BnButtonDecorator.java

/*
 * Beanfabrics Framework Copyright (C) by Michael Karneim, beanfabrics.org
 * Use is subject to license terms. See license.txt.
 */
package org.beanfabrics.swt;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

import org.beanfabrics.IModelProvider;
import org.beanfabrics.Link;
import org.beanfabrics.ModelSubscriber;
import org.beanfabrics.Path;
import org.beanfabrics.View;
import org.beanfabrics.event.WeakPropertyChangeListener;
import org.beanfabrics.model.ConversionException;
import org.beanfabrics.model.IBooleanPM;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;

/**
 * @author Michael Karneim
 */
public class BnButtonDecorator extends AbstractDecorator<Button> implements View<IBooleanPM>, ModelSubscriber {
    private final Link link = new Link(this);
    private final PropertyChangeListener listener = new WeakPropertyChangeListener() {
        public void propertyChange(PropertyChangeEvent evt) {
            refreshUI();
        }
    };
    private final SelectionListener uiListener = new SelectionListener() {
        public void widgetSelected(SelectionEvent arg0) {
            //System.out.println(".widgetSelected()");
            updateModel();
        }

        public void widgetDefaultSelected(SelectionEvent arg0) {
            //System.out.println("BnButton.widgetDefaultSelected()");
            // ignore
        }
    };

    private ValidationIndicator validationIndicator;
    private IBooleanPM pModel;
    private Button button;

    public BnButtonDecorator(Button button) {
        super(button);
        checkStyle(button.getStyle());
        this.button = button;
        hookControl(button);
    }

    private void checkStyle(int style) {
        if ((style & SWT.PUSH) != 0) {
            throw new IllegalArgumentException("Button must not be styled with SWT.PUSH");
        }
    }

    /**
     * Create the composite
     * 
     * @param parent
     * @param style is ignored
     */
    public BnButtonDecorator(Composite parent, int style) {
        this(new Button(parent, style));
    }

    private void hookControl(Button button) {
        Composite parent = button.getParent();
        if (parent instanceof ValidationIndicator) {
            setValidationIndicator((ValidationIndicator)parent);
        }
        button.addSelectionListener(uiListener);
        refreshUI();
    }

    /** {@inheritDoc} */
    public IBooleanPM getPresentationModel() {
        return pModel;
    }

    /** {@inheritDoc} */
    public void setPresentationModel(IBooleanPM pModel) {
        if (this.pModel != null) {
            this.pModel.removePropertyChangeListener(listener);
        }
        this.pModel = pModel;
        if (this.pModel != null) {
            this.pModel.addPropertyChangeListener(listener);
        }
        refreshUI();
    }

    protected void refreshUI() {
        refreshEnabled();
        refreshTooltip();
        refreshSelection();
        refreshValidationIndicator();
    }

    protected void refreshEnabled() {
        if (pModel != null) {
            button.setEnabled(pModel.isEditable());
        } else {
            button.setEnabled(false);
        }
    }

    protected void refreshTooltip() {
        if (pModel != null) {
            if (pModel.isValid() == false) {
                button.setToolTipText(pModel.getValidationState().getMessage());
            } else {
                button.setToolTipText(pModel.getDescription());
            }
        } else {
            button.setToolTipText(null);
        }
    }

    protected void refreshSelection() {
        if (pModel != null) {
            try {
                Boolean value = pModel.getBoolean();
                button.setSelection(value != null && value.booleanValue());
            } catch (ConversionException ex) {
                // ignore
            }
        } else {
            button.setSelection(false);
        }
    }

    protected void refreshValidationIndicator() {
        if (validationIndicator != null) {
            if (pModel != null) {
                validationIndicator.setValidationState(pModel.getValidationState());
            } else {
                validationIndicator.setValidationState(null);
            }
        }
    }

    protected void updateModel() {
        if (pModel != null) {
            pModel.setBoolean(button.getSelection());
        }
    }

    /** {@inheritDoc} */
    public void setModelProvider(IModelProvider provider) {
        this.link.setModelProvider(provider);
    }

    /** {@inheritDoc} */
    public IModelProvider getModelProvider() {
        return link.getModelProvider();
    }

    /** {@inheritDoc} */
    public void setPath(Path path) {
        this.link.setPath(path);
    }

    /** {@inheritDoc} */
    public Path getPath() {
        return link.getPath();
    }

    public ValidationIndicator getValidationIndicator() {
        return validationIndicator;
    }

    public void setValidationIndicator(ValidationIndicator validationIndicator) {
        this.validationIndicator = validationIndicator;
    }
}