/**
* Create preview component.
*
* @param comboBox the options.
* @return the component.
*/
private static Component createPreview(final JComboBox comboBox) {
final JComponent preview;
JLabel noPreview =
new JLabel(GuiActivator.getResources().getI18NString("impl.media.configform.NO_PREVIEW"));
noPreview.setHorizontalAlignment(SwingConstants.CENTER);
noPreview.setVerticalAlignment(SwingConstants.CENTER);
preview = createVideoContainer(noPreview);
preview.setPreferredSize(new Dimension(WIDTH, 280));
preview.setMaximumSize(new Dimension(WIDTH, 280));
final ActionListener comboBoxListener =
new ActionListener() {
public void actionPerformed(ActionEvent event) {
MediaDevice device = (MediaDevice) comboBox.getSelectedItem();
if ((device != null) && device.equals(videoDeviceInPreview)) return;
Exception exception;
try {
createPreview(device, preview);
exception = null;
} catch (IOException ex) {
exception = ex;
} catch (MediaException ex) {
exception = ex;
}
if (exception != null) {
logger.error("Failed to create preview for device " + device, exception);
device = null;
}
videoDeviceInPreview = device;
}
};
comboBox.addActionListener(comboBoxListener);
/*
* We have to initialize the controls to reflect the configuration
* at the time of creating this instance. Additionally, because the
* video preview will stop when it and its associated controls
* become unnecessary, we have to restart it when the mentioned
* controls become necessary again. We'll address the two goals
* described by pretending there's a selection in the video combo
* box when the combo box in question becomes displayable.
*/
comboBox.addHierarchyListener(
new HierarchyListener() {
public void hierarchyChanged(HierarchyEvent event) {
if (((event.getChangeFlags() & HierarchyEvent.DISPLAYABILITY_CHANGED) != 0)
&& comboBox.isDisplayable()) {
// let current changes end their execution
// and after that trigger action on combobox
SwingUtilities.invokeLater(
new Runnable() {
public void run() {
comboBoxListener.actionPerformed(null);
}
});
} else {
if (!comboBox.isDisplayable()) videoDeviceInPreview = null;
}
}
});
return preview;
}