+        Settings.setStatusBarVisible(visible);
         if (statusBarItem != null) {
             statusBarItem.setSelected(visible);
         }
@@ -1203,6 +1250,7 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
         if (screenUpdatePending.compareAndSet(false, true)) {
             SwingUtilities.invokeLater(() -> {
                 screenUpdatePending.set(false);
+                terminalPanel.onScreenUpdated();
                 if (fileTransfer != null) {
                     fileTransfer.onScreenUpdated();
                 }
@@ -1224,6 +1272,7 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
     @Override
     public void onScreenSizeChanged(int rows, int cols) {
         SwingUtilities.invokeLater(() -> {
+            terminalPanel.onScreenSizeChanged(rows, cols);
             terminalPanel.revalidate();
             terminalPanel.repaint();
             statusBar.updateStatus();
@@ -1504,7 +1553,7 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
 
         if (configFile != null) {
             try {
-                haus.nightmare.j3270.config.Settings.loadFromIniFile(configFile);
+                Settings.loadFromIniFile(configFile);
             } catch (Exception e) {
                 System.err.println("Failed to load config file: " + configFile);
                 System.err.println(e.getMessage());
@@ -1517,8 +1566,8 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
         } catch (Exception e) {
             log.fine("Could not set system look and feel");
         }
-        ThemeManager.applyUIManagerDefaults(haus.nightmare.j3270.config.Settings.getJavaUiTheme());
-        ThemeManager.setTheme(haus.nightmare.j3270.config.Settings.getJavaUiTheme());
+        ThemeManager.applyUIManagerDefaults(Settings.getJavaUiTheme());
+        ThemeManager.setTheme(Settings.getJavaUiTheme());
 
         System.setProperty("apple.laf.useScreenMenuBar", "true");
         System.setProperty("apple.awt.application.name", "j3270");
@@ -1590,12 +1639,12 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
                 if (finalAutoSysUnlock != null) {
                     config.setAutoSysUnlock(finalAutoSysUnlock);
                 } else {
-                    config.setAutoSysUnlock(haus.nightmare.j3270.config.Settings.getAutoSysUnlock());
+                    config.setAutoSysUnlock(Settings.getAutoSysUnlock());
                 }
                 if (finalGraphicsMode != null) {
                     config.setGraphicsMode(finalGraphicsMode);
                 } else {
-                    config.setGraphicsMode(haus.nightmare.j3270.config.Settings.getGraphicsMode());
+                    config.setGraphicsMode(Settings.getGraphicsMode());
                 }
                 if (finalProxyUrl != null) {
                     applyProxyUrl(config, finalProxyUrl);
@@ -1603,11 +1652,11 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
                 if (finalHostType != null) {
                     config.setHostType(finalHostType);
                 } else {
-                    config.setHostType(haus.nightmare.j3270.config.Settings.getDefaultHostType());
+                    config.setHostType(Settings.getDefaultHostType());
                 }
                 app.connect(config);
             } else {
-                haus.nightmare.j3270.config.Settings.StartupBehavior behavior = haus.nightmare.j3270.config.Settings
+                Settings.StartupBehavior behavior = Settings
                         .getStartupBehavior();
                 switch (behavior) {
                     case SHOW_CONNECT:
@@ -1626,22 +1675,22 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
                             if (finalProxyUrl != null) applyProxyUrl(config, finalProxyUrl);
                             app.connect(config);
                         } else {
-                            String host = haus.nightmare.j3270.config.Settings.getAutoConnectHost();
-                            int port = haus.nightmare.j3270.config.Settings.getAutoConnectPort();
-                            boolean tls = haus.nightmare.j3270.config.Settings.getAutoConnectTls();
-                            boolean verify = haus.nightmare.j3270.config.Settings.getAutoConnectVerifyCert();
-                            boolean tn3270e = haus.nightmare.j3270.config.Settings.getAutoConnectTn3270e();
+                            String host = Settings.getAutoConnectHost();
+                            int port = Settings.getAutoConnectPort();
+                            boolean tls = Settings.getAutoConnectTls();
+                            boolean verify = Settings.getAutoConnectVerifyCert();
+                            boolean tn3270e = Settings.getAutoConnectTn3270e();
                             if (host != null && !host.isEmpty()) {
                                 ConnectionConfig config = new ConnectionConfig(host, port, TerminalModel.IBM_3279_4, tls);
                                 config.setTlsVerifyCert(verify);
                                 config.setTn3270eEnabled(finalTn3270e != null ? finalTn3270e : tn3270e);
-                                config.setAutoReconnect(haus.nightmare.j3270.config.Settings.getAutoConnectAutoReconnect());
-                                config.setReconnectMaxRetries(haus.nightmare.j3270.config.Settings.getAutoConnectReconnectMaxRetries());
-                                config.setAutoSysUnlock(finalAutoSysUnlock != null ? finalAutoSysUnlock : haus.nightmare.j3270.config.Settings.getAutoSysUnlock());
+                                config.setAutoReconnect(Settings.getAutoConnectAutoReconnect());
+                                config.setReconnectMaxRetries(Settings.getAutoConnectReconnectMaxRetries());
+                                config.setAutoSysUnlock(finalAutoSysUnlock != null ? finalAutoSysUnlock : Settings.getAutoSysUnlock());
                                 if (finalGraphicsMode != null) {
                                     config.setGraphicsMode(finalGraphicsMode);
                                 } else {
-                                    config.setGraphicsMode(haus.nightmare.j3270.config.Settings.getGraphicsMode());
+                                    config.setGraphicsMode(Settings.getGraphicsMode());
                                 }
                                 if (finalProxyUrl != null) {
                                     applyProxyUrl(config, finalProxyUrl);
@@ -1649,7 +1698,7 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
                                 if (finalHostType != null) {
                                     config.setHostType(finalHostType);
                                 } else {
-                                    config.setHostType(haus.nightmare.j3270.config.Settings.getDefaultHostType());
+                                    config.setHostType(Settings.getDefaultHostType());
                                 }
                                 app.connect(config);
                             } else {

