Non-fullscreen view

- ViewComponent can take view and drive it as non-fullscreen
- ViewDoneEvent which InputView now uses
- ComponentUiCommands is a sample where we add ideas for
  views in flow components
- Allow View to set eventloop
- Relates #850

spring-shell-core/src/main/java/org/springframework/shell/component/ViewComponent.java

@@ -0,0 +1,76 @@
+/*
+ * Copyright 2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.shell.component;
+
+import org.jline.terminal.Terminal;
+
+import org.springframework.messaging.Message;
+import org.springframework.shell.component.view.TerminalUI;
+import org.springframework.shell.component.view.control.View;
+import org.springframework.shell.component.view.control.ViewDoneEvent;
+import org.springframework.shell.component.view.event.EventLoop;
+import org.springframework.shell.component.view.message.ShellMessageBuilder;
+import org.springframework.util.Assert;
+
+/**
+ * Handles view execution in a non-fullscreen setup.
+ *
+ * @author Janne Valkealahti
+ */
+public class ViewComponent {
+
+	private final Terminal terminal;
+	private final View view;
+	private EventLoop eventLoop;
+
+	public ViewComponent(Terminal terminal, View view) {
+		Assert.notNull(terminal, "terminal must be set");
+		Assert.notNull(view, "view must be set");
+		this.terminal = terminal;
+		this.view = view;
+	}
+
+	/**
+	 * Run a view execution loop.
+	 */
+	public void run() {
+		TerminalUI ui = new TerminalUI(terminal);
+		eventLoop = ui.getEventLoop();
+		eventLoop.onDestroy(eventLoop.viewEvents(ViewDoneEvent.class, view)
+			.subscribe(event -> {
+					exit();
+				}
+			));
+		view.setEventLoop(eventLoop);
+		ui.setRoot(view, false);
+		ui.run();
+	}
+
+	/**
+	 * Request exit from an execution loop.
+	 */
+	public void exit() {
+		if (eventLoop == null) {
+			return;
+		}
+		Message<String> msg = ShellMessageBuilder.withPayload("int")
+			.setEventType(EventLoop.Type.SYSTEM)
+			.setPriority(0)
+			.build();
+		eventLoop.dispatch(msg);
+	}
+
+}

spring-shell-core/src/main/java/org/springframework/shell/component/view/control/InputView.java

@@ -23,6 +23,7 @@
 import org.springframework.shell.component.view.event.KeyHandler;
 import org.springframework.shell.component.view.geom.Position;
 import org.springframework.shell.component.view.geom.Rectangle;
+import org.springframework.shell.component.view.message.ShellMessageBuilder;
 import org.springframework.shell.component.view.screen.Screen;
 
 /**
@@ -41,6 +42,7 @@ protected void initInternal() {
 		registerKeyBinding(Key.CursorRight, event -> right());
 		registerKeyBinding(Key.Delete, () -> delete());
 		registerKeyBinding(Key.Backspace, () -> backspace());
+		registerKeyBinding(Key.Enter, () -> done());
 	}
 
 	@Override
@@ -117,4 +119,9 @@ private void left() {
 	private void right() {
 		moveCursor(1);
 	}
+
+	private void done() {
+		dispatch(ShellMessageBuilder.ofView(this, ViewDoneEvent.of(this)));
+	}
+
 }

spring-shell-core/src/main/java/org/springframework/shell/component/view/control/View.java

@@ -16,6 +16,7 @@
 package org.springframework.shell.component.view.control;
 
 import org.springframework.lang.Nullable;
+import org.springframework.shell.component.view.event.EventLoop;
 import org.springframework.shell.component.view.event.KeyHandler;
 import org.springframework.shell.component.view.event.MouseHandler;
 
@@ -79,4 +80,11 @@ public interface View extends Control {
 	@Nullable
 	KeyHandler getHotKeyHandler();
 
