RadioButtons are a part of JavaFx package. RadioButtons are mainly used to create a series of items where only one can be selected. When a Radio button is pressed and released an Action event is sent, this Action Event can be handled using an Event Handler.
RadioButton can be added to Toggle Group so that the user cannot select more than one item . By default a radio button is not a part of any toggle group. The selected item of a toggle group can be found using getSelectedToggle() function.
Constructors of the RadioButton class:
- RadioButton():Creates a radio button with an empty string for its label.
- RadioButton(String t):Creates a radio button with the specified text as its label
Commonly used methods:
method | explanation |
---|---|
getText() | returns the textLabel for radio button |
isSelected() | returns whether the radiobutton is selected or not |
setSelected(boolean b) | sets whether the radiobutton is selected or not |
setToggleGroup(ToggleGroup tg) | sets the toggle group for the radio button |
fire() | Toggles the state of the radio button if and only if the RadioButton has not already selected or is not part of a ToggleGroup. |
Below programs illustrate the RadioButton class:
- Program to create RadioButton and add it to the stage: This program creates a RadioButton indicated by the name r1, r2, r3. The radio button will be created inside a scene, which in turn will be hosted inside a stage (which is the top level JavaFX container). The function setTitle() is used to provide title to the stage. Then a tile-pane is created, on which addChildren() method is called to attach the radio button inside the scene, along with the resolution specified by (200, 200) in the code. Finally, the show() method is called to display the final results.
// Java program to create RadioButton and add it to the stage
import
javafx.application.Application;
import
javafx.scene.Scene;
import
javafx.scene.control.*;
import
javafx.scene.layout.*;
import
javafx.event.ActionEvent;
import
javafx.event.EventHandler;
import
javafx.collections.*;
import
javafx.stage.Stage;
import
javafx.scene.text.Text.*;
import
javafx.scene.text.*;
public
class
radiobutton
extends
Application {
// launch the application
public
void
start(Stage s)
{
// set title for the stage
s.setTitle(
"creating RadioButton"
);
// create a tile pane
TilePane r =
new
TilePane();
// create a label
Label l =
new
Label(
"This is a Radiobutton example "
);
// create radiobuttons
RadioButton r1 =
new
RadioButton(
"male"
);
RadioButton r2 =
new
RadioButton(
"female"
);
RadioButton r3 =
new
RadioButton(
"others"
);
// add label
r.getChildren().add(l);
r.getChildren().add(r1);
r.getChildren().add(r2);
r.getChildren().add(r3);
// create a scene
Scene sc =
new
Scene(r,
200
,
200
);
// set the scene
s.setScene(sc);
s.show();
}
public
static
void
main(String args[])
{
// launch the application
launch(args);
}
}
Output:
- Program to create RadioButton and add it to a ToggleGroup: This program creates a RadioButton indicated by the name r1, r2, r3. The radio button will be created inside a scene, which in turn will be hosted inside a stage (which is the top level JavaFX container). The function setTitle() is used to provide title to the stage. A toggle group is created and the radio buttons are added to the toggle group using setToggleGroup() function. Then a tile-pane is created, on which addChildren() method is called to attach the radio button inside the scene, along with the resolution specified by (200, 200) in the code. Finally, the show() method is called to display the final results.