j3270/src/main/java/haus/nightmare/j3270/ui/FieldInspectorDialog.java

@@ -21,7 +21,7 @@ import java.util.List;
  */
 public class FieldInspectorDialog extends JDialog implements ScreenUpdateListener {
 
-    private final Telnet3270Client client;
+    private Telnet3270Client client;
     private final TerminalPanel terminalPanel;
 
     private DefaultTableModel tableModel;
@@ -46,13 +46,39 @@ public class FieldInspectorDialog extends JDialog implements ScreenUpdateListene
         addWindowListener(new WindowAdapter() {
             @Override
             public void windowClosing(WindowEvent e) {
-                if (client != null) {
-                    // Screen update listener removed on close
+                if (FieldInspectorDialog.this.client != null) {
+                    FieldInspectorDialog.this.client.removeScreenUpdateListener(FieldInspectorDialog.this);
                 }
             }
         });
     }
 
+    public void setClient(Telnet3270Client newClient) {
+        if (this.client != null) {
+            this.client.removeScreenUpdateListener(this);
+        }
+        this.client = newClient;
+        if (this.client != null) {
+            this.client.addScreenUpdateListener(this);
+            refreshFields();
+        } else if (tableModel != null && countLabel != null) {
+            tableModel.setRowCount(0);
+            countLabel.setText("Not connected");
+        }
+    }
+
+    public Telnet3270Client getClient() {
+        return this.client;
+    }
+
+    @Override
+    public void dispose() {
+        if (client != null) {
+            client.removeScreenUpdateListener(this);
+        }
+        super.dispose();
+    }
+
     private void buildUI() {
         JPanel mainPanel = new JPanel(new BorderLayout(8, 8));
         mainPanel.setBorder(new EmptyBorder(10, 10, 10, 10));

j3270/src/main/java/haus/nightmare/j3270/ui/FindDialog.java

@@ -15,7 +15,7 @@ import java.awt.event.KeyEvent;
  */
 public class FindDialog extends JDialog {
 
-    private final Telnet3270Client client;
+    private Telnet3270Client client;
     private final TerminalPanel terminalPanel;
 
     private JTextField searchField;
@@ -40,6 +40,24 @@ public class FindDialog extends JDialog {
         setResizable(false);
     }
 
+    public void setClient(Telnet3270Client client) {
+        this.client = client;
+    }
+
+    public Telnet3270Client getClient() {
+        return this.client;
+    }
+
+    public void setSearchText(String text) {
+        if (searchField != null) {
+            searchField.setText(text);
+        }
+    }
+
+    public String getSearchText() {
+        return searchField != null ? searchField.getText() : "";
+    }
+
     private void buildUI() {
         JPanel mainPanel = new JPanel(new BorderLayout(10, 10));
         mainPanel.setBorder(new EmptyBorder(12, 14, 12, 14));

j3270/src/main/java/haus/nightmare/j3270/ui/HotspotEngine.java

@@ -143,6 +143,9 @@ public class HotspotEngine {
     private int cachedRows = 0;
     private int cachedCols = 0;
     private List<Hotspot> cachedHotspots = Collections.emptyList();
+    private ScreenBuffer lastScreenBuffer;
+    private long lastSnapshotVersion = -1;
+    private long scanCount = 0;
 
     public HotspotEngine() {
     }
@@ -174,9 +177,19 @@ public class HotspotEngine {
         invalidateCache();
     }
 
-    public void invalidateCache() {
+    public synchronized void invalidateCache() {
         cachedScreenText = "";
         cachedHotspots = Collections.emptyList();
+        lastScreenBuffer = null;
+        lastSnapshotVersion = -1;
+    }
+
+    public synchronized void markDirty() {
+        invalidateCache();
+    }
+
+    public synchronized long getScanCount() {
+        return scanCount;
     }
 
