没有对应于 CheckBoxTreeCell 的单元格实现：即具有绑定到 CheckBoxTreeItem 的选定/不确定属性的复选框的单元格。明显的对应 CheckBoxTreeTableCell 只是一个带有复选框的单元格，它绑定到单元格数据。
需要的是一个 CheckBoxTreeTableRow：它是可以访问 TreeItem 并且可以管理 checkBox 和 treeItem 之间的绑定的单元层。下面是 CheckBoxTreeCell 的一个快速实现、简化和调整的副本。取消/绑定在 updateItem 中处理。
更新：清洁解决方案（冗长！）
看起来 TableRowSkinBase 准备处理自定义行图形，它有一个方法 graphicsProperty() 用于行皮肤内的所有布局代码。
/**
* Returns the graphic to draw on the inside of the disclosure node. Null
* is acceptable when no graphic should be shown. Commonly this is the
* graphic associated with a TreeItem (i.e. treeItem.getGraphic()), rather
* than a graphic associated with a cell.
*/
protected abstract ObjectProperty<Node> graphicProperty();
TreeTableRowSkin 实现它以返回 TreeItem 的图形，因此重写以返回 tableRow 的图形应该可以工作。除了......它不是 - 布局是弯曲的，如下面的原始hacky答案中所述。挖掘暴露了罪魁祸首：它是 TreeTableCellSkin，它硬编码它自己的布局代码，以将其填充中的任何图形解释为...... treeItem 的图形。
所以需要一个完整的解决方案
- 一个不对 treeItem 图形进行硬编码的 Tree/TableCellSkin（下面的示例仍然不完全干净，它依赖于 super 添加图形宽度并再次减去它）
- 安装增强皮肤的 Tree/TableCell
- 根据需要覆盖 graphicsProperty 的 Tree/TableRowSkin，在返回行图形下方
- 根据需要更新其图形的 Tree/TableRow，下面将其图形设置为一个复选框，该复选框反过来可能包含 treeItem 的图形
第一对命名为 DefaultTreeTableCell/Skin，第二对 CheckBoxTreeTableRow/Skin 下面。
用法（插入 OP 示例的片段）
// just for fun, have root items with some graphic
final CheckBoxTreeItem<Employee> root = new CheckBoxTreeItem<>(
new Employee("Sales Department", 0.0), new Circle(10, Color.RED));
final CheckBoxTreeItem<Employee> root2 = new CheckBoxTreeItem<>(
new Employee("Departments", 0.0), new Circle(10, Color.BLUE));
// configure treeTableView to use the extended tableRow
treeTableView.setRowFactory(item -> new CheckBoxTreeTableRow<>());
// configure table columns to use the extended table cell
empColumn.setCellFactory(p -> new DefaultTreeTableCell<>());
// all cell types must have a skin that copes with row graphics
salaryColumn.setCellFactory(e -> {
TreeTableCell cell = new ProgressBarTreeTableCell() {
@Override
protected Skin<?> createDefaultSkin() {
return new DefaultTreeTableCell.DefaultTreeTableCellSkin<>(this);
}
};
return cell;
});
单元格/行实现：
/**
* TreeTableCell actually showing something. This is copied from TreeTableColumn plus
* installs DefaultTreeTableCellSkin which handles row graphic width.
*/
public class DefaultTreeTableCell<S, T> extends TreeTableCell<S, T> {
@Override
protected void updateItem(T item, boolean empty) {
if (item == getItem()) return;
super.updateItem(item, empty);
if (item == null) {
super.setText(null);
super.setGraphic(null);
} else if (item instanceof Node) {
super.setText(null);
super.setGraphic((Node)item);
} else {
super.setText(item.toString());
super.setGraphic(null);
}
}
@Override
protected Skin<?> createDefaultSkin() {
return new DefaultTreeTableCellSkin<>(this);
}
/**
* TreeTableCellSkin that handles row graphic in its leftPadding, if
* it is in the treeColumn of the associated TreeTableView.
* <p>
* It assumes that per-row graphics - including the graphic of the TreeItem, if any -
* is folded into the TreeTableRow graphic and patches its leftLabelPadding
* to account for the graphic width.
