Base theming for views

- Control is now aware of active theme name and resolver.
- Theme some settings in BoxView, ListView and MenuView.
- Overhaul scenario system to make it work with themes.
- Add new "background" StyleSetting.
- Relates #824

spring-shell-samples/spring-shell-sample-catalog/src/main/java/org/springframework/shell/samples/catalog/Catalog.java

@@ -53,6 +53,7 @@ import org.springframework.shell.component.view.screen.Screen.Writer;
 import org.springframework.shell.component.view.screen.ScreenItem;
 import org.springframework.shell.samples.catalog.scenario.Scenario;
 import org.springframework.shell.samples.catalog.scenario.ScenarioComponent;
+import org.springframework.shell.style.ThemeResolver;
 import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
 
@@ -77,10 +78,15 @@ public class Catalog {
 	private View currentScenarioView = null;
 	private TerminalUI ui;
 	private ListView<String> categories;
+	private ListView<ScenarioData> scenarios;
+	private AppView app;
 	private EventLoop eventLoop;
+	private ThemeResolver themeResolver;
+	private String activeThemeName = "default";
 
-	public Catalog(Terminal terminal, List<Scenario> scenarios) {
+	public Catalog(Terminal terminal, List<Scenario> scenarios, ThemeResolver themeResolver) {
 		this.terminal = terminal;
+		this.themeResolver = themeResolver;
 		mapScenarios(scenarios);
 	}
 
@@ -117,7 +123,9 @@ public class Catalog {
 	public void run() {
 		ui = new TerminalUI(terminal);
 		eventLoop = ui.getEventLoop();
-		AppView app = buildScenarioBrowser(eventLoop, ui);
+		app = buildScenarioBrowser(eventLoop, ui);
+		app.setThemeResolver(themeResolver);
+		app.setThemeName(activeThemeName);
 
 		// handle logic to switch between main scenario browser
 		// and currently active scenario
@@ -146,12 +154,14 @@ public class Catalog {
 	private AppView buildScenarioBrowser(EventLoop eventLoop, TerminalUI component) {
 		// category selector on left, scenario selector on right
 		GridView grid = new GridView();
+		grid.setThemeResolver(themeResolver);
+		grid.setThemeName(activeThemeName);
 		grid.setEventLoop(eventLoop);
 		grid.setRowSize(0);
 		grid.setColumnSize(30, 0);
 
 		categories = buildCategorySelector(eventLoop);
-		ListView<ScenarioData> scenarios = buildScenarioSelector(eventLoop);
+		scenarios = buildScenarioSelector(eventLoop);
 
 		grid.addItem(categories, 0, 0, 1, 1, 0, 0);
 		grid.addItem(scenarios, 0, 1, 1, 1, 0, 0);
@@ -161,12 +171,16 @@ public class Catalog {
 
 		// we use main app view to represent scenario browser
 		AppView app = new AppView(grid, menuBar, statusBar);
+		app.setThemeResolver(themeResolver);
+		app.setThemeName(activeThemeName);
 		app.setEventLoop(eventLoop);
 
 		// handle event when scenario is chosen
 		eventLoop.onDestroy(eventLoop.viewEvents(LISTVIEW_SCENARIO_TYPEREF, scenarios)
 			.subscribe(event -> {
-				View view = event.args().item().scenario().configure(eventLoop).build();
+				View view = event.args().item().scenario()
+					.configure(eventLoop, themeResolver, activeThemeName)
+					.build();
 				component.setRoot(view, true);
 				currentScenarioView = view;
 			}));
@@ -212,6 +226,8 @@ public class Catalog {
 
 	private ListView<String> buildCategorySelector(EventLoop eventLoop) {
 		ListView<String> categories = new ListView<>();
+		categories.setThemeResolver(themeResolver);
+		categories.setThemeName(activeThemeName);
 		categories.setEventLoop(eventLoop);
 		List<String> items = List.copyOf(categoryMap.keySet());
 		categories.setItems(items);
@@ -234,6 +250,8 @@ public class Catalog {
 
 	private ListView<ScenarioData> buildScenarioSelector(EventLoop eventLoop) {
 		ListView<ScenarioData> scenarios = new ListView<>();
+		scenarios.setThemeResolver(themeResolver);
+		scenarios.setThemeName(activeThemeName);
 		scenarios.setEventLoop(eventLoop);
 		scenarios.setTitle("Scenarios");
 		scenarios.setFocusedTitleStyle(ScreenItem.STYLE_BOLD);
@@ -242,19 +260,36 @@ public class Catalog {
 		return scenarios;
 	}
 
