redesign pin and pattern UI, add settings for changing lock and enable/disable biometrics and add button to lock app from any screen

app/src/main/java/sh/sar/basedbank/LockActivity.kt

@@ -51,6 +51,10 @@ class LockActivity : AppCompatActivity() {
     }
 
     private fun buildNumpad() {
+        val dp = resources.displayMetrics.density
+        val btnSize = (68 * dp).toInt()
+        val btnMarginH = (10 * dp).toInt()
+        val rowMarginV = (6 * dp).toInt()
         val rows = listOf(
             listOf("1", "2", "3"),
             listOf("4", "5", "6"),
@@ -60,9 +64,11 @@ class LockActivity : AppCompatActivity() {
         rows.forEach { keys ->
             val row = LinearLayout(this).apply {
                 orientation = LinearLayout.HORIZONTAL
+                gravity = android.view.Gravity.CENTER
                 layoutParams = LinearLayout.LayoutParams(
-                    LinearLayout.LayoutParams.MATCH_PARENT, 0, 1f
+                    LinearLayout.LayoutParams.WRAP_CONTENT,
-                )
+                    LinearLayout.LayoutParams.WRAP_CONTENT
+                ).also { it.setMargins(0, rowMarginV, 0, rowMarginV) }
             }
             keys.forEach { key ->
                 val style = if (key == "✓")
@@ -71,10 +77,12 @@ class LockActivity : AppCompatActivity() {
                     com.google.android.material.R.attr.materialButtonOutlinedStyle
                 val btn = MaterialButton(this, null, style).apply {
                     text = key
-                    textSize = 20f
+                    textSize = 24f
                     insetTop = 0; insetBottom = 0
-                    layoutParams = LinearLayout.LayoutParams(0, LinearLayout.LayoutParams.MATCH_PARENT, 1f)
+                    minimumWidth = 0; minimumHeight = 0
-                        .also { it.setMargins(4, 4, 4, 4) }
+                    cornerRadius = btnSize / 2
+                    layoutParams = LinearLayout.LayoutParams(btnSize, btnSize)
+                        .also { it.setMargins(btnMarginH, 0, btnMarginH, 0) }
                 }
                 btn.setOnClickListener { handleKey(key) }
                 row.addView(btn)

app/src/main/java/sh/sar/basedbank/ui/home/HomeActivity.kt

@@ -2,6 +2,8 @@ package sh.sar.basedbank.ui.home
 
 import android.content.Intent
 import android.os.Bundle
+import android.view.Menu
+import android.view.MenuItem
 import android.view.View
 import android.widget.Toast
 import androidx.activity.viewModels
@@ -131,6 +133,21 @@ class HomeActivity : AppCompatActivity() {
             .commit()
     }
 
+    override fun onCreateOptionsMenu(menu: Menu): Boolean {
+        menuInflater.inflate(R.menu.toolbar_menu, menu)
+        return true
+    }
+
+    override fun onOptionsItemSelected(item: MenuItem): Boolean {
+        if (item.itemId == R.id.action_lock) {
+            startActivity(Intent(this, sh.sar.basedbank.LockActivity::class.java))
+            finish()
+            return true
+        }
+        return super.onOptionsItemSelected(item)
+    }
+
+
     private fun autoRefresh(
         mibCreds: CredentialStore.MibCredentials?,
         bmlCreds: CredentialStore.BmlCredentials?,

app/src/main/java/sh/sar/basedbank/ui/home/SettingsFragment.kt

@@ -7,10 +7,12 @@ import android.view.View
 import android.view.ViewGroup
 import androidx.appcompat.app.AppCompatDelegate
 import androidx.appcompat.app.AppCompatDelegate.setApplicationLocales
+import androidx.biometric.BiometricManager
 import androidx.core.os.LocaleListCompat
 import androidx.fragment.app.Fragment
 import sh.sar.basedbank.R
 import sh.sar.basedbank.databinding.FragmentSettingsBinding
+import sh.sar.basedbank.ui.onboarding.SecuritySetupFragment
 
 class SettingsFragment : Fragment() {
 
@@ -25,7 +27,7 @@ class SettingsFragment : Fragment() {
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         val prefs = requireContext().getSharedPreferences("prefs", Context.MODE_PRIVATE)
 
