How to make canvas Resizable in javaFX?

Question

In javaFX to resize a canvas there is no such method to do that, the only solution is to extends from Canvas.

class ResizableCanvas extends Canvas {

    pub         


        

Answer 1

Of all the answers given, none of them actually worked for me in terms of making the canvas automatically resize with its parent. I decided to take a crack at this and this is what I came up with:

import javafx.scene.canvas.Canvas;

public class ResizableCanvas extends Canvas {

    @Override
    public boolean isResizable() {
        return true;
    }

    @Override
    public double maxHeight(double width) {
        return Double.POSITIVE_INFINITY;
    }

    @Override
    public double maxWidth(double height) {
        return Double.POSITIVE_INFINITY;
    }

    @Override
    public double minWidth(double height) {
        return 1D;
    }

    @Override
    public double minHeight(double width) {
        return 1D;
    }

    @Override
    public void resize(double width, double height) {
        this.setWidth(width);
        this.setHeight(height);
    }
}

This was the only one that actually made the canvas truly resizable.

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My reasons for going with this approach is as follows:

• I didn't want to break encapsulation by forcing the parent component to send us a width and height in the constructor which would also mean that the canvas cannot be used in FXML.
• I also did not want to depend on the parent's width and height properties thus making the canvas the only child in it's parent, by taking up all the space.
• Finally, the canvas needed to have it's drawing done in another class, which meant I could not use the current accepted answer which also included drawing to canvas via a draw method.

With this canvas, I do not need to bind to its parent width/height properties to make the canvas resize. It just resizes with whatever size the parent chooses. In addition, anyone using the canvas can just bind to its width/height properties and manage their own drawing when these properties change.