vaadin-framework/src/com/itmill/toolkit/ui/AbstractComponent.java

/* 
@ITMillApache2LicenseForJavaFiles@
 */

package com.itmill.toolkit.ui;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Locale;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import com.itmill.toolkit.Application;
import com.itmill.toolkit.event.EventRouter;
import com.itmill.toolkit.event.MethodEventSource;
import com.itmill.toolkit.terminal.ErrorMessage;
import com.itmill.toolkit.terminal.PaintException;
import com.itmill.toolkit.terminal.PaintTarget;
import com.itmill.toolkit.terminal.Resource;
import com.itmill.toolkit.terminal.Terminal;

/**
 * An abstract class that defines default implementation for the
 * {@link Component} interface. Basic UI components that are not derived from an
 * external component can inherit this class to easily qualify as a IT Mill
 * Toolkit component. Most components in the toolkit do just that.
 * 
 * @author IT Mill Ltd.
 * @version
 * @VERSION@
 * @since 3.0
 */
public abstract class AbstractComponent implements Component, MethodEventSource {

    /* Private members */

    /**
     * Style names.
     */
    private ArrayList styles;

    /**
     * Caption text.
     */
    private String caption;

    /**
     * Application specific data object. The component does not use or modify
     * this.
     */
    private Object applicationData;

    /**
     * Icon to be shown together with caption.
     */
    private Resource icon;

    /**
     * Is the component enabled (its normal usage is allowed).
     */
    private boolean enabled = true;

    /**
     * Is the component visible (it is rendered).
     */
    private boolean visible = true;

    /**
     * Is the component read-only ?
     */
    private boolean readOnly = false;

    /**
     * Description of the usage (XML).
     */
    private String description = null;

    /**
     * The container this component resides in.
     */
    private Component parent = null;

    /**
     * The EventRouter used for the event model.
     */
    private EventRouter eventRouter = null;

    /**
     * The internal error message of the component.
     */
    private ErrorMessage componentError = null;

    /**
     * Immediate mode: if true, all variable changes are required to be sent
     * from the terminal immediately.
     */
    private boolean immediate = false;

    /**
     * Locale of this component.
     */
    private Locale locale;

    /**
     * List of repaint request listeners or null if not listened at all.
     */
    private LinkedList repaintRequestListeners = null;

    /**
     * Are all the repaint listeners notified about recent changes ?
     */
    private boolean repaintRequestListenersNotified = false;

    private String testingId;

    /* Sizeable fields */

    private float width = SIZE_UNDEFINED;
    private float height = SIZE_UNDEFINED;
    private int widthUnit = UNITS_PIXELS;
    private int heightUnit = UNITS_PIXELS;
    private static final Pattern sizePattern = Pattern
            .compile("^(-?\\d+(\\.\\d+)?)(%|px|em|ex|in|cm|mm|pt|pc)?$");

    private ComponentErrorHandler errorHandler = null;

    /* Constructor */

    /**
     * Constructs a new Component.
     */
    public AbstractComponent() {
    }

    /* Get/Set component properties */

    /**
     * Gets the UIDL tag corresponding to the component.
     * 
     * @return the component's UIDL tag as <code>String</code>
     */
    public abstract String getTag();

    public void setDebugId(String id) {
        testingId = id;
    }

    public String getDebugId() {
        return testingId;
    }

    /**
     * Gets style for component. Multiple styles are joined with spaces.
     * 
     * @return the component's styleValue of property style.
     * @deprecated Use getStyleName() instead; renamed for consistency and to
     *             indicate that "style" should not be used to switch client
     *             side implementation, only to style the component.
     */
    public String getStyle() {
        return getStyleName();
    }

    /**
     * Sets and replaces all previous style names of the component. This method
     * will trigger a
     * {@link com.itmill.toolkit.terminal.Paintable.RepaintRequestEvent
     * RepaintRequestEvent}.
     * 
     * @param style
     *            the new style of the component.
     * @deprecated Use setStyleName() instead; renamed for consistency and to
     *             indicate that "style" should not be used to switch client
     *             side implementation, only to style the component.
     */
    public void setStyle(String style) {
        setStyleName(style);
    }

