JavaFx CheckBoxTreeItem 选择根项目错误
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我正在尝试开发文件复制应用程序。我已经在文件系统上创建了一个包含当前目录的复选框树项。
但是当我选择第一个节点(c:/ directory)时,需要很长时间。如何轻松快速地选择所有目录?
这是我的第一个FXML加载类:
@Override
public void initialize(URL location, ResourceBundle resources) {
TreeView pathTree = new MyFileTreeView().getMyFilePathTree();
vBoxFileTree.getChildren().add(pathTree);
}
这是我的treeView组件:
public class MyFileTreeView {
private TreeView<Path> filePathTree;
private List<Path> rootDirectories;
private Logger logger = Logger.getLogger(MyFileTreeView.class);
public MyFileTreeView() {
rootDirectories = new ArrayList<>();
Iterable<Path> roots = FileSystems.getDefault().getRootDirectories();
for (Path root : roots) {
rootDirectories.add(root);
}
}
public TreeView getMyFilePathTree() {
if (filePathTree == null) {
filePathTree = new TreeView<>(getRootItem());
filePathTree.setPrefHeight(600.0d);
filePathTree.getSelectionModel().setSelectionMode(SelectionMode.MULTIPLE);
filePathTree.setCellFactory((TreeView<Path> t) -> new TreeCellImpl());
filePathTree.setShowRoot(false);
}
return filePathTree;
}
private TreeItem getRootItem() {
TreeItem rootItem = new TreeItem();
for (Path path : rootDirectories) {
MyFileTreeItem item = new MyFileTreeItem(path);
item.setIndependent(false);
rootItem.getChildren().add(item);
logger.info(path.toString() + " directory has been added to fileTree!");
}
return rootItem;
}
}
这是树项目:
public class MyFileTreeItem extends CheckBoxTreeItem<Path> {
private boolean isLeaf;
private boolean isFirstTimeChildren = true;
private boolean isFirstTimeLeaf = true;
public MyFileTreeItem(Path path) {
super(path);
}
@Override
public boolean isLeaf() {
if (isFirstTimeLeaf) {
isFirstTimeLeaf = false;
Path path = getValue();
isLeaf = Files.isRegularFile(path);
}
return isLeaf;
}
@Override
public ObservableList<TreeItem<Path>> getChildren() {
if (isFirstTimeChildren) {
isFirstTimeChildren = false;
super.getChildren().setAll(buildChildren(this));
}
return super.getChildren();
}
private ObservableList<TreeItem<Path>> buildChildren(CheckBoxTreeItem<Path> treeItem) {
Path path = treeItem.getValue();
if ((path != null) && (Files.isDirectory(path))) {
try (Stream<Path> pathStream = Files.list(path)) {
return pathStream
.map(p -> new MyFileTreeItem(p))
.collect(Collectors.toCollection(() ->
FXCollections.observableArrayList()));
} catch (IOException e) {
}
}
return FXCollections.emptyObservableList();
}
}
更新:
由于@fabian,我添加了不确定的属性
public class FileTreeItem extends TreeItem<Path> {
private boolean isLeaf;
private boolean isFirstTimeChildren = true;
private boolean isFirstTimeLeaf = true;
private BooleanProperty selected;
private BooleanProperty indeterminate;
public FileTreeItem(Path path) {
this(path, false, false);
}
protected FileTreeItem(Path path, boolean selected, boolean indeterminate) {
super(path);
this.selected = new SimpleBooleanProperty(selected);
this.indeterminate = new SimpleBooleanProperty(indeterminate);
this.selected.addListener((o, oldValue, newValue) -> {
if (!isLeaf() && !isFirstTimeChildren) {
if (!isIndeterminate()) {
for (TreeItem<Path> ti : getChildren()) {
((FileTreeItem) ti).setSelected(newValue);
