vegetablesdatamodel.cpp Example File

    /* Copyright (c) 2012, 2013  BlackBerry Limited.
    *
    * 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.
    */

    #include "vegetablesdatamodel.hpp"

    /**
     * The data of the VegetablesDataModel have the following form:
     *
     * - Green
     *   + Cucumber
     *   + Peas
     *   + Salad
     * - Red
     *   + Tomato
     *   + Red Radish
     *   + Carrot
     * - Yellow
     *   + Corn
     *   + Paprika
     */

    VegetablesDataModel::VegetablesDataModel(QObject *parent)
        : bb::cascades::DataModel(parent)
    {
    }

    int VegetablesDataModel::childCount(const QVariantList& indexPath)
    {
        /**
         * In this very simple data model, the first two headers has 3 children
         * and the third one has 2.
         */
        const int level = indexPath.size();

        if (level == 0) { // The number of top-level items is requested
            return 3; // headers "Green", "Red" and "Yellow"
        }

        if (level == 1) { // The number of child items for a header is requested
            const int header = indexPath[0].toInt();

            if (header == 0 || header == 1) // "Green" or "Red"
                return 3;
            else // "Yellow"
                return 2;
        }

        // The number of child items for 2nd level items is requested -> always 0
        return 0;
    }

    bool VegetablesDataModel::hasChildren(const QVariantList& indexPath)
    {
        // Performance is not an issue with this data model.
        // So just let childCount tell us if we have children.
        return childCount(indexPath) > 0;
    }

    /*
     * Return data as a string QVariant for any requested indexPath.
     * We could add defensive code to ensure that the data is not
     * out of range, but ListView honours the results of hasChildren
     * and childCount.
     */
    QVariant VegetablesDataModel::data(const QVariantList& indexPath)
    {
        QString value;

        if (indexPath.size() == 1) { // Header requested
            switch (indexPath[0].toInt()) {
                case 0:
                    value = tr("Green");
                    break;
                case 1:
                    value = tr("Red");
                    break;
                case 2:
                    value = tr("Yellow");
                    break;
            }
        }

        if (indexPath.size() == 2) { // 2nd-level item requested
            const int header = indexPath[0].toInt();
            const int childItem = indexPath[1].toInt();

            switch (header) {
                case 0: // "Green"
                    switch (childItem) {
                        case 0:
                            value = tr("Cucumber");
                            break;
                        case 1:
                            value = tr("Peas");
                            break;
                        case 2:
                            value = tr("Salad");
                            break;
                    }
                    break;
                case 1: // "Red"
                    switch (childItem) {
                        case 0:
                            value = tr("Tomato");
                            break;
                        case 1:
                            value = tr("Red Radish");
                            break;
                        case 2:
                            value = tr("Carrot");
                            break;
                    }
                    break;
                case 2: // "Yellow"
                    switch (childItem) {
                        case 0:
                            value = tr("Corn");
                            break;
                        case 1:
                            value = tr("Paprika");
                            break;
                    }
                    break;
            }
        }

        qDebug() << "Data for " << indexPath << " is " << value;

        return QVariant(value);
    }

    QString VegetablesDataModel::itemType(const QVariantList& indexPath)
    {
        switch (indexPath.size()) {
            case 0:
                return QString();
                break;
            case 1:
                return QLatin1String("header");
                break;
            default:
                return QLatin1String("item");
                break;
        }
    }