Better background handling in themes

- Modify view structures so that we're able to
  control background drawing better
- Remove transparent concept from box view
- Add background styles for dialog, menu/status bars
- Relates #824

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

@@ -108,8 +108,15 @@ public abstract class AbstractView extends AbstractControl implements View {
 		return layer;
 	}
 
+	/**
+	 * Calls drawing logic in two stages. First a background is drawn and then an
+	 * actual content. This logic allows to separate how child implementation
+	 * can use drawing logic from its parent as usually background should get
+	 * overridden in child but actual content should get overridden in a parent.
+	 */
 	@Override
 	public final void draw(Screen screen) {
+		drawBackground(screen);
 		drawInternal(screen);
 	}
 
@@ -121,6 +128,14 @@ public abstract class AbstractView extends AbstractControl implements View {
 	 */
 	protected abstract void drawInternal(Screen screen);
 
+	/**
+	 * Internal drawing method for background.
+	 *
+	 * @param screen the screen
+	 */
+	protected void drawBackground(Screen screen) {
+	}
+
 	@Override
 	public void focus(View view, boolean focus) {
 		log.debug("Focus view={} focus={}", view, focus);

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

@@ -45,7 +45,6 @@ public class BoxView extends AbstractView {
 	private int paddingBottom;
 	private int paddingLeft;
 	private int paddingRight;
-	private boolean transparent = true;
 	private int backgroundColor = -1;
 	private int titleColor = -1;
 	private int titleStyle = -1;
@@ -162,22 +161,15 @@ public class BoxView extends AbstractView {
 		this.titleAlign = titleAlign;
 	}
 
-	/**
-	 * Sets if box should be transparent, {@code true} by default.
-	 *
-	 * @param transparent a transparency flag
-	 */
-	public void setTransparent(boolean transparent) {
-		this.transparent = transparent;
+	protected String getBackgroundStyle() {
+		return StyleSettings.TAG_BACKGROUND;
 	}
 
-	/**
-	 * Is box transparent.
-	 *
-	 * @return box transparency
-	 */
-	protected boolean isTransparent() {
-		return transparent;
+	@Override
+	protected void drawBackground(Screen screen) {
+		int bgColor = resolveThemeBackground(getBackgroundStyle(), backgroundColor, -1);
+		Rectangle rect = getRect();
+		screen.writerBuilder().layer(getLayer()).build().background(rect, bgColor);
 	}
 
 	/**
@@ -192,14 +184,6 @@ public class BoxView extends AbstractView {
 		if (rect.width() <= 0 || rect.height() <= 0) {
 			return;
 		}
-		int bgColor;
-		if (isTransparent()) {
-			bgColor = backgroundColor > -1 ? backgroundColor : -1;
-		}
-		else {
-			bgColor = resolveThemeBackground(StyleSettings.TAG_BACKGROUND, backgroundColor, -1);
-		}
-		screen.writerBuilder().layer(getLayer()).build().background(rect, bgColor);
 		if (showBorder && rect.width() >= 2 && rect.height() >= 2) {
 			screen.writerBuilder().layer(getLayer()).build().border(rect.x(), rect.y(), rect.width(), rect.height());
 			if (StringUtils.hasText(title)) {

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

@@ -26,6 +26,7 @@ import org.springframework.shell.component.view.geom.VerticalAlign;
 import org.springframework.shell.component.view.message.ShellMessageBuilder;
 import org.springframework.shell.component.view.screen.Screen;
 import org.springframework.shell.component.view.screen.Screen.Writer;
+import org.springframework.shell.style.StyleSettings;
 
 /**
  * {@code ButtonView} is a {@link View} with border and text acting as a button.
@@ -66,6 +67,11 @@ public class ButtonView extends BoxView {
 		return super.getMouseHandler();
 	}
 
+	@Override
+	protected String getBackgroundStyle() {
+		return StyleSettings.TAG_BUTTON_BACKGROUND;
+	}
+
 	@Override
 	protected void drawInternal(Screen screen) {
 		Rectangle rect = getInnerRect();

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

@@ -27,6 +27,7 @@ import org.springframework.shell.component.view.geom.Rectangle;
 import org.springframework.shell.component.view.message.ShellMessageBuilder;
 import org.springframework.shell.component.view.screen.Screen;
 import org.springframework.shell.component.view.screen.Screen.Writer;
+import org.springframework.shell.style.StyleSettings;
 
 /**
  * {@code DialogView} is a {@link View} with border, number of buttons and area
@@ -59,6 +60,20 @@ public class DialogView extends WindowView {
 		hookButtonEvents();
 	}
 
