Accessing the Value of a CheckBox in TableView - javafx

I'm having trouble getting the boolean value of whether a checkbox in a tableView for JavaFX is selected or not.
(Link to Image)
https://i.imgur.com/pIWDcfI.png
For some reason the when I getCellObservableValue() to get the CheckBox at index 1, I get null as the result.
//From SceneBuilder/JavaFX file
<TableColumn fx:id="labelColumn" prefWidth="112.57145690917969" text="Use
as Label" />
//Setting Up Table, which displays everything correctly
TableColumn<Integer,CheckBox> labelColumn = (TableColumn<Integer,
CheckBox>) elements.get("labelColumn");
labelColumn.setCellFactory(data -> new CheckBoxTableCell<>());
monitorTable.setEditable(true);
//Trying to Access, which gives null pointer exception
CheckBox cb = (CheckBox) labelColumn.getCellObservableValue(1);
System.out.println(cb.isSelected());

That method returns null if there's no cellValueFactory set. Besides, you should really have a model to hold this stateā€”a TableView is just a view. Unlike the TableViewSelectionModel, which represents which items are selected solely in the context of the TableView itself, a column containing CheckBoxes represents the "boolean state" of a property of the model. For example:
public class ToDoTask {
private final StringProperty name = new SimpleStringProperty(this, "name");
private final BooleanProperty complete = new SimpleBooleanProperty(this, "complete");
// constructors, getters, setters, and property-getters omitted for brevity
}
A TableView for displaying that class could be configured like the following:
TableView<ToDoTask> table = new TableView<>();
table.setItems(...);
TableColumn<ToDoTask, String> nameCol = new TableColumn<>("Name");
nameCol.setCellValueFactory(features -> features.getValue().nameProperty());
table.getColumns().add(nameCol);
TableColumn<ToDoTask, Boolean> completeCol = new TableColumn<>("Complete");
completeCol.setCellValueFactory(features -> features.getValue().completeProperty());
completeCol.setCellFactory(CheckBoxTableCell.forTableColumn(completeCol));
table.getColumns().add(completeCol);
You would then query if a task is complete by accessing the model:
table.getItems().get(...).isComplete();
Another option to setting the cellValueFactory is to register a Callback with the CheckBoxTableCells themselves. See CheckBoxTableCell#forTableColumn(Callback).
Also, note that getCellObservableValue() returns an ObservableValue. A CheckBox is not an ObservableValue. If you weren't receiving null you'd be getting a ClassCastException.

Related

How to get the column title and first column row value for a cell in javafx

I have JavaFX tableview that I have created dynamically. When one double-clicks on a cell on the tableview, I need to get the name of the column the cell is in and the value of the first cell in the row this cell is in. I have tried searching over google and found no particular solution to this problem. Kindly show me some sample code.
Ok, so first, let's assume your TableView is attached to a model:
public TableView<MyModel> myTable;
where MyModel is something like:
public class MyModel {
private Integer id;
private String name;
// ... etc.
}
so, MyModel is a common POJO. You can have columns of your TableView like:
TableColumn<MyModel, Integer> id = new TableColumn<>("ID");
id.setCellValueFactory(new PropertyValueFactory<>("id"));
TableColumn<MyModel, String> name = new TableColumn<>("Name");
name.setCellValueFactory(new PropertyValueFactory<>("name"));
and then, to add the columns to your table:
myTable.getColumns().addAll(id, name);
Now, let's listen to the click event using a rowFactory:
myTable.setRowFactory(tv -> {
TableRow<MyModel> row = new TableRow<>();
row.setOnMouseClicked(event -> {
// check for non-empty rows, double-click with the primary button of the mouse
if (!row.isEmpty() && event.getClickCount() == 2 && event.getButton() == MouseButton.PRIMARY) {
MyModel element = row.getItem();
// now you can do whatever you want with the myModel variable.
System.out.println(element);
}
});
return row ;
});
That should do the work.