    /*
     * Gets the component's style. Don't add a JavaDoc comment here, we use the
     * default documentation from implemented interface.
     */
    public String getStyleName() {
        String s = "";
        if (styles != null) {
            for (final Iterator it = styles.iterator(); it.hasNext();) {
                s += (String) it.next();
                if (it.hasNext()) {
                    s += " ";
                }
            }
        }
        return s;
    }

    /*
     * Sets the component's style. Don't add a JavaDoc comment here, we use the
     * default documentation from implemented interface.
     */
    public void setStyleName(String style) {
        if (style == null || "".equals(style)) {
            styles = null;
            requestRepaint();
            return;
        }
        if (styles == null) {
            styles = new ArrayList();
        }
        styles.clear();
        styles.add(style);
        requestRepaint();
    }

    public void addStyleName(String style) {
        if (style == null || "".equals(style)) {
            return;
        }
        if (styles == null) {
            styles = new ArrayList();
        }
        if (!styles.contains(style)) {
            styles.add(style);
            requestRepaint();
        }
    }

    public void removeStyleName(String style) {
        styles.remove(style);
        requestRepaint();
    }

    /*
     * Get's the component's caption. Don't add a JavaDoc comment here, we use
     * the default documentation from implemented interface.
     */
    public String getCaption() {
        return caption;
    }

    /**
     * Sets the component's caption <code>String</code>. Caption is the visible
     * name of the component. This method will trigger a
     * {@link com.itmill.toolkit.terminal.Paintable.RepaintRequestEvent
     * RepaintRequestEvent}.
     * 
     * @param caption
     *            the new caption <code>String</code> for the component.
     */
    public void setCaption(String caption) {
        this.caption = caption;
        requestRepaint();
    }

    /*
     * Don't add a JavaDoc comment here, we use the default documentation from
     * implemented interface.
     */
    public Locale getLocale() {
        if (locale != null) {
            return locale;
        }
        if (parent != null) {
            return parent.getLocale();
        }
        final Application app = getApplication();
        if (app != null) {
            return app.getLocale();
        }
        return null;
    }

    /**
     * Sets the locale of this component.
     * 
     * @param locale
     *            the locale to become this component's locale.
     */
    public void setLocale(Locale locale) {
        this.locale = locale;
    }

    /*
     * Gets the component's icon resource. Don't add a JavaDoc comment here, we
     * use the default documentation from implemented interface.
     */
    public Resource getIcon() {
        return icon;
    }

    /**
     * Sets the component's icon. This method will trigger a
     * {@link com.itmill.toolkit.terminal.Paintable.RepaintRequestEvent
     * RepaintRequestEvent}.
     * 
     * @param icon
     *            the icon to be shown with the component's caption.
     */
    public void setIcon(Resource icon) {
        this.icon = icon;
        requestRepaint();
    }

    /*
     * Tests if the component is enabled or not. Don't add a JavaDoc comment
     * here, we use the default documentation from implemented interface.
     */
    public boolean isEnabled() {
        return enabled && (parent == null || parent.isEnabled()) && isVisible();
    }

    /*
     * Enables or disables the component. Don't add a JavaDoc comment here, we
     * use the default documentation from implemented interface.
     */
    public void setEnabled(boolean enabled) {
        if (this.enabled != enabled) {
            boolean wasEnabled = isEnabled();
            this.enabled = enabled;
            // don't repaint if ancestor is disabled
            if (wasEnabled != isEnabled()) {
                requestRepaint();
            }
        }
    }

    /*
     * Tests if the component is in the immediate mode. Don't add a JavaDoc
     * comment here, we use the default documentation from implemented
     * interface.
     */
    public boolean isImmediate() {
        return immediate;
    }

