ProgressView spinner calculation in item function

- Move spinner frame calculation to item itself so that
- Remove spinnerFrame from state and add
  start/update times
- view don't have hard dependency to it, as we'd
  need its interval
- Change spinner to run only when view is running
- Relates #995

Author: jvalkeal

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

@@ -15,10 +15,14 @@
  */
 package org.springframework.shell.component.view.control;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.function.Function;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import org.springframework.shell.component.message.ShellMessageBuilder;
 import org.springframework.shell.component.view.control.cell.TextCell;
 import org.springframework.shell.component.view.screen.Screen;
@@ -36,15 +40,18 @@
  */
 public class ProgressView extends BoxView {
 
+	private final static Logger log = LoggerFactory.getLogger(ProgressView.class);
 	private final int tickStart;
 	private final int tickEnd;
 	private int tickValue;
 	private boolean running = false;
 	private String description;
-	private Spinner spinner = Spinner.of(Spinner.LINE1, 130);
-	private int spinnerFrame;
+	private Spinner spinner;
 	private List<ProgressViewItem> items;
 	private GridView grid;
+	private long startTime;
+	private long updateTime;
+	private List<TextCell<Context>> cells = new ArrayList<>();
 
 	private final static Function<Context, TextCell<Context>> DEFAULT_DESCRIPTION_FACTORY =
 			(item) -> TextCell.of(item, ctx -> {
@@ -66,9 +73,27 @@ public class ProgressView extends BoxView {
 	private final static Function<Context, TextCell<Context>> DEFAULT_SPINNER_FACTORY =
 			item -> {
 				TextCell<Context> cell = TextCell.of(item, ctx -> {
-					Spinner spin = ctx.spinner();
-					int spinState = ctx.getState().sprinnerFrame();
-					return String.format("%s", spin.getFrames()[spinState]);
+					int frame = 0;
+
+					Spinner spin = ctx.getSpinner();
+					if (spin == null) {
+						spin = Spinner.of(Spinner.LINE1, 130);
+					}
+					if (ctx.getState().running()) {
+						// we know start time and current update time,
+						// calculate elapsed time "frame" to pick rolling
+						// spinner frame.
+						int interval = spin.getInterval();
+						long startTime = ctx.getState().startTime();
+						long updateTime = ctx.getState().updateTime();
+						long elapsedTime = updateTime - startTime;
+						long elapsedFrame = elapsedTime / interval;
+						frame = (int) elapsedFrame % spin.getFrames().length;
+						log.debug("Calculate frame {} {} {}", interval, elapsedTime, elapsedFrame);
+					}
+					log.debug("Drawing frame {}", frame);
+
+					return String.format("%s", spin.getFrames()[frame]);
 				});
 				return cell;
 			};
@@ -173,11 +198,21 @@ public void setDescription(String description) {
 		this.description = description;
 	}
 
+	/**
+	 * Sets an explicit spinner to use.
+	 *
+	 * @param spinner the spinner to use
+	 */
+	public void setSpinner(Spinner spinner) {
+		this.spinner = spinner;
+	}
+
 	public void start() {
 		if (running) {
 			return;
 		}
 		running = true;
+		startTime = System.currentTimeMillis();
 		ProgressState state = getState();
 		dispatch(ShellMessageBuilder.ofView(this, ProgressViewStartEvent.of(this, state)));
 	}
@@ -212,6 +247,7 @@ private void initLayout() {
 		for (ProgressViewItem item : items) {
 			columnSizes[index] = item.size;
 			TextCell<Context> cell = item.factory.apply(buildContext());
+			cells.add(cell);
 			cell.setHorizontalAlign(item.align);
 			grid.addItem(new BoxWrapper(cell), 0, index, 1, 1, 0, 0);
 			index++;
@@ -221,27 +257,17 @@ private void initLayout() {
 
 	}
 
-	boolean needLastMillisInit = true;
-	private long lastMillis;
-
 	@Override
 	protected void drawInternal(Screen screen) {
 		long current = System.currentTimeMillis();
-		if (needLastMillisInit) {
-			needLastMillisInit = false;
-			lastMillis = current;
-		}
 
-		long elapsedFromLast = current - lastMillis;
-		if (elapsedFromLast > spinner.getInterval()) {
-			spinnerFrame = (spinnerFrame + 1) % spinner.getFrames().length;
-			lastMillis = current;
+		updateTime = current;
+		Context context = buildContext();
+		for (TextCell<Context> cell : cells) {
+			cell.setItem(context);
 		}
 
 		Rectangle rect = getRect();
-		int width = rect.width();
-		width = width / 3;
-
 		grid.setRect(rect.x(), rect.y(), rect.width(), rect.height());
 		grid.draw(screen);
 
