Add input masking

build.sh

@@ -6,11 +6,11 @@ cd "$SCRIPT_DIR"
 
 echo "=== Building a3270 (Android APK) ==="
 
-# Set up JAVA_HOME if not already set
-if [ -z "$JAVA_HOME" ]; then
-    if [ -d "/Users/rudi/.sdkman/candidates/java/21.0.6-sem" ]; then
-        export JAVA_HOME="/Users/rudi/.sdkman/candidates/java/21.0.6-sem"
-    elif [ -d "/Users/rudi/.sdkman/candidates/java/current" ]; then
+# Set up JAVA_HOME (prefer JDK 21 if available)
+if [ -d "/Users/rudi/.sdkman/candidates/java/21.0.6-sem" ]; then
+    export JAVA_HOME="/Users/rudi/.sdkman/candidates/java/21.0.6-sem"
+elif [ -z "$JAVA_HOME" ]; then
+    if [ -d "/Users/rudi/.sdkman/candidates/java/current" ]; then
         export JAVA_HOME="/Users/rudi/.sdkman/candidates/java/current"
     fi
 fi

src/main/java/org/pubvm/a3270/MainActivity.kt

@@ -34,6 +34,7 @@ import org.pubvm.a3270.service.TerminalService
 import org.pubvm.a3270.storage.HostStorage
 import org.pubvm.a3270.ui.ConnectDialog
 import org.pubvm.a3270.ui.FileTransferDialog
+import org.pubvm.a3270.ui.SettingsDialog
 import org.pubvm.a3270.ui.TwoRowKeyBar
 import org.pubvm.a3270.ui.OiaStatusBar
 import org.pubvm.a3270.ui.TerminalView
@@ -156,9 +157,12 @@ fun MainScreen(
     val oiaText by viewModel.oiaText.collectAsState()
     val isKeyboardLocked by viewModel.isKeyboardLocked.collectAsState()
     val screenVersion by viewModel.screenVersion.collectAsState()
+    val maskHiddenInput by viewModel.maskHiddenInput.collectAsState()
+    val cursorBlink by viewModel.cursorBlink.collectAsState()
 
     var showConnectDialog by remember { mutableStateOf(false) }
     var showFtDialog by remember { mutableStateOf(false) }
+    var showSettingsDialog by remember { mutableStateOf(false) }
 
     val focusRequester = remember { FocusRequester() }
     val keyboardController = LocalSoftwareKeyboardController.current
@@ -213,6 +217,8 @@ fun MainScreen(
                 cols = cols,
                 cursorAddr = cursorAddr,
                 screenVersion = screenVersion,
+                maskHiddenFields = maskHiddenInput,
+                blinkCursor = cursorBlink,
                 onTapAddress = { addr ->
                     viewModel.setCursor(addr)
                     focusRequester.requestFocus()
@@ -279,6 +285,7 @@ fun MainScreen(
                 onConnectClick = { showConnectDialog = true },
                 onDisconnectClick = { viewModel.disconnect() },
                 onFtClick = { showFtDialog = true },
+                onSettingsClick = { showSettingsDialog = true },
                 onSendAid = { aid ->
                     viewModel.sendAid(aid)
                     focusRequester.requestFocus()
@@ -345,4 +352,17 @@ fun MainScreen(
             }
         )
     }
+
+    if (showSettingsDialog) {
+        SettingsDialog(
+            initialMaskHiddenInput = maskHiddenInput,
+            initialCursorBlink = cursorBlink,
+            onDismiss = { showSettingsDialog = false },
+            onSave = { mask, blink ->
+                showSettingsDialog = false
+                viewModel.updateSettings(mask, blink)
+                focusRequester.requestFocus()
+            }
+        )
+    }
 }

src/main/java/org/pubvm/a3270/TerminalViewModel.kt

@@ -18,6 +18,7 @@ import org.lib3270j.listener.ScreenUpdateListener
 import org.lib3270j.protocol.DS3270Constants.faIsProtected
 import org.lib3270j.screen.ScreenBuffer
 import org.pubvm.a3270.service.TerminalService
+import org.pubvm.a3270.storage.AppSettings
 import java.util.concurrent.Executors
 import java.util.logging.Logger
 