    /**
     * Sets the component's immediate mode to the specified status. This method
     * will trigger a
     * {@link com.itmill.toolkit.terminal.Paintable.RepaintRequestEvent
     * RepaintRequestEvent}.
     * 
     * @param immediate
     *            the boolean value specifying if the component should be in the
     *            immediate mode after the call.
     * @see Component#isImmediate()
     */
    public void setImmediate(boolean immediate) {
        this.immediate = immediate;
        requestRepaint();
    }

    /*
     * Tests if the component is visible. Don't add a JavaDoc comment here, we
     * use the default documentation from implemented interface.
     */
    public boolean isVisible() {
        return visible;
    }

    /*
     * Sets the components visibility. Don't add a JavaDoc comment here, we use
     * the default documentation from implemented interface.
     */
    public void setVisible(boolean visible) {

        if (this.visible != visible) {
            this.visible = visible;
            // Instead of requesting repaint normally we
            // fire the event directly to assure that the
            // event goes through event in the component might
            // now be invisible
            fireRequestRepaintEvent(null);
        }
    }

    /**
     * <p>
     * Gets the component's description. The description can be used to briefly
     * describe the state of the component to the user. The description string
     * may contain certain XML tags:
     * </p>
     * 
     * <p>
     * <table border=1>
     * <tr>
     * <td width=120><b>Tag</b></td>
     * <td width=120><b>Description</b></td>
     * <td width=120><b>Example</b></td>
     * </tr>
     * <tr>
     * <td>&lt;b></td>
     * <td>bold</td>
     * <td><b>bold text</b></td>
     * </tr>
     * <tr>
     * <td>&lt;i></td>
     * <td>italic</td>
     * <td><i>italic text</i></td>
     * </tr>
     * <tr>
     * <td>&lt;u></td>
     * <td>underlined</td>
     * <td><u>underlined text</u></td>
     * </tr>
     * <tr>
     * <td>&lt;br></td>
     * <td>linebreak</td>
     * <td>N/A</td>
     * </tr>
     * <tr>
     * <td>&lt;ul><br>
     * &lt;li>item1<br>
     * &lt;li>item1<br>
     * &lt;/ul></td>
     * <td>item list</td>
     * <td>
     * <ul>
     * <li>item1
     * <li>item2
     * </ul>
     * </td>
     * </tr>
     * </table>
     * </p>
     * 
     * <p>
     * These tags may be nested.
     * </p>
     * 
     * @return component's description <code>String</code>
     */
    public String getDescription() {
        return description;
    }

    /**
     * Sets the component's description. See {@link #getDescription()} for more
     * information on what the description is. This method will trigger a
     * {@link com.itmill.toolkit.terminal.Paintable.RepaintRequestEvent
     * RepaintRequestEvent}.
     * 
     * @param description
     *            the new description string for the component.
     */
    public void setDescription(String description) {
        this.description = description;
        requestRepaint();
    }

    /*
     * Gets the component's parent component. Don't add a JavaDoc comment here,
     * we use the default documentation from implemented interface.
     */
    public Component getParent() {
        return parent;
    }

    /*
     * Sets the parent component. Don't add a JavaDoc comment here, we use the
     * default documentation from implemented interface.
     */
    public void setParent(Component parent) {

        // If the parent is not changed, don't do anything
        if (parent == this.parent) {
            return;
        }

        if (parent != null && this.parent != null) {
            throw new IllegalStateException("Component already has a parent.");
        }

        // Send detach event if the component have been connected to a window
        if (getApplication() != null) {
            detach();
        }

        // Connect to new parent
        this.parent = parent;

        // Send attach event if connected to a window
        if (getApplication() != null) {
            attach();
        }
    }

    /**
     * Gets the error message for this component.
     * 
     * @return ErrorMessage containing the description of the error state of the
     *         component or null, if the component contains no errors. Extending
     *         classes should override this method if they support other error
     *         message types such as validation errors or buffering errors. The
     *         returned error message contains information about all the errors.
     */
    public ErrorMessage getErrorMessage() {
        return componentError;
    }

    /**
     * Gets the component's error message.
     * 
     * @link Terminal.ErrorMessage#ErrorMessage(String, int)
     * 
     * @return the component's error message.
     */
    public ErrorMessage getComponentError() {
        return componentError;
    }