+	private void setStyle(String name) {
+		log.debug("Setting active theme name {}", name);
+		activeThemeName = name;
+		scenarios.setThemeName(activeThemeName);
+		categories.setThemeName(activeThemeName);
+		app.setThemeName(activeThemeName);
+	}
+
+	private Runnable styleAction(String style) {
+		return () -> setStyle(style);
+	}
+
 	private MenuBarView buildMenuBar(EventLoop eventLoop) {
 		Runnable quitAction = () -> requestQuit();
+		MenuItem[] themeItems = themeResolver.themeNames().stream()
+			.map(tn -> {
+				return MenuItem.of(tn, MenuItemCheckStyle.RADIO, styleAction(tn), "default".equals(tn));
+			})
+			.toArray(MenuItem[]::new);
 		MenuBarView menuBar = MenuBarView.of(
 			MenuBarItem.of("File",
 				MenuItem.of("Quit", MenuItemCheckStyle.NOCHECK, quitAction)),
 			MenuBarItem.of("Theme",
-				MenuItem.of("Dump", MenuItemCheckStyle.RADIO),
-				MenuItem.of("Funky", MenuItemCheckStyle.RADIO)
-			),
+				themeItems),
 			MenuBarItem.of("Help",
 				MenuItem.of("About"))
 		);
 
+		menuBar.setThemeResolver(themeResolver);
+		menuBar.setThemeName(activeThemeName);
 		menuBar.setEventLoop(eventLoop);
 		return menuBar;
 	}
@@ -262,6 +297,8 @@ public class Catalog {
 	private StatusBarView buildStatusBar(EventLoop eventLoop) {
 		Runnable quitAction = () -> requestQuit();
 		StatusBarView statusBar = new StatusBarView();
+		statusBar.setThemeResolver(themeResolver);
+		statusBar.setThemeName(activeThemeName);
 		statusBar.setEventLoop(eventLoop);
 		StatusItem item1 = new StatusBarView.StatusItem("CTRL-Q Quit", quitAction);
 		StatusItem item2 = new StatusBarView.StatusItem("F10 Status Bar");

spring-shell-samples/spring-shell-sample-catalog/src/main/java/org/springframework/shell/samples/catalog/CatalogCommand.java

@@ -20,6 +20,7 @@ import java.util.List;
 import org.springframework.shell.command.annotation.Command;
 import org.springframework.shell.samples.catalog.scenario.Scenario;
 import org.springframework.shell.standard.AbstractShellComponent;
+import org.springframework.shell.style.ThemeResolver;
 
 /**
  * Main command access point to view showcase catalog.
@@ -30,14 +31,16 @@ import org.springframework.shell.standard.AbstractShellComponent;
 public class CatalogCommand extends AbstractShellComponent {
 
 	private final List<Scenario> scenarios;
+	private final ThemeResolver themeResolver;
 
-	public CatalogCommand(List<Scenario> scenarios) {
+	public CatalogCommand(List<Scenario> scenarios, ThemeResolver themeResolver) {
 		this.scenarios = scenarios;
+		this.themeResolver = themeResolver;
 	}
 
 	@Command(command = "catalog")
 	public void catalog() {
-		Catalog catalog = new Catalog(getTerminal(), scenarios);
+		Catalog catalog = new Catalog(getTerminal(), scenarios, themeResolver);
 		catalog.run();
 	}
 }

spring-shell-samples/spring-shell-sample-catalog/src/main/java/org/springframework/shell/samples/catalog/CatalogConfiguration.java

@@ -15,10 +15,50 @@
  */
 package org.springframework.shell.samples.catalog;
 
+import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.shell.command.annotation.CommandScan;
+import org.springframework.shell.style.FigureSettings;
+import org.springframework.shell.style.StyleSettings;
+import org.springframework.shell.style.Theme;
+import org.springframework.shell.style.ThemeSettings;
 
 @Configuration
 @CommandScan
 class CatalogConfiguration {
+
+	@Bean
+	public Theme customTheme() {
+		return new Theme() {
+			@Override
+			public String getName() {
+				return "custom";
+			}
+			@Override
+			public ThemeSettings getSettings() {
+				return new CustomThemeSettings();
+			}
+		};
+	}
+
+	static class CustomThemeSettings extends ThemeSettings {
+		CustomThemeSettings() {
+			super(new CustomStyleSettings(), FigureSettings.defaults());
+		}
+	}
+
+	static class CustomStyleSettings extends StyleSettings {
+
+		@Override
+		public String highlight() {
+			return "bold,italic,fg:bright-cyan";
+		}
+
+		@Override
+		public String background() {
+			return "bg:blue";
+		}
+
+	}
+
 }

spring-shell-samples/spring-shell-sample-catalog/src/main/java/org/springframework/shell/samples/catalog/scenario/AbstractScenario.java

