core/plugins/org.eclipse.dltk.ui/src/org/eclipse/dltk/internal/ui/callhierarchy/CopyCallHierarchyAction.java

/*******************************************************************************
 * Copyright (c) 2000, 2017 IBM Corporation and others.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 * 
 * SPDX-License-Identifier: EPL-2.0
 *

 *          (report 36180: Callers/Callees view)
 *******************************************************************************/
package org.eclipse.dltk.internal.ui.callhierarchy;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringReader;
import java.io.StringWriter;

import org.eclipse.dltk.core.DLTKCore;
import org.eclipse.dltk.internal.ui.util.SelectionUtil;
import org.eclipse.jface.action.Action;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.ISelectionProvider;
import org.eclipse.swt.SWTError;
import org.eclipse.swt.dnd.Clipboard;
import org.eclipse.swt.dnd.DND;
import org.eclipse.swt.dnd.TextTransfer;
import org.eclipse.swt.dnd.Transfer;
import org.eclipse.swt.widgets.TreeItem;


class CopyCallHierarchyAction extends Action {
    private static final char INDENTATION= '\t';

    private CallHierarchyViewPart fView;
    private CallHierarchyViewer fViewer;

	private final Clipboard fClipboard;

	public CopyCallHierarchyAction(CallHierarchyViewPart view, Clipboard clipboard, CallHierarchyViewer viewer) {
		super(CallHierarchyMessages.CopyCallHierarchyAction_label);
//		PlatformUI.getWorkbench().getHelpSystem().setHelp(this, IJavaHelpContextIds.CALL_HIERARCHY_COPY_ACTION);
		if (DLTKCore.DEBUG) {
			System.err.println("Add help support here..."); //$NON-NLS-1$
		}
		fView= view;
		fClipboard= clipboard;
        fViewer= viewer;
	}

    public boolean canActionBeAdded() {
        Object element = SelectionUtil.getSingleElement(getSelection());
        return element != null;
    }

    private ISelection getSelection() {
        ISelectionProvider provider = fView.getSite().getSelectionProvider();

        if (provider != null) {
            return provider.getSelection();
        }

        return null;
    }

	@Override
	public void run() {
        StringBuffer buf= new StringBuffer();
        addCalls(fViewer.getTree().getSelection()[0], 0, buf);

		TextTransfer plainTextTransfer = TextTransfer.getInstance();
		try{
			fClipboard.setContents(
				new String[]{ convertLineTerminators(buf.toString()) },
				new Transfer[]{ plainTextTransfer });
		}  catch (SWTError e){
			if (e.code != DND.ERROR_CANNOT_SET_CLIPBOARD)
				throw e;
			if (MessageDialog.openQuestion(fView.getViewSite().getShell(), CallHierarchyMessages.CopyCallHierarchyAction_problem, CallHierarchyMessages.CopyCallHierarchyAction_clipboard_busy))
				run();
		}
	}

	/**
     * Adds the specified TreeItem's text to the StringBuffer
     *
     * @param item
     * @param buf
     */
    private void addCalls(TreeItem item, int indent, StringBuffer buf) {
        for (int i= 0; i < indent; i++) {
            buf.append(INDENTATION);
        }

        buf.append(item.getText());
        buf.append('\n');

        if (item.getExpanded()) {
            TreeItem[] items= item.getItems();
            for (int i= 0; i < items.length; i++) {
                addCalls(items[i], indent + 1, buf);
            }
        }
    }

    private String convertLineTerminators(String in) {
		StringWriter stringWriter= new StringWriter();
		PrintWriter printWriter= new PrintWriter(stringWriter);
		StringReader stringReader= new StringReader(in);
		BufferedReader bufferedReader= new BufferedReader(stringReader);
		String line;
		try {
			while ((line= bufferedReader.readLine()) != null) {
				printWriter.println(line);
			}
		} catch (IOException e) {
			return in; // return the call hierarchy unfiltered
		}
		return stringWriter.toString();
	}
}