    /**
     * Sets the component's error message. The message may contain certain XML
     * tags, for more information see
     * 
     * @link Component.ErrorMessage#ErrorMessage(String, int)
     * 
     * @param componentError
     *            the new <code>ErrorMessage</code> of the component.
     */
    public void setComponentError(ErrorMessage componentError) {
        this.componentError = componentError;
        fireComponentErrorEvent();
        requestRepaint();
    }

    /*
     * Tests if the component is in read-only mode. Don't add a JavaDoc comment
     * here, we use the default documentation from implemented interface.
     */
    public boolean isReadOnly() {
        return readOnly;
    }

    /*
     * Sets the component's read-only mode. Don't add a JavaDoc comment here, we
     * use the default documentation from implemented interface.
     */
    public void setReadOnly(boolean readOnly) {
        this.readOnly = readOnly;
        requestRepaint();
    }

    /*
     * Gets the parent window of the component. Don't add a JavaDoc comment
     * here, we use the default documentation from implemented interface.
     */
    public Window getWindow() {
        if (parent == null) {
            return null;
        } else {
            return parent.getWindow();
        }
    }

    /*
     * Notify the component that it's attached to a window. Don't add a JavaDoc
     * comment here, we use the default documentation from implemented
     * interface.
     */
    public void attach() {
        requestRepaint();
    }

    /*
     * Detach the component from application. Don't add a JavaDoc comment here,
     * we use the default documentation from implemented interface.
     */
    public void detach() {
    }

    /*
     * Gets the parent application of the component. Don't add a JavaDoc comment
     * here, we use the default documentation from implemented interface.
     */
    public Application getApplication() {
        if (parent == null) {
            return null;
        } else {
            return parent.getApplication();
        }
    }

    /* Component painting */

    /* Documented in super interface */
    public void requestRepaintRequests() {
        repaintRequestListenersNotified = false;
    }

    /*
     * Paints the component into a UIDL stream. Don't add a JavaDoc comment
     * here, we use the default documentation from implemented interface.
     */
    public final void paint(PaintTarget target) throws PaintException {
        if (!target.startTag(this, getTag()) || repaintRequestListenersNotified) {

            // Paint the contents of the component

            // Only paint content of visible components.
            if (isVisible()) {

                if (getHeight() >= 0) {
                    target.addAttribute("height", "" + getCSSHeight());
                }
                if (getWidth() >= 0) {
                    target.addAttribute("width", "" + getCSSWidth());
                }

                if (styles != null && styles.size() > 0) {
                    target.addAttribute("style", getStyle());
                }
                if (isReadOnly()) {
                    target.addAttribute("readonly", true);
                }

                if (isImmediate()) {
                    target.addAttribute("immediate", true);
                }
                if (!isEnabled()) {
                    target.addAttribute("disabled", true);
                }
                if (getCaption() != null) {
                    target.addAttribute("caption", getCaption());
                }
                if (getIcon() != null) {
                    target.addAttribute("icon", getIcon());
                }

                if (getDescription() != null && getDescription().length() > 0) {
                    target.addAttribute("description", getDescription());
                }

                paintContent(target);

                final ErrorMessage error = getErrorMessage();
                if (error != null) {
                    error.paint(target);
                }
            } else {
                target.addAttribute("invisible", true);
            }
        } else {

            // Contents have not changed, only cached presentation can be used
            target.addAttribute("cached", true);
        }
        target.endTag(getTag());

        repaintRequestListenersNotified = false;
    }

    /**
     * Build CSS compatible string representation of height.
     * 
     * @return CSS height
     */
    private String getCSSHeight() {
        if (getHeightUnits() == UNITS_PIXELS) {
            return ((int) getHeight()) + UNIT_SYMBOLS[getHeightUnits()];
        } else {
            return getHeight() + UNIT_SYMBOLS[getHeightUnits()];
        }
    }