}
}
if (isIndeterminate() && newValue) {
setIndeterminate(false);
for (TreeItem<Path> ti : getChildren()) {
((FileTreeItem) ti).setSelected(newValue);
}
}
}
if (!newValue) {
if (getParent() instanceof FileTreeItem) {
FileTreeItem parent = (FileTreeItem) getParent();
parent.setIndeterminate(true);
parent.setSelected(false);
}
} else {
if (getParent() instanceof FileTreeItem) {
boolean allChildSelected = true;
FileTreeItem parent = (FileTreeItem) getParent();
for (TreeItem<Path> child : parent.getChildren()) {
if (!((FileTreeItem) child).isSelected()) {
allChildSelected = false;
break;
}
}
if (allChildSelected && !parent.isSelected()) {
setIndeterminate(false);
parent.setIndeterminate(false);
parent.setSelected(true);
}
}
}
});
}
@Override
public boolean isLeaf() {
if (isFirstTimeLeaf) {
isFirstTimeLeaf = false;
Path path = getValue();
isLeaf = Files.isRegularFile(path);
}
return isLeaf;
}
@Override
public ObservableList<TreeItem<Path>> getChildren() {
if (isFirstTimeChildren) {
isFirstTimeChildren = false;
super.getChildren().setAll(buildChildren(this));
}
return super.getChildren();
}
private List<TreeItem<Path>> buildChildren(FileTreeItem treeItem) {
Path path = treeItem.getValue();
if ((path != null) && (Files.isDirectory(path))) {
final boolean select = treeItem.isSelected();
boolean indeterminate = treeItem.isIndeterminate();
try (Stream<Path> pathStream = Files.list(path)) {
List<TreeItem<Path>> res = new ArrayList<>();
pathStream
.map(p -> new FileTreeItem(p, select, indeterminate))
.forEach(res::add);
return res;
} catch (IOException e) {
}
}
return Collections.emptyList();
}
public boolean isSelected() {
return selected.get();
}
public BooleanProperty selectedProperty() {
return selected;
}
public void setSelected(boolean value) {
selected.set(value);
}
public boolean isIndeterminate() {
return indeterminate.get();
}
public BooleanProperty indeterminateProperty() {
return indeterminate;
}
public void setIndeterminate(boolean indeterminate) {
this.indeterminate.set(indeterminate);
}
}
答案
当您更改CheckBoxTreeItem
的选定状态时,子项的状态将设置为相同的值。这意味着调用了getChildren
方法,并且对所有孩子也设置了selected
属性。这样,您可以有效地对目录的所有内容进行深度优先遍历。
因此,您需要直接扩展TreeItem
并实现所需的属性。您需要确保更新selected
属性时,只有在已调用getChildren
时才迭代子项:
public class FileTreeItem extends TreeItem<Path> {
private boolean isLeaf;
private boolean isFirstTimeChildren = true;
private boolean isFirstTimeLeaf = true;
private final BooleanProperty selected;
private final BooleanProperty indeterminate;
protected FileTreeItem(Path path, boolean selected) {
super(path);
this.indeterminate = new SimpleBooleanProperty();
this.selected = new SimpleBooleanProperty(selected);
this.selected.addListener((o, oldValue, newValue) -> {
if (!updating) {
if (!isLeaf() && !isFirstTimeChildren) {
// propagate selection to children if they were created yet
for (TreeItem<Path> ti : getChildren()) {
FileTreeItem fti = (FileTreeItem) ti;
fti.setSelected(newValue);
}
}
// update ancestors
TreeItem<Path> parent = getParent();
while ((parent instanceof FileTreeItem)
&& updateAncestorState((FileTreeItem) parent)) {
parent = parent.getParent();
}
}
});
}
/**
* flag preventing circular calls during update.