+	@Override
+	protected String getBackgroundStyle() {
+		return StyleSettings.TAG_DIALOG_BACKGROUND;
+	}
+
+	@Override
+	public void setLayer(int index) {
+		if (content != null) {
+			content.setLayer(index);
+		}
+		buttons.forEach(b -> b.setLayer(index + 1));
+		super.setLayer(index);
+	}
+
 	private void hookButtonEvents() {
 		buttons.forEach(b -> {
 			onDestroy(getEventLoop().viewEvents(ButtonViewSelectEvent.class, b)
@@ -95,13 +110,11 @@ public class DialogView extends WindowView {
 		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);
-			content.setLayer(getLayer());
 		}
 		int xx = rect.x();
 		ListIterator<ButtonView> iter = buttons.listIterator();
 		while (iter.hasNext()) {
 			ButtonView button = iter.next();
-			button.setLayer(getLayer());
 			button.setRect(xx, rect.y() + rect.height() - 3, 7, 3);
 			xx += 7;
 		}

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

@@ -36,6 +36,7 @@ import org.springframework.shell.component.view.geom.Rectangle;
 import org.springframework.shell.component.view.screen.Screen;
 import org.springframework.shell.component.view.screen.Screen.Writer;
 import org.springframework.shell.component.view.screen.ScreenItem;
+import org.springframework.shell.style.StyleSettings;
 import org.springframework.shell.style.ThemeResolver;
 
 /**
@@ -74,6 +75,11 @@ public class MenuBarView extends BoxView {
 		return new MenuBarView(items);
 	}
 
+	@Override
+	protected String getBackgroundStyle() {
+		return StyleSettings.TAG_MENUBAR_BACKGROUND;
+	}
+
 	@Override
 	protected void drawInternal(Screen screen) {
 		Rectangle rect = getInnerRect();
@@ -245,7 +251,6 @@ public class MenuBarView extends BoxView {
 		menuView.setThemeResolver(getThemeResolver());
 		menuView.setThemeName(getThemeName());
 		menuView.setShowBorder(true);
-		menuView.setTransparent(false);
 		menuView.setLayer(1);
 		Rectangle rect = getInnerRect();
 		int x = positionAtIndex(activeItemIndex);

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

@@ -29,6 +29,7 @@ import org.springframework.shell.component.view.geom.Rectangle;
 import org.springframework.shell.component.view.message.ShellMessageBuilder;
 import org.springframework.shell.component.view.screen.Screen;
 import org.springframework.shell.component.view.screen.Screen.Writer;
+import org.springframework.shell.style.StyleSettings;
 
 /**
  * {@link StatusBarView} shows {@link StatusItem items} horizontally and is
@@ -53,6 +54,11 @@ public class StatusBarView extends BoxView {
 		setItems(items);
 	}
 
+	@Override
+	protected String getBackgroundStyle() {
+		return StyleSettings.TAG_STATUSBAR_BACKGROUND;
+	}
+
 	@Override
 	protected void drawInternal(Screen screen) {
 		Rectangle rect = getInnerRect();

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

@@ -44,10 +44,14 @@ public class WindowView extends AbstractView {
 		this.backgroundColor = backgroundColor;
 	}
 
+	protected String getBackgroundStyle() {
+		return StyleSettings.TAG_BACKGROUND;
+	}
+
 	@Override
 	protected void drawInternal(Screen screen) {
 		Rectangle rect = getInnerRect();
-		int bgColor = resolveThemeBackground(StyleSettings.TAG_BACKGROUND, backgroundColor, -1);
+		int bgColor = resolveThemeBackground(getBackgroundStyle(), backgroundColor, -1);
 		screen.writerBuilder().layer(getLayer()).build().background(rect, bgColor);
 	}
 

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

@@ -16,6 +16,7 @@
 package org.springframework.shell.component.view.control.cell;
 
 import org.springframework.shell.component.view.control.AbstractControl;
+import org.springframework.shell.component.view.screen.Screen;
 
 /**
  * Base implementation of a {@link Cell}.
@@ -69,4 +70,17 @@ public abstract class AbstractCell<T> extends AbstractControl implements Cell<T>
 	public int getBackgroundColor() {
 		return backgroundColor;
 	}
+
+	@Override
+	public void draw(Screen screen) {
+		drawBackground(screen);
+		drawContent(screen);
+	}
+
+	protected void drawBackground(Screen screen) {
+	}
+
+	protected void drawContent(Screen screen) {
+	}
+
 }

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

@@ -19,6 +19,7 @@ import org.springframework.shell.component.view.control.ListView.ItemStyle;
 import org.springframework.shell.component.view.geom.Rectangle;
 import org.springframework.shell.component.view.screen.Screen;
 import org.springframework.shell.component.view.screen.Screen.Writer;
+import org.springframework.shell.style.StyleSettings;
 import org.springframework.util.StringUtils;
 
 /**
@@ -51,8 +52,21 @@ public abstract class AbstractListCell<T> extends AbstractCell<T> implements Lis
 		return null;
 	}
 