@@ -55,6 +56,19 @@ class TerminalViewModel(application: Application) : AndroidViewModel(application
     private val _isKeyboardLocked = MutableStateFlow(false)
     val isKeyboardLocked: StateFlow<Boolean> = _isKeyboardLocked.asStateFlow()
 
+    private val _maskHiddenInput = MutableStateFlow(AppSettings.isMaskHiddenInputEnabled(application))
+    val maskHiddenInput: StateFlow<Boolean> = _maskHiddenInput.asStateFlow()
+
+    private val _cursorBlink = MutableStateFlow(AppSettings.isCursorBlinkEnabled(application))
+    val cursorBlink: StateFlow<Boolean> = _cursorBlink.asStateFlow()
+
+    fun updateSettings(maskHidden: Boolean, blink: Boolean) {
+        AppSettings.setMaskHiddenInputEnabled(getApplication(), maskHidden)
+        AppSettings.setCursorBlinkEnabled(getApplication(), blink)
+        _maskHiddenInput.value = maskHidden
+        _cursorBlink.value = blink
+    }
+
     private var client: Telnet3270Client? = null
     var currentHost: String = ""
         private set

src/main/java/org/pubvm/a3270/storage/AppSettings.kt

@@ -0,0 +1,30 @@
+package org.pubvm.a3270.storage
+
+import android.content.Context
+import android.content.SharedPreferences
+
+object AppSettings {
+    private const val PREFS_NAME = "a3270_settings"
+    private const val KEY_MASK_HIDDEN_INPUT = "mask_hidden_input"
+    private const val KEY_CURSOR_BLINK = "cursor_blink"
+
+    private fun getPrefs(context: Context): SharedPreferences {
+        return context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE)
+    }
+
+    fun isMaskHiddenInputEnabled(context: Context): Boolean {
+        return getPrefs(context).getBoolean(KEY_MASK_HIDDEN_INPUT, true)
+    }
+
+    fun setMaskHiddenInputEnabled(context: Context, enabled: Boolean) {
+        getPrefs(context).edit().putBoolean(KEY_MASK_HIDDEN_INPUT, enabled).apply()
+    }
+
+    fun isCursorBlinkEnabled(context: Context): Boolean {
+        return getPrefs(context).getBoolean(KEY_CURSOR_BLINK, true)
+    }
+
+    fun setCursorBlinkEnabled(context: Context, enabled: Boolean) {
+        getPrefs(context).edit().putBoolean(KEY_CURSOR_BLINK, enabled).apply()
+    }
+}

src/main/java/org/pubvm/a3270/ui/FunctionKeyBar.kt

@@ -26,6 +26,7 @@ fun TwoRowKeyBar(
     onConnectClick: () -> Unit,
     onDisconnectClick: () -> Unit,
     onFtClick: () -> Unit,
+    onSettingsClick: () -> Unit = {},
     onSendAid: (Int) -> Unit,
     onReset: () -> Unit,
     onTab: () -> Unit,
@@ -51,7 +52,7 @@ fun TwoRowKeyBar(
                 .padding(horizontal = 1.dp, vertical = 1.dp),
             verticalAlignment = Alignment.CenterVertically
         ) {
-            // 1. Menu Dropdown Button (Connect/Disconnect/FT)
+            // 1. Menu Dropdown Button (Connect/Disconnect/FT/Settings)
             Box(modifier = Modifier.weight(1f)) {
                 KeyButton(
                     label = "⋮",
@@ -89,6 +90,13 @@ fun TwoRowKeyBar(
                             }
                         )
                     }
+                    DropdownMenuItem(
+                        text = { Text("Settings", color = Color.White, fontWeight = FontWeight.SemiBold) },
+                        onClick = {
+                            menuExpanded = false
+                            onSettingsClick()
+                        }
+                    )
                 }
             }
 