    /**
     * Build CSS compatible string representation of width.
     * 
     * @return CSS width
     */
    private String getCSSWidth() {
        if (getWidthUnits() == UNITS_PIXELS) {
            return ((int) getWidth()) + UNIT_SYMBOLS[getWidthUnits()];
        } else {
            return getWidth() + UNIT_SYMBOLS[getWidthUnits()];
        }
    }

    /**
     * Paints any needed component-specific things to the given UIDL stream. The
     * more general {@link #paint(PaintTarget)} method handles all general
     * attributes common to all components, and it calls this method to paint
     * any component-specific attributes to the UIDL stream.
     * 
     * @param target
     *            the target UIDL stream where the component should paint itself
     *            to
     * @throws PaintException
     *             if the paint operation failed.
     */
    public void paintContent(PaintTarget target) throws PaintException {

    }

    /* Documentation copied from interface */
    public void requestRepaint() {

        // The effect of the repaint request is identical to case where a
        // child requests repaint
        childRequestedRepaint(null);
    }

    /* Documentation copied from interface */
    public void childRequestedRepaint(Collection alreadyNotified) {
        // Invisible components do not need repaints
        if (!isVisible()) {
            return;
        }

        fireRequestRepaintEvent(alreadyNotified);
    }

    /**
     * Fires the repaint request event.
     * 
     * @param alreadyNotified
     */
    private void fireRequestRepaintEvent(Collection alreadyNotified) {
        // Notify listeners only once
        if (!repaintRequestListenersNotified) {
            // Notify the listeners
            if (repaintRequestListeners != null
                    && !repaintRequestListeners.isEmpty()) {
                final Object[] listeners = repaintRequestListeners.toArray();
                final RepaintRequestEvent event = new RepaintRequestEvent(this);
                for (int i = 0; i < listeners.length; i++) {
                    if (alreadyNotified == null) {
                        alreadyNotified = new LinkedList();
                    }
                    if (!alreadyNotified.contains(listeners[i])) {
                        ((RepaintRequestListener) listeners[i])
                                .repaintRequested(event);
                        alreadyNotified.add(listeners[i]);
                        repaintRequestListenersNotified = true;
                    }
                }
            }

            // Notify the parent
            final Component parent = getParent();
            if (parent != null) {
                parent.childRequestedRepaint(alreadyNotified);
            }
        }
    }

    /* Documentation copied from interface */
    public void addListener(RepaintRequestListener listener) {
        if (repaintRequestListeners == null) {
            repaintRequestListeners = new LinkedList();
        }
        if (!repaintRequestListeners.contains(listener)) {
            repaintRequestListeners.add(listener);
        }
    }

    /* Documentation copied from interface */
    public void removeListener(RepaintRequestListener listener) {
        if (repaintRequestListeners != null) {
            repaintRequestListeners.remove(listener);
            if (repaintRequestListeners.isEmpty()) {
                repaintRequestListeners = null;
            }
        }
    }

    /* Component variable changes */

    /*
     * Invoked when the value of a variable has changed. Don't add a JavaDoc
     * comment here, we use the default documentation from implemented
     * interface.
     */
    public void changeVariables(Object source, Map variables) {
    }

    /* General event framework */

    private static final Method COMPONENT_EVENT_METHOD;

    static {
        try {
            COMPONENT_EVENT_METHOD = Component.Listener.class
                    .getDeclaredMethod("componentEvent",
                            new Class[] { Component.Event.class });
        } catch (final java.lang.NoSuchMethodException e) {
            // This should never happen
            throw new java.lang.RuntimeException(
                    "Internal error finding methods in AbstractComponent");
        }
    }

    /**
     * <p>
     * Registers a new listener with the specified activation method to listen
     * events generated by this component. If the activation method does not
     * have any arguments the event object will not be passed to it when it's
     * called.
     * </p>
     * 
     * <p>
     * For more information on the inheritable event mechanism see the
     * {@link com.itmill.toolkit.event com.itmill.toolkit.event package
     * documentation}.
     * </p>
     * 
     * @param eventType
     *            the type of the listened event. Events of this type or its
     *            subclasses activate the listener.
     * @param object
     *            the object instance who owns the activation method.
     * @param method
     *            the activation method.
     */
    public void addListener(Class eventType, Object object, Method method) {
        if (eventRouter == null) {
            eventRouter = new EventRouter();
        }
        eventRouter.addListener(eventType, object, method);
    }

