BnPushButtonDecorator.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.IOperationPM;
import org.beanfabrics.util.ExceptionUtil;
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 BnPushButtonDecorator extends AbstractDecorator<Button> implements View<IOperationPM>, ModelSubscriber {
    private final Link link = new Link(this);
    private final PropertyChangeListener listener = new WeakPropertyChangeListener() {
        public void propertyChange(PropertyChangeEvent evt) {
            refreshUI();
        }
    };

    private Button button;
    private IOperationPM pModel;
    private boolean textSetManually = false;

    /**
     * Create the BnPushButtonDecorator
     */
    public BnPushButtonDecorator(Button button) {
        super(button);
        checkStyle(button.getStyle());
        this.button = button;
        if (button.getText().length() > 0) {
            textSetManually = true;
        }
        hookControl(button);
    }

    private void checkStyle(int style) {
        if ((style & SWT.PUSH) == 0) {
            throw new IllegalArgumentException("Button must be styled with SWT.PUSH");
        }
    }

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

    /**
     * Create the BnPushButtonDecorator
     * 
     * @param parent
     */
    public BnPushButtonDecorator(Composite parent) {
        this(new Button(parent, SWT.PUSH));
    }

    protected void hookControl(Button button) {
        button.addSelectionListener(new SelectionListener() {
            public void widgetSelected(SelectionEvent evt) {
                boolean doContinue = executeOperation();
                if ( !doContinue) {
                	// We should stop any further processing of this event
                	evt.doit = false;
                }
            }

            public void widgetDefaultSelected(SelectionEvent evt) {
                // ignore
            }
        });
    }

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

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

    protected void refreshUI() {
        refreshText();
        refreshEnabled();
        refreshTooltip();
    }

    private void refreshText() {
        if (textSetManually == false) {
            if (pModel != null && pModel.getTitle() != null) {
                button.setText(pModel.getTitle());
            } else {
                button.setText("");
            }
        }
    }

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

    private boolean executeOperation() {
        try {
            if (pModel != null) {
                return pModel.execute();
            }
        } catch (Throwable e) {
            ExceptionUtil.getInstance().handleException("", e);
        }
        return true; 
    }

    /** {@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();
    }

    /**
     * @deprecated use {@link #getControl()}
     */
    public Button getButton() {
        return getControl();
    }
}