     /**
@@ -186,6 +199,13 @@ public class HotspotEngine {
         if (sb == null) return Collections.emptyList();
         int rows = sb.getDisplayRows();
         int cols = sb.getDisplayCols();
+        long version = sb.getSnapshotVersion();
+
+        if (sb == lastScreenBuffer && version == lastSnapshotVersion && rows == cachedRows && cols == cachedCols) {
+            return cachedHotspots;
+        }
+
+        scanCount++;
 
         // Build plain text representation
         StringBuilder fullText = new StringBuilder(rows * (cols + 1));
@@ -204,7 +224,10 @@ public class HotspotEngine {
             }
         }
 
-        return scanText(fullText.toString(), rows, cols);
+        List<Hotspot> results = scanText(fullText.toString(), rows, cols);
+        lastScreenBuffer = sb;
+        lastSnapshotVersion = version;
+        return results;
     }
 
     /**

j3270/src/main/java/haus/nightmare/j3270/ui/ScriptDialog.java

@@ -15,7 +15,7 @@ import java.nio.charset.StandardCharsets;
  */
 public class ScriptDialog extends JDialog {
 
-    private final Telnet3270Client client;
+    private Telnet3270Client client;
     private final TerminalPanel terminalPanel;
 
     private JTextArea scriptArea;
@@ -32,6 +32,24 @@ public class ScriptDialog extends JDialog {
         setLocationRelativeTo(parent);
     }
 
+    public void setClient(Telnet3270Client client) {
+        this.client = client;
+    }
+
+    public Telnet3270Client getClient() {
+        return this.client;
+    }
+
+    public void setScriptText(String text) {
+        if (scriptArea != null) {
+            scriptArea.setText(text);
+        }
+    }
+
+    public String getScriptText() {
+        return scriptArea != null ? scriptArea.getText() : "";
+    }
+
     private void buildUI() {
         JPanel mainPanel = new JPanel(new BorderLayout(10, 10));
         mainPanel.setBorder(new EmptyBorder(12, 14, 12, 14));

j3270/src/main/java/haus/nightmare/j3270/ui/TerminalPanel.java

@@ -64,6 +64,8 @@ public class TerminalPanel extends JPanel implements java.awt.print.Printable, I
             CHAR_STRINGS[i] = String.valueOf((char) i);
         }
     }
+    // Reusable single-character buffer for drawing non-ASCII cells (Phase 27.4 / T1-A)
+    private final char[] charScratch = new char[1];
     public enum CursorStyle {
         BLOCK,
         UNDERLINE
@@ -110,10 +112,14 @@ public class TerminalPanel extends JPanel implements java.awt.print.Printable, I
     // ========== Phase 25: Hotspots & Mouse Wheel ==========
     private final HotspotEngine hotspotEngine = new HotspotEngine();
     private HotspotEngine.Hotspot hoveredHotspot = null;
+    private static final Color HOTSPOT_HOVER_COLOR = new Color(0, 220, 255);
+    private static final Stroke HOTSPOT_HOVER_STROKE = new BasicStroke(2.0f);
     private boolean hotspotsEnabled = haus.nightmare.j3270.config.Settings.getHotspotsEnabled();
     private boolean mouseWheelEnabled = haus.nightmare.j3270.config.Settings.getMouseWheelEnabled();
     private String mouseWheelUpAction = haus.nightmare.j3270.config.Settings.getMouseWheelUpKey();
     private String mouseWheelDownAction = haus.nightmare.j3270.config.Settings.getMouseWheelDownKey();
+    private boolean hotspotsDirty = true;
+    private boolean[] selectedCellsScratch = new boolean[0];
 
     // ========== Mode and Listener State ==========
     private boolean insertMode = false;
@@ -400,7 +406,10 @@ public class TerminalPanel extends JPanel implements java.awt.print.Printable, I
                     int col = (e.getX() - ox) / cellWidth;
                     int row = (e.getY() - oy) / cellHeight;
                     if (row >= 0 && row < rows && col >= 0 && col < cols) {
+                        if (hotspotsDirty) {
                             hotspotEngine.scan(sb);
+                            hotspotsDirty = false;
+                        }
                         HotspotEngine.Hotspot h = hotspotEngine.findHotspot(row, col);
                         if (h != null) {
                             if (hoveredHotspot != h) {
@@ -515,6 +524,10 @@ public class TerminalPanel extends JPanel implements java.awt.print.Printable, I
 
