I would like to have a window that shows an image. That is the main purpose of the window. However it should be possible to also have controls on the top. The number is not known beforehand. Could be 3 or 15. They should just pile up there for now. So the upper part grows and the image below is just being pushed down.
void createNewWindow() {
Stage stage = new Stage();
BorderPane pane = new BorderPane();
ImageView imageView = new ImageView("path");
pane.setCenter(imageView);
HBox controlBox = new HBox(10);
pane.setTop(controlBox);
Scene scene = new Scene(pane);
stage.setScene(scene);
stage.setResizable(true);
stage.show();
}
This code barely works. I have to add the width and height manually because the scene or the stage doesn't look for anything to fit to. And when I am adding buttons later to the HBox on the top the window doesn't increase in size, neither does the HBox (height stays at 0). Only the image gets pushed down it is not fully visible anymore.
How would I go about this instead?
You should use the HBox.setHgrow method on each of the children of controlBox.
// for each button
HBox.setHgrow(child, Priority.ALWAYS);
This will align the buttons next to each other, reducing the sizes so that all of them fit in one line and they fill the available space.
JavaFX nodes are dynamically re-sizable i.e. the child will fill the space provided by parent and Parent will expand in accordance to the minimum space the child needs.
I don't face issue that have been raised by you while trying to add a HBox to a BorderPane. The BorderPane height increased (more than the image height) after the HBox got added to it. In case you want to see if the Image gets pushed down, try replacing a VBox to the HBox.
A simple example where I use an image of 365 and a HBox of 26, which result in a BorderPane of 391 height
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;
public class BorderPaneHeight extends Application{
#Override
public void start(Stage primaryStage) throws Exception {
BorderPane borderPane = new BorderPane();
HBox box = new HBox(10);
ImageView imageView = new ImageView(new Image("file:///home/itachi/Pictures/aaa.png")); // Replace with your image path
Button button1 = new Button("Add");
Button button2 = new Button("Add");
box.getChildren().addAll(button1, button2);
borderPane.setTop(box);
borderPane.setCenter(imageView);
Scene scene = new Scene(borderPane);
primaryStage.setScene(scene);
primaryStage.show();
System.out.println("Image height : " + imageView.getImage().getHeight());
System.out.println("Hbox height : " + box.getHeight());
System.out.println("BorderPane Height : " + borderPane.getHeight());
}
public static void main(String[] args) {
launch(args);
}
}
Output on Console
Image height : 365.0
Hbox height : 26.0
BorderPane Height : 391.0
For the window to grow as the content inside the window expands I did like this(looked but haven't found another solution)
In this case a new window is open from MainController and this window contents can grow and I want this new window to grow with it, so in the controller for the new window I add a listener...
containerPane.heightProperty().addListener((observable, oldValue, newValue) -> {
MainController.theStage.setHeight(MainController.theStage.getHeight() + (newValue.doubleValue() - oldValue.doubleValue()));
});
Related
package example;
import javafx.application.Application;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.scene.text.Text;
import javafx.stage.Stage;
public class Main extends Application {
#Override
public void start(Stage primaryStage) {
Text text = new Text("This is a Text");
VBox box = new VBox();
box.setAlignment(Pos.CENTER);
box.setStyle("-fx-background-color: yellow;");
box.getChildren().add(text);
StackPane container = new StackPane();
container.getChildren().add(box);
BorderPane bp = new BorderPane();
bp.setCenter(container);
Scene scene = new Scene(bp, 300, 250);
primaryStage.setTitle("Hello World!");
primaryStage.setScene(scene);
primaryStage.show();
}
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
launch(args);
}
}
Here's the output:
Question: Can someone explain to me why the Vbox fill the whole screen? Is there a method that is similar to Android's wrap_content? I want the image below to be the output:
Solution
Wrap the VBox in a Group; e.g. use:
container.getChildren().add(new Group(box));
instead of:
container.getChildren().add(box);
Why it works
From the Group javadoc:
By default, a Group will "auto-size" its managed resizable children to their preferred sizes during the layout pass.
