VersionPreference: account for checking state and move away from tools installer

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

app/src/main/java/com/wireguard/android/Application.java

@@ -67,6 +67,8 @@ public class Application extends android.app.Application {
         ToolsInstaller getToolsInstaller();
 
         TunnelManager getTunnelManager();
+
+        RootShell getRootShell();
     }
 
     @Qualifier

app/src/main/java/com/wireguard/android/preference/VersionPreference.java

@@ -16,6 +16,14 @@ import com.wireguard.android.BuildConfig;
 import com.wireguard.android.R;
 import com.wireguard.android.backend.GoBackend;
 import com.wireguard.android.backend.WgQuickBackend;
+import com.wireguard.android.util.RootShell;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import javax.inject.Inject;
+
+import java9.util.concurrent.CompletionStage;
 
 public class VersionPreference extends Preference {
     private String versionSummary;
@@ -26,10 +34,17 @@ public class VersionPreference extends Preference {
         if (Application.getComponent().getBackendType() == GoBackend.class) {
             versionSummary = getContext().getString(R.string.version_userspace_summary, GoBackend.getVersion());
         } else if (Application.getComponent().getBackendType() == WgQuickBackend.class) {
-            Application.getComponent().getToolsInstaller().getVersion().whenComplete((version, exception) -> {
+            versionSummary = getContext().getString(R.string.version_kernel_summary_checking);
+            Application.getComponent().getAsyncWorker().supplyAsync(() -> {
+                final List<String> output = new ArrayList<>();
+                if (Application.getComponent().getRootShell()
+                        .run(output, "cat /sys/module/wireguard/version") != 0 || output.isEmpty())
+                    throw new RuntimeException("Unable to determine kernel module version");
+                return output.get(0);
+            }).whenComplete((version, exception) -> {
                 versionSummary = exception == null
                         ? getContext().getString(R.string.version_kernel_summary, version)
-                        : getContext().getString(R.string.version_kernel_unknown_summary);
+                        : getContext().getString(R.string.version_kernel_summary_unknown);
                 notifyChanged();
             });
         }

app/src/main/java/com/wireguard/android/util/ToolsInstaller.java

@@ -58,15 +58,6 @@ public final class ToolsInstaller {
         this.rootShell = rootShell;
     }
 
-    public CompletionStage<String> getVersion() {
-        return Application.getComponent().getAsyncWorker().supplyAsync(() -> {
-            final List<String> output = new ArrayList<>();
-            if (rootShell.run(output, "cat /sys/module/wireguard/version") != 0 || output.isEmpty())
-                throw new RuntimeException("Unable to determine kernel module version");
-            return output.get(0);
-        });
-    }
-
     private static File getInstallDir() {
         final String path = System.getenv("PATH");
         if (path == null)

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

@@ -83,7 +83,8 @@
     <string name="tunnel_rename_success">Successfully renamed tunnel to “%s”</string>
     <string name="version_title">WireGuard for Android v%s"</string>
     <string name="version_kernel_summary">Kernel module backend v%s</string>
-    <string name="version_kernel_unknown_summary">Unknown kernel module version</string>
+    <string name="version_kernel_summary_checking">Checking kernel module backend version</string>
+    <string name="version_kernel_summary_unknown">Unknown kernel module version</string>
     <string name="version_userspace_summary">Go userspace backend v%s</string>
     <string name="zip_exporter_title">Export tunnels to zip file</string>
     <string name="zip_export_error">Unable to export tunnels: %s</string>