                         // Phase 25.2: Interactive Hotspot click execution (URLs, PF keys, choices)
                         if (hotspotsEnabled && client.getConnectionState().isFullSession()) {
+                            if (hotspotsDirty) {
+                                hotspotEngine.scan(sb);
+                                hotspotsDirty = false;
+                            }
                             HotspotEngine.Hotspot h = hotspotEngine.findHotspot(row, col);
                             if (h != null) {
                                 if (h.getType() == HotspotEngine.HotspotType.URL) {
@@ -1054,7 +1067,7 @@ public class TerminalPanel extends JPanel implements java.awt.print.Printable, I
         popup.show(this, e.getX(), e.getY());
     }
 
-    private boolean isCellSelected(int row, int col) {
+    public boolean isCellSelected(int row, int col) {
         if (!hasSelection()) return false;
 
         int r1 = Math.min(selectionStartRow, selectionEndRow);
@@ -1066,7 +1079,7 @@ public class TerminalPanel extends JPanel implements java.awt.print.Printable, I
             return row >= r1 && row <= r2 && col >= c1 && col <= c2;
         } else {
             int cols = 80;
-            if (client != null) cols = client.getScreenBuffer().getCols();
+            if (client != null && client.getScreenBuffer() != null) cols = client.getScreenBuffer().getDisplayCols();
             int addr = row * cols + col;
             int startAddr, endAddr;
             if (selectionStartRow < selectionEndRow ||
@@ -1081,6 +1094,51 @@ public class TerminalPanel extends JPanel implements java.awt.print.Printable, I
         }
     }
 
+    public void precomputeSelectionScratch(int rows, int cols) {
+        int totalCells = rows * cols;
+        if (selectedCellsScratch == null || selectedCellsScratch.length < totalCells) {
+            selectedCellsScratch = new boolean[totalCells];
+        }
+        java.util.Arrays.fill(selectedCellsScratch, 0, totalCells, false);
+        if (hasSelection()) {
+            int r1 = Math.min(selectionStartRow, selectionEndRow);
+            int r2 = Math.max(selectionStartRow, selectionEndRow);
+            if (blockSelectMode || trimRectSizingHandles) {
+                int c1 = Math.min(selectionStartCol, selectionEndCol);
+                int c2 = Math.max(selectionStartCol, selectionEndCol);
+                int minR = Math.max(0, r1);
+                int maxR = Math.min(rows - 1, r2);
+                int minC = Math.max(0, c1);
+                int maxC = Math.min(cols - 1, c2);
+                if (minC <= maxC) {
+                    for (int r = minR; r <= maxR; r++) {
+                        int rowBase = r * cols;
+                        java.util.Arrays.fill(selectedCellsScratch, rowBase + minC, rowBase + maxC + 1, true);
+                    }
+                }
+            } else {
+                int startAddr, endAddr;
+                if (selectionStartRow < selectionEndRow ||
+                    (selectionStartRow == selectionEndRow && selectionStartCol <= selectionEndCol)) {
+                startAddr = selectionStartRow * cols + selectionStartCol;
+                endAddr = selectionEndRow * cols + selectionEndCol;
+            } else {
+                startAddr = selectionEndRow * cols + selectionEndCol;
+                endAddr = selectionStartRow * cols + selectionStartCol;
+            }
+            int s = Math.max(0, startAddr);
+            int e = Math.min(totalCells - 1, endAddr);
+            if (s <= e) {
+                java.util.Arrays.fill(selectedCellsScratch, s, e + 1, true);
+            }
+        }
+    }
+}
+
+    public boolean[] getSelectedCellsScratch() {
+        return selectedCellsScratch;
+    }
+
 
     public void packForModel(int modelRows, int modelCols) {
         if (isDisplayable() && !SwingUtilities.isEventDispatchThread()) {
@@ -1687,6 +1745,7 @@ public class TerminalPanel extends JPanel implements java.awt.print.Printable, I
     }
 
     public void applyModeSettings() {
+        hotspotsDirty = true;
         if (client != null) {
             ScreenBuffer sb = client.getScreenBuffer();
             if (sb != null) {
@@ -1723,6 +1782,7 @@ public class TerminalPanel extends JPanel implements java.awt.print.Printable, I
     }
 
     public void refreshScreen() {
+        hotspotsDirty = true;
         if (client != null) {
             client.getScreenBuffer().updateDisplaySnapshot();
         }
@@ -1740,6 +1800,26 @@ public class TerminalPanel extends JPanel implements java.awt.print.Printable, I
         }
     }
 
+    public void onScreenUpdated() {
+        hotspotsDirty = true;
+    }
+
+    public void onScreenSizeChanged() {
+        hotspotsDirty = true;
+    }
+
+    public void onScreenSizeChanged(int rows, int cols) {
+        hotspotsDirty = true;
+    }
+
+    public boolean isHotspotsDirty() {
+        return hotspotsDirty;
+    }
+
+    public void setHotspotsDirty(boolean hotspotsDirty) {
+        this.hotspotsDirty = hotspotsDirty;
+    }
+
     private void setupFont() {
         currentFontSize = haus.nightmare.j3270.config.Settings.getFontSize();
         String fontFamily = haus.nightmare.j3270.config.Settings.getFontFamily();
@@ -1880,6 +1960,7 @@ public class TerminalPanel extends JPanel implements java.awt.print.Printable, I
 
     public void setClient(Telnet3270Client client) {
         this.client = client;
+        hotspotsDirty = true;
         if (client != null) {
             setupGraphicsPlaneRenderer();
             updateCellSize();
@@ -2076,6 +2157,9 @@ public class TerminalPanel extends JPanel implements java.awt.print.Printable, I
             g2.fillRect(cx, oy, cellWidth, gridH);
         }
 