+	/**
+	 * Sets an {@link EventLoop}.
+	 *
+	 * @param eventLoop the event loop
+	 */
+	void setEventLoop(@Nullable EventLoop eventLoop);
+
 }

spring-shell-core/src/main/java/org/springframework/shell/component/view/control/ViewDoneEvent.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.shell.component.view.control;
+
+/**
+ * Spesialisation of a {@link ViewEvent} indicating that a {@link View} is done.
+ *
+ * @author Janne Valkealahti
+ */
+public interface ViewDoneEvent extends ViewEvent {
+
+	/**
+	 * Create a generic event with empty view args.
+	 *
+	 * @param view the view
+	 * @return a generic view done event
+	 */
+	static ViewDoneEvent of(View view) {
+		return new GenericViewDoneEvent(view, ViewEventArgs.EMPTY);
+	}
+
+	record GenericViewDoneEvent(View view, ViewEventArgs args) implements ViewDoneEvent {
+	}
+
+}

spring-shell-core/src/test/java/org/springframework/shell/component/view/control/InputViewTests.java

@@ -15,12 +15,17 @@
  */
 package org.springframework.shell.component.view.control;
 
+import java.time.Duration;
+
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
+import reactor.core.publisher.Flux;
+import reactor.test.StepVerifier;
 
 import org.springframework.shell.component.view.event.KeyEvent;
 import org.springframework.shell.component.view.event.KeyEvent.Key;
+import org.springframework.shell.component.view.event.KeyHandler.KeyHandlerResult;
 import org.springframework.test.util.ReflectionTestUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -30,11 +35,11 @@ class InputViewTests extends AbstractViewTests {
 	private static final String CURSOR_INDEX_FIELD = "cursorIndex";
 	private static final String CURSOR_POSITION_METHOD = "cursorPosition";
 
+	InputView view;
+
 	@Nested
 	class Input {
 
-		InputView view;
-
 		@BeforeEach
 		void setup() {
 			view = new InputView();
@@ -82,8 +87,6 @@ void shouldShowUnicodeEmoji() {
 	@Nested
 	class CursorPositions {
 
-		InputView view;
-
 		@BeforeEach
 		void setup() {
 			view = new InputView();
@@ -128,8 +131,6 @@ void shouldMoveWithInputKeysWide() {
 	@Nested
 	class MoveAndDeletions {
 
-		InputView view;
-
 		@BeforeEach
 		void setup() {
 			view = new InputView();
@@ -157,8 +158,6 @@ void deleteFromLastPosition() {
 	@Nested
 	class MoveAndMods {
 
-		InputView view;
-
 		@BeforeEach
 		void setup() {
 			view = new InputView();
@@ -183,4 +182,33 @@ void shouldAddToCursorPosition() {
 
 	}
 
+	@Nested
+	class Events {
+
+		@BeforeEach
+		void setup() {
+			view = new InputView();
+			view.setRect(0, 0, 10, 1);
+			configure(view);
+		}
+
+		@Test
+		void handlesKeyEnter() {
+			Flux<ViewDoneEvent> actions = eventLoop
+					.viewEvents(ViewDoneEvent.class);
+			StepVerifier verifier = StepVerifier.create(actions)
+				.expectNextCount(1)
+				.thenCancel()
+				.verifyLater();
+
+			KeyHandlerResult result = handleKey(view, KeyEvent.Key.Enter);
+
+			assertThat(result).isNotNull().satisfies(r -> {
+				assertThat(r.consumed()).isTrue();
+			});
+			verifier.verify(Duration.ofSeconds(1));
+		}
+
+	}
+
 }

spring-shell-samples/spring-shell-sample-commands/src/main/java/org/springframework/shell/samples/standard/ComponentUiCommands.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.shell.samples.standard;
+
+import org.springframework.shell.command.annotation.Command;
+import org.springframework.shell.component.ViewComponent;
+import org.springframework.shell.component.view.control.InputView;
+import org.springframework.shell.standard.AbstractShellComponent;
+
+@Command
+public class ComponentUiCommands extends AbstractShellComponent {
+
+	@Command(command = "componentui string")
+	public String stringInput() {
+		InputView view = new InputView();
+		view.setRect(0, 0, 10, 1);
+		ViewComponent component = new ViewComponent(getTerminal(), view);
+		component.run();
+		String input = view.getInputText();
+		return String.format("Input was '%s'", input);
+	}
+
+}