AuditLogEntryCommentColumn.java

/*
 * Copyright 2012 Red Hat, Inc. and/or its affiliates.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package org.drools.workbench.screens.guided.dtable.client.widget.auditlog;

import com.google.gwt.cell.client.FieldUpdater;
import com.google.gwt.cell.client.TextInputCell;
import com.google.gwt.core.client.GWT;
import com.google.gwt.safehtml.client.SafeHtmlTemplates;
import com.google.gwt.safehtml.shared.SafeHtml;
import com.google.gwt.safehtml.shared.SafeHtmlBuilder;
import com.google.gwt.safehtml.shared.SafeHtmlUtils;
import com.google.gwt.user.cellview.client.Column;
import org.drools.workbench.models.datamodel.auditlog.AuditLogEntry;
import org.drools.workbench.screens.guided.dtable.client.resources.i18n.GuidedDecisionTableConstants;

/**
 * A column for Audit Log User comments
 * <p/>
 * NOTE: BZ-996942: Replace input text for a textarea element, allows comments more legible and putting a helper placeholder.
 */
public class AuditLogEntryCommentColumn extends Column<AuditLogEntry, String> {

    /**
     * The instance for the textarea cell.
     */
    private static final TextAreaInputCell cell = new TextAreaInputCell( 2, 50 );

    public AuditLogEntryCommentColumn() {
        super( cell );
        setFieldUpdater( new FieldUpdater<AuditLogEntry, String>() {

            @Override
            public void update( int index,
                                AuditLogEntry object,
                                String value ) {
                object.setUserComment( value );
            }

        } );
    }

    @Override
    public String getValue( AuditLogEntry object ) {
        return object.getUserComment();
    }

    /**
     * The HTML templates used to render the textarea cell.
     */
    interface TextAreaTemplate extends SafeHtmlTemplates {

        /**
         * Tempate when textarea has value .
         */
        @Template("<textarea style=\"width: 98% !important; resize: none;\" class=\"{1}\" rows=\"{2}\" cols=\"{3}\">{0}</textarea>")
        SafeHtml textarea( SafeHtml value,
                           String className,
                           String rows,
                           String cols );

        /**
         * Tempate when textarea is empty.
         */
        @Template("<textarea style=\"width: 98% !important; resize: none;\" class=\"{0}\" rows=\"{1}\" cols=\"{2}\" placeholder=\"{3}\"></textarea>")
        SafeHtml textareaEmpty( String className,
                                String rows,
                                String cols,
                                String placeholder );
    }

    /**
     * Create a singleton instance of the textarea template used to render the cell.
     */
    private static TextAreaTemplate textAreaTemplate = GWT.create( TextAreaTemplate.class );

    /**
     * <p>Custom implementation for a Cell using a textarea element.</p>
     * <p>Available parameters:</p>
     * <ul>
     * <li>rows: The number of rows for the text area</li>
     * <li>cols: The number of columns for the text area</li>
     * <li>value: The text value</li>
     * </ul>
     * <p>In addition, a helper placeholder is used.</p>
     */
    private static class TextAreaInputCell extends TextInputCell {

        private int rows;
        private int cols;

        /**
         * Default constructor.
         * @param rows The number of rows for the <code>textarea</code> element.
         * @param cols The number of cols for the <code>textarea</code> element.
         */
        private TextAreaInputCell( int rows,
                                   int cols ) {
            this.rows = rows;
            this.cols = cols;
        }

        /**
         * Custom render for text area cell.
         * @param context The current context.
         * @param value The value for the text area.
         * @param sb The html buffer to generate.
         */
        @Override
        public void render( Context context,
                            String value,
                            SafeHtmlBuilder sb ) {
            // Get the view data.
            Object key = context.getKey();
            ViewData viewData = getViewData( key );
            if ( viewData != null && viewData.getCurrentValue().equals( value ) ) {
                clearViewData( key );
                viewData = null;
            }

            String s = ( viewData != null ) ? viewData.getCurrentValue() : value;
            if ( s != null && s.trim().length() > 0 ) {
                // If the value comes from the user, escape it to avoid XSS attacks.
                SafeHtml safeValue = SafeHtmlUtils.fromString( value );

                // Use the template to create the Cell's html.
                SafeHtml rendered = textAreaTemplate.textarea( safeValue, "", Integer.toString( rows ), Integer.toString( cols ) );
                sb.append( rendered );
            } else {

                // Add the placeholder helper text.
                String placeholderText = GuidedDecisionTableConstants.INSTANCE.InsertYourCommentsHere();
                String placeholderHtml = SafeHtmlUtils.htmlEscape( placeholderText );

                // Create an empty text area.
                SafeHtml rendered = textAreaTemplate.textareaEmpty( "", Integer.toString( rows ), Integer.toString( cols ), placeholderHtml );
                sb.append( rendered );
            }
        }
    }

}