    /**
     * <p>
     * Convenience method for registering a new listener with the specified
     * activation method to listen events generated by this component. If the
     * activation method does not have any arguments the event object will not
     * be passed to it when it's called.
     * </p>
     * 
     * <p>
     * This version of <code>addListener</code> gets the name of the activation
     * method as a parameter. The actual method is reflected from
     * <code>object</code>, and unless exactly one match is found,
     * <code>java.lang.IllegalArgumentException</code> is thrown.
     * </p>
     * 
     * <p>
     * For more information on the inheritable event mechanism see the
     * {@link com.itmill.toolkit.event com.itmill.toolkit.event package
     * documentation}.
     * </p>
     * 
     * <p>
     * Note: Using this method is discouraged because it cannot be checked
     * during compilation. Use {@link #addListener(Class, Object, Method)} or
     * {@link #addListener(com.itmill.toolkit.ui.Component.Listener)} instead.
     * </p>
     * 
     * @param eventType
     *            the type of the listened event. Events of this type or its
     *            subclasses activate the listener.
     * @param object
     *            the object instance who owns the activation method.
     * @param methodName
     *            the name of the activation method.
     */
    public void addListener(Class eventType, Object object, String methodName) {
        if (eventRouter == null) {
            eventRouter = new EventRouter();
        }
        eventRouter.addListener(eventType, object, methodName);
    }

    /**
     * Removes all registered listeners matching the given parameters. Since
     * this method receives the event type and the listener object as
     * parameters, it will unregister all <code>object</code>'s methods that are
     * registered to listen to events of type <code>eventType</code> generated
     * by this component.
     * 
     * <p>
     * For more information on the inheritable event mechanism see the
     * {@link com.itmill.toolkit.event com.itmill.toolkit.event package
     * documentation}.
     * </p>
     * 
     * @param eventType
     *            the exact event type the <code>object</code> listens to.
     * @param target
     *            the target object that has registered to listen to events of
     *            type <code>eventType</code> with one or more methods.
     */
    public void removeListener(Class eventType, Object target) {
        if (eventRouter != null) {
            eventRouter.removeListener(eventType, target);
        }
    }

    /**
     * Removes one registered listener method. The given method owned by the
     * given object will no longer be called when the specified events are
     * generated by this component.
     * 
     * <p>
     * For more information on the inheritable event mechanism see the
     * {@link com.itmill.toolkit.event com.itmill.toolkit.event package
     * documentation}.
     * </p>
     * 
     * @param eventType
     *            the exact event type the <code>object</code> listens to.
     * @param target
     *            target object that has registered to listen to events of type
     *            <code>eventType</code> with one or more methods.
     * @param method
     *            the method owned by <code>target</code> that's registered to
     *            listen to events of type <code>eventType</code>.
     */
    public void removeListener(Class eventType, Object target, Method method) {
        if (eventRouter != null) {
            eventRouter.removeListener(eventType, target, method);
        }
    }

    /**
     * <p>
     * Removes one registered listener method. The given method owned by the
     * given object will no longer be called when the specified events are
     * generated by this component.
     * </p>
     * 
     * <p>
     * This version of <code>removeListener</code> gets the name of the
     * activation method as a parameter. The actual method is reflected from
     * <code>target</code>, and unless exactly one match is found,
     * <code>java.lang.IllegalArgumentException</code> is thrown.
     * </p>
     * 
     * <p>
     * For more information on the inheritable event mechanism see the
     * {@link com.itmill.toolkit.event com.itmill.toolkit.event package
     * documentation}.
     * </p>
     * 
     * @param eventType
     *            the exact event type the <code>object</code> listens to.
     * @param target
     *            the target object that has registered to listen to events of
     *            type <code>eventType</code> with one or more methods.
     * @param methodName
     *            the name of the method owned by <code>target</code> that's
     *            registered to listen to events of type <code>eventType</code>.
     */
    public void removeListener(Class eventType, Object target, String methodName) {
        if (eventRouter != null) {
            eventRouter.removeListener(eventType, target, methodName);
        }
    }

