How to implement a JPanel that shows/hide content depending on its width?
I'm trying to implement a JPanel that displays more or less information depending on the available size.
Basically, the idea is have a default content like this:
That can shrinks to this when the space is reduced:
My code is like this:
import net.miginfocom.swing.MigLayout;
import javax.swing.*;
class PanelDemo extends JPanel {
private final JLabel title = new JLabel();
private final JLabel counter1 = new JLabel("00");
private final JLabel counter1Label = new JLabel();
private final JLabel counter2 = new JLabel("00");
private final JLabel counter2Label = new JLabel();
/**
* Instantiates a new obs app cadre message bloc panel.
*/
public PanelDemo() {
this.setOpaque(false);
initGUI();
}
private final void initGUI() {
// 1°)
final MigLayout migLayout = new MigLayout(
"fillx, hidemode 2, debug",
"[growprio 0][]" //define 4 columns
);
setLayout(migLayout);
// 2°)
//
add(title, "spanx");
add(counter1, "newline");
add(counter1Label);
add(counter2);
add(counter2Label);
}
public static void main(String[] args) {
final JFrame jFrame = new JFrame("test 4");
jFrame.getContentPane().setLayout(new MigLayout("fillx, debug"));
final PanelDemo item1 = new PanelDemo();
item1.title.setText("Element 1");
item1.counter1Label.setText("First lbl");
item1.counter2Label.setText("Second lbl");
jFrame.getContentPane().add(item1, "growx, gpx 110");
final PanelDemo item2 = new PanelDemo();
item2.title.setText("Element 2");
item2.counter1Label.setText("First lbl");
item2.counter2Label.setText("Second lbl");
jFrame.getContentPane().add(item2, "growx, gpx 100");
jFrame.pack();
jFrame.setVisible(true);
} }
I tried to add a ComponentListener and override componentResized() to find when I could show/hide my secondary labels but I was not successful.
Does anybody know how to implement such a behaviour that goes well with MigLayout grow priorities?
Update1: I was thinking... what if I set the minimum width to counter1+label1, and the maximum size to counter2+label2 and then listen to resize operations and change the preferred size to either its minimum or its maximum. Would that mecanism work?
How about this:
public static JPanel panel(String name) {
JPanel panel = new JPanel(new MigLayout("insets 0, wrap 4, fillx, debug", "[][][shrink 200][shrink 200, grow 200]"));
panel.add(new JLabel(name), "spanx 4");
panel.add(new JLabel("00"));
panel.add(new JLabel("First lbl"));
panel.add(new JLabel("01"));
panel.add(new JLabel("Second lbl"));
return panel;
}
public static void main(String[] args) {
JPanel panel = new JPanel(new MigLayout("insets 10, gap 10, fillx, debug"));
panel.add(panel("Element 1"), "w (50% - 15)!");
panel.add(panel("Element 2"), "w (50% - 15)!");
JFrame frame = new JFrame();
frame.setContentPane(panel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
I had trouble getting the two main columns to resize equally; I had to do it by setting a width on the components rather than the columns. I'm not sure why that is.
I implemented an autohide mechanism with a LayoutCallback switching the visibility of the component depending on the width of the panel.
Here is an example:
MigLayout layout = new MigLayout("fill");
JPanel panel = new JPanel(layout);
JLabel label1 = new JLabel("Label 1");
label1.putClientProperty("autohide.width", 300);
JLabel label2 = new JLabel("Label 2");
label2.putClientProperty("autohide.width", 200);
panel.add(label1, "grow");
panel.add(label2, "grow");
layout.addLayoutCallback(new LayoutCallback() {
@Override
public void correctBounds(ComponentWrapper wrapper) {
JComponent component = (JComponent) wrapper.getComponent();
Number width = (Number) component.getClientProperty("autohide.width");
if (width != null) {
if (component.isVisible() && wrapper.getParent().getWidth() < width.intValue()) {
component.setVisible(false);
} else if (!component.isVisible() && wrapper.getParent().getWidth() > width.intValue()) {
component.setVisible(true);
}
}
}
});
Here the label1 is hidden when the width of the panel shrinks below 300 pixels, and label2 disappears when the width is less than 200 pixels.
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