Adding background image to button in SWT

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感动是毒
感动是毒 2020-12-22 12:07

Can anyone please tell me how to add background image to a button in SWT? I need something like in the attachment. \"bg

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  • 2020-12-22 12:57

    Alright, Button isn't the best starting point if you basically want to draw a completely different type of button. You can however, create your own widget using this tutorial. I wrote an example here:

    public class ImageButton extends Composite
    {
        private Color   textColor;
        private Image   image;
        private String  text;
        private int     width;
        private int     height;
    
        public ImageButton(Composite parent, int style)
        {
            super(parent, style);
    
            textColor = Display.getDefault().getSystemColor(SWT.COLOR_WHITE);
    
            /* Add dispose listener for the image */
            addListener(SWT.Dispose, new Listener()
            {
                @Override
                public void handleEvent(Event arg0)
                {
                    if (image != null)
                        image.dispose();
                }
            });
    
            /* Add custom paint listener that paints the stars */
            addListener(SWT.Paint, new Listener()
            {
                @Override
                public void handleEvent(Event e)
                {
                    paintControl(e);
                }
            });
    
            /* Listen for click events */
            addListener(SWT.MouseDown, new Listener()
            {
                @Override
                public void handleEvent(Event arg0)
                {
                    System.out.println("Click");
                }
            });
        }
    
        private void paintControl(Event event)
        {
            GC gc = event.gc;
    
            if (image != null)
            {
                gc.drawImage(image, 1, 1);
                Point textSize = gc.textExtent(text);
                gc.setForeground(textColor);
                gc.drawText(text, (width - textSize.x) / 2 + 1, (height - textSize.y) / 2 + 1, true);
            }
        }
    
        public void setImage(Image image)
        {
            this.image = new Image(Display.getDefault(), image, SWT.IMAGE_COPY);
            width = image.getBounds().width;
            height = image.getBounds().height;
            redraw();
        }
    
        public void setText(String text)
        {
            this.text = text;
            redraw();
        }
    
        @Override
        public Point computeSize(int wHint, int hHint, boolean changed)
        {
            int overallWidth = width;
            int overallHeight = height;
    
            /* Consider hints */
            if (wHint != SWT.DEFAULT && wHint < overallWidth)
                overallWidth = wHint;
    
            if (hHint != SWT.DEFAULT && hHint < overallHeight)
                overallHeight = hHint;
    
            /* Return computed dimensions plus border */
            return new Point(overallWidth + 2, overallHeight + 2);
        }
    
        public static void main(String[] args)
        {
            Display display = Display.getDefault();
            Shell shell = new Shell(display);
            shell.setLayout(new GridLayout(1, false));
    
            ImageButton button = new ImageButton(shell, SWT.NONE);
            button.setImage(new Image(display, "button.png"));
            button.setText("Button");
    
            shell.pack();
            shell.open();
    
            while (!shell.isDisposed())
            {
                if (!display.readAndDispatch())
                    display.sleep();
            }
            display.dispose();
        }
    }
    

    Looks like this:

    enter image description here


    Of course you'd have to take care of different states like pressed, hover and so on.

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