com/tailscale/ipn,cmd/tailscale: handle quick tile clicks while signed out

Specifically, start the main activity to prompt the user to sign in or
be notified of a pending machine auth.

Fixes tailscale/tailscale#1225

Signed-off-by: Elias Naur <mail@eliasnaur.com>

android/src/main/java/com/tailscale/ipn/App.java

@@ -98,11 +98,18 @@ public class App extends Application {
 		);
 	}
 
-	void setTileStatus(boolean wantRunning) {
+	void setTileReady(boolean ready) {
 		if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N) {
 			return;
 		}
-		QuickToggleService.setStatus(this, wantRunning);
+		QuickToggleService.setReady(this, ready);
+	}
+
+	void setTileStatus(boolean status) {
+		if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N) {
+			return;
+		}
+		QuickToggleService.setStatus(this, status);
 	}
 
 	String getHostname() {

android/src/main/java/com/tailscale/ipn/QuickToggleService.java

@@ -6,6 +6,7 @@ package com.tailscale.ipn;
 
 import android.content.Context;
 import android.content.ComponentName;
+import android.content.Intent;
 import android.service.quicksettings.Tile;
 import android.service.quicksettings.TileService;
 
@@ -13,33 +14,68 @@ import java.util.concurrent.atomic.AtomicReference;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 public class QuickToggleService extends TileService {
-	private static AtomicBoolean active = new AtomicBoolean();
-	private static AtomicReference<Tile> currentTile = new AtomicReference<Tile>();
+	// lock protects the static fields below it.
+	private static Object lock = new Object();
+	// Active tracks whether the VPN is active.
+	private static boolean active;
+	// Ready tracks whether the tailscale backend is
+	// ready to switch on/off.
+	private static boolean ready;
+	// currentTile tracks getQsTile while service is listening.
+	private static Tile currentTile;
 
 	@Override public void onStartListening() {
-		currentTile.set(getQsTile());
+		synchronized (lock) {
+			currentTile = getQsTile();
+		}
 		updateTile();
 	}
 
 	@Override public void onStopListening() {
-		currentTile.set(null);
+		synchronized (lock) {
+			currentTile = null;
+		}
 	}
 
 	@Override public void onClick() {
-		onTileClick();
+		boolean r;
+		synchronized (lock) {
+			r = ready;
+		}
+		if (r) {
+			onTileClick();
+		} else {
+			// Start main activity.
+			Intent i = getPackageManager().getLaunchIntentForPackage(getPackageName());
+			startActivityAndCollapse(i);
+		}
 	}
 
 	private static void updateTile() {
-		Tile t = currentTile.get();
+		Tile t;
+		boolean act;
+		synchronized (lock) {
+			t = currentTile;
+			act = active && ready;
+		}
 		if (t == null) {
 			return;
 		}
-		t.setState(active.get() ? Tile.STATE_ACTIVE : Tile.STATE_INACTIVE);
+		t.setState(act ? Tile.STATE_ACTIVE : Tile.STATE_INACTIVE);
 		t.updateTile();
 	}
 
-	static void setStatus(Context ctx, boolean wantRunning) {
-		active.set(wantRunning);
+	static void setReady(Context ctx, boolean rdy) {
+		synchronized (lock) {
+			ready = rdy;
+		}
+		updateTile();
+	}
+
+	static void setStatus(Context ctx, boolean act) {
+		synchronized (lock) {
+			active = act;
+		}
 		updateTile();
 	}
 

cmd/tailscale/main.go

@@ -468,6 +468,13 @@ func (a *App) notify(state BackendState) {
 	case a.updates <- struct{}{}:
 	default:
 	}
+	ready := jni.False
+	if state.State >= ipn.Stopped {
+		ready = jni.True
+	}
+	if err := a.callVoidMethod(a.appCtx, "setTileReady", "(Z)V", jni.Value(ready)); err != nil {
+		fatalErr(err)
+	}
 }
 
 func (a *App) setPrefs(prefs *ipn.Prefs) {