This means that the VBox won't grow past the preferred size of it's content (which is just enough area to display the label inside it).
Alternate implementation
Set the maximum size of the VBox to the preferred size. Then the VBox will only ever grow large enough to fit the preferred size of the content inside it and will never grow any larger.
box.setMaxSize(VBox.USE_PREF_SIZE, VBox.USE_PREF_SIZE);
Why VBox grows by default
It is a resizable container which will stretch to fill available area.
Note
I don't know that the effect is exactly the same as an Android wrap_content method as I have never developed for Android, however the effect does seem to exactly match the second image you provided in your question, which appears to be what you want.
VBox automatically resizes itself to the size of the Parent, so it is better not to set background color to it. Instead, you can use a Label in place of a Text and then add background color to the Label instead of the VBox.
public class Main extends Application {
#Override
public void start(Stage primaryStage) {
Label text = new Label("This is a Text");
VBox box = new VBox();
box.setAlignment(Pos.CENTER);
text.setStyle("-fx-background-color: yellow;");
box.getChildren().add(text);
StackPane container = new StackPane();
container.getChildren().add(box);
BorderPane bp = new BorderPane();
bp.setCenter(container);
Scene scene = new Scene(bp, 300, 250);
primaryStage.setTitle("Hello World!");
primaryStage.setScene(scene);
primaryStage.show();
}
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
launch(args);
}
}
This will give you an output like an image below:
I am using a BorderPane to implement a layout in JavaFX.
Suppose the BorderPane's maxPrefWidth is set to 1000. There is a button in the left pane, and a button in the right pane. In the center pane, there is another button with an unknown size.
If: the middle element's width is 500, then the left and right nodes
should be 250 in width.
If: the middle element's width is 600, then the left and right nodes
should be 200 in width.
Is there a way to tell the left and right pane to automatically grow (horizontally) until the center node's is hit?
BorderPane expands middle area, by design
Your intentions do not mesh with the design intentions of BorderPane.
To quote the Javadoc:
The top and bottom children will be resized to their preferred heights and extend the width of the border pane. The left and right children will be resized to their preferred widths and extend the length between the top and bottom nodes. And the center node will be resized to fill the available space in the middle. Any of the positions may be null.
This means:
The center expands to take all extra space.
The top and bottom take maximum width and their preferred height.
The left and right areas take their preferred width and maximum height.
Imagine the middle as a box with a strongman inside pushing up, down, and out.
This logic is often quite handy for many business apps. The outside areas are often used for navigation, breadcrumbs, menu bar, tool bar, status bar, and so on. The inner area then holds the main content of interest. Given such usage, it makes sense to allocate only necessary space to the outer areas, and allocate most space to the inner content area.
For example, here is an entire example app using JavaFX 14.
In the center area of this example app, we place an HBox layout containing a single button. We set the background color of that layout to cornflowerblue color to make visible how the content of the center area expands to take all extra space.
package work.basil.example;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.ToolBar;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;
import java.time.ZonedDateTime;
/**
* JavaFX App
*/
public class App extends Application
{
#Override
public void start ( Stage stage )
{
// Widgets
ToolBar toolBar = new ToolBar();
Button button = new Button( "Click Me" );
toolBar.getItems().add( button );
Button buttonLeft = new Button( "Left" );
Button buttonRight = new Button( "Right" );
HBox appContent = new HBox( new Button( "Bonjour le monde" ) );
appContent.setStyle( "-fx-background-color: cornflowerblue;" );
HBox statusBar = new HBox( new Label( "Status goes here. Now: " + ZonedDateTime.now() ) );
// Arrange
BorderPane borderPane = new BorderPane();
borderPane.setTop( toolBar );
borderPane.setLeft( buttonLeft );
borderPane.setCenter( appContent );
borderPane.setRight( buttonRight );
borderPane.setBottom( statusBar );
var scene = new Scene( borderPane , 1000 , 1000 );
stage.setScene( scene );
stage.show();
}
public static void main ( String[] args )
{
launch();
}
}
Choose another layout
As commented on the Question, you should be using a different layout manager given your intentions.