// Java Program to create RadioButton and add it to a ToggleGroup
import
javafx.application.Application;
import
javafx.scene.Scene;
import
javafx.scene.control.*;
import
javafx.scene.layout.*;
import
javafx.event.ActionEvent;
import
javafx.event.EventHandler;
import
javafx.collections.*;
import
javafx.stage.Stage;
import
javafx.scene.text.Text.*;
import
javafx.scene.text.*;
public
class
radiobutton_1
extends
Application {
// labels
Label l;
// launch the application
public
void
start(Stage s)
{
// set title for the stage
s.setTitle(
"creating RadioButton"
);
// create a tile pane
TilePane r =
new
TilePane();
// create a label
l =
new
Label(
"This is a Radiobutton example "
);
// create a toggle group
ToggleGroup tg =
new
ToggleGroup();
// create radiobuttons
RadioButton r1 =
new
RadioButton(
"male"
);
RadioButton r2 =
new
RadioButton(
"female"
);
RadioButton r3 =
new
RadioButton(
"others"
);
// add radiobuttons to toggle group
r1.setToggleGroup(tg);
r2.setToggleGroup(tg);
r3.setToggleGroup(tg);
// add label
r.getChildren().add(l);
r.getChildren().add(r1);
r.getChildren().add(r2);
r.getChildren().add(r3);
// create a scene
Scene sc =
new
Scene(r,
200
,
200
);
// set the scene
s.setScene(sc);
s.show();
}
public
static
void
main(String args[])
{
// launch the application
launch(args);
}
}
Output:
- Program to create RadioButton, add it to a ToggleGroup and add a listener to it: This program creates a RadioButton indicated by the name r1, r2, r3. The radio button will be created inside a scene, which in turn will be hosted inside a stage (which is the top level JavaFX container). The function setTitle() is used to provide title to the stage. A toggle group is created and the radio buttons are added to the toggle group using setToggleGroup() function. A label l2 is created to show which radio button is selected. A change listener is added to handle any change in the selection of the radio buttons (using the addListener() function). The change in selection is depicted by changing the text of label l2. Then a tile-pane is created, on which addChildren() method is called to attach the radio button inside the scene, along with the resolution specified by (200, 200) in the code. Finally, the show() method is called to display the final results.
// Java Program to create RadioButton, add it to a ToggleGroup and add a listener to it
import
javafx.application.Application;
import
javafx.scene.Scene;
import
javafx.scene.control.*;
import
javafx.scene.layout.*;
import
javafx.event.ActionEvent;
import
javafx.event.*;
import
javafx.collections.*;
import
javafx.stage.Stage;
import
javafx.scene.text.Text.*;
import
javafx.scene.text.*;
import
javafx.beans.value.*;
public
class
radiobutton_2
extends
Application {
// launch the application
public
void
start(Stage s)
{
// set title for the stage
s.setTitle(
"creating RadioButton"
);
// create a tile pane
TilePane r =
new
TilePane();
// create a label
Label l =
new
Label(
"This is a Radiobutton example "
);
Label l2 =
new
Label(
"nothing selected"
);
// create a toggle group
ToggleGroup tg =
new
ToggleGroup();
// create radiobuttons
RadioButton r1 =
new
RadioButton(
"male"
);
RadioButton r2 =
new
RadioButton(
"female"
);
RadioButton r3 =
new
RadioButton(
"others"
);
// add radiobuttons to toggle group
r1.setToggleGroup(tg);
r2.setToggleGroup(tg);
r3.setToggleGroup(tg);
// add label
r.getChildren().add(l);
r.getChildren().add(r1);
r.getChildren().add(r2);
r.getChildren().add(r3);
r.getChildren().add(l2);
// create a scene
Scene sc =
new
Scene(r,
200
,
200
);
// add a change listener
tg.selectedToggleProperty().addListener(
new
ChangeListener<Toggle>()
{
public
void
changed(ObservableValue<?
extends
Toggle> ob,
Toggle o, Toggle n)
{
RadioButton rb = (RadioButton)tg.getSelectedToggle();
if
(rb !=
null
) {
String s = rb.getText();
// change the label
l2.setText(s +
" selected"
);
}
}
});
// set the scene
s.setScene(sc);
s.show();
}
public
static
void
main(String args[])
{
// launch the application
launch(args);
}
}
Output:
Note: The above programs will not run in an online IDE please use an offline compiler
Reference: https://docs.oracle.com/javase/8/javafx/api/javafx/scene/control/RadioButton.html