hides private key on login

app/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedOff/LoginScreen.kt

@@ -14,12 +14,19 @@ import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.foundation.text.ClickableText
 import androidx.compose.foundation.text.KeyboardOptions
 import androidx.compose.material.Button
+import androidx.compose.material.Icon
+import androidx.compose.material.IconButton
 import androidx.compose.material.MaterialTheme
 import androidx.compose.material.OutlinedTextField
 import androidx.compose.material.Text
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.outlined.Visibility
+import androidx.compose.material.icons.outlined.VisibilityOff
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.layout.ContentScale
@@ -28,7 +35,9 @@ import androidx.compose.ui.text.AnnotatedString
 import androidx.compose.ui.text.TextStyle
 import androidx.compose.ui.text.input.ImeAction
 import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.text.input.PasswordVisualTransformation
 import androidx.compose.ui.text.input.TextFieldValue
+import androidx.compose.ui.text.input.VisualTransformation
 import androidx.compose.ui.text.style.TextDecoration
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
@@ -47,7 +56,7 @@ fun LoginPage(accountViewModel: AccountStateViewModel) {
             style = TextStyle(
                 fontSize = 14.sp,
                 textDecoration = TextDecoration.Underline,
-                color = Purple700
+                color = MaterialTheme.colors.primary
             )
         )
     }
@@ -70,6 +79,10 @@ fun LoginPage(accountViewModel: AccountStateViewModel) {
 
         //Text(text = "Insert your private or public key (view-only)")
 
+        var showPassword by remember {
+            mutableStateOf(false)
+        }
+
         OutlinedTextField(
             value = key.value,
             onValueChange = { key.value = it },
@@ -83,7 +96,16 @@ fun LoginPage(accountViewModel: AccountStateViewModel) {
                     text = "nsec / npub / hex private key",
                     color = MaterialTheme.colors.onSurface.copy(alpha = 0.32f)
                 )
-            }
+            },
+            trailingIcon = {
+                IconButton(onClick = { showPassword = !showPassword }) {
+                    Icon(
+                        imageVector = if (showPassword) Icons.Outlined.VisibilityOff else Icons.Outlined.Visibility,
+                        contentDescription = if (showPassword) "Show Password" else "Hide Password"
+                    )
+                }
+            },
+            visualTransformation = if (showPassword) VisualTransformation.None else PasswordVisualTransformation()
         )
 
         Spacer(modifier = Modifier.height(20.dp))