You might be able to get by with a HBox. For maximum control, you will need to invest some time into mastering the GridPane.
GridPane
Your Question is not completely clear. If what you want is for the center content to be fixed width of 500 pixels while the left and right are flexible, being allocated any extra space proportionally, then use GridPane while setting the ColumnConstraints to Priority.SOMETIMES or Priority.ALWAYS on the left and right cells.
Here is a complete example app.
We put one button, each nested in a colored HBox, in each cell of the single-row GridPane. The colors dramatize the sizing behavior being shown here. Alternatively, you could drop the colored HBox, instead calling gridPane.setStyle( "-fx-grid-lines-visible: true ;" ) to show border lines around each cell.
package work.basil.example;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.ToolBar;
import javafx.scene.layout.*;
import javafx.stage.Stage;
import java.time.ZonedDateTime;
/**
* JavaFX App
*/
public class App extends Application
{
#Override
public void start ( Stage stage )
{
// Widgets
Button buttonLeft = new Button( "Left" );
HBox left = new HBox( buttonLeft );
left.setStyle( "-fx-background-color: Salmon;" );
Button buttonCenter = new Button( "Center" );
HBox center = new HBox( buttonCenter );
center.setStyle( "-fx-background-color: CornflowerBlue;" );
Button buttonRight = new Button( "Right" );
HBox right = new HBox( buttonRight );
right.setStyle( "-fx-background-color: MediumSeaGreen;" );
// GridPane
GridPane gridPane = new GridPane();
gridPane.addRow( 0 , left , center , right ); // Add these widgets in first row (annoying zero-based counting means index 0 is row 1).
gridPane.setStyle( "-fx-grid-lines-visible: true ;" ); // Add lines to the edges of each cell (row/column) in the grid. Useful for learning and debugging. https://docs.oracle.com/javafx/2/api/javafx/scene/doc-files/cssref.html#gridpane
// Grid constraints
ColumnConstraints column1 = new ColumnConstraints();
column1.setHgrow( Priority.SOMETIMES ); // Extra space alloted to this column.
ColumnConstraints column2 = new ColumnConstraints( 500 ); // Fixed width of 500 pixels.
ColumnConstraints column3 = new ColumnConstraints();
column3.setHgrow( Priority.SOMETIMES );// Extra space alloted to this column.
gridPane.getColumnConstraints().addAll( column1 , column2 , column3 ); // first column gets any extra width
// Render
var scene = new Scene( gridPane , 1000 , 150 );
stage.setScene( scene );
stage.setTitle( "Example of JavaFX GridPane, by Basil Bourque" );
stage.show();
}
public static void main ( String[] args )
{
launch();
}
}
Screenshot of the app running. Notice how the left and right get remaining space of 250 pixels each. We set the window (Stage) to 1,000 pixels, and fixed the width of the center piece to 500 pixels. That leaves 500 pixels remaining to allocate. Both left and right cells were set to the same priority level, so they split the space evenly between them: 500/2 = 250 pixels each.
If the user narrows the width of the window to 600 pixels, the left and right cells will be 50 pixels each: 600 - 500 = 100, 100/2 = 50 pixels each.