    /**
     * Sends the event to all listeners.
     * 
     * @param event
     *            the Event to be sent to all listeners.
     */
    protected void fireEvent(Component.Event event) {
        if (eventRouter != null) {
            eventRouter.fireEvent(event);
        }

    }

    /* Component event framework */

    /*
     * Registers a new listener to listen events generated by this component.
     * Don't add a JavaDoc comment here, we use the default documentation from
     * implemented interface.
     */
    public void addListener(Component.Listener listener) {
        if (eventRouter == null) {
            eventRouter = new EventRouter();
        }

        eventRouter.addListener(Component.Event.class, listener,
                COMPONENT_EVENT_METHOD);
    }

    /*
     * Removes a previously registered listener from this component. Don't add a
     * JavaDoc comment here, we use the default documentation from implemented
     * interface.
     */
    public void removeListener(Component.Listener listener) {
        if (eventRouter != null) {
            eventRouter.removeListener(Component.Event.class, listener,
                    COMPONENT_EVENT_METHOD);
        }
    }

    /**
     * Emits the component event. It is transmitted to all registered listeners
     * interested in such events.
     */
    protected void fireComponentEvent() {
        fireEvent(new Component.Event(this));
    }

    /**
     * Emits the component error event. It is transmitted to all registered
     * listeners interested in such events.
     */
    protected void fireComponentErrorEvent() {
        fireEvent(new Component.ErrorEvent(getComponentError(), this));
    }

    /**
     * Sets the data object, that can be used for any application specific data.
     * The component does not use or modify this data.
     * 
     * @param data
     *            the Application specific data.
     * @since 3.1
     */
    public void setData(Object data) {
        applicationData = data;
    }

    /**
     * Gets the application specific data. See {@link #setData(Object)}.
     * 
     * @return the Application specific data set with setData function.
     * @since 3.1
     */
    public Object getData() {
        return applicationData;
    }

    /* Sizeable and other size related methods */

    public float getHeight() {
        return height;
    }

    public int getHeightUnits() {
        return heightUnit;
    }

    public float getWidth() {
        return width;
    }

    public int getWidthUnits() {
        return widthUnit;
    }

    public void setHeight(float height) {
        this.height = height;
        requestRepaint();
    }

    /**
     * Sets the height property units.
     * 
     * @param units
     *            the units used in height property.
     * @deprecated Consider setting height and unit simultaneously using
     *             {@link #setHeight(String)} or {@link #setHeight(float, int)},
     *             which is less error-prone.
     */
    public void setHeightUnits(int unit) {
        heightUnit = unit;
        requestRepaint();
    }

    /**
     * Sets the height of the object. Negative number implies unspecified size
     * (terminal is free to set the size).
     * 
     * @param height
     *            the height of the object in units specified by heightUnits
     *            property.
     * @deprecated Consider using {@link #setHeight(String)} or
     *             {@link #setHeight(float, int)} instead. This method works,
     *             but is error-prone since the unit must be set separately (and
     *             components might have different default unit).
     */
    public void setHeight(float height, int unit) {
        this.height = height;
        heightUnit = unit;
        requestRepaint();
    }

    public void setSizeFull() {
        height = 100;
        width = 100;
        heightUnit = UNITS_PERCENTAGE;
        widthUnit = UNITS_PERCENTAGE;
        requestRepaint();
    }

    public void setSizeUndefined() {
        height = -1;
        width = -1;
        heightUnit = UNITS_PIXELS;
        widthUnit = UNITS_PIXELS;
        requestRepaint();
    }

    /**
     * Sets the width of the object. Negative number implies unspecified size
     * (terminal is free to set the size).
     * 
     * @param width
     *            the width of the object in units specified by widthUnits
     *            property.
     * @deprecated Consider using {@link #setWidth(String)} instead. This method
     *             works, but is error-prone since the unit must be set
     *             separately (and components might have different default
     *             unit).
     */
    public void setWidth(float width) {
        this.width = width;
        requestRepaint();
    }