+        // Phase 28.2 / T2-B: Precompute selection scratch lookup once per frame
+        precomputeSelectionScratch(rows, cols);
+
         // Layer 3: Character / Text Plane
         byte currentFA = 0;
         ExtendedAttribute currentFieldEa = null;
@@ -2097,7 +2181,7 @@ public class TerminalPanel extends JPanel implements java.awt.print.Printable, I
                 if (ea.isFieldAttribute()) {
                     currentFA = ea.fa;
                     currentFieldEa = ea;
-                    if (isCellSelected(row, col)) {
+                    if (selectedCellsScratch[baddr]) {
                         g2.setColor(SELECTION_COLOR);
                         g2.fillRect(x, y, cellWidth, cellHeight);
                     }
@@ -2142,7 +2226,7 @@ public class TerminalPanel extends JPanel implements java.awt.print.Printable, I
                     // Field Outlining (0xC2 / TY_FOUTLINE)
                     drawOutlining(g2, ea, currentFieldEa, baddr, row, col, x, y, cellWidth, cellHeight, rows, cols, sb, fgColor);
 
-                    if (isCellSelected(row, col)) {
+                    if (selectedCellsScratch[baddr]) {
                         g2.setColor(SELECTION_COLOR);
                         g2.fillRect(x, y, cellWidth, cellHeight);
                     }
@@ -2194,7 +2278,8 @@ public class TerminalPanel extends JPanel implements java.awt.print.Printable, I
                         if (ch < 128) {
                             g2.drawString(CHAR_STRINGS[ch], x, textY);
                         } else {
-                            g2.drawString(String.valueOf(ch), x, textY);
+                            charScratch[0] = ch;
+                            g2.drawChars(charScratch, 0, 1, x, textY);
                         }
                     }
                 }
@@ -2215,7 +2300,7 @@ public class TerminalPanel extends JPanel implements java.awt.print.Printable, I
                 }
 
                 // Draw selection highlight (40% alpha blend over cell)
-                if (isCellSelected(row, col)) {
+                if (selectedCellsScratch[baddr]) {
                     g2.setColor(SELECTION_COLOR);
                     g2.fillRect(x, y, cellWidth, cellHeight);
                 }
@@ -2261,8 +2346,8 @@ public class TerminalPanel extends JPanel implements java.awt.print.Printable, I
         if (hotspotsEnabled && hoveredHotspot != null) {
             Color oldColor = g2.getColor();
             Stroke oldStroke = g2.getStroke();
-            g2.setColor(new Color(0, 220, 255)); // Bright cyan hotspot underline
-            g2.setStroke(new BasicStroke(2.0f));
+            g2.setColor(HOTSPOT_HOVER_COLOR); // Bright cyan hotspot underline
+            g2.setStroke(HOTSPOT_HOVER_STROKE);
 
             int hr0 = hoveredHotspot.getStartRow();
             int hr1 = hoveredHotspot.getEndRow();

lib3270j/build.gradle

@@ -1,5 +1,11 @@
 plugins {
     id 'java-library'
+    id 'maven-publish'
+}
+
+java {
+    withSourcesJar()
+    withJavadocJar()
 }
 
 dependencies {
@@ -17,3 +23,39 @@ jar {
                    'Implementation-Version': archiveVersion
     }
 }
+
+publishing {
+    publications {
+        mavenJava(MavenPublication) {
+            from components.java
+            groupId = 'haus.nightmare.j3270'
+            artifactId = 'lib3270j'
+            version = project.version
+
+            pom {
+                name = 'lib3270j'
+                description = 'Pure Java IBM 3270 terminal emulation and protocol library with Host On-Demand (HOD) parity'
+                url = 'https://github.com/rudi/j3270'
+                licenses {
+                    license {
+                        name = 'The Unlicense'
+                        url = 'https://unlicense.org/'
+                        distribution = 'repo'
+                    }
+                }
+                developers {
+                    developer {
+                        id = 'rudi'
+                        name = 'Rudi'
+                    }
+                }
+                scm {
+                    connection = 'scm:git:git://github.com/rudi/j3270.git'
+                    developerConnection = 'scm:git:ssh://github.com/rudi/j3270.git'
+                    url = 'https://github.com/rudi/j3270'
+                }
+            }
+        }
+    }
+}
+

