Is there a way to update the display window when the user loads a new image?

Question

I am writing a program that loads an image(stack of images in one file) and do some operations on the image with the controls (buttons) and being able to load another image on the frame without having to change previous controls.

The frame has a default window image at the start of the program. There is a button that loads a new image from the wanted directory.

However the image never gets updated when the loadImage button is pressed.

How do I get my frame to update the image window when a new image is loaded?

Also my JScrollbar does not appear in the frame as I want it. It does not scroll trough and does not have the same width as my image window. How do I change the parameters of the scroll bar to reflect that?

Here is my code below:

I have tried using the repaint function from the frame inside the loadImage method but it would not work. I have also tried some other methods to update the frame when the load new image button is being called but it would not work.

    import org.scijava.command.Command;
    import org.scijava.plugin.Plugin;

    import ij.ImagePlus;
    import ij.gui.NewImage;
    import net.imagej.ImageJ;


    @Plugin(name = "counting_2", type = Command.class, menuPath = "Plugins 
    > counting_2", headless = true)
    public class counting_2 implements Command {

static  ImagePlus img;


public void run(){

    img = null;
    ImagePlus tmpImg = NewImage.createImage("", 521, 609, 100, 8, NewImage.FILL_BLACK);

    img = tmpImg;
    tmpImg.close();
    new MySuperFrameUI();


}

public static void main(String[] args){
    ImageJ ij = new ImageJ();
    ij.launch();

    ij.command().run(counting_2.class, true);


}

}

    import java.awt.Adjustable;
    import java.awt.Dimension;
    import java.awt.GridBagConstraints;
    import java.awt.GridBagLayout;
    import java.awt.Insets;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    import java.awt.event.AdjustmentEvent;
    import java.awt.event.AdjustmentListener;
    import java.awt.event.MouseEvent;
    import java.awt.event.MouseListener;
    import java.awt.event.MouseWheelEvent;
    import java.awt.event.MouseWheelListener;

    import javax.swing.JButton;
    import javax.swing.JFrame;
    import javax.swing.JLabel;
    import javax.swing.JPanel;
    import javax.swing.JScrollBar;
    import javax.swing.border.EmptyBorder;

    import ij.ImagePlus;
    import ij.WindowManager;
    import ij.gui.ImageCanvas;
    import ij.gui.ImageWindow;
    import ij.io.OpenDialog;
    import ij.io.Opener;
    import ij.plugin.frame.ContrastAdjuster;


    public class MySuperFrameUI extends JFrame {

private JPanel contentPane;
ImagePlus img;
ImageWindow win;
ImageCanvas can;

int currSlice;

// some variables 

int x;
int y;



public MySuperFrameUI() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Dimension screenSize =  new Dimension(1280 ,720);

    // Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
    x=  screenSize.width;
    y= screenSize.height;
    setBounds(0,0,x, y);
    setVisible(true);

    // frame title 
    setTitle("Counting");


    contentPane = new JPanel();
    contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
    setContentPane(contentPane);
    GridBagLayout gbl_contentPane = new GridBagLayout();
    gbl_contentPane.columnWidths = new int[]{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -7, 0, 0, 0, 0, 0, 0, 0, 53, 102, 0, 0, 0, 0, 129, 0, -86, 0};
    gbl_contentPane.rowHeights = new int[]{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 88, 0};
    gbl_contentPane.columnWeights = new double[]{0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, Double.MIN_VALUE};
    gbl_contentPane.rowWeights = new double[]{0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, Double.MIN_VALUE};
    contentPane.setLayout(gbl_contentPane);




    Dimension dim = new Dimension(x, y);

    img = counting_2.img;
    win = new ImageWindow(img);
    img.setWindow(win);
    win.setVisible(false);
    win.setMinimumSize(dim);
    win.setSize(dim);
    can = img.getWindow().getCanvas();
    can.fitToWindow();