    /**
     * Sets the width property units.
     * 
     * @param units
     *            the units used in width property.
     * @deprecated Consider setting width and unit simultaneously using
     *             {@link #setWidth(String)} or {@link #setWidth(float, int)},
     *             which is less error-prone.
     */
    public void setWidthUnits(int unit) {
        widthUnit = unit;
        requestRepaint();
    }

    public void setWidth(float width, int unit) {
        this.width = width;
        widthUnit = unit;
        requestRepaint();
    }

    public void setWidth(String width) {
        float[] p = parseStringSize(width);
        this.width = p[0];
        widthUnit = (int) p[1];
        requestRepaint();
    }

    public void setHeight(String height) {
        float[] p = parseStringSize(height);
        this.height = p[0];
        heightUnit = (int) p[1];
        requestRepaint();
    }

    /*
     * Returns array with size in index 0 unit in index 1. Null or empty string
     * will produce {-1,UNITS_PIXELS}
     */
    private static float[] parseStringSize(String s) {
        float[] values = { -1, UNITS_PIXELS };
        if (s == null) {
            return values;
        }
        s = s.trim();
        if ("".equals(s)) {
            return values;
        }

        Matcher matcher = sizePattern.matcher(s);
        if (matcher.find()) {
            values[0] = Float.parseFloat(matcher.group(1));
            if (values[0] < 0) {
                values[0] = -1;
            } else {
                String unit = matcher.group(3);
                if (unit == null) {
                    values[1] = UNITS_PIXELS;
                } else if (unit.equals("px")) {
                    values[1] = UNITS_PIXELS;
                } else if (unit.equals("%")) {
                    values[1] = UNITS_PERCENTAGE;
                } else if (unit.equals("em")) {
                    values[1] = UNITS_EM;
                } else if (unit.equals("ex")) {
                    values[1] = UNITS_EX;
                } else if (unit.equals("in")) {
                    values[1] = UNITS_INCH;
                } else if (unit.equals("cm")) {
                    values[1] = UNITS_CM;
                } else if (unit.equals("mm")) {
                    values[1] = UNITS_MM;
                } else if (unit.equals("pt")) {
                    values[1] = UNITS_POINTS;
                } else if (unit.equals("pc")) {
                    values[1] = UNITS_PICAS;
                }
            }
        } else {
            throw new IllegalArgumentException("Invalid size argument: \"" + s
                    + "\" (should match " + sizePattern.pattern() + ")");
        }
        return values;
    }

    public interface ComponentErrorEvent extends Terminal.ErrorEvent {
    }

    public interface ComponentErrorHandler {
        /**
         * Handle the component error
         * 
         * @param event
         * @return True if the error has been handled False, otherwise
         */
        public boolean handleComponentError(ComponentErrorEvent event);
    }

    /**
     * Gets the error handler for the component.
     * 
     * The error handler is dispatched whenever there is an error processing the
     * data coming from the client.
     * 
     * @return
     */
    public ComponentErrorHandler getErrorHandler() {
        return errorHandler;
    }

    /**
     * Sets the error handler for the component.
     * 
     * The error handler is dispatched whenever there is an error processing the
     * data coming from the client.
     * 
     * If the error handler is not set, the application error handler is used to
     * handle the exception.
     * 
     * @param errorHandler
     *            AbstractField specific error handler
     */
    public void setErrorHandler(ComponentErrorHandler errorHandler) {
        this.errorHandler = errorHandler;
    }

    /**
     * Handle the component error event.
     * 
     * @param error
     *            Error event to handle
     * @return True if the error has been handled False, otherwise. If the error
     *         haven't been handled by this component, it will be handled in the
     *         application error handler.
     */
    public boolean handleError(ComponentErrorEvent error) {
        if (errorHandler != null) {
            return errorHandler.handleComponentError(error);
        }
        return false;

    }

}