@@ -291,7 +317,7 @@ else if (value < tickStart) {
 	 * @return a view progress state
 	 */
 	public ProgressState getState() {
-		return ProgressState.of(tickStart, tickEnd, tickValue, running, spinnerFrame);
+		return ProgressState.of(tickStart, tickEnd, tickValue, running, startTime, updateTime);
 	}
 
 	private Context buildContext() {
@@ -318,7 +344,7 @@ public int resolveThemeStyle(String tag, int defaultStyle) {
 			}
 
 			@Override
-			public Spinner spinner() {
+			public Spinner getSpinner() {
 				return ProgressView.this.spinner;
 			}
 		};
@@ -355,7 +381,7 @@ public interface Context {
 		 *
 		 * @return spinner frames
 		 */
-		Spinner spinner();
+		Spinner getSpinner();
 
 		/**
 		 * Resolve style using existing {@link ThemeResolver} and {@code theme name}.
@@ -376,12 +402,15 @@ public interface Context {
 	 * @param tickEnd the tick end value, positive and more than tick start
 	 * @param tickValue the current tick value, within inclusive bounds of tick start/end
 	 * @param running the running state
-	 * @param spinnerFrame the current spinner frame index
+	 * @param startTime the running start time
+	 * @param updateTime the last running update time
 	 */
-	public record ProgressState(int tickStart, int tickEnd, int tickValue, boolean running, int sprinnerFrame) {
+	public record ProgressState(int tickStart, int tickEnd, int tickValue, boolean running, long startTime,
+			long updateTime) {
 
-		public static ProgressState of(int tickStart, int tickEnd, int tickValue, boolean running, int spinnerFrame) {
-			return new ProgressState(tickStart, tickEnd, tickValue, running, spinnerFrame);
+		public static ProgressState of(int tickStart, int tickEnd, int tickValue, boolean running, long startTime,
+				long updateTime) {
+			return new ProgressState(tickStart, tickEnd, tickValue, running, startTime, updateTime);
 		}
 	}
 

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

@@ -31,6 +31,7 @@
 import org.springframework.shell.component.view.control.InputView;
 import org.springframework.shell.component.view.control.ProgressView;
 import org.springframework.shell.component.view.control.ProgressView.ProgressViewItem;
+import org.springframework.shell.component.view.control.Spinner;
 import org.springframework.shell.component.view.event.EventLoop;
 import org.springframework.shell.geom.HorizontalAlign;
 import org.springframework.shell.geom.VerticalAlign;
@@ -95,13 +96,7 @@ public String stringInput() {
 		return String.format("Input was '%s'", input);
 	}
 
-	@Command(command = "componentui progress1")
-	public void progress1() {
-		ProgressView view = new ProgressView();
-		view.setDescription("name");
-		view.setRect(0, 0, 20, 1);
-
-
+	private void runProgress(ProgressView view) {
 		ViewComponent component = new ViewComponent(getTerminal(), view);
 		EventLoop eventLoop = component.getEventLoop();
 
@@ -123,42 +118,40 @@ public void progress1() {
 				}
 			}));
 
-
 		component.run();
 	}
 
+	@Command(command = "componentui progress1")
+	public void progress1() {
+		ProgressView view = new ProgressView();
+		view.setDescription("name");
+		view.setRect(0, 0, 20, 1);
+		view.start();
+
+		runProgress(view);
+	}
+
 	@Command(command = "componentui progress2")
 	public void progress2() {
 		ProgressView view = new ProgressView(0, 100, ProgressViewItem.ofText(10, HorizontalAlign.LEFT),
 				ProgressViewItem.ofSpinner(3, HorizontalAlign.LEFT),
 				ProgressViewItem.ofPercent(0, HorizontalAlign.RIGHT));
 		view.setDescription("name");
 		view.setRect(0, 0, 20, 1);
+		view.start();
 
+		runProgress(view);
+	}
 
-		ViewComponent component = new ViewComponent(getTerminal(), view);
-		EventLoop eventLoop = component.getEventLoop();
-
-		Flux<Message<?>> ticks = Flux.interval(Duration.ofMillis(100)).map(l -> {
-			Message<Long> message = MessageBuilder
-				.withPayload(l)
-				.setHeader(ShellMessageHeaderAccessor.EVENT_TYPE, EventLoop.Type.USER)
-				.build();
-			return message;
-		});
-		eventLoop.dispatch(ticks);
-
-		eventLoop.onDestroy(eventLoop.events()
-			.filter(m -> EventLoop.Type.USER.equals(StaticShellMessageHeaderAccessor.getEventType(m)))
-			.subscribe(m -> {
-				if (m.getPayload() instanceof Long) {
-					view.tickAdvance(5);
-					eventLoop.dispatch(ShellMessageBuilder.ofRedraw());
-				}
-			}));
-
+	@Command(command = "componentui progress3")
+	public void progress3() {
+		ProgressView view = new ProgressView();
+		view.setDescription("name");
+		view.setRect(0, 0, 20, 1);
+		view.setSpinner(Spinner.of(Spinner.DOTS1, 80));
+		view.start();
 
-		component.run();
+		runProgress(view);
 	}
 
 }