Dialog should float

- New WindowView which can be partially atop of background.
- DialogView now extends WindowView
- Change dialog in Catalog sample and Dialog scenario
- Relates #825
- Relates #855

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

@@ -34,7 +34,7 @@ import org.springframework.shell.component.view.screen.Screen.Writer;
  *
  * @author Janne Valkealahti
  */
-public class DialogView extends BoxView {
+public class DialogView extends WindowView {
 
 	private View content;
 	private List<ButtonView> buttons;
@@ -92,7 +92,6 @@ public class DialogView extends BoxView {
 		super.setRect(x, y, width, height);
 
 		Rectangle rect = getInnerRect();
-		rect = new Rectangle(rect.x() + rect.width() / 4, rect.y() + rect.height() / 4, rect.width() / 2, rect.height() / 2);
 		rect = new Rectangle(rect.x() + 1, rect.y() + 1, rect.width() - 2, rect.height() - 2);
 		if (content != null) {
 			content.setRect(rect.x(), rect.y(), rect.width(), rect.height() - 3);
@@ -111,7 +110,6 @@ public class DialogView extends BoxView {
 	@Override
 	protected void drawInternal(Screen screen) {
 		Rectangle rect = getInnerRect();
-		rect = new Rectangle(rect.x() + rect.width() / 4, rect.y() + rect.height() / 4, rect.width() / 2, rect.height() / 2);
 		Writer writer = screen.writerBuilder().layer(getLayer()).build();
 		writer.border(rect.x(), rect.y(), rect.width(), rect.height());
 		if (content != null) {

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

@@ -0,0 +1,96 @@
+/*
+ * 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;
+
+import org.springframework.shell.component.view.geom.Rectangle;
+import org.springframework.shell.component.view.screen.Screen;
+import org.springframework.shell.style.StyleSettings;
+
+
+/**
+ * {@code WindowView} is a {@link View} defining area within view itself.
+ *
+ * @author Janne Valkealahti
+ */
+public class WindowView extends AbstractView {
+
+	private int backgroundColor = -1;
+	private int minWidth = 30;
+	private int maxWidth = 60;
+	private int minHeight = 8;
+	private int maxHeight = 12;
+
+	/**
+	 * Sets a background color. If color is set to {@code null} it indicates that
+	 * background should be set to be {@code empty} causing possible layer to be
+	 * non-transparent.
+	 *
+	 * @param backgroundColor the background color
+	 */
+	public void setBackgroundColor(int backgroundColor) {
+		this.backgroundColor = backgroundColor;
+	}
+
+	@Override
+	protected void drawInternal(Screen screen) {
+		Rectangle rect = getInnerRect();
+		int bgColor = resolveThemeBackground(StyleSettings.TAG_BACKGROUND, backgroundColor, -1);
+		screen.writerBuilder().layer(getLayer()).build().background(rect, bgColor);
+	}
+
+	/**
+	 * Gets an inner rectangle of this view.
+	 *
+	 * @return an inner rectangle of this view
+	 */
+	protected Rectangle getInnerRect() {
+		Rectangle rect = getRect();
+
+		int w;
+		int x;
+		if (rect.width() <= minWidth) {
+			w = rect.width();
+			x = rect.x();
+		}
+		else if (rect.width() >= maxWidth) {
+			w = maxWidth;
+			x = (rect.width() - w) / 2;
+		}
+		else {
+			w = minWidth;
+			x = (rect.width() - w) / 2;
+		}
+
+		int h;
+		int y;
+		if (rect.height() <= minHeight) {
+			h = rect.height();
+			y = rect.y();
+		}
+		else if (rect.height() >= maxHeight) {
+			h = maxHeight;
+			y = (rect.height() - h) / 2;
+		}
+		else {
+			h = rect.height();
+			y = (rect.height() - h) / 2;
+		}
+
+		rect = new Rectangle(x, y, w, h);
+		return rect;
+	}
+
+}

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

@@ -62,7 +62,7 @@ class DialogViewTests extends AbstractViewTests {
 
 		@Test
 		void handlesMouseClick() {
-			MouseEvent click = mouseClick(3, 3);
+			MouseEvent click = mouseClick(1, 6);
 
 			Flux<ButtonViewSelectEvent> actions1 = eventLoop
 					.viewEvents(ButtonViewSelectEvent.class);

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

@@ -295,7 +295,6 @@ public class Catalog {
 		dialog.setEventLoop(eventLoop);
 		dialog.setViewService(ui);
 
-		dialog.setTransparent(false);
 		return dialog;
 	}
 

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

@@ -51,7 +51,6 @@ public class DialogScenario extends AbstractScenario {
 		});
 		DialogView dialog = new DialogView(content, button);
 		configure(dialog);
-		dialog.setTransparent(false);
 		dialog.setViewService(getViewService());
 		return dialog;
 	}