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)
-                        .also { it.setMargins(4, 4, 4, 4) }
+                    minimumWidth = 0; minimumHeight = 0
+                    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
-                    insetTop = 0
-                    insetBottom = 0
-                    layoutParams = LinearLayout.LayoutParams(0, LinearLayout.LayoutParams.MATCH_PARENT, 1f)
-                        .also { it.setMargins(4, 4, 4, 4) }
+                    textSize = 24f
+                    insetTop = 0; insetBottom = 0
+                    minimumWidth = 0; minimumHeight = 0
+                    cornerRadius = btnSize / 2
+                    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() {