    JPanel ViewPane = new JPanel();
    GridBagConstraints gbc_ViewPane = new GridBagConstraints();
    gbc_ViewPane.anchor = GridBagConstraints.SOUTH;
    gbc_ViewPane.gridwidth = 15;
    gbc_ViewPane.gridheight = 23;
    gbc_ViewPane.insets = new Insets(0, 0, 5, 5);
    gbc_ViewPane.gridx = 1;
    gbc_ViewPane.gridy = 8;
    contentPane.add(ViewPane, gbc_ViewPane);
    GridBagLayout gbl_ViewPane = new GridBagLayout();
    gbl_ViewPane.columnWidths = new int[]{0, 0, 0, 0, 0, 222, 0};
    gbl_ViewPane.rowHeights = new int[]{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
    gbl_ViewPane.columnWeights = new double[]{0.0, 0.0, 0.0, 0.0, 0.0, 0.0, Double.MIN_VALUE};
    gbl_ViewPane.rowWeights = new double[]{0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, Double.MIN_VALUE};
    ViewPane.setLayout(gbl_ViewPane);




    GridBagConstraints gbc_can = new GridBagConstraints();
    gbc_can.gridwidth = 6;
    gbc_can.insets = new Insets(0, 0, 5, 0);
    gbc_can.gridx = 0;
    gbc_can.gridy = 21;
    ViewPane.add(can, gbc_can);




    JScrollBar SB = new JScrollBar();
    SB.setOrientation(Adjustable.HORIZONTAL);
    SB.setMinimum(1);
    SB.setMaximum(counting_2.img.getNSlices() + 9);

    SB.setVisibleAmount(win.getWidth());
    SB.setValue(img.getCurrentSlice());
    GridBagConstraints gbc_SB = new GridBagConstraints();
    gbc_SB.insets = new Insets(0, 0, 5, 0);
    gbc_SB.gridwidth = 6;
    gbc_SB.gridx = 0;
    gbc_SB.gridy = 22;
    ViewPane.add(SB, gbc_SB);



    JLabel sliceNum = new JLabel(String.valueOf(img.getCurrentSlice()));
    GridBagConstraints gbc_sliceNum = new GridBagConstraints();
    gbc_sliceNum.gridx = 5;
    gbc_sliceNum.gridy = 23;
    ViewPane.add(sliceNum, gbc_sliceNum);



    JPanel controlsPane = new JPanel();
    GridBagConstraints gbc_controlsPane = new GridBagConstraints();
    gbc_controlsPane.anchor = GridBagConstraints.NORTH;
    gbc_controlsPane.gridwidth = 7;
    gbc_controlsPane.gridheight = 23;
    gbc_controlsPane.insets = new Insets(0, 0, 0, 5);
    gbc_controlsPane.gridx = 16;
    gbc_controlsPane.gridy = 8;


    contentPane.add(controlsPane, gbc_controlsPane); 
    GridBagLayout
    gbl_controlsPane = new GridBagLayout(); 
    gbl_controlsPane.columnWidths = new
            int[]{0, 0, 0, 0, 0, 0, 0, 0, 0}; 
    gbl_controlsPane.rowHeights = new int[]{0, 0,
            0, 0, 0, 0, 0, 0, 0, 0, 0, 0}; 
    gbl_controlsPane.columnWeights = new double[]{0.0, 0.0, 0.0, 0.0,
            0.0, 0.0, 0.0, 0.0, Double.MIN_VALUE}; 
    gbl_controlsPane.rowWeights = new
            double[]{0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, Double.MIN_VALUE};
    controlsPane.setLayout(gbl_controlsPane);


    JButton loadImageB = new JButton("Load an Image");
    loadImageB.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent arg0) {

            loadImageF();



        }
    });

    GridBagConstraints gbc_loadImageB = new GridBagConstraints();
    gbc_loadImageB.insets = new Insets(0, 0, 5, 0);
    gbc_loadImageB.gridx = 7;
    gbc_loadImageB.gridy = 1;
    controlsPane.add(loadImageB, gbc_loadImageB);