lib3270j/src/main/java/haus/nightmare/lib3270j/datastream/FastByteBuffer.java

@@ -8,6 +8,12 @@ import java.util.Arrays;
  * Reusable, resizable byte buffer that provides zero-copy access to its internal
  * array and supports ByteBuffer slicing to minimize heap allocations during
  * network stream processing.
+ * <p>
+ * <b>Threading Contract:</b> This class is NOT thread-safe and is designed for
+ * high-throughput single-threaded or thread-confined stream accumulation (such as
+ * Telnet network receiver loops matching IBM Host On-Demand {@code sArray} and
+ * {@code sb_buffer}). External synchronization must be used if instances are shared
+ * across threads.
  */
 public class FastByteBuffer extends OutputStream {
 
@@ -31,13 +37,13 @@ public class FastByteBuffer extends OutputStream {
     }
 
     @Override
-    public synchronized void write(int b) {
+    public void write(int b) {
         ensureCapacity(count + 1);
         buf[count++] = (byte) b;
     }
 
     @Override
-    public synchronized void write(byte[] b, int off, int len) {
+    public void write(byte[] b, int off, int len) {
         if (b == null || len <= 0) return;
         ensureCapacity(count + len);
         System.arraycopy(b, off, buf, count, len);
@@ -48,29 +54,29 @@ public class FastByteBuffer extends OutputStream {
      * Direct reference to internal buffer array.
      * Use {@link #size()} to determine active length.
      */
-    public synchronized byte[] buffer() {
+    public byte[] buffer() {
         return buf;
     }
 
-    public synchronized int size() {
+    public int size() {
         return count;
     }
 
-    public synchronized void reset() {
+    public void reset() {
         count = 0;
     }
 
     /**
      * Creates a read-only ByteBuffer view wrapping active bytes without copying.
      */
-    public synchronized ByteBuffer asByteBuffer() {
+    public ByteBuffer asByteBuffer() {
         return ByteBuffer.wrap(buf, 0, count).asReadOnlyBuffer();
     }
 
     /**
      * Creates a read-only ByteBuffer slice for a sub-range without copying.
      */
-    public synchronized ByteBuffer slice(int offset, int length) {
+    public ByteBuffer slice(int offset, int length) {
         if (offset < 0 || length < 0 || offset + length > count) {
             throw new IndexOutOfBoundsException("offset=" + offset + " length=" + length + " size=" + count);
         }
@@ -80,7 +86,7 @@ public class FastByteBuffer extends OutputStream {
     /**
      * Produces a copied byte array if an isolated copy is explicitly required.
      */
-    public synchronized byte[] toByteArray() {
+    public byte[] toByteArray() {
         return Arrays.copyOf(buf, count);
     }
 }

lib3270j/src/main/java/haus/nightmare/lib3270j/screen/ExtendedAttribute.java

@@ -110,6 +110,14 @@ public class ExtendedAttribute {
      */
     public char ucs4;
 
+    public ExtendedAttribute() {}
+
+    public ExtendedAttribute(ExtendedAttribute other) {
+        if (other != null) {
+            copyFrom(other);
+        }
+    }
+
     /** Clear all attributes. */
     public void clear() {
         ec = 0;

lib3270j/src/main/java/haus/nightmare/lib3270j/screen/ScreenBuffer.java

@@ -197,48 +197,99 @@ public class ScreenBuffer {
         return buffer[addr];
     }
 
+    /**
+     * Immutable snapshot container for tear-free, lock-free screen display.
+     * Published atomically to UI thread / EDT via volatile reference release.
+     */
+    public static final class DisplaySnapshot {
+        public final ExtendedAttribute[] cells;
+        public final int rows;
+        public final int cols;
+        public final int cursorAddress;
+        public final long version;
+
+        public DisplaySnapshot(ExtendedAttribute[] cells, int rows, int cols, int cursorAddress) {
+            this(cells, rows, cols, cursorAddress, 0L);
+        }
+
+        public DisplaySnapshot(ExtendedAttribute[] cells, int rows, int cols, int cursorAddress, long version) {
+            this.cells = cells;
+            this.rows = rows;
+            this.cols = cols;
+            this.cursorAddress = cursorAddress;
+            this.version = version;
+        }
+
+        public ExtendedAttribute getCell(int addr) {
+            if (cells == null || addr < 0 || addr >= cells.length) {
+                return null;
+            }
+            return cells[addr];
+        }
+
+        public int getRows() { return rows; }
+        public int getCols() { return cols; }
+        public int getCursorAddress() { return cursorAddress; }
+        public long getVersion() { return version; }
+    }
+
+    private volatile DisplaySnapshot currentSnapshot;
     private ExtendedAttribute[] displaySnapshot;
     private int displayRows;
     private int displayCols;
     private int displayCursorAddress;
+    private long snapshotVersion = 0;
 
