Java FX Delete TreeView root item - javafx

In my app I need to be able to remove every item from TreeView.
I have my TreeView injected i controller
private #FXML TreeView<Component> treeView;
My deletion code:
private void deleteSelectedNode() {
TreeItem<Component> node = treeView.getSelectionModel().getSelectedItem();
if (node == null) {
return;
}
TreeItem<Component> parent = node.getParent();
if (parent != null) {
parent.getChildren().remove(node);
} else {
//how to delete root item without parent?
}
}
Actual question is: how to remove root element? I could not find any method in api and I don't want to create new instance, I prefer dependency injection solution.
I think I can hide this item untill next node is created, but it seems to be little hacky.
Thank you for your time spent in this topic!

treeView.setRoot(null);
should work.

Related

JavaFX - using setRowFactory to highlight new rows

I am writing a JavaFX app where a series of messages appear in a TableView. When a new message appears, its row in the table should be highlighted, meaning its background color should be orange or something. Once the user clicks it, the background color should clear, acknowledging the message was read. Should be simple.
I've done enough research to realize that I need to use a rowFactory to set or clear a row's background. But I'm struggling with the mechanics of setRowFactory(). The documentation on Oracle is over my head, and every example I pull up online seems radically different than the last one.
Here's what I have:
public class Message {
private boolean readOnce;
private int date;
private String msg;
public Message(int date, String msg, String msg2){
this.readOnce = false;
this.date = date;
this.msg = msg;
}
public boolean isReadOnce() {
return readOnce;
}
public void setReadOnce(){
readOnce = true;
}
// ...and more standard getters & setters here...
}
The TableView is set up in the main controller:
#FXML TableView<Message> messageTable;
#FXML TableColumn<Message, Integer> Col1;
#FXML TableColumn<Message, String> Col2;
ObservableList<Message> tableItems;
// ...
// Setting up the Table:
PropertyValueFactory<Message, Integer> dateProperty = new PropertyValueFactory<Message, Integer>("date");
PropertyValueFactory<Message, String> msgProperty = new PropertyValueFactory<Message, String>("msg");
Col1.setCellValueFactory( dateProperty );
Col2.setCellValueFactory( msgProperty );
messageTable.setItems( tableItems );
// If we click an item in the table: messageTable.getSelectionModel().selectedItemProperty().addListener((obs, oldSelection, newSelection) -> {
if (newSelection != null) {
System.out.println("Troubleshoot: You clicked: "+newSelection.getMsg());
newSelection.setReadOnce(true);
}
});
And if I want to add a new message to the table, I just add it into the observable list:
public void addMsg(int num, String msg){
tableItems.add(new Message(num, msg));
}
So far, pretty easy. But I'm all thumbs when it comes to the rowFactory:
messageTable.setRowFactory(messageTable -> {
TableRow<Message> row = new TableRow<>();
ObjectProperty<Message> opMsg = row.itemProperty();
Message tmpMsg = opMsg.get();
if(!tmpMsg.isReadOnce()){
row.getStyleClass().add("highlight-message"); // defined in CSS
} else {
row.getStyleClass().add("clear-message"); // defined in CSS
}
return row;
});
To be very honest, I have no idea what I'm doing here. I understand that the rowFactory takes in the entire table and regenerates each row one-by-one. What I don't understand is how does the RowFactory code examine each Message in the table and how can I access them? Originally I thought these line might allow me to see the Message within the row:
TableRow<Message> row = new TableRow<>();
ObjectProperty<Message> opMsg = row.itemProperty();
Message tmpMsg = opMsg.get();
But when I debug the code, tmpMsg == NULL. So that's a big fat dead end.
Anyone see what I'm doing wrong? I've been researching this for about a week, getting absolutely no-where. Any help anyone can offer is wildly appreciated.
Many thanks,
-RAO
TableRows are created by TableView to fill it's viewport and contain TableCells. At the time they are created the item property still contains the default value null. You could register a listener to that property but usually I prefer overriding the updateItem method of a cell.
Also using PseudoClass is simpler than using style classes. New items can be assigned to a row; this could result in the same style class being added multiple times and even both style classes could be added to the same cell. PseudoClasses however can be switched on/of without the need to take care of removing other classes.
final PseudoClass highlightMessage = PseudoClass.getPseudoClass("highlight-message");
messageTable.setRowFactory(messageTable -> new TableRow<Message>() {
{
selectedProperty().addListener((o, oldVal, newVal) -> {
if (newVal) {
Message item = getItem();
if (item != null) {
item.setReadOnce();
pseudoClassStateChanged(highlightMessage, false);
}
}
});
}
#Override
protected void updateItem(Message item, boolean empty) {
super.updateItem(item, empty);
pseudoClassStateChanged(highlightMessage, item != null && !item.isReadOnce());
}
});
In a CSS stylesheet you could use rules like this:
.table-row-cell:filled {
/* style for non-highlighted rows */
}
.table-row-cell:filled:highlight-message {
/* style for highlighted rows */
}
Note that this does not allow you to programmatically alter the read state. It updates the state on selecting a cell. You could add a BooleanProperty to Message or use a ObservableSet to store the highlighted messages and update the state of cells from a listener if you need to programmatically update the readOnce property. In the latter case you do not need to store a readOnce property in the Message itself...