-        // Set initial selection
+        // Theme
         val saved = prefs.getString("theme", "system")
         val initialId = when (saved) {
             "light" -> R.id.btnThemeLight
@@ -57,6 +59,24 @@ class SettingsFragment : Fragment() {
             val tag = if (checkedId == R.id.btnLangDhivehi) "dv" else "en"
             setApplicationLocales(LocaleListCompat.forLanguageTags(tag))
         }
+
+        // Change lock
+        binding.btnChangeLock.setOnClickListener {
+            (requireActivity() as HomeActivity).showWithBackStack(
+                SecuritySetupFragment.newInstance(changeMode = true)
+            )
+        }
+
+        // Biometrics toggle — only show if device supports it
+        val canUseBiometrics = BiometricManager.from(requireContext())
+            .canAuthenticate(BiometricManager.Authenticators.BIOMETRIC_WEAK) == BiometricManager.BIOMETRIC_SUCCESS
+        if (canUseBiometrics) {
+            binding.rowBiometrics.visibility = View.VISIBLE
+            binding.switchBiometrics.isChecked = prefs.getBoolean("biometrics_enabled", false)
+            binding.switchBiometrics.setOnCheckedChangeListener { _, isChecked ->
+                prefs.edit().putBoolean("biometrics_enabled", isChecked).apply()
+            }
+        }
     }
 
     override fun onResume() {

app/src/main/java/sh/sar/basedbank/ui/onboarding/SecuritySetupFragment.kt

@@ -21,6 +21,13 @@ class SecuritySetupFragment : Fragment() {
         fun onSecuritySetupComplete()
     }
 
+    companion object {
+        private const val ARG_CHANGE_MODE = "change_mode"
+        fun newInstance(changeMode: Boolean = false) = SecuritySetupFragment().apply {
+            arguments = android.os.Bundle().also { it.putBoolean(ARG_CHANGE_MODE, changeMode) }
+        }
+    }
+
     private var _b: FragmentSecuritySetupBinding? = null
     private val b get() = _b!!
 
@@ -38,7 +45,8 @@ class SecuritySetupFragment : Fragment() {
 
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         val prefs = requireContext().getSharedPreferences("prefs", Context.MODE_PRIVATE)
-        if (prefs.getString("security_method", null) != null) {
+        val changeMode = arguments?.getBoolean(ARG_CHANGE_MODE, false) ?: false
+        if (!changeMode && prefs.getString("security_method", null) != null) {
             (activity as? Callback)?.onSecuritySetupComplete()
         }
 