@@ -178,6 +186,7 @@ fun TwoRowKeyBar(
         }
     }
 }
+
 @Composable
 private fun KeyButton(
     label: String,

src/main/java/org/pubvm/a3270/ui/SettingsDialog.kt

@@ -0,0 +1,132 @@
+package org.pubvm.a3270.ui
+
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.*
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import androidx.compose.ui.window.Dialog
+
+@Composable
+fun SettingsDialog(
+    initialMaskHiddenInput: Boolean,
+    initialCursorBlink: Boolean,
+    onDismiss: () -> Unit,
+    onSave: (maskHiddenInput: Boolean, cursorBlink: Boolean) -> Unit
+) {
+    var maskHiddenInput by remember { mutableStateOf(initialMaskHiddenInput) }
+    var cursorBlink by remember { mutableStateOf(initialCursorBlink) }
+
+    Dialog(onDismissRequest = onDismiss) {
+        Card(
+            shape = RoundedCornerShape(12.dp),
+            colors = CardDefaults.cardColors(containerColor = Color(0xFF1E1E1E)),
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(16.dp)
+        ) {
+            Column(
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .padding(20.dp)
+            ) {
+                Text(
+                    text = "Terminal Settings",
+                    fontSize = 18.sp,
+                    fontWeight = FontWeight.Bold,
+                    color = Color.White
+                )
+
+                Spacer(modifier = Modifier.height(16.dp))
+
+                // Setting 1: Mask Protected/Hidden Input with '*'
+                Row(
+                    modifier = Modifier.fillMaxWidth(),
+                    verticalAlignment = Alignment.CenterVertically,
+                    horizontalArrangement = Arrangement.SpaceBetween
+                ) {
+                    Column(modifier = Modifier.weight(1f).padding(end = 12.dp)) {
+                        Text(
+                            text = "Show '*' for Hidden Fields",
+                            fontSize = 14.sp,
+                            fontWeight = FontWeight.SemiBold,
+                            color = Color.White
+                        )
+                        Text(
+                            text = "Display asterisks for typed characters in non-display / password fields rather than blank spaces.",
+                            fontSize = 12.sp,
+                            color = Color.LightGray
+                        )
+                    }
+                    Switch(
+                        checked = maskHiddenInput,
+                        onCheckedChange = { maskHiddenInput = it },
+                        colors = SwitchDefaults.colors(
+                            checkedThumbColor = Color.White,
+                            checkedTrackColor = Color(0xFF2B8A3E)
+                        )
+                    )
+                }
+
+                Spacer(modifier = Modifier.height(16.dp))
+                HorizontalDivider(color = Color(0xFF2C2D30))
+                Spacer(modifier = Modifier.height(16.dp))
+
+                // Setting 2: Blinking Cursor
+                Row(
+                    modifier = Modifier.fillMaxWidth(),
+                    verticalAlignment = Alignment.CenterVertically,
+                    horizontalArrangement = Arrangement.SpaceBetween
+                ) {
+                    Column(modifier = Modifier.weight(1f).padding(end = 12.dp)) {
+                        Text(
+                            text = "Blinking Cursor",
+                            fontSize = 14.sp,
+                            fontWeight = FontWeight.SemiBold,
+                            color = Color.White
+                        )
+                        Text(
+                            text = "Blink the terminal cursor to clearly indicate current screen position.",
+                            fontSize = 12.sp,
+                            color = Color.LightGray
+                        )
+                    }
+                    Switch(
+                        checked = cursorBlink,
+                        onCheckedChange = { cursorBlink = it },
+                        colors = SwitchDefaults.colors(
+                            checkedThumbColor = Color.White,
+                            checkedTrackColor = Color(0xFF2B8A3E)
+                        )
+                    )
+                }
+
+                Spacer(modifier = Modifier.height(24.dp))
+
+                // Action Buttons
+                Row(
+                    modifier = Modifier.fillMaxWidth(),
+                    horizontalArrangement = Arrangement.End
+                ) {
+                    TextButton(onClick = onDismiss) {
+                        Text("Cancel", color = Color.LightGray)
+                    }
+                    Spacer(modifier = Modifier.width(8.dp))
+                    Button(
+                        onClick = {
+                            onSave(maskHiddenInput, cursorBlink)
+                        },
+                        colors = ButtonDefaults.buttonColors(containerColor = Color(0xFF2B8A3E))
+                    ) {
+                        Text("Save", color = Color.White)
+                    }
+                }
+            }
+        }
+    }
+}