Javafx : ComboBoxTableCell - how to select a value in one click?

I have a TableView with a ComboBoxTableCell, when using the default implementation the user have to click three times to select a value from of the ComboBox's list.
I want when the user clicks on the cell to show the combo box list. I based my solution on this one:
JavaFX editable ComboBox in a table view
The cell does get into edit mode (startEdit() is called) but it takes another click to show the list of values, what am I missing?
table.addEventHandler(MouseEvent.MOUSE_CLICKED, (e) ->
{
if (table.getEditingCell() == null)
{
TablePosition focusedCellPos = table.getFocusModel().getFocusedCell();
table.edit(focusedCellPos.getRow(), focusedCellPos.getTableColumn());
}
});
Thanks.
Interesting problem - bubbling up again after quite a while :)
Looks like the approach of the OP is indeed working (as of fx11, some bugs around its editing seem to be fixed) - with a little help from the combo cell:
start editing in a single click handler on the tableView (from OP)
extend ComboBoxTableCell and override its startEdit to open the dropDown
Code snippet:
// set editable to see the combo
table.setEditable(true);
// keep approach by OP
table.addEventHandler(MouseEvent.MOUSE_CLICKED, (e) -> {
TablePosition<Person, ?> focusedCellPos = table.getFocusModel()
.getFocusedCell();
if (table.getEditingCell() == null) {
table.edit(focusedCellPos.getRow(),
focusedCellPos.getTableColumn());
}
});
// use modified standard combo cell shows its popup on startEdit
firstName.setCellFactory(cb -> new ComboBoxTableCell<>(firstNames) {
#Override
public void startEdit() {
super.startEdit();
if (isEditing() && getGraphic() instanceof ComboBox) {
// needs focus for proper working of esc/enter
getGraphic().requestFocus();
((ComboBox<?>) getGraphic()).show();
}
}
});
Maybe not the cleanest solution to this problem, but I found a workaround to make the ComboBoxTableCells drop down its menu in just 1 click:
column.setCellFactory(new Callback<TableColumn<Person, String>, TableCell<Person, String>>() {
#Override
public TableCell<Person, String> call(TableColumn<Person, String> column) {
ComboBoxTableCell cbtCell = new ComboBoxTableCell<>(cbValues);
cbtCell.setOnMouseEntered(new EventHandler<Event>() {
#Override
public void handle(Event event) {
// Without a Person object, a combobox shouldn't open in that row
if (((Person)((TableRow)cbtCell.getParent()).getItem()) != null) {
Robot r = new Robot();
r.mouseClick(MouseButton.PRIMARY);
r.mouseClick(MouseButton.PRIMARY);
}
}
});
return cbtCell;
}
});
PS: I know that this topic is a bit old, but I also stumbled upon this problem recently and could not find any working solution to it online. As I sad, it's not the cleanest workaround, but at least it does its job. ;)