Generally I would recommend posting code rather than attempting to describe it. For example this mre can represent your question:
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;
public class Main extends Application {
#Override
public void start(Stage stage) throws Exception {
Button leftBtn = new Button("Left");
Button centerBtn = new Button("Center");
centerBtn.widthProperty().addListener((obs, oldValue,newValue)-> {
//change the logic as needed
leftBtn.setPrefWidth(newValue.doubleValue() >= 600 ? 200 : 250);
});
centerBtn.setPrefSize(600, 0);
Button rightBtn = new Button("Right");
Pane root = new BorderPane(centerBtn, null, rightBtn, null, leftBtn);
root.setPrefSize(1000, 150);
Scene scene = new Scene(root);
stage.setScene(scene);
stage.show();
}
public static void main(String[] args) {
launch(args);
}
}
This also makes helping much easier. For example a solution with HBox as proposed in the comments just requires minor changes in the mre (action box added to the center button to change its width):
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Pane;
import javafx.scene.layout.Priority;
import javafx.stage.Stage;
public class Main extends Application {
private static final double MIN = 300, MAX = 700, DELTA = 100;
private Button centerBtn;
#Override
public void start(Stage stage) throws Exception {
Button leftBtn = new Button("Left");
HBox.setHgrow(leftBtn, Priority.NEVER);
centerBtn = new Button("Click to change width");
HBox.setHgrow(leftBtn, Priority.NEVER);
centerBtn.widthProperty().addListener((obs, oldValue,newValue)-> {
//change the logic as needed
leftBtn.setPrefWidth(newValue.doubleValue() >= 600 ? 200 : 250);
});
centerBtn.setPrefSize(600, 0);
centerBtn.setOnAction(e-> changeCenterBtnWidth());
Button rightBtn = new Button("Right");
HBox.setHgrow(rightBtn, Priority.ALWAYS);
Pane root = new HBox(leftBtn,centerBtn,rightBtn);
root.setPrefSize(1000, 150);
Scene scene = new Scene(root);
stage.setScene(scene);
stage.show();
}
private void changeCenterBtnWidth() {
double newWidth = centerBtn.getWidth() + DELTA;
newWidth = newWidth < MAX ? newWidth : MIN;
centerBtn.setPrefWidth(newWidth);
}
public static void main(String[] args) {
launch(args);
}
}
Demonstrating a solution based on GridPane rquires only some samll changes:
public void start(Stage stage) throws Exception {
Button leftBtn = new Button("Left");
centerBtn = new Button("Click to change width");
centerBtn.widthProperty().addListener((obs, oldValue,newValue)-> {
//change the logic as needed
leftBtn.setPrefWidth(newValue.doubleValue() >= 600 ? 200 : 250);
});
centerBtn.setPrefSize(600, 0);
centerBtn.setOnAction(e-> changeCenterBtnWidth());
Button rightBtn = new Button("Right");
GridPane root = new GridPane();
root.add(leftBtn,0, 0);
root.add(centerBtn,1, 0);
root.add(rightBtn,2, 0);
root.setPrefSize(1000, 150);
Scene scene = new Scene(root);
stage.setScene(scene);
stage.show();
}
I currently have a ScrollPane with a FlowPane as content. The FlowPane currently initializes with no children nodes, a fixed width and a pref/min height (but no max height).
While adding items to the FlowPane at runtime (I click some UI element and something is added to the FlowPane), the ScrollPane should adjust its height in the case that the addition to the FlowPane no longer fits.
I don't understand how to set the height of the flowPane and ScrollPane so that this works - if that's the problem to begin with. At the moment, whenever the addition to the FlowPane doesn't fit its initial height, the content is added, but not visible. The scrollbar belonging to the ScrollPane never adjusts its height - if it did, I could just scroll further down and see the content.
Let's say I have a ScrollPane with some width and height, some viewport width/height, and a FlowPane with some width/height - What should my settings be for the min/pref/max sizes? How can I make a scrollPane adjust its scrollbar behaviour or make the content visible?