+	protected String getBackgroundStyle() {
+		return StyleSettings.TAG_BACKGROUND;
+	}
+
 	@Override
-	public void draw(Screen screen) {
+	protected void drawBackground(Screen screen) {
+		Rectangle rect = getRect();
+		int bgColor = resolveThemeBackground(getBackgroundStyle(), getBackgroundColor(), -1);
+		if (bgColor > -1) {
+			screen.writerBuilder().build().background(rect, bgColor);
+		}
+	}
+
+	@Override
+	protected void drawContent(Screen screen) {
 		String indicator = getIndicator();
 		String text = null;
 		if (StringUtils.hasText(indicator)) {
@@ -64,7 +78,6 @@ public abstract class AbstractListCell<T> extends AbstractCell<T> implements Lis
 		Rectangle rect = getRect();
 		Writer writer = screen.writerBuilder().style(getStyle()).color(getForegroundColor()).build();
 		writer.text(text, rect.x(), rect.y());
-		writer.background(rect, getBackgroundColor());
 	}
 
 	@Override

spring-shell-core/src/main/java/org/springframework/shell/style/StyleSettings.java

@@ -96,6 +96,26 @@ public abstract class StyleSettings {
 	 */
 	public final static String TAG_BACKGROUND = "style-background";
 
+	/**
+	 * Styling for dialog background.
+	 */
+	public final static String TAG_DIALOG_BACKGROUND = "style-dialog-background";
+
+	/**
+	 * Styling for button background.
+	 */
+	public final static String TAG_BUTTON_BACKGROUND = "style-button-background";
+
+	/**
+	 * Styling for menubar background.
+	 */
+	public final static String TAG_MENUBAR_BACKGROUND = "style-menubar-background";
+
+	/**
+	 * Styling for statusbar background.
+	 */
+	public final static String TAG_STATUSBAR_BACKGROUND = "style-statusbar-background";
+
 	public String title() {
 		return "bold";
 	}
@@ -152,6 +172,22 @@ public abstract class StyleSettings {
 		return "default";
 	}
 
+	public String dialogBackground() {
+		return "default";
+	}
+
+	public String buttonBackground() {
+		return "default";
+	}
+
+	public String menubarBackground() {
+		return "default";
+	}
+
+	public String statusbarBackground() {
+		return "default";
+	}
+
 	/**
 	 * Resolve a theme setting from a given tag.
 	 *
@@ -188,6 +224,14 @@ public abstract class StyleSettings {
 				return highlight();
 			case TAG_BACKGROUND:
 				return background();
+			case TAG_DIALOG_BACKGROUND:
+				return dialogBackground();
+			case TAG_BUTTON_BACKGROUND:
+				return buttonBackground();
+			case TAG_MENUBAR_BACKGROUND:
+				return menubarBackground();
+			case TAG_STATUSBAR_BACKGROUND:
+				return statusbarBackground();
 		}
 		throw new IllegalArgumentException(String.format("Unknown tag '%s'", tag));
 	}
@@ -225,7 +269,11 @@ public abstract class StyleSettings {
 				TAG_ITEM_UNSELECTED,
 				TAG_ITEM_SELECTOR,
 				TAG_HIGHLIGHT,
-				TAG_BACKGROUND
+				TAG_BACKGROUND,
+				TAG_DIALOG_BACKGROUND,
+				TAG_BUTTON_BACKGROUND,
+				TAG_MENUBAR_BACKGROUND,
+				TAG_STATUSBAR_BACKGROUND
 		};
 	}
 

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

@@ -245,11 +245,19 @@ public class Catalog {
 		}
 
 		@Override
-		public void draw(Screen screen) {
+		protected void drawBackground(Screen screen) {
+			int bgColor = resolveThemeBackground(getBackgroundStyle(), getBackgroundColor(), -1);
+			if (bgColor > -1) {
+				Rectangle rect = getRect();
+				screen.writerBuilder().build().background(rect, bgColor);
+			}
+		}
+
+		@Override
+		protected void drawContent(Screen screen) {
 			Rectangle rect = getRect();
 			Writer writer = screen.writerBuilder().style(getStyle()).build();
 			writer.text(String.format("%-20s %s", getItem().name(), getItem().description()), rect.x(), rect.y());
-			writer.background(rect, getBackgroundColor());
 		}
 	}
 

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

@@ -59,6 +59,26 @@ class CatalogConfiguration {
 			return "bg:blue";
 		}
 
+		@Override
+		public String dialogBackground() {
+			return "bg:green";
+		}
+
+		@Override
+		public String buttonBackground() {
+			return "bg:red";
+		}
+
+		@Override
+		public String menubarBackground() {
+			return "bg:magenta";
+		}
+
+		@Override
+		public String statusbarBackground() {
+			return "bg:cyan";
+		}
+
 	}
 
 }