* <p>
*
* Note: TableRowSkinBase seems to be designed to cope with variations of row
* graphic - it has a method <code>graphicProperty()</code> that's always used
* internally when calculating offsets in the treeColumn.
* Subclasses override as needed, the layout code remains constant. The real
* problem is the TreeTableCell hard-codes the TreeItem as the only graphic
* owner.
*
*/
public static class DefaultTreeTableCellSkin<S, T> extends TreeTableCellSkin<S, T> {
/**
* @param treeTableCell
*/
public DefaultTreeTableCellSkin(TreeTableCell<S, T> treeTableCell) {
super(treeTableCell);
}
/**
* Overridden to adjust the padding returned by super for row graphic.
*/
@Override
protected double leftLabelPadding() {
double padding = super.leftLabelPadding();
padding += getRowGraphicPatch();
return padding;
}
/**
* Returns the patch for leftPadding if the tableRow has a graphic of
* its own.<p>
*
* Note: this implemenation is a bit whacky as it relies on super's
* handling of treeItems graphics offset. A cleaner
* implementation would override leftLabelPadding from scratch.
* <p>
* PENDING JW: doooooo it!
*
* @return
*/
protected double getRowGraphicPatch() {
if (!isTreeColumn()) return 0;
Node graphic = getSkinnable().getTreeTableRow().getGraphic();
if (graphic != null) {
double height = getCellSize();
// start with row's graphic
double patch = graphic.prefWidth(height);
// correct for super's having added treeItem's graphic
TreeItem<S> item = getSkinnable().getTreeTableRow().getTreeItem();
if (item.getGraphic() != null) {
double correct = item.getGraphic().prefWidth(height);
patch -= correct;
}
return patch;
}
return 0;
}
/**
* Checks and returns whether our cell is attached to a treeTableView/column
* and actually has a TreeItem.
* @return
*/
protected boolean isTreeColumn() {
if (getSkinnable().isEmpty()) return false;
TreeTableColumn<S, T> column = getSkinnable().getTableColumn();
TreeTableView<S> view = getSkinnable().getTreeTableView();
if (column.equals(view.getTreeColumn())) return true;
return view.getVisibleLeafColumns().indexOf(column) == 0;
}
}
}
/**
* Support custom graphic for Tree/TableRow. Here in particular a checkBox.
* http://stackoverflow.com/q/29300551/203657
* <p>
* Basic idea: implement custom TreeTableRow that set's its graphic to the
* graphic/checkBox. Doesn't work: layout is broken, graphic appears
* over the text. All fine if we set the graphic to the TreeItem that's
* shown. Possible as long as the treeItem doesn't have a graphic of
* its own.
* <p>
* Basic problem:
* <li> TableRowSkinBase seems to be able to cope: has protected method
* graphicsProperty that should be implemented to return the graphic
* if any. That graphic is added to the children list and sized/located
* in layoutChildren.
* <li> are added the graphic/disclosureNode as needed before
* calling super.layoutChildren,
* <li> graphic/disclosure are placed inside the leftPadding of the tableCell
* that is the treeColumn
* <li> TreeTableCellSkin must cooperate in taking into account the graphic/disclosure
* when calculating its leftPadding
* <li> cellSkin is hard-coded to use the TreeItem's graphic (vs. the rowCell's)
*
* PENDING JW:
* <li>- would expect to not alter the scenegraph during layout (might lead to
* endless loops or not) but done frequently in core code
* <p>
*
* Outline of the solution as implemented:
* <li> need a TreeTableCell with a custom skin
* <li> override leftPadding in skin to add row graphic if available
* <li> need CheckBoxTreeTableRow that sets its graphic to checkBox (or a combination
* of checkBox and treeItem's)
* <li> need custom rowSkin that implements graphicProperty to return the row graphic
*
* @author Jeanette Winzenburg, Berlin
*
* @see DefaultTreeTableCell
* @see DefaultTreeTableCellSkin
*
*/
public class CheckBoxTreeTableRow<T> extends TreeTableRow<T> {
private CheckBox checkBox;
private ObservableValue<Boolean> booleanProperty;
private BooleanProperty indeterminateProperty;
public CheckBoxTreeTableRow() {
this(item -> {
if (item instanceof CheckBoxTreeItem<?>) {
return ((CheckBoxTreeItem<?>)item).selectedProperty();
}
return null;
});
}
public CheckBoxTreeTableRow(
final Callback<TreeItem<T>, ObservableValue<Boolean>> getSelectedProperty) {
this.getStyleClass().add("check-box-tree-cell");
setSelectedStateCallback(getSelectedProperty);
checkBox = new CheckBox();
checkBox.setAlignment(Pos.TOP_LEFT);
}
// --- selected state callback property
private ObjectProperty<Callback<TreeItem<T>, ObservableValue<Boolean>>>
selectedStateCallback =
new SimpleObjectProperty<Callback<TreeItem<T>, ObservableValue<Boolean>>>(
this, "selectedStateCallback");
/**
* Property representing the {@link Callback} that is bound to by the
* CheckBox shown on screen.