@@ -15,7 +15,9 @@
  */
 package org.springframework.shell.samples.catalog.scenario;
 
+import org.springframework.shell.component.view.control.AbstractView;
 import org.springframework.shell.component.view.event.EventLoop;
+import org.springframework.shell.style.ThemeResolver;
 
 /**
  * Base implementation of a {@link Scenario} helping to avoid some bloatware.
@@ -25,10 +27,14 @@ import org.springframework.shell.component.view.event.EventLoop;
 public abstract class AbstractScenario implements Scenario {
 
 	private EventLoop eventloop;
+	private ThemeResolver themeResolver;
+	private String themeName;
 
 	@Override
-	public Scenario configure(EventLoop eventloop) {
+	public Scenario configure(EventLoop eventloop, ThemeResolver themeResolver, String themeName) {
 		this.eventloop = eventloop;
+		this.themeResolver = themeResolver;
+		this.themeName = themeName;
 		return this;
 	}
 
@@ -36,4 +42,17 @@ public abstract class AbstractScenario implements Scenario {
 		return eventloop;
 	}
 
+	protected ThemeResolver getThemeResolver() {
+		return themeResolver;
+	}
+
+	protected String getThemeName() {
+		return themeName;
+	}
+
+	protected void configure(AbstractView view) {
+		view.setEventLoop(getEventloop());
+		view.setThemeResolver(getThemeResolver());
+		view.setThemeName(getThemeName());
+	}
 }

spring-shell-samples/spring-shell-sample-catalog/src/main/java/org/springframework/shell/samples/catalog/scenario/Scenario.java

@@ -17,6 +17,7 @@ package org.springframework.shell.samples.catalog.scenario;
 
 import org.springframework.shell.component.view.control.View;
 import org.springframework.shell.component.view.event.EventLoop;
+import org.springframework.shell.style.ThemeResolver;
 
 /**
  * {@link Scenario} participates in a catalog showcase.
@@ -43,8 +44,10 @@ public interface Scenario {
 	 * Configure scenario.
 	 *
 	 * @param eventloop eventloop for scenario
+	 * @param themeResolver theme resolver for scenario
+	 * @param themeName theme name for scenario
 	 * @return scenario for chaining
 	 */
-	Scenario configure(EventLoop eventloop);
+	Scenario configure(EventLoop eventloop, ThemeResolver themeResolver, String themeName);
 
 }

spring-shell-samples/spring-shell-sample-catalog/src/main/java/org/springframework/shell/samples/catalog/scenario/box/SimpleBoxViewScenario.java

@@ -31,6 +31,7 @@ public class SimpleBoxViewScenario extends AbstractScenario {
 	@Override
 	public View build() {
 		BoxView box = new BoxView();
+		configure(box);
 		box.setTitle("Title");
 		box.setShowBorder(true);
 		box.setBackgroundColor(Color.KHAKI4);

spring-shell-samples/spring-shell-sample-catalog/src/main/java/org/springframework/shell/samples/catalog/scenario/grid/SimpleGridViewScenario.java

@@ -29,31 +29,37 @@ public class SimpleGridViewScenario extends AbstractScenario {
 	@Override
 	public View build() {
 		BoxView menu = new BoxView();
+		configure(menu);
 		menu.setBackgroundColor(Color.KHAKI4);
 		menu.setTitle("Menu");
 		menu.setShowBorder(true);
 
 		BoxView main = new BoxView();
+		configure(main);
 		main.setBackgroundColor(Color.KHAKI4);
 		main.setTitle("Main");
 		main.setShowBorder(true);
 
 		BoxView sideBar = new BoxView();
+		configure(sideBar);
 		sideBar.setBackgroundColor(Color.KHAKI4);
 		sideBar.setTitle("Sidebar");
 		sideBar.setShowBorder(true);
 
 		BoxView header = new BoxView();
+		configure(header);
 		header.setBackgroundColor(Color.KHAKI4);
 		header.setTitle("Header");
 		header.setShowBorder(true);
 
 		BoxView footer = new BoxView();
+		configure(footer);
 		footer.setBackgroundColor(Color.KHAKI4);
 		footer.setTitle("Footer");
 		footer.setShowBorder(true);
 
 		GridView grid = new GridView();
+		configure(grid);
 		grid.setBackgroundColor(Color.KHAKI3);
 		grid.setTitle("Grid");
 		grid.setShowBorder(true);