Javafx TableView not showing data

I used ObservableList to populate the TableView but the problem is that the data is not showing in the table I don't know what is the problem because the number of rows is exactly like I added them capture but there is nothing in the cells!
here is the code of the controller:
public class EnlistDim {
private static final String DEFAULT="-fx-text-background-color: black; -fx-background-color: steelblue;-fx-fill: red ;";
#FXML
private TableView<Parameter> tab;
#FXML
public void initialize() {
final ObservableList<Parameter> data = FXCollections.observableArrayList(
new Parameter("Query","Access method","Sequential scan"),
new Parameter("Query","Access method","in memory"),
new Parameter("Query","Operation","join"),
new Parameter("Query","Operation","Scan"),
new Parameter("Query","Operation","Sort"),
new Parameter("Database","Buffer management","Without buffer"),
new Parameter("Database","Buffer management","FIFO"),
new Parameter("Database","Buffer management","LIFO"),
new Parameter("Database","Buffer management","LRU"),
new Parameter("Database","Buffer management","Other"),
new Parameter("Database","Optimization structure","Not used"),
new Parameter("Database","Optimization structure","Partionning"),
new Parameter("Database","Optimization structure","Materialized View"),
new Parameter("Database","Optimization structure","compresssion"),
new Parameter("Database","System storage type","Database SQL"),
new Parameter("Database","System storage type","New SQL"),
new Parameter("Database","System storage type","Document"),
new Parameter("Database","System storage type","Graph"),
new Parameter("Database","System storage type","NVRAM"),
new Parameter("Database","System storage type","key value store"),
new Parameter("Database","Data storage type","Row Oriented"),
new Parameter("Database","Data storage type","Column Oriented"),
new Parameter("Database","Data storage type","Hybrid Oriented"),
new Parameter("Hardware","Processing device","CPU"),
new Parameter("Hardware","Processing device","GPU"),
new Parameter("Hardware","Processing device","FPGA"),
new Parameter("Hardware","Storage device","RAM"),
new Parameter("Hardware","Storage device","SSD"),
new Parameter("Hardware","Storage device","NVRAM"),
new Parameter("Hardware","Communication device","Modem"),
new Parameter("Hardware","Communication device","Cable"),
new Parameter("Hardware","Communication device","FaxModem"),
new Parameter("Hardware","Communication device","Router")
);
tab.setEditable(true);
tab.setItems(data);
tab.setStyle(DEFAULT);
}
}
and the code of Parameter class:
class Parameter {
SimpleStringProperty cat;
SimpleStringProperty subCat;
SimpleStringProperty subSubCat;
Parameter(String cat, String subCat, String subSubCat) {
this.cat = new SimpleStringProperty(cat);
this.subCat = new SimpleStringProperty(subCat);
this.subSubCat = new SimpleStringProperty(subSubCat);
}
public String getCat() {
return cat.get();
}
public void setCat(String c) {
cat.set(c);
}
public String getSubCat() {
return subCat.get();
}
public void setSubCat(String sc) {
subCat.set(sc);
}
public String getSubSubCat() {
return subSubCat.get();
}
public void setSubSubCat(String ssc) {
subSubCat.set(ssc);
}
}
You need to actually tell the TableView HOW to display the data. This is done using a CellValueFactory. Basically, you need to tell each column of the table what type of data it holds and where it gets that data from.
You need to start by defining your columns (give them an fx:id either in the FXML file or in SceneBuilder):
#FXML
TableColumn<Parameter, String> colCategory;
#FXML
TableColumn<Parameter, String> colSubCategory;
#FXML
TableColumn<Parameter, String> colSubSubCategory;
Each TableColumn takes two Type parameters. The first defines the object being displayed (Parameter). The second is the data type for this column (all yours are String).
Once the columns are defined, you need to set their CellValueFactory in your initialize() method:
colCategory.setCellValueFactory(new PropertyValueFactory<Parameter, String>("cat"));
colSubCategory.setCellValueFactory(new PropertyValueFactory<Parameter, String>("subCat"));
colSubSubCategory.setCellValueFactory(new PropertyValueFactory<Parameter, String>("subSubCat"));
Here you are telling each column where to find the data to be displayed. The last argument on the line, in the quotes, is the name of your property within the Parameter object.
So, when JavaFX populates your table, it will takes these steps to populate each column (colCategory, for example):
Get the CellValueFactory for colCategory.
The factory is a PropertyValueFactory, so determine which class holds the property (in this case it is the Parameter class)
Look in the Parameter class for a String property by the name of "cat"
Populate the column's cell with the value of the cat property.

