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package net.sf.cuf.state.ui;

import net.sf.cuf.state.State;

import javax.swing.Action;
import javax.swing.JComponent;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

/**
 * The SwingSelectedState class models a State with a Swing JComponent or
 * Action as the state source.

 */
public class SwingEnabledState extends AbstractSwingState implements State, PropertyChangeListener
{
    // null or the JComponent we use as enable/disable source
    private JComponent        mComponent;
    // null or the Action we use as enable/disable source
    private Action            mAction;

    // for the property change stuff
    private static final String ENABLED_NAME = "enabled";

    /**
     * Creates a new initialized state with the Swing JComponent as its
     * state backing store.
     * @param pComponent the state source for this state
     * @throws IllegalArgumentException if pComponent is null
     */
    public SwingEnabledState(final JComponent pComponent)
    {
        super();
        if (pComponent==null)
        {
            throw new IllegalArgumentException("component must not be null");
        }
        mAction   = null;
        mComponent= pComponent;
        mName     = mComponent.getName();
        if (mName==null)
            mName= "";

        // initially set the state according to the document
        mIsEnabled= getInternalState();

        mComponent.addPropertyChangeListener(ENABLED_NAME, this);
    }

    /**
     * Creates a new initialized state with the Swing Action as its
     * state backing store.
     * @param pAction the state source for this state
     * @throws IllegalArgumentException if pAction is null
     */
    public SwingEnabledState(final Action pAction)
    {
        super();
        if (pAction==null)
        {
            throw new IllegalArgumentException("component must not be null");
        }
        mAction   = pAction;
        mComponent= null;
        mName     = "";
        mAction.addPropertyChangeListener(this);
    }

    /**
     * This method gets called when a bound property is changed.
     * @param  pEvent A PropertyChangeEvent object describing the event source
     *         and the property that has changed.
     */
    public void propertyChange(final PropertyChangeEvent pEvent)
    {
        if (ENABLED_NAME.equals(pEvent.getPropertyName()))
        {
            checkStateChange();
        }
    }

    /**
     * Set the source of the state as the reason for a change.
     */
    protected void setReason()
    {
        if (mComponent != null)
        {
            mReason= mComponent;
        }
        else
        {
            mReason= mAction;
        }
    }

    /**
     * Returns the enabled state of our component/action.
     * @return true if our component or action is enabled
     */
    protected boolean getInternalState()
    {
        if (mComponent != null)
        {
            return mComponent.isEnabled();
        }
        else
        {
            return mAction.isEnabled();
        }
    }
}