src/main/java/org/pubvm/a3270/ui/TerminalView.kt

@@ -24,6 +24,7 @@ import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.text.AnnotatedString
 import androidx.compose.ui.unit.DpOffset
 import androidx.compose.ui.unit.dp
+import kotlinx.coroutines.delay
 import org.lib3270j.protocol.DS3270Constants.*
 import org.lib3270j.screen.ExtendedAttribute
 import org.lib3270j.screen.ScreenBuffer
@@ -57,6 +58,8 @@ fun TerminalView(
     cols: Int,
     cursorAddr: Int,
     screenVersion: Long,
+    maskHiddenFields: Boolean = true,
+    blinkCursor: Boolean = true,
     onTapAddress: (Int) -> Unit,
     onPasteText: (String) -> Unit = {},
     modifier: Modifier = Modifier
@@ -70,6 +73,20 @@ fun TerminalView(
     var showContextMenu by remember { mutableStateOf(false) }
     var contextMenuOffset by remember { mutableStateOf(Offset.Zero) }
 
+    // Blinking cursor state (~530ms interval matching j3270)
+    var cursorVisible by remember { mutableStateOf(true) }
+    LaunchedEffect(cursorAddr, blinkCursor) {
+        if (!blinkCursor) {
+            cursorVisible = true
+            return@LaunchedEffect
+        }
+        cursorVisible = true
+        while (true) {
+            delay(530L)
+            cursorVisible = !cursorVisible
+        }
+    }
+
     Box(modifier = modifier.fillMaxSize()) {
         Canvas(
             modifier = Modifier
@@ -213,9 +230,19 @@ fun TerminalView(
                             isBold = true
                         }
 
-                        // Invisible fields (passwords / hidden)
+                        // Invisible fields (passwords / hidden inputs)
                         if (faIsZero(currentFA.toInt() and 0xFF)) {
-                            continue
+                            if (maskHiddenFields && ea.ucs4 > ' ' && ea.ucs4.code != 0xFFFF) {
+                                charVal = '*'
+                            } else {
+                                // Blanks out character
+                                charVal = ' '
+                            }
+                        } else {
+                            // Normal visible character
+                            if (ea.ucs4 > ' ' && ea.ucs4.code != 0xFFFF) {
+                                charVal = ea.ucs4
+                            }
                         }
 
                         // Extended Graphic Rendition
@@ -226,10 +253,6 @@ fun TerminalView(
                             if ((grVal and GR_UNDERLINE) != 0) isUnderline = true
                             if ((grVal and GR_REVERSE) != 0) isReverse = true
                         }
-
-                        if (ea.ucs4 > ' ' && ea.ucs4.code != 0xFFFF) {
-                            charVal = ea.ucs4
-                        }
                     } else {
                         fgColor = HOST_COLORS[HOST_COLOR_GREEN]
                     }
@@ -258,7 +281,8 @@ fun TerminalView(
                         )
                     }
 
-                    if (addr == cursorAddr && !isSelected) {
+                    // Cursor indicator (respects blinking toggle & timer)
+                    if (addr == cursorAddr && !isSelected && cursorVisible) {
                         drawRect(
                             color = HOST_COLORS[HOST_COLOR_TURQUOISE].copy(alpha = 0.5f),
                             topLeft = Offset(left, top),