The ScrollPane's setFitToHeight is already set to true, which didn't seem to change anything.
import javafx.application.Application;
import javafx.event.Event;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.ScrollPane;
import javafx.scene.control.ScrollPane.ScrollBarPolicy;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.FlowPane;
import javafx.stage.Stage;
public class FlowPaneTest extends Application
{
public static void main(String[] args)
{
launch(args);
}
#Override
public void start(Stage primaryStage) throws Exception
{
// borderPane rootPane
BorderPane borderPane = new BorderPane();
borderPane.setMinSize(600, 600);
borderPane.setPrefSize(600, 600);
borderPane.setMaxSize(600, 600);
// container for the two scrollPanes below
FlowPane flow = new FlowPane();
borderPane.setRight(flow);
// two scrollPanes, each should resize it's height (width should be fixed) if
// children are added beyond it's current height
ScrollPane top = new ScrollPane();
ScrollPane bottom = new ScrollPane();
FlowPane scrollPaneContent = new FlowPane();
top.setContent(scrollPaneContent);
bottom.setContent(scrollPaneContent);
flow.getChildren().add(top);
flow.getChildren().add(bottom);
borderPane.setOnMouseClicked(new EventHandler<Event>()
{
#Override
public void handle(Event event)
{
Label l = new Label("test");
l.setMinSize(100, 100);
l.setPrefSize(100, 100);
l.setMaxSize(100, 100);
scrollPaneContent.getChildren().add(l);
}
});
// size settings
int width = 300, height = 300;
top.setHvalue(0.5);
top.setMinViewportHeight(height);
top.setPrefViewportHeight(height);
top.setMinViewportWidth(width);
top.setPrefViewportWidth(width);
top.setHbarPolicy(ScrollBarPolicy.ALWAYS);
top.setFitToHeight(true);
top.setMinSize(width, height);
top.setPrefSize(width, height);
top.setMaxWidth(width);
scrollPaneContent.setMinSize(width, height);
scrollPaneContent.setPrefSize(width, height);
scrollPaneContent.setMaxWidth(width);
scrollPaneContent.setPrefHeight(height);
bottom.setMinSize(width, height);
bottom.setPrefSize(width, height);
bottom.setMaxWidth(width);
bottom.setHvalue(0.5);
bottom.setMinViewportHeight(height);
bottom.setPrefViewportHeight(height);
bottom.setMinViewportWidth(width);
bottom.setPrefViewportWidth(width);
bottom.setHbarPolicy(ScrollBarPolicy.ALWAYS);
top.setFitToHeight(true);
bottom.setFitToHeight(true);
// stage
Scene scene = new Scene(borderPane, 600.0, 600.0);
primaryStage.setScene(scene);
primaryStage.show();
}
}
Try to give the ScrollPane pref height and width and add this line
scrollPane.setFitToWidth(true);
Ending up with something similar to this ugly bit of code - It listens to the number of children in the pane and increases the size every time something is added to the list of children:
topSubPane.getChildren().addListener(new ListChangeListener()
{
#Override
public void onChanged(Change c)
{
c.next();
topSubPane.setPrefHeight(topSubPane.getHeight() + 50);
}
});
Works, but feels like an unorthodox hack. Is there really no regular way of doing this?
I'm writing a GUI application with a ScrollPane, but had some issues with resizing. I extracted the essential code in the following example:
import javafx.application.Application;
import javafx.geometry.Bounds;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.stage.Stage;
import javafx.scene.layout.VBox;
import javafx.scene.control.ScrollPane;
public class JavaFXExample extends Application {
final int width = 300;
final int height = 300;
#Override
public void start(Stage primaryStage) {
Button b = new Button("This should be at the bottom!");
//this vbox goes inside the scrollpane
VBox boxInScrollPane = new VBox(10);
boxInScrollPane.setAlignment(Pos.BOTTOM_CENTER);
boxInScrollPane.getChildren().add(b);
//main content
ScrollPane scrollPane = new ScrollPane();
scrollPane.setContent(boxInScrollPane);
scrollPane.setHbarPolicy(ScrollPane.ScrollBarPolicy.NEVER);
scrollPane.setVbarPolicy(ScrollPane.ScrollBarPolicy.AS_NEEDED);
//Doesn't do anything!
