Update docs

Author: jvalkeal

spring-shell-docs/modules/ROOT/nav.adoc

@@ -54,6 +54,7 @@
 *** xref:components/ui/multiselect.adoc[]
 * xref:tui/index.adoc[]
 ** xref:tui/intro/index.adoc[]
+*** xref:tui/intro/terminalui.adoc[]
 ** xref:tui/views/index.adoc[]
 *** xref:tui/views/box.adoc[]
 *** xref:tui/views/button.adoc[]

spring-shell-docs/modules/ROOT/pages/tui/intro/terminalui.adoc

@@ -0,0 +1,17 @@
+= TerminalUI
+:page-section-summary-toc: 1
+
+ifndef::snippets[:snippets: ../../../../../src/test/java/org/springframework/shell/docs]
+
+`TerminalUI` is a main implementation to drive ui execution logic.
+Running `TerminalUI` execution loop is a blocking operation.
+
+== Exiting App
+
+If you want to exit from an app using normal _CTRL-Q_ key combination listen
+events and request _interrupt_.
+
+[source, java, indent=0]
+----
+include::{snippets}/TerminalUiSnippets.java[tag=snippet3]
+----

spring-shell-docs/src/test/java/org/springframework/shell/docs/TerminalUiSnippets.java

@@ -20,8 +20,11 @@
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.shell.component.view.TerminalUI;
 import org.springframework.shell.component.view.control.BoxView;
+import org.springframework.shell.component.view.event.EventLoop;
+import org.springframework.shell.component.view.event.KeyEvent.Key;
 import org.springframework.shell.component.view.geom.HorizontalAlign;
 import org.springframework.shell.component.view.geom.VerticalAlign;
+import org.springframework.shell.component.view.message.ShellMessageBuilder;
 
 class TerminalUiSnippets {
 
@@ -67,4 +70,26 @@ void sample() {
 		// end::snippet2[]
 	}
 
+	class Sample3 {
+
+		// tag::snippet3[]
+		@Autowired
+		Terminal terminal;
+
+		void sample() {
+			TerminalUI ui = new TerminalUI(terminal);
+			BoxView view = new BoxView();
+			ui.setRoot(view, true);
+			EventLoop eventLoop = ui.getEventLoop();
+			eventLoop.keyEvents()
+				.subscribe(event -> {
+					if (event.getPlainKey() == Key.q && event.hasCtrl()) {
+						eventLoop.dispatch(ShellMessageBuilder.ofInterrupt());
+					}
+				});
+			ui.run();
+		}
+		// end::snippet3[]
+	}
+
 }