@@ -69,6 +77,10 @@ class SecuritySetupFragment : Fragment() {
     }
 
     private fun buildNumpad() {
+        val dp = resources.displayMetrics.density
+        val btnSize = (68 * dp).toInt()
+        val btnMarginH = (10 * dp).toInt()
+        val rowMarginV = (6 * dp).toInt()
         val rows = listOf(
             listOf("1", "2", "3"),
             listOf("4", "5", "6"),
@@ -78,9 +90,11 @@ class SecuritySetupFragment : Fragment() {
         rows.forEach { keys ->
             val row = LinearLayout(requireContext()).apply {
                 orientation = LinearLayout.HORIZONTAL
+                gravity = android.view.Gravity.CENTER
                 layoutParams = LinearLayout.LayoutParams(
-                    LinearLayout.LayoutParams.MATCH_PARENT, 0, 1f
+                    LinearLayout.LayoutParams.WRAP_CONTENT,
-                )
+                    LinearLayout.LayoutParams.WRAP_CONTENT
+                ).also { it.setMargins(0, rowMarginV, 0, rowMarginV) }
             }
             keys.forEach { key ->
                 val style = if (key == "✓")
@@ -89,11 +103,12 @@ class SecuritySetupFragment : Fragment() {
                     com.google.android.material.R.attr.materialButtonOutlinedStyle
                 val btn = MaterialButton(requireContext(), null, style).apply {
                     text = key
-                    textSize = 20f
+                    textSize = 24f
-                    insetTop = 0
+                    insetTop = 0; insetBottom = 0
-                    insetBottom = 0
+                    minimumWidth = 0; minimumHeight = 0
-                    layoutParams = LinearLayout.LayoutParams(0, LinearLayout.LayoutParams.MATCH_PARENT, 1f)
+                    cornerRadius = btnSize / 2
-                        .also { it.setMargins(4, 4, 4, 4) }
+                    layoutParams = LinearLayout.LayoutParams(btnSize, btnSize)
+                        .also { it.setMargins(btnMarginH, 0, btnMarginH, 0) }
                 }
                 btn.setOnClickListener { handleKey(key) }
                 row.addView(btn)
@@ -223,7 +238,12 @@ class SecuritySetupFragment : Fragment() {
         .digest(input.toByteArray()).joinToString("") { "%02x".format(it) }
 
     private fun finishSetup() {
-        (activity as? Callback)?.onSecuritySetupComplete()
+        val cb = activity as? Callback
+        if (cb != null) {
+            cb.onSecuritySetupComplete()
+        } else {
+            parentFragmentManager.popBackStack()
+        }
     }
 
     override fun onDestroyView() {

app/src/main/res/drawable/ic_lock.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?attr/colorControlNormal">
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M18,8h-1V6c0-2.76-2.24-5-5-5S7,3.24 7,6v2H6c-1.1,0-2,0.9-2,2v10c0,1.1 0.9,2 2,2h12c1.1,0 2,-0.9 2,-2V10c0,-1.1-0.9,-2-2,-2zm-6,9c-1.1,0-2,-0.9-2,-2s0.9,-2 2,-2 2,0.9 2,2-0.9,2-2,2zm3.1,-9H8.9V6c0,-1.71 1.39,-3.1 3.1,-3.1 1.71,0 3.1,1.39 3.1,3.1v2z" />
+</vector>

app/src/main/res/layout/activity_lock.xml

@@ -11,11 +11,16 @@
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:orientation="vertical"
-        android:paddingTop="48dp"
+        android:paddingHorizontal="24dp"
-        android:paddingHorizontal="16dp"
+        android:paddingBottom="40dp"
-        android:paddingBottom="16dp"
         android:visibility="gone">
 
+        <!-- Top spacer: equal weight to bottom spacer centers the title between screen top and numpad -->
+        <View
+            android:layout_width="match_parent"
+            android:layout_height="0dp"
+            android:layout_weight="1" />
+
         <TextView
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
@@ -31,8 +36,13 @@
             android:text="@string/unlock_pin_subtitle"
             android:textAppearance="?attr/textAppearanceBodyMedium"
             android:textColor="?attr/colorOnSurfaceVariant"
-            android:gravity="center"
+            android:gravity="center" />
-            android:layout_marginBottom="24dp" />
+
+        <!-- Bottom spacer: equal weight centers title in the space above the numpad -->
+        <View
+            android:layout_width="match_parent"
+            android:layout_height="0dp"
+            android:layout_weight="1" />
 
         <TextView
             android:id="@+id/tvLockPinDots"
@@ -42,14 +52,14 @@
             android:textSize="26sp"
             android:letterSpacing="0.3"
             android:textColor="?attr/colorPrimary"
-            android:layout_marginBottom="20dp" />
+            android:layout_marginBottom="24dp" />
 
         <LinearLayout
             android:id="@+id/lockNumpadContainer"
             android:layout_width="match_parent"
-            android:layout_height="0dp"
+            android:layout_height="wrap_content"
-            android:layout_weight="1"
+            android:orientation="vertical"
-            android:orientation="vertical" />
+            android:gravity="center_horizontal" />
 
