AbstractToggleFrameworkAction.java

/*******************************************************************************
 * Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.tools.workbench.framework.action;

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

import org.eclipse.persistence.tools.workbench.framework.app.AbstractApplicationNode;
import org.eclipse.persistence.tools.workbench.framework.app.ApplicationNode;
import org.eclipse.persistence.tools.workbench.framework.context.WorkbenchContext;


/**
 * Updating framework action that implements the <code>ToggleFrameworkAction</code>
 * interface.  Provides a notion of toggle state in addition to the inherited enabled
 * state identity.
 *
 * @see org.eclipse.persistence.tools.workbench.framework.app.ToggleToolBarButton
 * @version 10.1.3
 */
public abstract class AbstractToggleFrameworkAction
    extends AbstractEnablableFrameworkAction
    implements    ToggleFrameworkAction
{
    private boolean selectionState;
    private PropertyChangeListener selectionStateListener;

    /** the model properties that drive the action's toggle property */
    protected static final String[] DEFAULT_SELECTED_PROPERTY_NAMES = {};


    protected AbstractToggleFrameworkAction(WorkbenchContext context) {
        super(context);
    }

    public void setUp() {
        super.setUp();
        updateSelectionState();
    }


    /**
     * The tree selection changed, update the action's selection state as necessary.
     * The selected nodes are available via #selectedNodes().
     */
    protected void updateSelectionState() {
        ApplicationNode[] selectedNodes = selectedNodes();
        for (int i = 0; i < selectedNodes.length; i++) {
            ApplicationNode selectedNode = selectedNodes[i];
            if (!this.shouldBeSelected(selectedNode)) {
                setSelected(false);
                return;
            }
        }

        setSelected(true);
    }

    /**
     * Subclasses implement this and return whether this action should be selected given
     * the current selected node's state.
     *
     * This does not refer to the node selection, it refers to the action's selection state.
     * If the action is used for a toolBar button it can appear selected.
     * If the action is used as a checkBox menu item the check will appear/disappear based on
     * selection state.
     */
    protected abstract boolean shouldBeSelected(ApplicationNode selectedNode);


    public void setSelected(boolean selectionState) {
        boolean oldValue = this.selectionState;
        this.selectionState = selectionState;
        firePropertyChange(TOGGLE_STATE_PROPERTY, Boolean.valueOf(oldValue), Boolean.valueOf(this.selectionState));
    }

    public boolean isSelected() {
        return this.selectionState;
    }

    protected void engageListeners(AbstractApplicationNode node) {
        super.engageListeners(node);
        engageValueSelected(node);
    }

    protected void engageValueSelected(AbstractApplicationNode node) {
        this.engageValue(node, this.selectedPropertyNames(), getSelectionStateListener());
    }

    protected void disengageListeners(AbstractApplicationNode node) {
        super.disengageListeners(node);
        disengageValueSelected(node);
    }

    protected void disengageValueSelected(AbstractApplicationNode node) {
        this.disengageValue(node, this.selectedPropertyNames(), getSelectionStateListener());
    }

    protected PropertyChangeListener getSelectionStateListener() {
        if (this.selectionStateListener == null) {
            this.selectionStateListener = buildSelectionStateListener();
        }
        return this.selectionStateListener;
    }

    protected PropertyChangeListener buildSelectionStateListener() {
        return new PropertyChangeListener() {
            public void propertyChange(PropertyChangeEvent evt) {
                updateSelectionState();
            }
        };
    }

    /**
     * Return the names of the value's properties that affect
     * the action's selection state.
     */
    protected String[] selectedPropertyNames() {
        return DEFAULT_SELECTED_PROPERTY_NAMES;
    }
}