     /**
-     * Atomically creates a snapshot of the current presentation buffer for tear-free rendering.
-     * Takes ~2 microseconds and eliminates mutual thread contention with the UI thread.
+     * Atomically creates an immutable snapshot of the current presentation buffer for tear-free rendering.
+     * Published via a volatile release fence, eliminating mutual monitor contention with the UI paint loop.
      */
     public synchronized void updateDisplaySnapshot() {
         int size = rows * cols;
-        if (displaySnapshot == null || displaySnapshot.length < size) {
-            displaySnapshot = new ExtendedAttribute[size];
+        ExtendedAttribute[] snapshotCells = new ExtendedAttribute[size];
         for (int i = 0; i < size; i++) {
-                displaySnapshot[i] = new ExtendedAttribute();
-            }
-        }
-        for (int i = 0; i < size; i++) {
-            displaySnapshot[i].copyFrom(buffer[i]);
+            ExtendedAttribute ea = new ExtendedAttribute();
+            ea.copyFrom(buffer[i]);
+            snapshotCells[i] = ea;
         }
         this.displayRows = rows;
         this.displayCols = cols;
         this.displayCursorAddress = cursorAddress;
+        this.snapshotVersion++;
+        this.displaySnapshot = snapshotCells;
+        this.currentSnapshot = new DisplaySnapshot(snapshotCells, rows, cols, cursorAddress, snapshotVersion);
     }
 
-    public synchronized ExtendedAttribute getDisplayCell(int addr) {
-        if (displaySnapshot == null || addr < 0 || addr >= displayRows * displayCols) {
+    public DisplaySnapshot getDisplaySnapshot() {
+        return currentSnapshot;
+    }
+
+    public long getSnapshotVersion() {
+        DisplaySnapshot snap = this.currentSnapshot;
+        return snap != null ? snap.version : snapshotVersion;
+    }
+
+    public ExtendedAttribute getDisplayCell(int addr) {
+        DisplaySnapshot snap = this.currentSnapshot;
+        if (snap == null || addr < 0 || addr >= snap.cells.length) {
             return getCell(addr);
         }
-        return displaySnapshot[addr];
+        return snap.cells[addr];
     }
 
-    public synchronized int getDisplayRows() {
-        return displayRows > 0 ? displayRows : rows;
+    public int getDisplayRows() {
+        DisplaySnapshot snap = this.currentSnapshot;
+        return (snap != null && snap.rows > 0) ? snap.rows : (displayRows > 0 ? displayRows : rows);
     }
 
-    public synchronized int getDisplayCols() {
-        return displayCols > 0 ? displayCols : cols;
+    public int getDisplayCols() {
+        DisplaySnapshot snap = this.currentSnapshot;
+        return (snap != null && snap.cols > 0) ? snap.cols : (displayCols > 0 ? displayCols : cols);
     }
 
-    public synchronized int getDisplayCursorAddress() {
-        return displayRows > 0 ? displayCursorAddress : cursorAddress;
+    public int getDisplayCursorAddress() {
+        DisplaySnapshot snap = this.currentSnapshot;
+        return (snap != null && snap.rows > 0) ? snap.cursorAddress : (displayRows > 0 ? displayCursorAddress : cursorAddress);
     }
 
     // ========== Dimension accessors ==========
@@ -346,6 +397,10 @@ public class ScreenBuffer {
             oldAddr = this.cursorAddress;
             this.cursorAddress = addr;
             this.displayCursorAddress = addr;
+            DisplaySnapshot snap = this.currentSnapshot;
+            if (snap != null) {
+                this.currentSnapshot = new DisplaySnapshot(snap.cells, snap.rows, snap.cols, addr, snap.version);
+            }
         }
         if (oldAddr != addr) {
             notifyCursorMoved(oldAddr, addr);

lib3270j/src/main/java/haus/nightmare/lib3270j/telnet/TelnetFSM.java

@@ -49,6 +49,9 @@ public class TelnetFSM {
     // 3270 input buffer (accumulated between telnet framing)
     private final haus.nightmare.lib3270j.datastream.FastByteBuffer ibuf = new haus.nightmare.lib3270j.datastream.FastByteBuffer(32768);
 
+    // Reusable single-byte scratch buffer for plain NVT data dispatch (Phase 27.5 / T1-C)
+    private final byte[] nvtSingleByteScratch = new byte[1];
+
     // Sub-negotiation buffer
     private final ByteArrayOutputStream sbbuf = new ByteArrayOutputStream(4096);
 