    SB.addAdjustmentListener(new AdjustmentListener() {
        @Override
        public void adjustmentValueChanged(AdjustmentEvent e) {
            img.setSlice(e.getValue());
            currSlice = e.getValue();
            sliceNum.setText(currSlice + " / " + img.getNSlices());

        }
    });
    ViewPane.addMouseWheelListener(new MouseWheelListener() {
        @Override
        public void mouseWheelMoved(MouseWheelEvent e) {
            WindowManager.setCurrentWindow(win);
            int action = e.getWheelRotation();
            boolean zoom = e.isControlDown();
            int ox = can.offScreenX(e.getX());
            int oy = can.offScreenY(e.getY());
            if (zoom) {
                if (action < 0)
                    can.zoomIn(ox, oy);
                else can.zoomOut(ox, oy);
                can.setPreferredSize(dim);
                can.repaint();

            } 

            else {
                if (action < 0) {
                    if (currSlice > 1) {
                        currSlice--;
                        img.setSlice(currSlice);
                    }
                }
                if (action > 0) {
                    if (currSlice < img.getNSlices()) {
                        currSlice++;
                        img.setSlice(currSlice);
                    }
                }
                SB.setValue(img.getCurrentSlice());
                sliceNum.setText(currSlice + " / " + img.getNSlices());
            }

        }
    });



    can.addMouseListener(new MouseListener() {
        @Override
        public void mouseClicked(MouseEvent e) {

        }


        public void mouseReleased(MouseEvent e) {


        }

        @Override
        public void mouseEntered(MouseEvent e) {

        }

        @Override
        public void mouseExited(MouseEvent e) {

        }


        @Override
        public void mousePressed(MouseEvent e) {
            // TODO Auto-generated method stub

        }
    });


}


private void loadImageF() {

    counting_2.img.close();;
    OpenDialog od = new OpenDialog(getName());
    counting_2.img =Opener.openUsingBioFormats(od.getPath());
    can.repaint();
    can.revalidate();


    win.repaint();
    win.revalidate();

    if (counting_2.img == null)
        return;
}

}

enter image description here

1) For better help sooner, [edit] to add a [MCVE] or [Short, Self Contained, Correct Example](http://www.sscce.org/). 2) One way to get image(s) for an example is to hot link to images seen in [this Q&A](http://stackoverflow.com/q/19209650/418556). E.G. [This answer](https://stackoverflow.com/a/10862262/418556) hot links to an image embedded in [this question](https://stackoverflow.com/q/10861852/418556). 3) A single blank line of white space in source code is all that is *ever* needed. Blank lines after `{` or before `}` are also typically redundant. — Andrew Thompson, Jan 24 '19 at 04:35

score 1 · Answer 1 · answered Jan 24 '19 at 00:42

You're using 3rd party/custom components, to which we don't have access to, so it's impossible to provide any "real" solutions, however...

However the image never gets updated when the loadImage button is pressed

This could be for any number of reasons, assuming that the image was loaded correctly, its possible that:

The image hasn't been added to anything which can render it on the screen and/or the render hasn't been added to anything attached to the screen
Generally, you can call repaint on the component you want updated, which "should" trigger a new paint pass (not the image, but what ever is been used to render it)
You may need to call revalidate on the component used to display the image to trigger a new layout pass, which, if you've built your UI correctly, will update the component hierarchy.

Also my JScrollbar does not appear in the frame as I want it. It does not scroll trough and does not have the same width as my image window. How do I change the parameters of my JScrollbar to reflect that?

That's a much more complicated issue. First, you should call setVisible on your frame AFTER you've established the UI, otherwise it may not layout/paint the contents (unless you call revalidate/repaint manually).

You shouldn't need to use JScrollBar, but instead, should be using JScrollPane.

I would, strongly, recommend you start by reading through:

to get a better basic understand of the UI its API and components

Is there a way to update the display window when the user loads a new image?

1 Answers1

Linked