         <com.google.android.material.button.MaterialButton
             android:id="@+id/btnLockBiometricFromPin"
@@ -57,7 +67,7 @@
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_gravity="center_horizontal"
-            android:layout_marginTop="4dp"
+            android:layout_marginTop="8dp"
             android:text="@string/use_biometrics"
             android:visibility="gone" />
 
@@ -69,12 +79,16 @@
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:orientation="vertical"
-        android:paddingTop="48dp"
+        android:paddingHorizontal="24dp"
-        android:paddingHorizontal="32dp"
+        android:paddingBottom="40dp"
-        android:paddingBottom="16dp"
-        android:gravity="center_horizontal"
         android:visibility="gone">
 
+        <!-- Top spacer: equal weight to bottom spacer centers the title -->
+        <View
+            android:layout_width="match_parent"
+            android:layout_height="0dp"
+            android:layout_weight="1" />
+
         <TextView
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
@@ -90,8 +104,13 @@
             android:text="@string/unlock_pattern_subtitle"
             android:textAppearance="?attr/textAppearanceBodyMedium"
             android:textColor="?attr/colorOnSurfaceVariant"
-            android:gravity="center"
+            android:gravity="center" />
-            android:layout_marginBottom="24dp" />
+
+        <!-- Bottom spacer: equal weight centers title in the space above the pattern -->
+        <View
+            android:layout_width="match_parent"
+            android:layout_height="0dp"
+            android:layout_weight="1" />
 
         <TextView
             android:id="@+id/tvPatternHint"
@@ -106,13 +125,15 @@
             android:id="@+id/lockPatternView"
             android:layout_width="match_parent"
             android:layout_height="0dp"
-            android:layout_weight="1" />
+            android:layout_weight="2"
+            android:layout_gravity="center_horizontal" />
 
         <com.google.android.material.button.MaterialButton
             android:id="@+id/btnLockBiometricFromPattern"
             style="@style/Widget.Material3.Button.TextButton"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
+            android:layout_gravity="center_horizontal"
             android:layout_marginTop="8dp"
             android:text="@string/use_biometrics"
             android:visibility="gone" />

app/src/main/res/layout/fragment_security_setup.xml

@@ -138,11 +138,15 @@
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:orientation="vertical"
-        android:paddingTop="32dp"
+        android:paddingHorizontal="24dp"
-        android:paddingHorizontal="16dp"
+        android:paddingBottom="40dp"
-        android:paddingBottom="8dp"
         android:visibility="gone">
 
+        <View
+            android:layout_width="match_parent"
+            android:layout_height="0dp"
+            android:layout_weight="1" />
+
         <TextView
             android:id="@+id/tvPinTitle"
             android:layout_width="match_parent"
@@ -159,8 +163,12 @@
             android:text="@string/pin_min_digits"
             android:textAppearance="?attr/textAppearanceBodySmall"
             android:textColor="?attr/colorOnSurfaceVariant"
-            android:gravity="center"
+            android:gravity="center" />
-            android:layout_marginBottom="20dp" />
+
+        <View
+            android:layout_width="match_parent"
+            android:layout_height="0dp"
+            android:layout_weight="1" />
 
         <TextView
             android:id="@+id/tvPinDots"
@@ -170,14 +178,14 @@
             android:textSize="26sp"
             android:letterSpacing="0.3"
             android:textColor="?attr/colorPrimary"
-            android:layout_marginBottom="20dp" />
+            android:layout_marginBottom="24dp" />
 
         <LinearLayout
             android:id="@+id/numpadContainer"
             android:layout_width="match_parent"
-            android:layout_height="0dp"
+            android:layout_height="wrap_content"
-            android:layout_weight="1"
+            android:orientation="vertical"
-            android:orientation="vertical" />
+            android:gravity="center_horizontal" />
 
