如何在TreeView中仅更改所选项目的字体?
只需在您的CSS文件中定义.tree-cell:selected
的字体即可。
.tree-cell:selected {
-fx-font-weight: bold ;
}
如何在选定的子树上设置背景?
这个有点棘手。您希望任何展开的节点以及其父节点不是根节点的节点具有不同的背景颜色(虽然您没有这样表述,但我认为它在逻辑上相当)。一个展开的节点已经有一个CSS伪类。对于“父节点不是根节点”,您需要定义自己的伪类:
PseudoClass subElementPseudoClass = PseudoClass.getPseudoClass("sub-tree-item");
现在观察单元格的treeItem
属性,并在其更改时更新伪类状态:
treeView.setCellFactory(tv -> {
TreeCell<TabMenuElement> cell = new TreeCell<TabMenuElement>() {
@Override
public void updateItem(TabMenuElement item, boolean empty) {
super.updateItem(item, empty);
setDisclosureNode(null);
if (empty) {
setText("");
setGraphic(null);
} else {
setText(item.getName());
if (item.getIv() != null) {
setGraphic(item.getIv());
}
}
}
};
cell.treeItemProperty().addListener((obs, oldTreeItem, newTreeItem) -> {
cell.pseudoClassStateChanged(subElementPseudoClass,
newTreeItem != null && newTreeItem.getParent() != cell.getTreeView().getRoot());
}
return cell ;
});
现在在你的CSS文件中可以这样写:
.tree-cell:expanded, .tree-cell:sub-tree-item {
-fx-background-color: ... ;
}
将以下的 `ChangeListener` 添加到每个 `TreeItem` 的扩展属性中,以强制最多只能展开一棵子树:
```html
如何强制只有最多一个子树可以展开
将以下的 ChangeListener
添加到每个 TreeItem
的扩展属性中:
```
ChangeListener<Boolean> expandedListener = (obs, wasExpanded, isNowExpanded) -> {
if (isNowExpanded) {
ReadOnlyProperty<?> expandedProperty = (ReadOnlyProperty<?>) obs ;
Object itemThatWasJustExpanded = expandedProperty.getBean();
for (TreeItem<TabMenuElement> item : treeView.getRoot().getChildren()) {
if (item != itemThatWasJustExpanded) {
item.setExpanded(false);
}
}
}
};
TreeItem<TabMenuElement> biblioteka = new TreeItem<>(...);
biblioteka.expandedProperty().addListener(expandedListener);
TreeItem<TabMenuElement> analiza = new TreeItem<>(...);
analiza.expandedProperty().addListener(expandedListener);
如何将顶层项目设置为更大的尺寸?
.tree-cell {
-fx-padding: 0.75em 0em 0.75em 0em ;
}
.tree-cell:sub-tree-item {
-fx-padding: 0.25em ;
}
(或更改字体大小或类似的内容。)
以下是一个完整的示例:
import javafx.application.Application;
import javafx.beans.property.ReadOnlyProperty;
import javafx.beans.value.ChangeListener;
import javafx.css.PseudoClass;
import javafx.scene.Scene;
import javafx.scene.control.TreeCell;
import javafx.scene.control.TreeItem;
import javafx.scene.control.TreeView;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;
public class StyledUniqueExpandingTree extends Application {
@Override
public void start(Stage primaryStage) {
TreeView<String> tree = new TreeView<>();
tree.setShowRoot(false);
TreeItem<String> root = new TreeItem<>("");
tree.setRoot(root);
ChangeListener<Boolean> expandedListener = (obs, wasExpanded, isNowExpanded) -> {
if (isNowExpanded) {
ReadOnlyProperty<?> expandedProperty = (ReadOnlyProperty<?>) obs ;
Object itemThatWasJustExpanded = expandedProperty.getBean();
for (TreeItem<String> item : tree.getRoot().getChildren()) {
if (item != itemThatWasJustExpanded) {
item.setExpanded(false);
}
}
}
};
for (int i=1; i<=4; i++) {
TreeItem<String> item = new TreeItem<>("Top level "+i);
item.expandedProperty().addListener(expandedListener);
root.getChildren().add(item);
for (int j=1; j<=4; j++) {
TreeItem<String> subItem = new TreeItem<>("Sub item "+i+":"+j);
item.getChildren().add(subItem);
}
}
PseudoClass subElementPseudoClass = PseudoClass.getPseudoClass("sub-tree-item");
tree.setCellFactory(tv -> {
TreeCell<String> cell = new TreeCell<String>() {
@Override
public void updateItem(String item, boolean empty) {
super.updateItem(item, empty);
setDisclosureNode(null);
if (empty) {
setText("");
setGraphic(null);
} else {
setText(item);
}
}
};
cell.treeItemProperty().addListener((obs, oldTreeItem, newTreeItem) -> {
cell.pseudoClassStateChanged(subElementPseudoClass,
newTreeItem != null && newTreeItem.getParent() != cell.getTreeView().getRoot());
});
return cell ;
});
BorderPane uiRoot = new BorderPane(tree);
Scene scene = new Scene(uiRoot, 250, 400);
scene.getStylesheets().add("styled-unique-expanded-tree.css");
primaryStage.setScene(scene);
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
使用styled-unique-expanded-tree.css:
.tree-view, .tree-cell {
-fx-background-color: black ;
-fx-text-fill: white ;
}
.tree-cell:expanded, .tree-cell:sub-tree-item {
-fx-background-color: #404040 ;
}
.tree-cell:selected {
-fx-font-weight: bold ;
}
.tree-cell {
-fx-padding: 0.75em 0em 0.75em 0em ;
}
.tree-cell:sub-tree-item {
-fx-padding: 0.25em ;
}