javafx CheckBoxTreeItem update parents programmatically

I have to retrieve some data from my database to dynamically create a TreeView and select some CheckBoxTreeItems from this TreeView. This TreeView represents permissions to a menu structure.
My doubt is when I create the TreeView and select specific items from the Tree according to the user's permissions programmatically, the parents items don't have any status change (selected or indeterminate). But when I select any item directly from the interface, the parents get updated.
For example, here I have my screen when I select the items programmatically:
You can see that I have two menu items selected, but the parents aren't.
On this image, I have selected the same menu items using the screen, and the parents were updated with indeterminate status or selected if I select all children inside the submenu.
I have gone through the documentation, google and here on Stack Overflow, but only found examples to update the children.
Is there a way to update the parents programmatically or to call the event executed from the screen when an item is selected?
EDIT:
All items from the Tree have the independent property set to false.
I came with a workaround for this problem.
I had to first create all the TreeView structure, and change the selected property after using this code snippet:
Platform.runLater(new Runnable() {
#Override
public void run() {
selectItems();
}
});
Here is the code to verify the TreeItems:
private void selectItems(){
TreeItem root = tree.getRoot();
if (root != null) {
selectChildren(root);
}
}
private void selectChildren(TreeItem<TesteVO> root){
for(TreeItem<TesteVO> child: root.getChildren()){
// HERE I CHECK IF THE USER HAS PERMISSION FOR THE MENU ITEM
// IF SO, I CHANGE THE SELECTED PROPERTY TO TRUE
if (child.getValue().id == 4) {
((CheckBoxTreeItem) child).setSelected(true);
}
// IF THERE ARE CHILD NODES, KEEP DIGGING RECURSIVELY
if(!child.getChildren().isEmpty()) {
selectChildren(child);
}
}
}
If there is a simpler way, please let me know!
This is not the case. Parent items do get automatically get set to the indeterminate state when you select a child item. I'm not sure if this is something that got corrected from the time that this question was posted, probably not.
My guess is that there's a programming bug in how the node was selected or how the TableView was constructed and initialized.
Here's some code that shows what I'm doing, and it works! In my case, I'm using a CheckBoxTreeItem<File> for the TreeItem.
How the treeview was created
treeView = new TreeView(root);
treeView.getSelectionModel().selectedItemProperty().addListener(new ChangeListener() {
#Override
public void changed(ObservableValue observableValue, Object o, Object t1) {
CheckBoxTreeItem<File> node = (CheckBoxTreeItem<File>)t1;
if (node.getValue() != currentFile) {
setFileDetail(node);
showChildren(node);
}
}
});
treeView.setCellFactory(new CallBackWrapper());
treeView.setShowRoot(false);
Below show the CallBackWrapper class.
private class CallBackWrapper implements Callback<TreeView<File>, TreeCell<File>> {
Callback<TreeView<File>, TreeCell<File>> theCallback;
private CallBackWrapper() {
theCallback = CheckBoxTreeCell.<File>forTreeView(getSelectedProperty, converter);
}
#Override
public TreeCell<File> call(TreeView<File> fileTreeView) {
return theCallback.call(fileTreeView);
}
final Callback<TreeItem<File>, ObservableValue<Boolean>> getSelectedProperty = (TreeItem<File> item) -> {
if (item instanceof CheckBoxTreeItem<?>) {
return ((CheckBoxTreeItem<?>) item).selectedProperty();
}
return null;
};
final StringConverter<TreeItem<File>> converter = new StringConverter<TreeItem<File>>() {
#Override
public String toString(TreeItem<File> object) {
File item = object.getValue();
return fileSystemView.getSystemDisplayName(item);
}
#Override
public TreeItem<File> fromString(String string) {
return new TreeItem<File>(new File(string));
}
};
}
And lastly here some code that the selection was made in:
boolean selectNode(CheckBoxTreeItem<File> parentNode, String name) {
Object[] children = parentNode.getChildren().toArray();
for (Object child : children) {
CheckBoxTreeItem<File> childItem = (CheckBoxTreeItem<File>) child;
if (name.equals(childItem.getValue().getName())) {
childItem.setSelected(true);
//treeView.getSelectionModel().select(child); <-- this does not work!
return true;
}
}
return false;
}

