How to force TableRow repaint - javafx

Question

How to force TableRow repaint ?.
Imagine the following scenario: The tableView is updated every 180 milliseconds, but the cell that receives the TableRow style information is not visible, and every time it is upgraded TableRow needs to be repainted. When I use refresh() method, it does not look good, especially with the mouse positioning on the TableView, it blinks and in this case consuming cpu.
myTableView.setRowFactory( new Callback<TableView, TableRow<Line>>() {
#Override
public TableRow call(final TableView p) {
return new TableRow<Line>() {
#Override
public void updateItem(Line item, boolean empty) {
super.updateItem(item, empty);
if(item != null) {
if(item.statusProperty().getValue().equals("BORDER")) {
setStyle("-fx-border-color:green;-fx-border-width:2;-fx-opacity:1;");
}
}
}
};
}
});

Answer 1

Since the style depends on the statusProperty() of the Line, which is observable, you can use a binding:
#Override
public void updateItem(Line item, boolean empty) {
super.updateItem(item, empty);
if(item != null) {
styleProperty().bind(Bindings
.when(item.statusProperty().isEqualTo("BORDER"))
.then("-fx-border-color:green;-fx-border-width:2;-fx-opacity:1;")
.otherwise(""));
} else {
styleProperty().unbind();
setStyle("");
}
}
An alternative way to create the binding, which is probably more convenient if the logic is more complicated, is
#Override
public void updateItem(Line item, boolean empty) {
super.updateItem(item, empty);
if(item != null) {
styleProperty().bind(Bindings.createStringBinding(() -> {
if ("BORDER".equals(item.getStyle())) {
return "-fx-border-color:green;-fx-border-width:2;-fx-opacity:1;" ;
} else {
return "" ;
}
}, item.statusProperty());
} else {
styleProperty().unbind();
setStyle("");
}
}
This way the table row will observe the current item's status property, and automatically update the style if that property changes.
If you really want to make the code cleaner, of course, you should move the styles to an external CSS file. You can create a CSS PseudoClass (or more than one) which you can set and unset on the row:
final PseudoClass borderPC = PseudoClass.getPseudoClass("border");
myTableView.setRowFactory(p -> {
TableRow<Line> row = new TableRow<>();
ChangeListener<String> statusListener = (obs, oldStatus, newStatus) ->
row.pseudoClassStateChanged(borderPC, "BORDER".equals(newStatus)) ;
row.itemProperty().addListener((obs, oldLine, newLine) -> {
if (oldLine != null) {
oldLine.statusProperty().removeListener(statusListener);
}
if (newLine == null) {
row.pseudoClassStateChanged(borderPC, false);
} else {
newLine.statusProperty().addListener(statusListener);
row.pseudoClassStateChanged(borderPC, "BORDER".equals(newLine.getStatus()));
}
};
return row ;
});
Then in your external CSS file, do
.table-row-cell:border {
-fx-border-color:green;
-fx-border-width:2;
-fx-opacity:1;
}
Again, you can easily add more psuedoclasses, more rules to the CSS, and additional tests and pseudoclass updates using this approach.