Dynamically Adding context menu items to tableview columns

I have the following controller that is instantiated many times on my gui. The reason is beacause it has a tableview that gets filled with different kind of data. Looks like this
class Controller {
#FXML
TableView<Map<String, String> myTable;
private Manager manager;
//Each TableView has different ammount of columns with different names that get dynamically added to the table view using this function
public void setUpColumns(List<TableColumn<Map<String, String>, String>> columns){
myTable.getColumns().addAll(columns);
addContextMenuToColumnHeaders();
}
private addContextMenuToColumnHeaders(){
for (TableColumn<Map<String, String>, ?> tc : myTable.getColumns()){
ContextMenu addToGraphContextMenu = createAddToGraphContextMenu(tc);
tc.setContextMenu(addToGraphContextMenu);
}
}
private ContextMenu createAddToGraphContextMenu(TableColumn<Map<String, String> String> tc){
for (MangerHandledObject mHO : manager.getHandledObjects()){
MenuItem menuItem = new MenuItem(mHO.getName());
menuItem.setOnAction(new EventHandler<ActionEvent>(){
#Override
public void handle(ActionEvent event){
//I want each menu item to have access to the column that is added to get the name of the column. Even after dynamically adding new menuItems
manager.callMethod(tc.getName());
}
});
}
}
}
The manager handled objects are not static. So the are added and deleted from the list that the manager keeps. I tried this
contextMenu.setOnShowing(......)
and before showing it will always check for the list from the manager and re-make the context menu items. But the problems is that when this executes I don't have access to the columns anymore. Is there any way to bypass this? Should I implement my own context menu to have a field of the column Name?
It worked. But I had to add at least one dummy MenuItem on my context menu in order for it to appear.

How to import database data into combo box in javafx

Using this code I Initialized Combo box
#FXML
private ComboBox category;
And get value using:
String Category = category.getValue().toString();
And inserted value to mysql database.
Now before inserting next value in category Combo box I need to import the values in the database to the drop down in Combo Box and value should be displayed in the combo box.
I recommend to read the values from the database and save it into a ObservableList, once you get all the values you can fill the combobox with:
combobox.setItems(myObservableList);
if your type of combobox is not "String" you should use a String converter, for example, if you wanna fill the combobox with the name of users, being "user" a class and name an attribute, you just have to:
myCombo.setConverter(new StringConverter<user>() {
#Override
public String toString(user object) {
return object.getName();
}
#Override
public user fromString(String string) {
// TODO Auto-generated method stub
return null;
}
});

JavaFX 8 update TableView after new Data added

My TableView is not updating, do i need a listener ?
(m is my Model)
#FXML
private TableView<Mitarbeiter> mitarbeiter;
ObservableList<Mitarbeiter> data =
FXCollections.observableArrayList(m.getMitarbeiterListe()
);
mitarbeiter.setItems(data);
public ArrayList getMitarbeiterListe(){
return mitarbeiterliste;
}
In a new Stage i add some Mitarbeiter to the List in my Model
m.addMitarbeiterToList(mitarbeiter)
public void addMitarbeiterToList(Mitarbeiter mitarbeiter){
mitarbeiterliste.add(mitarbeiter);
}
But the TableView in the other Stage is not updating the new data.
In the end, is the ObservableList not pointed to the ArrayList from the Model ?
Instead of adding items to mitarbeiterliste (which is an ArrayList, and is not observable), add them to data, which is the ObservableList holding the items for the table. The TableView observes this list and automatically updates the view when the list contents changes.
The context of your code snippets is not very clear, but you would do something like
public ArrayList getMitarbeiterListe(){
return data;
}
or instead of
mitarbeiterliste.add(mitarbeiter);
do
data.add(mitarbeiter);

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