scrollPane.setPrefSize(100, 100);
scrollPane.setMaxSize(100, 100);
scrollPane.setMinSize(100, 100);
Scene scene = new Scene(scrollPane, width, height);
primaryStage.setScene(scene);
primaryStage.show();
//set size of boxInScrollPane to be equal to the viewport
Bounds viewportBounds = scrollPane.getViewportBounds();
double innerWidth = viewportBounds.getMaxX() - viewportBounds.getMinX();
double innerHeight = viewportBounds.getMaxY() - viewportBounds.getMinY();
System.out.println(innerWidth + " " + innerHeight);
boxInScrollPane.setPrefSize(innerWidth, innerHeight);
}
public static void main(String[] args) {
launch(args);
}
}
So I have a window, which contains a ScrollPane, which contains a VBox, which contains a button. The example here, where I resize the scrollpane to be 100x100px in a 300x300px window, is arbitrary. What's important is that when I run this code, I get a scrollpane that fills the entire window! Here's my output:
What's going on here?
The root of the scene is sized to fill the entire scene, irrespective of its min/pref/max size. If you want the ScrollPane to remain 100 pixels wide and 100 pixels high, wrap it in another container (pretty much any container will do); the container will then be resized, but the ScrollPane will respect its layout sizes:
Scene scene = new Scene(new StackPane(scrollPane), width, height);
By default a StackPane centers its content, so this results in
Solution:
Pane pane = new Pane(scrollPane);
Scene scene = new Scene(pane, width, height);
primaryStage.setScene(scene);
primaryStage.show();
From Scene constuctor doc:
Creates a Scene for a specific root Node with a specific size.
Setting ScrollPane as root node will make it resize to given size in constructor so the previous settings will not work.
Solution will be to make a simple pane that will be resized so ScrollPane will be on his own rules.
I'm relatively new to Java and I'm having difficulty with running a program. Now, as a heads up, this is a homework assignment. The problem is to create a program with the output as "Welcome to Java" in a circle.
Here is my code thus far:
import java.awt.Color;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.Parent;
import javafx.scene.layout.Pane;
import javafx.scene.text.*;
import javafx.stage.Stage;
public class Characters extends Application {
public void start(Stage stage) {
Pane canvas = new Pane();
canvas.setStyle("-fx-background-color: black;");
canvas.setPrefSize(200, 200); // set size of pane
Font f = Font.font("Times New Roman", FontWeight.BOLD, 35);
String s = "Welcome to Java";
String c;
double d = 25.0, x = 10.0, y = 20.0;
for (int i = 0; i < s.length(); i++) {
c = "" + s.charAt(i);
Text t = new Text(x, y, c);
t.setFont(f);
t.setRotate(d);
d++;
x++;
y++;
canvas.getChildren().add(t);
}
Scene scene = new Scene(root,500, 500, Color.BLACK);
stage.setTitle("Characters around a circle");
stage.setScene(scene);
stage.show();
}
public static void main(String[] args) {
launch(args);
}
}
I keep receiving an error at Scene scene = new Scene(root,500, 500, Color.BLACK); and I haven't been able to find a solution. Any help is appreciated. Thanks.
root is not declared anywhere in your program. Try adding canvas to a layout and add the layout to the scene.
BorderPane rootLayout = new BorderPane();
rootLayout.getChildren().add(canvas);
Scene scene = new Scene(rootLayout, 500,500);
It doesn't look like root (the first parameter in your constructor) is defined anywhere in the scope.
In the docs they do this:
Group root = new Group();
Scene s = new Scene(root, 300, 300, Color.BLACK);
But I'm not sure if you want to put in the canvas somewhere.
Something to note (copy-pasted from the docs):
The application must specify the root Node for the scene graph by setting the root property. If a Group is used as the root, the contents of the scene graph will be clipped by the scene's width and height and changes to the scene's size (if user resizes the stage) will not alter the layout of the scene graph. If a resizable node (layout Region or Control is set as the root, then the root's size will track the scene's size, causing the contents to be relayed out as necessary.
Basically, if you want the components to be forced within the Scene, it looks like you want a Group. If you want the components to change the size of the Scene then use a resizable node (e.g. Region or Control).