ModifiersKeySequenceText.java

package com.chookapp.org.bracketeer.preferences;

import org.eclipse.jface.bindings.keys.KeyStroke;
import org.eclipse.jface.bindings.keys.SWTKeySupport;
import org.eclipse.jface.preference.FieldEditor;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.events.KeyEvent;
import org.eclipse.swt.events.KeyListener;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Text;


public class ModifiersKeySequenceText extends FieldEditor implements KeyListener
{
    Text _textField;
    int _mask;
    
    public ModifiersKeySequenceText(String name, String labelText, Composite parent)
    {
        init(name, labelText);
        createControl(parent);
    }
    
    @Override
    public void keyPressed(KeyEvent e)
    {
        switch(e.keyCode)
        {
        case SWT.CTRL:
        case SWT.ALT:
        case SWT.COMMAND:
        case SWT.SHIFT:
            _mask |= e.keyCode;
            generateTextFromMask();
            break;
        case SWT.DEL:
        case SWT.BS:
            _mask = 0;
            generateTextFromMask();
            break;
        }
    }

    private void generateTextFromMask()
    {
        if( _textField == null )
            return;
        
        KeyStroke stroke = SWTKeySupport
                .convertAcceleratorToKeyStroke(_mask);
        String str = stroke.format();
        if(str.endsWith("+")) //$NON-NLS-1$
            str = str.substring(0, str.length()-1);
        _textField.setText(str);
    }

    @Override
    public void keyReleased(KeyEvent e)
    {
        // nothing
    }

    @Override
    protected void adjustForNumColumns(int numColumns) 
    {
        GridData gd = (GridData) _textField.getLayoutData();
        gd.horizontalSpan = numColumns - 1;
        // We only grab excess space if we have to
        // If another field editor has more columns then
        // we assume it is setting the width.
        gd.grabExcessHorizontalSpace = gd.horizontalSpan == 1;
    }

    @Override
    protected void doFillIntoGrid(Composite parent, int numColumns) 
    {
        getLabelControl(parent);

        _textField = getTextControl(parent);
        GridData gd = new GridData();
        gd.horizontalSpan = numColumns - 1;
        
        gd.horizontalAlignment = GridData.FILL;
        gd.grabExcessHorizontalSpace = true;
        
        _textField.setLayoutData(gd);
        _textField.setToolTipText(Messages.ModifiersKeySequenceText_ModifiersToolTip);
    }

    @Override
    protected void doLoad()
    {
        _mask = getPreferenceStore().getInt(getPreferenceName());
        generateTextFromMask();
    }

    @Override
    protected void doLoadDefault()
    {
        _mask = getPreferenceStore().getDefaultInt(getPreferenceName());
        generateTextFromMask();
    }

    @Override
    protected void doStore()
    {
        getPreferenceStore().setValue(getPreferenceName(), _mask);
    }

    @Override
    public int getNumberOfControls()
    {
        return 2;
    }    
    
    @Override
    public void dispose()
    {
        if( _textField != null )
            _textField.removeKeyListener(this);
        
        super.dispose();
    }

    /* (non-Javadoc)
     * Method declared on FieldEditor.
     */
    public void setFocus() 
    {
        if (_textField != null) 
            _textField.setFocus();
    }
    
    /*
     * @see FieldEditor.setEnabled(boolean,Composite).
     */
    public void setEnabled(boolean enabled, Composite parent) 
    {
        super.setEnabled(enabled, parent);
        getTextControl(parent).setEnabled(enabled);
    }
    
    public Text getTextControl(Composite parent) 
    {
        if (_textField == null) 
        {
            _textField = new Text(parent, SWT.SINGLE | SWT.BORDER);
            _textField.setFont(parent.getFont());
            
            _textField.addDisposeListener(new DisposeListener() {
                public void widgetDisposed(DisposeEvent event) {
                    _textField = null;
                }
            });
            
            _textField.addKeyListener(this);
        } else {
            checkParent(_textField, parent);
        }
        return _textField;
    }

}