read vault config async

src/main/java/org/cryptomator/ui/health/StartController.java

@@ -18,11 +18,15 @@ import org.slf4j.LoggerFactory;
 
 import javax.inject.Inject;
 import javafx.application.Platform;
+import javafx.beans.binding.BooleanBinding;
+import javafx.beans.property.ObjectProperty;
+import javafx.beans.property.SimpleObjectProperty;
 import javafx.fxml.FXML;
 import javafx.scene.Scene;
 import javafx.stage.Stage;
 import java.io.IOException;
-import java.util.Optional;
+import java.io.UncheckedIOException;
+import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.atomic.AtomicReference;
 
@@ -31,38 +35,40 @@ public class StartController implements FxController {
 
 	private static final Logger LOG = LoggerFactory.getLogger(StartController.class);
 
+	private final Vault vault;
 	private final Stage window;
-	private final Optional<VaultConfig.UnverifiedVaultConfig> unverifiedVaultConfig;
+	private final CompletableFuture<VaultConfig.UnverifiedVaultConfig> unverifiedVaultConfig;
 	private final KeyLoadingStrategy keyLoadingStrategy;
 	private final ExecutorService executor;
 	private final AtomicReference<Masterkey> masterkeyRef;
 	private final AtomicReference<VaultConfig> vaultConfigRef;
 	private final Lazy<Scene> checkScene;
 	private final Lazy<ErrorComponent.Builder> errorComponent;
+	private final ObjectProperty<State> state = new SimpleObjectProperty<>(State.LOADING);
+	private final BooleanBinding loading = state.isEqualTo(State.LOADING);
+	private final BooleanBinding failed = state.isEqualTo(State.FAILED);
+	private final BooleanBinding loaded = state.isEqualTo(State.LOADED);
+
+	public enum State {
+		LOADING,
+		FAILED,
+		LOADED
+	}
 
 	/* FXML */
 
 	@Inject
 	public StartController(@HealthCheckWindow Vault vault, @HealthCheckWindow Stage window, @HealthCheckWindow KeyLoadingStrategy keyLoadingStrategy, ExecutorService executor, AtomicReference<Masterkey> masterkeyRef, AtomicReference<VaultConfig> vaultConfigRef, @FxmlScene(FxmlFile.HEALTH_CHECK_LIST) Lazy<Scene> checkScene, Lazy<ErrorComponent.Builder> errorComponent) {
+		this.vault = vault;
 		this.window = window;
+		this.unverifiedVaultConfig = CompletableFuture.supplyAsync(this::loadConfig, executor);
 		this.keyLoadingStrategy = keyLoadingStrategy;
 		this.executor = executor;
 		this.masterkeyRef = masterkeyRef;
 		this.vaultConfigRef = vaultConfigRef;
 		this.checkScene = checkScene;
 		this.errorComponent = errorComponent;
-
-		//TODO: this is ugly
-		//idea: delay the loading of the vault config and show a spinner (something like "check/load config") and react to the result of the loading
-		//or: load vault config in a previous step to see if it is loadable.
-		VaultConfig.UnverifiedVaultConfig tmp;
-		try {
-			tmp = vault.getUnverifiedVaultConfig();
-		} catch (IOException e) {
-			e.printStackTrace();
-			tmp =  null;
-		}
-		this.unverifiedVaultConfig = Optional.ofNullable(tmp);
+		this.unverifiedVaultConfig.whenCompleteAsync(this::loadedConfig, Platform::runLater);
 	}
 
 	@FXML
@@ -77,11 +83,29 @@ public class StartController implements FxController {
 		executor.submit(this::loadKey);
 	}
 
+	private VaultConfig.UnverifiedVaultConfig loadConfig() {
+		try {
+			return this.vault.getUnverifiedVaultConfig();
+		} catch (IOException e) {
+			throw new UncheckedIOException(e);
+		}
+	}
+
+	private void loadedConfig(VaultConfig.UnverifiedVaultConfig cfg, Throwable exception) {
+		assert Platform.isFxApplicationThread();
+		if (exception != null) {
+			state.set(State.FAILED);
+		} else {
+			assert cfg != null;
+			state.set(State.LOADED);
+		}
+	}
+
 	private void loadKey() {
 		assert !Platform.isFxApplicationThread();
-		assert unverifiedVaultConfig.isPresent();
-		try (var masterkey = keyLoadingStrategy.loadKey(unverifiedVaultConfig.orElseThrow().getKeyId())) {
-			var unverifiedCfg = unverifiedVaultConfig.get();
+		assert unverifiedVaultConfig.isDone();
+		var unverifiedCfg = unverifiedVaultConfig.join();
+		try (var masterkey = keyLoadingStrategy.loadKey(unverifiedCfg.getKeyId())) {
 			var verifiedCfg = unverifiedCfg.verify(masterkey.getEncoded(), unverifiedCfg.allegedVaultVersion());
 			vaultConfigRef.set(verifiedCfg);
 			var old = masterkeyRef.getAndSet(masterkey.clone());
@@ -96,8 +120,6 @@ public class StartController implements FxController {
 			} else {
 				Platform.runLater(() -> loadingKeyFailed(e));
 			}
-		} catch (VaultKeyInvalidException e) {
-			Platform.runLater(() -> loadingKeyFailed(e));
 		} catch (VaultConfigLoadException e) {
 			Platform.runLater(() -> loadingKeyFailed(e));
 		}
@@ -120,8 +142,29 @@ public class StartController implements FxController {
 		}
 	}
 
-	public boolean isInvalidConfig() {
-		return unverifiedVaultConfig.isEmpty();
+	/* Getter */
+
+	public BooleanBinding loadingProperty() {
+		return loading;
 	}
 
+	public boolean isLoading() {
+		return loading.get();
+	}
+
+	public BooleanBinding failedProperty() {
+		return failed;
+	}
+
+	public boolean isFailed() {
+		return failed.get();
+	}
+
+	public BooleanBinding loadedProperty() {
+		return loaded;
+	}
+
+	public boolean isLoaded() {
+		return loaded.get();
+	}
 }