         <com.google.android.material.button.MaterialButton
             android:id="@+id/btnPinBack"
@@ -185,7 +193,7 @@
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_gravity="center_horizontal"
-            android:layout_marginTop="4dp"
+            android:layout_marginTop="8dp"
             android:text="@string/back" />
 
     </LinearLayout>
@@ -196,12 +204,15 @@
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:orientation="vertical"
-        android:paddingTop="32dp"
+        android:paddingHorizontal="24dp"
-        android:paddingHorizontal="32dp"
+        android:paddingBottom="40dp"
-        android:paddingBottom="8dp"
-        android:gravity="center_horizontal"
         android:visibility="gone">
 
+        <View
+            android:layout_width="match_parent"
+            android:layout_height="0dp"
+            android:layout_weight="1" />
+
         <TextView
             android:id="@+id/tvPatternTitle"
             android:layout_width="match_parent"
@@ -219,20 +230,26 @@
             android:text="@string/pattern_min_dots"
             android:textAppearance="?attr/textAppearanceBodySmall"
             android:textColor="?attr/colorOnSurfaceVariant"
-            android:gravity="center"
+            android:gravity="center" />
-            android:layout_marginBottom="16dp" />
+
+        <View
+            android:layout_width="match_parent"
+            android:layout_height="0dp"
+            android:layout_weight="1" />
 
         <sh.sar.basedbank.ui.onboarding.PatternView
             android:id="@+id/patternView"
             android:layout_width="match_parent"
             android:layout_height="0dp"
-            android:layout_weight="1" />
+            android:layout_weight="2"
+            android:layout_gravity="center_horizontal" />
 
         <com.google.android.material.button.MaterialButton
             android:id="@+id/btnPatternBack"
             style="@style/Widget.Material3.Button.TextButton"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
+            android:layout_gravity="center_horizontal"
             android:layout_marginTop="8dp"
             android:text="@string/back" />
 

app/src/main/res/layout/fragment_settings.xml

@@ -85,6 +85,45 @@
 
         </com.google.android.material.button.MaterialButtonToggleGroup>
 
+        <TextView
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="@string/settings_security"
+            android:textAppearance="?attr/textAppearanceTitleMedium"
+            android:layout_marginTop="24dp"
+            android:layout_marginBottom="12dp" />
+
+        <com.google.android.material.button.MaterialButton
+            android:id="@+id/btnChangeLock"
+            style="@style/Widget.Material3.Button.OutlinedButton"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="@string/settings_change_lock" />
+
+        <LinearLayout
+            android:id="@+id/rowBiometrics"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:orientation="horizontal"
+            android:gravity="center_vertical"
+            android:layout_marginTop="16dp"
+            android:visibility="gone">
+
+            <TextView
+                android:layout_width="0dp"
+                android:layout_height="wrap_content"
+                android:layout_weight="1"
+                android:text="@string/settings_biometrics"
+                android:textAppearance="?attr/textAppearanceBodyLarge"
+                android:textColor="?attr/colorOnSurface" />
+
+            <com.google.android.material.materialswitch.MaterialSwitch
+                android:id="@+id/switchBiometrics"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content" />
+
+        </LinearLayout>
+
     </LinearLayout>
 
 </ScrollView>

app/src/main/res/menu/toolbar_menu.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<menu xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+
+    <item
+        android:id="@+id/action_lock"
+        android:icon="@drawable/ic_lock"
+        android:title="@string/action_lock"
+        app:showAsAction="always" />
+
+</menu>

app/src/main/res/values/strings.xml

@@ -82,7 +82,13 @@
     <string name="transfer">Transfer</string>
     <string name="pay_mv_qr">PayMV QR</string>
 
+    <!-- Toolbar -->
+    <string name="action_lock">Lock app</string>
+
     <!-- Settings -->
+    <string name="settings_security">Security</string>
+    <string name="settings_change_lock">Change PIN / Pattern</string>
+    <string name="settings_biometrics">Use Biometrics</string>
     <string name="theme">Theme</string>
     <string name="theme_system">System</string>
     <string name="theme_light">Light</string>