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    41 

    42 /*

    43   model.cpp

    44 

    45   A simple model that uses a QStringList as its data source.

    46 */

    47 

    48 #include "model.h"

    49 

    50 /*!

    51     Returns the number of items in the string list as the number of rows

    52     in the model.

    53 */

    54 

    55 //! [0]

    56 int StringListModel::rowCount(const QModelIndex &parent) const

    57 {

    58     return stringList.count();

    59 }

    60 //! [0]

    61 

    62 

    63 #ifdef 0

    64 // This represents a read-only version of data(), an early stage in the 

    65 // development of the example leading to an editable StringListModel.

    66 

    67 /*!

    68     Returns an appropriate value for the requested data.

    69     If the view requests an invalid index, an invalid variant is returned.

    70     Any valid index that corresponds to a string in the list causes that

    71     string to be returned.

    72 */

    73 

    74 //! [1-data-read-only]

    75 QVariant StringListModel::data(const QModelIndex &index, int role) const

    76 {

    77     if (!index.isValid())

    78         return QVariant();

    79 

    80     if (index.row() >= stringList.size())

    81         return QVariant();

    82 

    83     if (role == Qt::DisplayRole)

    84         return stringList.at(index.row());

    85     else

    86         return QVariant();

    87 }

    88 //! [1-data-read-only]

    89 #endif

    90 

    91 

    92 /*!

    93     Returns an appropriate value for the requested data.

    94     If the view requests an invalid index, an invalid variant is returned.

    95     Any valid index that corresponds to a string in the list causes that

    96     string to be returned.

    97 */

    98 

    99 //! [1]

   100 QVariant StringListModel::data(const QModelIndex &index, int role) const

   101 {

   102     if (!index.isValid())

   103         return QVariant();

   104 

   105     if (index.row() >= stringList.size())

   106         return QVariant();

   107         

   108     if (role == Qt::DisplayRole || role == Qt::EditRole)

   109         return stringList.at(index.row());

   110     else

   111         return QVariant();

   112 }

   113 //! [1]

   114 

   115 /*!

   116     Returns the appropriate header string depending on the orientation of

   117     the header and the section. If anything other than the display role is

   118     requested, we return an invalid variant.

   119 */

   120 

   121 //! [2]

   122 QVariant StringListModel::headerData(int section, Qt::Orientation orientation,

   123                                      int role) const

   124 {

   125     if (role != Qt::DisplayRole)

   126         return QVariant();

   127 

   128     if (orientation == Qt::Horizontal)

   129         return QString("Column %1").arg(section);

   130     else

   131         return QString("Row %1").arg(section);

   132 }

   133 //! [2]

   134 

   135 /*!

   136     Returns an appropriate value for the item's flags. Valid items are

   137     enabled, selectable, and editable.

   138 */

   139 

   140 //! [3]

   141 Qt::ItemFlags StringListModel::flags(const QModelIndex &index) const

   142 {

   143     if (!index.isValid())

   144         return Qt::ItemIsEnabled;

   145 

   146     return QAbstractItemModel::flags(index) | Qt::ItemIsEditable;

   147 }

   148 //! [3]

   149 

   150 /*!

   151     Changes an item in the string list, but only if the following conditions

   152     are met:

   153 

   154     * The index supplied is valid.

   155     * The index corresponds to an item to be shown in a view.

   156     * The role associated with editing text is specified.

   157 

   158     The dataChanged() signal is emitted if the item is changed.

   159 */

   160 

   161 //! [4]

   162 bool StringListModel::setData(const QModelIndex &index,

   163                               const QVariant &value, int role)

   164 {

   165     if (index.isValid() && role == Qt::EditRole) {

   166 

   167         stringList.replace(index.row(), value.toString());

   168         emit dataChanged(index, index);

   169         return true;

   170     }

   171 //! [4] //! [5]

   172     return false;

   173 }

   174 //! [5]

   175 

   176 /*!

   177     Inserts a number of rows into the model at the specified position.

   178 */

   179 

   180 //! [6]

   181 bool StringListModel::insertRows(int position, int rows, const QModelIndex &parent)

   182 {

   183     beginInsertRows(QModelIndex(), position, position+rows-1);

   184 

   185     for (int row = 0; row < rows; ++row) {

   186         stringList.insert(position, "");

   187     }

   188 

   189     endInsertRows();

   190     return true;

   191 //! [6] //! [7]

   192 }

   193 //! [7]

   194 

   195 /*!

   196     Removes a number of rows from the model at the specified position.

   197 */

   198 

   199 //! [8]

   200 bool StringListModel::removeRows(int position, int rows, const QModelIndex &parent)

   201 {

   202     beginRemoveRows(QModelIndex(), position, position+rows-1);

   203 

   204     for (int row = 0; row < rows; ++row) {

   205         stringList.removeAt(position);

   206     }

   207 

   208     endRemoveRows();

   209     return true;

   210 //! [8] //! [9]

   211 }

   212 //! [9]