How to access GUI elements in a dynamic user interface

I am trying to develop a dynamic user interface. When the user clicks at a certain indicator a graph of it is instantiated together with some manipulation buttons. See the image for an example. The graph is created in an HBox, together with the buttons and next added to a VBox. The problem I cannot solve is: when a button is clicked, how can I access the corresponding element?
The problem simply boils down to this:
Button buttonRemove = new Button ();
buttonRemove.setMinWidth (80);
buttonRemove.setText ("Remove");
buttonMap.getProperties ().put ("--IndicatorRemoveButton", indicator.getName ());
buttonRemove.setOnAction (e -> buttonRemoveClick ());
private Object buttonRemoveClick ()
{
// Which button clicked me??
return null;
} /*** buttonRemoveClick ***/
Any help will be greatly appreciated. I'm kind of stuck with this.
.
It's possible to pass a parameter to the buttonRemoveClick method in the lambda, as long as it's effectively final or a parameter.
private void buttonRemoveClick (HBox group) {...}
buttonRemove.setOnAction (e -> buttonRemoveClick (theGroup));
In this case you could also pass the ActionEvent and get the source to retrieve the Button; this may not be enough to remove the element, but for this you could traverse to the parent until you reach a child of the HBox
private void buttonRemoveClick (ActionEvent event) {
Node currentNode = (Node) event.getSource(); // this is the button
// traverse to HBox of container
Node p;
while ((p = currentNode.getParent()) != containerVBox) {
currentNode = p;
}
// remove part including the Button from container
containerVBox.getChildren().remove(currentNode);
}
buttonRemove.setOnAction (this::buttonRemoveClick);

.NET 4.0 DataGridCombobox SelectionChanged issue

I have a requirement in my program that the object bound (from ViewModel) in a Combobox is updated as soon as an item is selected in the combobox. Currently, the object only updates once the edit is committed by either pressing Enter or leaving the cell. The user does not want the extra step.
My thought would be to have the act of selecting an item in the combobox trigger the CommitEdit() method and then CancelEdit(). However, I cannot seem to find a way to hook into the SelectionChanged event for the DataGridComboBoxColumn as it is not available.
Other suggestions have been to listen in the viewmodel for a property change event but the property is not changed until the Cell Edit is finished.
Can anyone think of a way to cause the selection of a new item (index) in a DataGridCombobox to close the edit of the cell as if the user pressed Enter or left the cell?
NOTE: I cannot use .NET 4.5 due to customer limitations.
I've had similar issue but i just found out the solution using attached property, This may not exactly fix your problem but it will help in datagrid selection changed issue.
Below is the attached property and handler methods
public static readonly DependencyProperty ComboBoxSelectionChangedProperty = DependencyProperty.RegisterAttached("ComboBoxSelectionChangedCommand",
typeof(ICommand),
typeof(SpDataGrid),
new PropertyMetadata(new PropertyChangedCallback(AttachOrRemoveDataGridEvent)));
public static void AttachOrRemoveDataGridEvent(DependencyObject obj, DependencyPropertyChangedEventArgs args)
{
DataGrid dataGrid = obj as DataGrid;
if (dataGrid != null)
{
if (args.Property == ComboBoxSelectionChangedProperty)
{
dataGrid.SelectionChanged += OnComboBoxSelectionChanged;
}
}
else if (args.OldValue != null && args.NewValue == null)
{ if (args.Property == ComboBoxSelectionChangedProperty)
{
dataGrid.SelectionChanged -= OnComboBoxSelectionChanged;
}
}
}
private static void OnComboBoxSelectionChanged(object sender, SelectionChangedEventArgs args)
{
DependencyObject obj = sender as DependencyObject;
ICommand cmd = (ICommand)obj.GetValue(ComboBoxSelectionChangedProperty);
DataGrid grid = sender as DataGrid;
if (args.OriginalSource is ComboBox)
{
if (grid.CurrentCell.Item != DependencyProperty.UnsetValue)
{
//grid.CommitEdit(DataGridEditingUnit.Row, true);
ExecuteCommand(cmd, grid.CurrentCell.Item);
}
}
}
SpDataGrid is the custom control that i inherited from data grid.
I added below style in generic.xaml as i use the resourcedictionary for style (you can certainly add inside the datagrid).
<Style TargetType="{x:Type Custom:SpDataGrid}">
<Setter Property="Custom:SpDataGrid.ComboBoxSelectionChangedCommand" Value="{Binding ComboBoxSelectionChanged}"/>
</Style>
ComboBoxSelectionChanged is the command in my viewmodel. OnComboBoxSelectionChanged i commented the commitedit because in my case the values were already updated.
Let me know if anything is not clear or any questions. Hope this helps.

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