*/
public final ObjectProperty<Callback<TreeItem<T>, ObservableValue<Boolean>>> selectedStateCallbackProperty() {
return selectedStateCallback;
}
/**
* Sets the {@link Callback} that is bound to by the CheckBox shown on screen.
*/
public final void setSelectedStateCallback(Callback<TreeItem<T>, ObservableValue<Boolean>> value) {
selectedStateCallbackProperty().set(value);
}
/**
* Returns the {@link Callback} that is bound to by the CheckBox shown on screen.
*/
public final Callback<TreeItem<T>, ObservableValue<Boolean>> getSelectedStateCallback() {
return selectedStateCallbackProperty().get();
}
/** {@inheritDoc} */
@Override
protected void updateItem(T item, boolean empty) {
super.updateItem(item, empty);
if (empty) {
setText(null);
setGraphic(null);
} else {
TreeItem<T> treeItem = getTreeItem();
checkBox.setGraphic(treeItem == null ? null : treeItem.getGraphic());
setGraphic(checkBox);
// uninstall bindings
if (booleanProperty != null) {
checkBox.selectedProperty().unbindBidirectional((BooleanProperty)booleanProperty);
}
if (indeterminateProperty != null) {
checkBox.indeterminateProperty().unbindBidirectional(indeterminateProperty);
}
// install new bindings.
// this can only handle TreeItems of type CheckBoxTreeItem
if (treeItem instanceof CheckBoxTreeItem) {
CheckBoxTreeItem<T> cbti = (CheckBoxTreeItem<T>) treeItem;
booleanProperty = cbti.selectedProperty();
checkBox.selectedProperty().bindBidirectional((BooleanProperty)booleanProperty);
indeterminateProperty = cbti.indeterminateProperty();
checkBox.indeterminateProperty().bindBidirectional(indeterminateProperty);
} else {
throw new IllegalStateException("item must be CheckBoxTreeItem");
}
}
}
@Override
protected Skin<?> createDefaultSkin() {
return new CheckBoxTreeTableRowSkin<>(this);
}
public static class CheckBoxTreeTableRowSkin<S> extends TreeTableRowSkin<S> {
protected ObjectProperty<Node> checkGraphic;
/**
* @param control
*/
public CheckBoxTreeTableRowSkin(TreeTableRow<S> control) {
super(control);
}
/**
* Note: this is implicitly called from the constructor of LabeledSkinBase.
* At that time, checkGraphic is not yet instantiated. So we do it here,
* still having to create it at least twice. That'll be a problem if
* anybody would listen to changes ...
