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    41 

    42 /*

    43     treemodel.cpp

    44 

    45     Provides a simple tree model to show how to create and use hierarchical

    46     models.

    47 */

    48 

    49 #include <QtGui>

    50 

    51 #include "treeitem.h"

    52 #include "treemodel.h"

    53 

    54 //! [0]

    55 TreeModel::TreeModel(const QString &data, QObject *parent)

    56     : QAbstractItemModel(parent)

    57 {

    58     QList<QVariant> rootData;

    59     rootData << "Title" << "Summary";

    60     rootItem = new TreeItem(rootData);

    61     setupModelData(data.split(QString("\n")), rootItem);

    62 }

    63 //! [0]

    64 

    65 //! [1]

    66 TreeModel::~TreeModel()

    67 {

    68     delete rootItem;

    69 }

    70 //! [1]

    71 

    72 //! [2]

    73 int TreeModel::columnCount(const QModelIndex &parent) const

    74 {

    75     if (parent.isValid())

    76         return static_cast<TreeItem*>(parent.internalPointer())->columnCount();

    77     else

    78         return rootItem->columnCount();

    79 }

    80 //! [2]

    81 

    82 //! [3]

    83 QVariant TreeModel::data(const QModelIndex &index, int role) const

    84 {

    85     if (!index.isValid())

    86         return QVariant();

    87 

    88     if (role != Qt::DisplayRole)

    89         return QVariant();

    90 

    91     TreeItem *item = static_cast<TreeItem*>(index.internalPointer());

    92 

    93     return item->data(index.column());

    94 }

    95 //! [3]

    96 

    97 //! [4]

    98 Qt::ItemFlags TreeModel::flags(const QModelIndex &index) const

    99 {

   100     if (!index.isValid())

   101         return 0;

   102 

   103     return Qt::ItemIsEnabled | Qt::ItemIsSelectable;

   104 }

   105 //! [4]

   106 

   107 //! [5]

   108 QVariant TreeModel::headerData(int section, Qt::Orientation orientation,

   109                                int role) const

   110 {

   111     if (orientation == Qt::Horizontal && role == Qt::DisplayRole)

   112         return rootItem->data(section);

   113 

   114     return QVariant();

   115 }

   116 //! [5]

   117 

   118 //! [6]

   119 QModelIndex TreeModel::index(int row, int column, const QModelIndex &parent)

   120             const

   121 {

   122     if (!hasIndex(row, column, parent))

   123         return QModelIndex();

   124 

   125     TreeItem *parentItem;

   126 

   127     if (!parent.isValid())

   128         parentItem = rootItem;

   129     else

   130         parentItem = static_cast<TreeItem*>(parent.internalPointer());

   131 

   132     TreeItem *childItem = parentItem->child(row);

   133     if (childItem)

   134         return createIndex(row, column, childItem);

   135     else

   136         return QModelIndex();

   137 }

   138 //! [6]

   139 

   140 //! [7]

   141 QModelIndex TreeModel::parent(const QModelIndex &index) const

   142 {

   143     if (!index.isValid())

   144         return QModelIndex();

   145 

   146     TreeItem *childItem = static_cast<TreeItem*>(index.internalPointer());

   147     TreeItem *parentItem = childItem->parent();

   148 

   149     if (parentItem == rootItem)

   150         return QModelIndex();

   151 

   152     return createIndex(parentItem->row(), 0, parentItem);

   153 }

   154 //! [7]

   155 

   156 //! [8]

   157 int TreeModel::rowCount(const QModelIndex &parent) const

   158 {

   159     TreeItem *parentItem;

   160     if (parent.column() > 0)

   161         return 0;

   162 

   163     if (!parent.isValid())

   164         parentItem = rootItem;

   165     else

   166         parentItem = static_cast<TreeItem*>(parent.internalPointer());

   167 

   168     return parentItem->childCount();

   169 }

   170 //! [8]

   171 

   172 void TreeModel::setupModelData(const QStringList &lines, TreeItem *parent)

   173 {

   174     QList<TreeItem*> parents;

   175     QList<int> indentations;

   176     parents << parent;

   177     indentations << 0;

   178 

   179     int number = 0;

   180 

   181     while (number < lines.count()) {

   182         int position = 0;

   183         while (position < lines[number].length()) {

   184             if (lines[number].mid(position, 1) != " ")

   185                 break;

   186             position++;

   187         }

   188 

   189         QString lineData = lines[number].mid(position).trimmed();

   190 

   191         if (!lineData.isEmpty()) {

   192             // Read the column data from the rest of the line.

   193             QStringList columnStrings = lineData.split("\t", QString::SkipEmptyParts);

   194             QList<QVariant> columnData;

   195             for (int column = 0; column < columnStrings.count(); ++column)

   196                 columnData << columnStrings[column];

   197 

   198             if (position > indentations.last()) {

   199                 // The last child of the current parent is now the new parent

   200                 // unless the current parent has no children.

   201 

   202                 if (parents.last()->childCount() > 0) {

   203                     parents << parents.last()->child(parents.last()->childCount()-1);

   204                     indentations << position;

   205                 }

   206             } else {

   207                 while (position < indentations.last() && parents.count() > 0) {

   208                     parents.pop_back();

   209                     indentations.pop_back();

   210                 }

   211             }

   212 

   213             // Append a new item to the current parent's list of children.

   214             parents.last()->appendChild(new TreeItem(columnData, parents.last()));

   215         }

   216 

   217         number++;

   218     }

   219 }