@@ -324,7 +327,8 @@ public class TelnetFSM {
         boolean isPlainNvt = (connectionState == ConnectionState.CONNECTED_NVT || connectionState == ConnectionState.CONNECTED_NVT_CHAR)
             && !(hisOpts[TELOPT_BINARY] && hisOpts[TELOPT_EOR]);
         if (isPlainNvt) {
-            nvtProcessor.processNVTData(new byte[] { (byte) c }, 0, 1);
+            nvtSingleByteScratch[0] = (byte) c;
+            nvtProcessor.processNVTData(nvtSingleByteScratch, 0, 1);
             return;
         }
 

setup.ps1

@@ -413,11 +413,19 @@ if (Test-Path $libResDir) {
 }
 
 # ------------------------------------------------------------------------------
-# 7. Package Standalone Executable JAR
+# 7. Package Standalone JARs
 # ------------------------------------------------------------------------------
+Write-LogInfo "Packaging standalone lib3270j library JAR..."
+$libManifestFile = Join-Path $BuildDir "LIB_MANIFEST.MF"
+$libManifestText = "Manifest-Version: 1.0`r`nImplementation-Title: lib3270j`r`nImplementation-Version: 1.2.4`r`nCreated-By: j3270 setup.ps1`r`n`r`n"
+[System.IO.File]::WriteAllText($libManifestFile, $libManifestText)
+
+$libJarFile = Join-Path $BuildDir "lib3270j.jar"
+& $detectedJdk.Jar cvfm $libJarFile $libManifestFile -C $LibBuildDir . | Out-Null
+
 Write-LogInfo "Packaging standalone executable JAR..."
 $manifestFile = Join-Path $BuildDir "MANIFEST.MF"
-$manifestText = "Manifest-Version: 1.0`r`nMain-Class: haus.nightmare.j3270.J3270App`r`nImplementation-Title: j3270`r`nImplementation-Version: 0.1.0`r`nCreated-By: j3270 setup.ps1`r`n`r`n"
+$manifestText = "Manifest-Version: 1.0`r`nMain-Class: haus.nightmare.j3270.J3270App`r`nImplementation-Title: j3270`r`nImplementation-Version: 1.2.4`r`nCreated-By: j3270 setup.ps1`r`n`r`n"
 [System.IO.File]::WriteAllText($manifestFile, $manifestText)
 
 $jarFile = Join-Path $BuildDir "j3270.jar"
@@ -428,10 +436,13 @@ if (-not (Test-Path $jarFile)) {
     exit 1
 }
 
+$libJarItem = Get-Item $libJarFile
+$libJarSizeKB = [math]::Round($libJarItem.Length / 1KB, 1)
 $jarItem = Get-Item $jarFile
 $jarSizeKB = [math]::Round($jarItem.Length / 1KB, 1)
 
 Write-Host "`n=== Build Successful ===`n" -ForegroundColor Green
+Write-LogSuccess "Library JAR created:    $libJarFile (${libJarSizeKB} KB)"
 Write-LogSuccess "Executable JAR created: $jarFile (${jarSizeKB} KB)"
 
 Write-Host @"

setup.sh

@@ -369,15 +369,28 @@ if [ -d "$SCRIPT_DIR/lib3270j/src/main/resources" ]; then
 fi
 
 # ------------------------------------------------------------------------------
-# 5. Package Standalone Executable JAR
+# 5. Package Standalone JARs
 # ------------------------------------------------------------------------------
+log_info "Packaging standalone lib3270j library JAR..."
+
+cat << 'EOF' > "$BUILD_DIR/LIB_MANIFEST.MF"
+Manifest-Version: 1.0
+Implementation-Title: lib3270j
+Implementation-Version: 1.2.4
+Created-By: j3270 setup.sh
+
+EOF
+
+"$JAR_BIN" cvfm "$BUILD_DIR/lib3270j.jar" "$BUILD_DIR/LIB_MANIFEST.MF" \
+    -C "$BUILD_DIR/lib3270j" . > /dev/null
+
 log_info "Packaging standalone executable JAR..."
 
 cat << 'EOF' > "$BUILD_DIR/MANIFEST.MF"
 Manifest-Version: 1.0
 Main-Class: haus.nightmare.j3270.J3270App
 Implementation-Title: j3270
-Implementation-Version: 0.1.0
+Implementation-Version: 1.2.4
 Created-By: j3270 setup.sh
 
 EOF
@@ -391,8 +404,10 @@ if [ ! -f "$BUILD_DIR/j3270.jar" ]; then
     exit 1
 fi
 
-JAR_SIZE=$(ls -lh "$BUILD_DIR/j3270.jar" | awk '{print $5}')
+LIB_JAR_SIZE=$(du -h "$BUILD_DIR/lib3270j.jar" | awk '{print $1}')
+JAR_SIZE=$(du -h "$BUILD_DIR/j3270.jar" | awk '{print $1}')
 printf "\n%b=== Build Successful ===%b\n" "$BOLD" "$RESET"
+log_success "Library JAR:    $BUILD_DIR/lib3270j.jar ($LIB_JAR_SIZE)"
 log_success "Executable JAR: $BUILD_DIR/j3270.jar ($JAR_SIZE)"
 
 printf "\n%bTo run j3270:%b\n" "$BOLD" "$RESET"