/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ui.views.navigator;

import java.util.Iterator;
import java.util.List;

import org.eclipse.core.resources.IContainer;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.IPath;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.util.Assert;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.swt.SWTError;
import org.eclipse.swt.dnd.Clipboard;
import org.eclipse.swt.dnd.DND;
import org.eclipse.swt.dnd.FileTransfer;
import org.eclipse.swt.dnd.TextTransfer;
import org.eclipse.swt.dnd.Transfer;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.actions.SelectionListenerAction;
import org.eclipse.ui.help.WorkbenchHelp;
import org.eclipse.ui.part.ResourceTransfer;

/**
 * Standard action for copying the currently selected resources to the clipboard.
 * <p>
 * This class may be instantiated; it is not intended to be subclassed.
 * </p>
 * 
 * @since 2.0
 */
/*package*/class CopyAction extends SelectionListenerAction {

    /**
     * The id of this action.
     */
    public static final String ID = PlatformUI.PLUGIN_ID + ".CopyAction"; //$NON-NLS-1$

    /**
     * The shell in which to show any dialogs.
     */
    private Shell shell;

    /**
     * System clipboard
     */
    private Clipboard clipboard;

    /**
     * Associated paste action. May be <code>null</code>
     */
    private PasteAction pasteAction;

    /**
     * Creates a new action.
     *
     * @param shell the shell for any dialogs
     * @param clipboard a platform clipboard
     */
    public CopyAction(Shell shell, Clipboard clipboard) {
        super(ResourceNavigatorMessages.getString("CopyAction.title")); //$NON-NLS-1$
        Assert.isNotNull(shell);
        Assert.isNotNull(clipboard);
        this.shell = shell;
        this.clipboard = clipboard;
        setToolTipText(ResourceNavigatorMessages
                .getString("CopyAction.toolTip")); //$NON-NLS-1$
        setId(CopyAction.ID);
        WorkbenchHelp.setHelp(this, INavigatorHelpContextIds.COPY_ACTION);
    }

    /**
     * Creates a new action.
     *
     * @param shell the shell for any dialogs
     * @param clipboard a platform clipboard
     * @param pasteAction a paste action
     * 
     * @since 2.0
     */
    public CopyAction(Shell shell, Clipboard clipboard, PasteAction pasteAction) {
        this(shell, clipboard);
        this.pasteAction = pasteAction;
    }

    /**
     * The <code>CopyAction</code> implementation of this method defined 
     * on <code>IAction</code> copies the selected resources to the 
     * clipboard.
     */
    public void run() {
        List selectedResources = getSelectedResources();
        IResource[] resources = (IResource[]) selectedResources
                .toArray(new IResource[selectedResources.size()]);

        // Get the file names and a string representation
        final int length = resources.length;
        int actualLength = 0;
        String[] fileNames = new String[length];
        StringBuffer buf = new StringBuffer();
        for (int i = 0; i < length; i++) {
            IPath location = resources[i].getLocation();
            // location may be null. See bug 29491.
            if (location != null)
                fileNames[actualLength++] = location.toOSString();
            if (i > 0)
                buf.append("\n"); //$NON-NLS-1$
            buf.append(resources[i].getName());
        }
        // was one or more of the locations null?
        if (actualLength < length) {
            String[] tempFileNames = fileNames;
            fileNames = new String[actualLength];
            for (int i = 0; i < actualLength; i++)
                fileNames[i] = tempFileNames[i];
        }
        setClipboard(resources, fileNames, buf.toString());

        // update the enablement of the paste action
        // workaround since the clipboard does not suppot callbacks
        if (pasteAction != null && pasteAction.getStructuredSelection() != null)
            pasteAction.selectionChanged(pasteAction.getStructuredSelection());
    }

    /**
     * Set the clipboard contents. Prompt to retry if clipboard is busy.
     * 
     * @param resources the resources to copy to the clipboard
     * @param fileNames file names of the resources to copy to the clipboard
     * @param names string representation of all names
     */
    private void setClipboard(IResource[] resources, String[] fileNames,
            String names) {
        try {
            // set the clipboard contents
            if (fileNames.length > 0) {
                clipboard.setContents(new Object[] { resources, fileNames,
                        names },
                        new Transfer[] { ResourceTransfer.getInstance(),
                                FileTransfer.getInstance(),
                                TextTransfer.getInstance() });
            } else {
                clipboard.setContents(new Object[] { resources, names },
                        new Transfer[] { ResourceTransfer.getInstance(),
                                TextTransfer.getInstance() });
            }
        } catch (SWTError e) {
            if (e.code != DND.ERROR_CANNOT_SET_CLIPBOARD)
                throw e;
            if (MessageDialog
                    .openQuestion(
                            shell,
                            ResourceNavigatorMessages
                                    .getString("CopyToClipboardProblemDialog.title"), ResourceNavigatorMessages.getString("CopyToClipboardProblemDialog.message"))) //$NON-NLS-1$ //$NON-NLS-2$
                setClipboard(resources, fileNames, names);
        }
    }

    /**
     * The <code>CopyAction</code> implementation of this
     * <code>SelectionListenerAction</code> method enables this action if 
     * one or more resources of compatible types are selected.
     */
    protected boolean updateSelection(IStructuredSelection selection) {
        if (!super.updateSelection(selection))
            return false;

        if (getSelectedNonResources().size() > 0)
            return false;

        List selectedResources = getSelectedResources();
        if (selectedResources.size() == 0)
            return false;

        boolean projSelected = selectionIsOfType(IResource.PROJECT);
        boolean fileFoldersSelected = selectionIsOfType(IResource.FILE
                | IResource.FOLDER);
        if (!projSelected && !fileFoldersSelected)
            return false;

        // selection must be homogeneous
        if (projSelected && fileFoldersSelected)
            return false;

        // must have a common parent	
        IContainer firstParent = ((IResource) selectedResources.get(0))
                .getParent();
        if (firstParent == null)
            return false;

        Iterator resourcesEnum = selectedResources.iterator();
        while (resourcesEnum.hasNext()) {
            IResource currentResource = (IResource) resourcesEnum.next();
            if (!currentResource.getParent().equals(firstParent))
                return false;
            // resource location must exist
            if (currentResource.getLocation() == null)
                return false;
        }

        return true;
    }

}