org.eclipse.help.ui.internal.views.ScopePreferenceDialog.java Source code

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Here is the source code for org.eclipse.help.ui.internal.views.ScopePreferenceDialog.java

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/*******************************************************************************
 * Copyright (c) 2004, 2005 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.help.ui.internal.views;

import java.util.ArrayList;

import org.eclipse.help.ui.internal.Messages;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.preference.*;
import org.eclipse.jface.viewers.*;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.wizard.WizardDialog;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;

public class ScopePreferenceDialog extends PreferenceDialog {
    private EngineDescriptorManager descManager;
    private ArrayList pendingOperations;

    class PendingOperation {
        int action;
        EngineDescriptor desc;

        public PendingOperation(int action, EngineDescriptor desc) {
            this.action = action;
            this.desc = desc;
        }
    }

    /**
     * The Add button id.
     */
    private final static int NEW_ID = IDialogConstants.CLIENT_ID + 1;

    /**
     * The Remove button id.
     */
    private final static int DELETE_ID = IDialogConstants.CLIENT_ID + 2;

    public ScopePreferenceDialog(Shell parentShell, PreferenceManager manager, EngineDescriptorManager descManager,
            boolean editable) {
        super(parentShell, manager);
        this.descManager = descManager;
    }

    protected Control createTreeAreaContents(Composite parent) {
        GridLayout layout = new GridLayout();
        layout.marginWidth = layout.marginHeight = 0;
        Composite container = new Composite(parent, SWT.NULL);
        container.setLayout(layout);
        Control treeControl = super.createTreeAreaContents(container);
        GridData treeGd = (GridData) treeControl.getLayoutData();
        GridData gd = new GridData(GridData.FILL_BOTH);
        gd.horizontalSpan = 2;
        treeControl.setLayoutData(gd);

        Button lbutton = createButton(container, NEW_ID, Messages.ScopePreferenceDialog_new, false);
        gd = (GridData) lbutton.getLayoutData();
        gd.horizontalAlignment = GridData.HORIZONTAL_ALIGN_BEGINNING;
        Button rbutton = createButton(container, DELETE_ID, Messages.ScopePreferenceDialog_delete, false);
        rbutton.setEnabled(false);
        gd = (GridData) rbutton.getLayoutData();
        gd.horizontalAlignment = GridData.HORIZONTAL_ALIGN_BEGINNING;
        layout.numColumns = 2;
        container.setLayoutData(treeGd);
        Point size = container.computeSize(SWT.DEFAULT, SWT.DEFAULT, true);
        treeGd.widthHint = Math.max(treeGd.widthHint, size.x);
        return container;
    }

    protected TreeViewer createTreeViewer(Composite parent) {
        TreeViewer viewer = super.createTreeViewer(parent);
        viewer.addSelectionChangedListener(new ISelectionChangedListener() {
            public void selectionChanged(SelectionChangedEvent event) {
                IStructuredSelection ssel = (IStructuredSelection) event.getSelection();
                Object obj = ssel.getFirstElement();
                treeSelectionChanged(obj);
            }
        });
        return viewer;
    }

    protected void buttonPressed(int buttonId) {
        switch (buttonId) {
        case NEW_ID:
            doNew();
            break;
        case DELETE_ID:
            doDelete();
            break;
        default:
            super.buttonPressed(buttonId);
        }
    }

    private void treeSelectionChanged(Object obj) {
        boolean removable = false;
        if (obj instanceof ScopePreferenceManager.EnginePreferenceNode) {
            ScopePreferenceManager.EnginePreferenceNode node = (ScopePreferenceManager.EnginePreferenceNode) obj;
            EngineDescriptor desc = node.getDescriptor();
            removable = desc.isUserDefined();
        }
        getButton(DELETE_ID).setEnabled(removable);
    }

    private void doNew() {
        NewEngineWizard wizard = new NewEngineWizard(descManager.getEngineTypes());
        WizardDialog dialog = new WizardDialog(getShell(), wizard);
        dialog.create();
        dialog.getShell().setSize(400, 500);
        if (dialog.open() == WizardDialog.OK) {
            EngineTypeDescriptor etdesc = wizard.getSelectedEngineType();
            EngineDescriptor desc = new EngineDescriptor(descManager);
            desc.setEngineType(etdesc);
            desc.setUserDefined(true);
            desc.setId(descManager.computeNewId(etdesc.getId()));
            ScopePreferenceManager mng = (ScopePreferenceManager) getPreferenceManager();
            IPreferenceNode node = mng.addNode(desc);
            getTreeViewer().refresh();
            getTreeViewer().setSelection(new StructuredSelection(node));
            scheduleOperation(NEW_ID, desc);
        }
    }

    private void doDelete() {
        Object obj = ((IStructuredSelection) getTreeViewer().getSelection()).getFirstElement();
        if (obj instanceof ScopePreferenceManager.EnginePreferenceNode) {
            ScopePreferenceManager.EnginePreferenceNode node = (ScopePreferenceManager.EnginePreferenceNode) obj;
            EngineDescriptor desc = node.getDescriptor();
            //ScopePreferenceManager mng = (ScopePreferenceManager)getPreferenceManager();
            getTreeViewer().remove(node);
            scheduleOperation(DELETE_ID, desc);
        }
    }

    private void scheduleOperation(int action, EngineDescriptor desc) {
        if (pendingOperations == null)
            pendingOperations = new ArrayList();
        pendingOperations.add(new PendingOperation(action, desc));
    }

    protected void okPressed() {
        super.okPressed();
        if (pendingOperations != null) {
            // process pending operations
            for (int i = 0; i < pendingOperations.size(); i++) {
                PendingOperation op = (PendingOperation) pendingOperations.get(i);
                if (op.action == NEW_ID)
                    descManager.add(op.desc);
                else
                    descManager.remove(op.desc);
            }
            pendingOperations = null;
        }
        descManager.save();
    }
}