Kernel: Fixed dangling icons and background color in TreeTableViewers

- Icons are now removed, if a row does not contains an element anymore.

- Fixed a formating issue which prevented displaying background color on
some systems.

Issue-Ref: 4147
Issue-Url: af3#4147

Signed-off-by: Andreas Bayha <bayha@fortiss.org>

org.fortiss.tooling.common.ui/src/org/fortiss/tooling/common/ui/javafx/control/treetableview/.ratings

@@ -5,8 +5,8 @@ DynamicTextFieldTreeTableCell.java de24117e6f785b328f1ff62383626a0b4b54e8ff GREE
 DynamicTreeContentProviderBase.java 91896b1fb5104d126544c44c1ff8c30f2a13a8d6 GREEN
 DynamicTreeItem.java 7486071d20e896d6ca9a9101bf105caccf3656d0 GREEN
 DynamicTreeItemBase.java d883066ecc181120302ca32f328538de7a45b093 GREEN
-DynamicTreeTableUIProviderBase.java 735766bf3b046dc696eb3324378754ae6db5f4d0 GREEN
-DynamicTreeTableViewer.java 9198fbd64af2c15829e63bafcab8095a173c6ff4 GREEN
+DynamicTreeTableUIProviderBase.java d150a4c379cc41aab2a44a5f1643f4956332c8e3 YELLOW
+DynamicTreeTableViewer.java cb289413d15159abbcccfea87d731738905b4b28 YELLOW
 DynamicTreeUIProviderBase.java 82d3c051213f0147f4c67ad247a08696cee73110 GREEN
 DynamicTreeViewer.java 545f1ca10b7b3cad171b294a4b447875da45c9ed GREEN
 DynamicTreeViewerBase.java a2013538b62d86f6a09efdf2cd78babac2072484 GREEN

org.fortiss.tooling.common.ui/src/org/fortiss/tooling/common/ui/javafx/control/treetableview/DynamicTreeTableUIProviderBase.java

@@ -77,7 +77,6 @@ public abstract class DynamicTreeTableUIProviderBase<T> {
 
 	/**
 	 * Returns the style that shall be applied to the {@link TreeItem} of the given element. Return
-	 * 
 	 * {@code null} for the default style.
 	 * 
 	 * @param element
@@ -87,6 +86,19 @@ public abstract class DynamicTreeTableUIProviderBase<T> {
 	 * @return style of the element in the CSS format.
 	 */
 	public String getCellStyle(T element, int column) {
+		if(element == null) {
+			return null;
+		}
+
+		Color bgColor = getBackgroundColor(column, element);
+		if(bgColor != null) {
+			// Some transparency is necessary here, for correctly displaying the selection
+			// bar when selecting a row. WIth out transparency, it would not be visible on
+			// this cell.
+			double alpha = 0.5;
+			String colorStr = colorToRgbaString(bgColor, alpha);
+			return "-fx-background-color: " + colorStr + ";";
+		}
 		return null;
 	}
 
@@ -294,25 +306,20 @@ public abstract class DynamicTreeTableUIProviderBase<T> {
 			T data = cell.getTreeTableRow().getItem();
 
 			if(data != null) {
-				Color bgColor = getBackgroundColor(columnIndex, data);
-				if(bgColor != null) {
-					// Some transparency is necessary here, for correctly displaying the selection
-					// bar when selecting a row. WIth out transparency, it would not be visible on
-					// this cell.
-					double alpha = 0.5;
-					String colorStr = colorToRgbaString(bgColor, alpha);
-					cell.setStyle("-fx-background-color: " + colorStr);
-				}
-
 				final Node icon = getIconNode(data, columnIndex);
 				cell.setGraphic(icon);
+				cell.setStyle(getCellStyle(data, columnIndex));
+			} else {
+				// reset icon for cases, in which a row was styled before, but became empty by now.
+				cell.setGraphic(null);
+				cell.setStyle(null);
 			}
 		}
 	}
 
 	/** Converts a {@link Color} object into a rgba format as used in css. */
 	private final static String colorToRgbaString(Color color, double alpha) {
-		return String.format("rgba(%d,%d,%d,%.1f)", (int)(color.getRed() * 255),
+		return String.format("rgba(%d,%d,%d,%s)", (int)(color.getRed() * 255),
 				(int)(color.getGreen() * 255), (int)(color.getBlue() * 255), alpha);
 	}
 
@@ -511,11 +518,6 @@ public abstract class DynamicTreeTableUIProviderBase<T> {
 							// JFX-builtin handling is non-operation in Linux.
 							addContextMenuHandler(menu, data);
 						}
-
-						String style = getCellStyle(data, colIndex);
-						if(style != null) {
-							this.setStyle(style);
-						}
 					}
 
 					this.setContextMenu(menu);

org.fortiss.tooling.common.ui/src/org/fortiss/tooling/common/ui/javafx/control/treetableview/DynamicTreeTableViewer.java

@@ -278,7 +278,8 @@ public final class DynamicTreeTableViewer<T> extends DynamicTreeViewerBase<T> {
 	/** {@inheritDoc} */
 	@Override
 	protected T getSelectedObject() {
-		T value = view.getSelectionModel().getSelectedItem().getValue();
+		final TreeItem<T> selectedItem = view.getSelectionModel().getSelectedItem();
+		T value = selectedItem != null ? selectedItem.getValue() : null;
 
 		return value;
 	}