org.olat.modules.qpool.ui.TextPreviewController.java Source code

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Here is the source code for org.olat.modules.qpool.ui.TextPreviewController.java

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/**
 * <a href="http://www.openolat.org">
 * OpenOLAT - Online Learning and Training</a><br>
 * <p>
 * Licensed under the Apache License, Version 2.0 (the "License"); <br>
 * you may not use this file except in compliance with the License.<br>
 * You may obtain a copy of the License at the
 * <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache homepage</a>
 * <p>
 * Unless required by applicable law or agreed to in writing,<br>
 * software distributed under the License is distributed on an "AS IS" BASIS, <br>
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. <br>
 * See the License for the specific language governing permissions and <br>
 * limitations under the License.
 * <p>
 * Initial code contributed and copyrighted by<br>
 * frentix GmbH, http://www.frentix.com
 * <p>
 */
package org.olat.modules.qpool.ui;

import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.StringWriter;

import org.apache.commons.io.IOUtils;
import org.olat.core.CoreSpringFactory;
import org.olat.core.gui.UserRequest;
import org.olat.core.gui.components.Component;
import org.olat.core.gui.components.velocity.VelocityContainer;
import org.olat.core.gui.control.Event;
import org.olat.core.gui.control.WindowControl;
import org.olat.core.gui.control.controller.BasicController;
import org.olat.core.util.vfs.VFSLeaf;
import org.olat.modules.qpool.QuestionItem;
import org.olat.modules.qpool.QPoolService;

/**
 * 
 * Initial date: 27.02.2013<br>
 * @author srosse, stephane.rosse@frentix.com, http://www.frentix.com
 *
 */
public class TextPreviewController extends BasicController {

    private final VelocityContainer mainVC;
    private final QPoolService qpoolService;

    public TextPreviewController(UserRequest ureq, WindowControl wControl, QuestionItem qitem, boolean summary) {
        super(ureq, wControl);
        qpoolService = CoreSpringFactory.getImpl(QPoolService.class);
        mainVC = createVelocityContainer("text_preview");

        VFSLeaf leaf = qpoolService.getRootFile(qitem);
        if (leaf == null) {
            //no data to preview
        } else {
            String txt = readSummary(leaf);
            if (summary && txt.length() > 2000) {
                txt = txt.substring(0, 2000);
            }
            mainVC.contextPut("text", txt);
        }
        putInitialPanel(mainVC);
    }

    @Override
    protected void doDispose() {
        //
    }

    protected String readSummary(VFSLeaf leaf) {
        StringWriter out = new StringWriter();
        InputStream in = leaf.getInputStream();
        InputStreamReader inr = new InputStreamReader(in);
        try {
            char[] buffer = new char[4096];

            int count = 0;
            int n = 0;
            while (-1 != (n = inr.read(buffer))) {
                out.write(buffer, 0, n);
                count += n;
                if (count >= 10000) {
                    break;
                }
            }
        } catch (Exception e) {
            logError("", e);
        } finally {
            IOUtils.closeQuietly(inr);
            IOUtils.closeQuietly(in);
        }
        return out.toString();
    }

    @Override
    protected void event(UserRequest ureq, Component source, Event event) {
        //
    }
}