*/
@Override
protected ObjectProperty<Node> graphicProperty() {
if (checkGraphic == null) {
checkGraphic = new SimpleObjectProperty<Node>(this, "checkGraphic");
}
CheckBoxTreeTableRow<S> treeTableRow = getTableRow();
if (treeTableRow.getTreeItem() == null) {
checkGraphic.set(null);
} else {
checkGraphic.set(treeTableRow.getGraphic());
}
return checkGraphic;
}
protected CheckBoxTreeTableRow<S> getTableRow() {
return (CheckBoxTreeTableRow<S>) super.getSkinnable();
}
}
@SuppressWarnings("unused")
private static final Logger LOG = Logger
.getLogger(CheckBoxTreeTableRow.class.getName());
}
原始答案：破解！
里面有一段很牛逼的代码：
treeItem.setGraphics(checkBox);
这真的很奇怪，最终可能会造成严重破坏 - 这是围绕 TreeTableRowSkin 中的布局故障的黑客攻击，由于某种原因（我无法挖掘）无法将图形集定位到单元格。无法使其在自定义 CheckBoxTreeTableRowSkin 中运行，该 CheckBoxTreeTableRowSkin 直接在其中返回 checkBox graphicProperty()- 所以我们现在就使用 hack。
/**
* @author Jeanette Winzenburg, Berlin
*/
public class CheckBoxTreeTableRowHack<T> extends TreeTableRow<T> {
private CheckBox checkBox;
private ObservableValue<Boolean> booleanProperty;
private BooleanProperty indeterminateProperty;
public CheckBoxTreeTableRowHack() {
setSelectedStateCallback(item -> {
if (item instanceof CheckBoxTreeItem<?>) {
return ((CheckBoxTreeItem<?>)item).selectedProperty();
}
return null;
});
this.checkBox = new CheckBox();
// something weird going on with layout
checkBox.setAlignment(Pos.TOP_LEFT);
}
// --- selected state callback property
private ObjectProperty<Callback<TreeItem<T>, ObservableValue<Boolean>>>
selectedStateCallback =
new SimpleObjectProperty<Callback<TreeItem<T>, ObservableValue<Boolean>>>(
this, "selectedStateCallback");
/**
* Property representing the {@link Callback} that is bound to by the
* CheckBox shown on screen.
*/
public final ObjectProperty<Callback<TreeItem<T>, ObservableValue<Boolean>>> selectedStateCallbackProperty() {
return selectedStateCallback;
}
/**
* Sets the {@link Callback} that is bound to by the CheckBox shown on screen.
*/
public final void setSelectedStateCallback(Callback<TreeItem<T>, ObservableValue<Boolean>> value) {
selectedStateCallbackProperty().set(value);
}
/**
* Returns the {@link Callback} that is bound to by the CheckBox shown on screen.
*/
public final Callback<TreeItem<T>, ObservableValue<Boolean>> getSelectedStateCallback() {
return selectedStateCallbackProperty().get();
}
/** {@inheritDoc} */
@Override
public void updateItem(T item, boolean empty) {
super.updateItem(item, empty);
if (empty) {
setText(null);
setGraphic(null);
} else {
//
TreeItem<T> treeItem = getTreeItem();
// PENDING JW: this is nuts but working .. certainly will pose problems
// when re-using the cell
treeItem.setGraphic(checkBox);
// this is what CheckBoxTreeCell does, setting the graphic
// of the tableRow confuses the layout
// checkBox.setGraphic(treeItem == null ? null : treeItem.getGraphic());
// setGraphic(checkBox);
// uninstall bindings
if (booleanProperty != null) {
checkBox.selectedProperty().unbindBidirectional((BooleanProperty)booleanProperty);
}
if (indeterminateProperty != null) {
checkBox.indeterminateProperty().unbindBidirectional(indeterminateProperty);
}
// install new bindings.
// We special case things when the TreeItem is a CheckBoxTreeItem
if (treeItem instanceof CheckBoxTreeItem) {
CheckBoxTreeItem<T> cbti = (CheckBoxTreeItem<T>) treeItem;
booleanProperty = cbti.selectedProperty();
checkBox.selectedProperty().bindBidirectional((BooleanProperty)booleanProperty);
indeterminateProperty = cbti.indeterminateProperty();
checkBox.indeterminateProperty().bindBidirectional(indeterminateProperty);
} else {
throw new IllegalStateException("item must be CheckBoxTreeItem");
}
}
}
}
// usage: in the example add
treeTableView.setRowFactory(f -> new CheckBoxTreeTableRowHack<>());