*/
private boolean updating;
protected static boolean updateAncestorState(FileTreeItem item) {
List<TreeItem<Path>> children = item.getChildren();
boolean hasUnselected = false;
boolean hasSelected = false;
for (Iterator<TreeItem<Path>> it = children.iterator();!(hasSelected && hasUnselected) && it.hasNext();) {
TreeItem<Path> ti = it.next();
FileTreeItem child = (FileTreeItem) ti;
if (child.isSelected()) {
hasSelected = true;
} else {
hasUnselected = true;
if (child.isIndeterminate()) {
hasSelected = true;
}
}
}
item.updating = true;
boolean changed = false;
if (hasUnselected) {
if (item.isSelected() || item.isIndeterminate() != hasSelected) {
changed = true;
item.setSelected(false);
item.setIndeterminate(hasSelected);
}
} else {
if (!item.isSelected()) {
changed = true;
item.setSelected(true);
}
item.setIndeterminate(false);
}
item.updating = false;
return changed;
}
public FileTreeItem(Path path) {
this(path, false);
}
@Override
public boolean isLeaf() {
if (isFirstTimeLeaf) {
isFirstTimeLeaf = false;
Path path = getValue();
isLeaf = Files.isRegularFile(path);
}
return isLeaf;
}
@Override
public ObservableList<TreeItem<Path>> getChildren() {
if (isFirstTimeChildren) {
isFirstTimeChildren = false;
super.getChildren().setAll(buildChildren(this));
}
return super.getChildren();
}
private List<TreeItem<Path>> buildChildren(FileTreeItem treeItem) {
Path path = treeItem.getValue();
if ((path != null) && (Files.isDirectory(path))) {
final boolean select = treeItem.isSelected();
try (Stream<Path> pathStream = Files.list(path)) {
List<TreeItem<Path>> res = new ArrayList<>();
pathStream
.map(p -> new FileTreeItem(p, select))
.forEach(res::add);
return res;
} catch (IOException e) {
}
}
return Collections.emptyList();
}
/* methods for selected & indeterminate properties */
}
编辑
显示indeterminate
属性需要您实现自己的TreeCell
:
public class FileItemCheckBoxTreeCell extends TreeCell<Path> {
private BooleanProperty oldSelectedProperty;
private BooleanProperty oldIndeterminateProperty;
private final CheckBox checkBox;
private final StringConverter<TreeItem<Path>> converter;
public FileItemCheckBoxTreeCell(StringConverter<TreeItem<Path>> converter) {
if (converter == null) {
throw new IllegalArgumentException();
}
this.converter = converter;
this.checkBox = new CheckBox();
}
@Override
protected void updateItem(Path item, boolean empty) {
// clear old binding
if (oldSelectedProperty != null) {
checkBox.selectedProperty().unbindBidirectional(oldSelectedProperty);
checkBox.indeterminateProperty().unbindBidirectional(oldIndeterminateProperty);
oldSelectedProperty = null;
oldIndeterminateProperty = null;
}
checkBox.indeterminateProperty().unbind();
super.updateItem(item, empty);
if (empty) {
setGraphic(null);
setText("");
} else {
TreeItem<Path> treeItem = getTreeItem();
setText(converter.toString(treeItem));
if (treeItem instanceof FileTreeItem) {
setGraphic(checkBox);
FileTreeItem fti = (FileTreeItem) treeItem;
oldSelectedProperty = fti.selectedProperty();
oldIndeterminateProperty = fti.indeterminateProperty();
checkBox.selectedProperty().bindBidirectional(oldSelectedProperty);
checkBox.indeterminateProperty().bindBidirectional(oldIndeterminateProperty);
} else {
setGraphic(null);
}
}
}
public static Callback<TreeView<Path>, TreeCell<Path>> forTreeView(StringConverter<TreeItem<Path>> converter) {
if (converter == null) {
throw new IllegalArgumentException();
}
return tv -> new FileItemCheckBoxTreeCell(converter);
}
}
public TreeView getMyFilePathTree() {
if (filePathTree == null) {
filePathTree = new TreeView<>(getRootItem());
filePathTree.setPrefHeight(600.0d);
filePathTree.getSelectionModel().setSelectionMode(SelectionMode.MULTIPLE);
// tell cell factory to use the selected property for checkbox
filePathTree.setCellFactory(FileItemCheckBoxTreeCell.forTreeView(new StringConverter<TreeItem<Path>>() {
@Override
public String toString(TreeItem<Path> object) {
if (object == null) {
return "";
}
Path p = object.getValue();
if (p == null) {
return "";
}
p = p.getFileName();
return p == null ? object.getValue().toString() : p.toString();
}
@Override
public TreeItem<Path> fromString(String string) {
throw new UnsupportedOperationException();
}
}));
filePathTree.setShowRoot(false);
}
return filePathTree;
}
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