define our four screens

app/src/main/java/com/geeksville/mesh/MainActivity.kt

@@ -42,23 +42,23 @@ title.
 
 Fragments:
 
-SettingsFragment shows
+SettingsFragment shows "Settings"
   username
   shortname
   bluetooth pairing list
   (eventually misc device settings that are not channel related)
 
-Channel fragment
+Channel fragment "Channel"
   qr code, copy link button
   ch number
   misc other settings
   (eventually a way of choosing between past channels)
 
-ChatFragment
+ChatFragment "Messages"
   a text box to enter new texts
   a scrolling list of rows.  each row is a text and a sender info layout
 
-NodeListFragment
+NodeListFragment "Users"
   a node info row for every node
 
 ViewModels:

app/src/main/java/com/geeksville/mesh/ui/MeshApp.kt

@@ -152,7 +152,7 @@ fun MeshApp() {
     }
 }
 
-@Preview
+// @Preview
 @Composable
 fun previewView() {
     // It seems modaldrawerlayout not yet supported in preview
@@ -161,6 +161,15 @@ fun previewView() {
     }
 }
 
+@Preview
+@Composable
+fun previewDrawer() {
+    AppDrawer(
+        currentScreen = AppStatus.currentScreen,
+        closeDrawer = { }
+    )
+}
+
 @Composable
 private fun AppContent(openDrawer: () -> Unit) {
     Crossfade(AppStatus.currentScreen) { screen ->
@@ -178,11 +187,9 @@ private fun AppContent(openDrawer: () -> Unit) {
 
                 VerticalScroller(modifier = LayoutFlexible(1f)) {
                     when (screen) {
-                        is Screen.Home -> HomeContent()
-                        is Screen.SelectRadio -> BTScanScreen()
-                        // Question: how to get hooks invoked when this screen gets shown/removed?
-                        // i.e. I need to start/stop a bluetooth scan operation. depending on the
-                        // appearance/disappearance of this screen.
+                        Screen.messages -> HomeContent()
+                        Screen.settings -> BTScanScreen()
+                        else -> TODO()
                     }
                 }
             }
@@ -192,7 +199,7 @@ private fun AppContent(openDrawer: () -> Unit) {
 
 @Composable
 private fun AppDrawer(
-    currentScreen: Screen,
+    currentScreen: ScreenInfo,
     closeDrawer: () -> Unit
 ) {
     Column(modifier = LayoutSize.Fill) {
@@ -203,15 +210,15 @@ private fun AppDrawer(
                 tint = (MaterialTheme.colors()).primary
             )
             Spacer(LayoutWidth(8.dp))
-            VectorImage(id = R.drawable.ic_launcher_new_foreground)
+            // VectorImage(id = R.drawable.ic_launcher_new_foreground)
         }
         Divider(color = Color(0x14333333))
 
         @Composable
-        fun ScreenButton(icon: Int, label: String, screen: Screen) {
+        fun ScreenButton(screen: ScreenInfo) {
             DrawerButton(
-                icon = icon,
-                label = label,
+                icon = screen.icon,
+                label = screen.label,
                 isSelected = currentScreen == screen
             ) {
                 navigateTo(screen)
@@ -219,8 +226,10 @@ private fun AppDrawer(
             }
         }
 
-        ScreenButton(R.drawable.ic_launcher_new_foreground, "Home", Screen.Home)
-        ScreenButton(R.drawable.ic_launcher_new_foreground, "Setup", Screen.SelectRadio)
+        ScreenButton(Screen.messages)
+        ScreenButton(Screen.users)
+        ScreenButton(Screen.channel)
+        ScreenButton(Screen.settings)
     }
 }
 

app/src/main/java/com/geeksville/mesh/ui/Status.kt

@@ -3,22 +3,25 @@ package com.geeksville.mesh.ui
 import android.util.Base64
 import androidx.compose.Model
 import androidx.compose.mutableStateOf
-import com.geeksville.mesh.MeshProtos
-import com.geeksville.mesh.MeshUser
-import com.geeksville.mesh.NodeInfo
-import com.geeksville.mesh.Position
+import com.geeksville.mesh.*
 import com.google.android.gms.auth.api.signin.GoogleSignInClient
 import java.util.*
 
+
+data class ScreenInfo(val icon: Int, val label: String)
+
 // defines the screens we have in the app
-sealed class Screen {
-    object Home : Screen()
-    object SelectRadio : Screen()
+object Screen {
+    val settings = ScreenInfo(R.drawable.ic_twotone_settings_applications_24, "Settings")
+    val channel = ScreenInfo(R.drawable.ic_twotone_contactless_24, "Channel")
+    val users = ScreenInfo(R.drawable.ic_twotone_people_24, "Users")
+    val messages = ScreenInfo(R.drawable.ic_twotone_message_24, "Messages")
 }
 
+
 @Model
 object AppStatus {
-    var currentScreen: Screen = Screen.Home
+    var currentScreen: ScreenInfo = Screen.messages
 }
 
 data class TextMessage(val date: Date, val from: String, val text: String)
@@ -96,6 +99,6 @@ object UIState {
 /**
  * Temporary solution pending navigation support.
  */
-fun navigateTo(destination: Screen) {
+fun navigateTo(destination: ScreenInfo) {
     AppStatus.currentScreen = destination
 }