content: package tim.prune.function;
  
  import java.awt.BorderLayout;
  import java.awt.FlowLayout;
  import java.awt.event.ActionListener;
  import java.awt.event.KeyAdapter;
  import java.awt.event.KeyEvent;
  import java.awt.event.MouseAdapter;
  import java.util.ArrayList;
  
  import javax.swing.BorderFactory;
  import javax.swing.JButton;
  import javax.swing.JDialog;
  import javax.swing.JLabel;
  import javax.swing.JPanel;
  import javax.swing.JTextField;
  
  import tim.prune.App;
  import tim.prune.GenericFunction;
  import tim.prune.I18nManager;
  import tim.prune.cmd.EditSingleFieldCmd;
  import tim.prune.data.DataPoint;
  import tim.prune.data.Distance;
  import tim.prune.data.Field;
  import tim.prune.data.Unit;
  import tim.prune.data.UnitSetLibrary;
  import tim.prune.function.edit.PointEdit;
  
  /**
   * Class to provide the function to add an altitude offset to a track range
   */
  public class AddAltitudeOffset extends GenericFunction
  {
  	private JDialog _dialog = null;
  	private JLabel _descLabel = null;
  	private JTextField _editField = null;
  	private JButton _okButton = null;
  	private Unit _altUnit = null;
  
  
  	/**
  	 * Constructor
  	 * @param inApp application object for callback
  	 */
  	public AddAltitudeOffset(App inApp)
  	{
  		super(inApp);
  	}
  
  	/** Get the name key */
  	public String getNameKey() {
  		return "function.addaltitudeoffset";
  	}
  
  	/**
  	 * Begin the function
  	 */
  	public void begin()
  	{
  		int selStart = _app.getTrackInfo().getSelection().getStart();
  		int selEnd = _app.getTrackInfo().getSelection().getEnd();
  		if (!_app.getTrackInfo().getTrack().hasData(Field.ALTITUDE, selStart, selEnd))
  		{
  			_app.showErrorMessage(getNameKey(), "dialog.addaltitude.noaltitudes");
  			return;
  		}
  		// Make dialog window
  		if (_dialog == null)
  		{
  			_dialog = new JDialog(_parentFrame, getName(), true);
  			_dialog.setLocationRelativeTo(_parentFrame);
  			_dialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
  			_dialog.getContentPane().add(makeDialogComponents());
  			_dialog.pack();
  		}
  		// Set label according to altitude units
  		setLabelText();
  		// Select the contents of the edit field
  		_editField.selectAll();
  		_dialog.setVisible(true);
  	}
  
  
  	/**
  	 * Create dialog components
  	 * @return Panel containing all gui elements in dialog
  	 */
  	private JPanel makeDialogComponents()
  	{
  		JPanel dialogPanel = new JPanel();
  		dialogPanel.setLayout(new BorderLayout());
  		JPanel mainPanel = new JPanel();
  		_descLabel = new JLabel(I18nManager.getText("dialog.addaltitude.desc") + " (ft)");
  		// Note, this label will be reset at each run
  		mainPanel.add(_descLabel);
  		_editField = new JTextField("0", 6);
  		// Listeners to enable/disable ok button
  		KeyAdapter keyListener = new KeyAdapter() {
  			/** Key released */
  			public void keyReleased(KeyEvent arg0) {
  				_okButton.setEnabled(Math.abs(getOffset()) > 0.001);
  			}
  		};
  		MouseAdapter mouseListener = new MouseAdapter() {
  			public void mouseReleased(java.awt.event.MouseEvent arg0) {
  				_okButton.setEnabled(Math.abs(getOffset()) > 0.001);
  			}
  		};
  		_editField.addKeyListener(keyListener);
  		_editField.addMouseListener(mouseListener);
  		mainPanel.add(_editField);
  		dialogPanel.add(mainPanel, BorderLayout.CENTER);
  		// button panel at bottom
  		JPanel buttonPanel = new JPanel();
  		buttonPanel.setLayout(new FlowLayout(FlowLayout.RIGHT));
  		_okButton = new JButton(I18nManager.getText("button.ok"));
  		ActionListener okListener = e -> finish();
  		_okButton.addActionListener(okListener);
  		_okButton.setEnabled(false);
  		_editField.addActionListener(okListener);
  		buttonPanel.add(_okButton);
  		JButton cancelButton = new JButton(I18nManager.getText("button.cancel"));
  		cancelButton.addActionListener(e -> _dialog.dispose());
  		buttonPanel.add(cancelButton);
  		dialogPanel.add(buttonPanel, BorderLayout.SOUTH);
  		dialogPanel.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 15));
  		return dialogPanel;
  	}
  
  	/**
  	 * Get the value of the altitude to add
  	 * @return entered altitude offset as numeric value
  	 */
  	private double getOffset()
  	{
  		double ans = 0.0;
  		try {
  			ans = Double.parseDouble(_editField.getText());
  		}
  		catch (Exception e) {}
  		return ans;
  	}
  
  	/**
  	 * Set the label text according to the current units
  	 */
  	private void setLabelText()
  	{
  		_altUnit = UnitSetLibrary.UNITS_FEET;
  		if (getConfig().getUnitSet().getAltitudeUnit().isStandard()) {
  			_altUnit = UnitSetLibrary.UNITS_METRES;
  		}
  		final String unitKey = _altUnit.getShortnameKey();
  		_descLabel.setText(I18nManager.getText("dialog.addaltitude.desc") + " (" + I18nManager.getText(unitKey) + ")");
  	}
  
  	/**
  	 * Finish the dialog when OK pressed
  	 */
  	private void finish()
  	{
  		final double offset = getOffset();
  		if (offset == 0.0) {
  			return;
  		}
  		ArrayList<PointEdit> edits = new ArrayList<>();
  		final int selStart = _app.getTrackInfo().getSelection().getStart();
  		final int selEnd = _app.getTrackInfo().getSelection().getEnd();
  		for (int i=selStart; i<=selEnd; i++)
  		{
  			DataPoint point = _app.getTrackInfo().getTrack().getPoint(i);
  			if (point.hasAltitude())
  			{
  				Unit pointUnit = point.getAltitude().getUnit();
  				double valueToAdd = Distance.convertBetweenUnits(offset, _altUnit, pointUnit);
  				double changedValue = point.getAltitude().getValue(pointUnit) + valueToAdd;
  				edits.add(new PointEdit(i, Double.toString(changedValue)));
  			}
  		}
  		if (!edits.isEmpty())
  		{
  			EditSingleFieldCmd command = new EditSingleFieldCmd(Field.ALTITUDE, edits, getConfig().getUnitSet());
  			command.setDescription(getName());
  			command.setConfirmText(I18nManager.getText("confirm.addaltitudeoffset"));
  			_app.execute(command);
  			_dialog.dispose();
  		}
  	}
  }
  