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    41 

    42 /*!

    43     view.cpp

    44 

    45     Provides a view to represent a one-dimensional sequence of integers

    46     obtained from a list model as a series of rows.

    47 */

    48 

    49 #include <QAbstractItemModel>

    50 #include <QBrush>

    51 #include <QItemSelection>

    52 #include <QPainter>

    53 #include <QPaintEvent>

    54 #include <QPen>

    55 #include <QPoint>

    56 #include <QResizeEvent>

    57 #include <QScrollBar>

    58 #include <QSizePolicy>

    59 

    60 #include "view.h"

    61 

    62 LinearView::LinearView(QWidget *parent)

    63     : QAbstractItemView(parent)

    64 {

    65     setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Fixed);

    66 }

    67 

    68 /*!

    69     Returns the position of the item in viewport coordinates.

    70 */

    71 

    72 QRect LinearView::itemViewportRect(const QModelIndex &index) const

    73 {

    74     QRect rect = itemRect(index);

    75     QRect result(rect.left() - horizontalScrollBar()->value(),

    76                  rect.top() - verticalScrollBar()->value(),

    77                  rect.width(), viewport()->height());

    78 

    79     return result;

    80 }

    81 

    82 /*!

    83     Returns the rectangle of the item at position \a index in the

    84     model. The rectangle is in contents coordinates.

    85 */

    86 

    87 QRect LinearView::itemRect(const QModelIndex &index) const

    88 {

    89     if (!index.isValid())

    90         return QRect();

    91     else

    92         return QRect(index.row(), 0, 1, 1);

    93 }

    94 

    95 

    96 void LinearView::ensureVisible(const QModelIndex &index)

    97 {

    98     QRect area = viewport()->rect();

    99     QRect rect = itemViewportRect(index);

   100 

   101     if (rect.left() < area.left())

   102         horizontalScrollBar()->setValue(

   103             horizontalScrollBar()->value() - rect.left());

   104     else if (rect.right() > area.right())

   105         horizontalScrollBar()->setValue(

   106             horizontalScrollBar()->value() + rect.left() - area.width());

   107 }

   108 

   109 /*!

   110     Returns the item that covers the coordinate given in the view.

   111 */

   112 

   113 QModelIndex LinearView::itemAt(int x, int /* y */) const

   114 {

   115     int row = x + horizontalScrollBar()->value();

   116 

   117     return model()->index(row, 0, QModelIndex());

   118 }

   119 

   120 //void LinearView::dataChanged(const QModelIndex &/* topLeft */,

   121 //    const QModelIndex &/* bottomRight */)

   122 //{

   123 //    updateGeometries();

   124 //    if (isVisible())

   125 //        repaint();

   126 //}

   127 

   128 void LinearView::rowsInserted(const QModelIndex &/* parent */, int /* start */,

   129     int /* end */)

   130 {

   131     updateGeometries();

   132     if (isVisible())

   133         repaint();

   134 }

   135 

   136 void LinearView::rowsRemoved(const QModelIndex &/* parent */, int /* start */,

   137     int /* end */)

   138 {

   139     updateGeometries();

   140     if (isVisible())

   141         repaint();

   142 }

   143 /*

   144 void LinearView::verticalScrollbarAction(int action)

   145 {

   146 }

   147 

   148 void LinearView::horizontalScrollbarAction(int action)

   149 {

   150 }

   151 */

   152 

   153 /*!

   154     Select the items in the model that lie within the rectangle specified by

   155     \a rect, using the selection \a command.

   156 */

   157 

   158 void LinearView::setSelection(const QRect &rect, QItemSelectionModel::SelectionFlags command)

   159 {

   160     QModelIndex leftIndex = itemAt(rect.left(), 0);

   161     QModelIndex rightIndex = itemAt(rect.right(), 0);

   162 

   163     QItemSelection selection(leftIndex, rightIndex);

   164 

   165     selectionModel()->select(selection, command);

   166 }

   167 

   168 QModelIndex LinearView::moveCursor(QAbstractItemView::CursorAction cursorAction,

   169                                    Qt::KeyboardModifiers)

   170 {

   171     QModelIndex current = currentIndex();

   172 

   173     switch (cursorAction) {

   174     case MoveLeft:{

   175         if (current.row() > 0)

   176             return model()->index(current.row() - 1, 0, QModelIndex());

   177         else

   178             return model()->index(0, 0, QModelIndex());

   179         break;}

   180     case MoveRight:{

   181         if (current.row() < rows(current) - 1)

   182             return model()->index(current.row() + 1, 0, QModelIndex());

   183         else

   184             return model()->index(rows(current) - 1, 0,QModelIndex());

   185         break;}

   186     case MoveUp:

   187         return current;

   188     case MoveDown:

   189         return current;

   190     case MovePageUp:

   191         return current;

   192     case MovePageDown:

   193         return current;

   194     case MoveHome:

   195         return model()->index(0, 0, QModelIndex());

   196     case MoveEnd:

   197         return model()->index(rows(current) - 1, 0, QModelIndex());

   198     default:

   199         return current;

   200     }

   201 }

   202 

   203 int LinearView::horizontalOffset() const

   204 {

   205     return horizontalScrollBar()->value();

   206 }

   207 

   208 int LinearView::verticalOffset() const

   209 {

   210     return verticalScrollBar()->value();

   211 }

   212 

   213 /*!

   214     Returns a rectangle corresponding to the selection in viewport cooridinates.

   215 */

   216 

   217 QRect LinearView::selectionViewportRect(const QItemSelection &selection) const

   218 {

   219     int ranges = selection.count();

   220 

   221     if (ranges == 0)

   222         return QRect();

   223 

   224     // Note that we use the top and bottom functions of the selection range

   225     // since the data is stored in rows.

   226 

   227     int firstRow = selection.at(0).top();

   228     int lastRow = selection.at(0).top();

   229 

   230     for (int i = 0; i < ranges; ++i) {

   231         firstRow = qMin(firstRow, selection.at(i).top());

   232         lastRow = qMax(lastRow, selection.at(i).bottom());

   233     }

   234 

   235     QModelIndex firstItem = model()->index(qMin(firstRow, lastRow), 0,

   236         QModelIndex());

   237     QModelIndex lastItem = model()->index(qMax(firstRow, lastRow), 0,

   238         QModelIndex());

   239 

   240     QRect firstRect = itemViewportRect(firstItem);

   241     QRect lastRect = itemViewportRect(lastItem);

   242 

   243     return QRect(firstRect.left(), firstRect.top(),

   244         lastRect.right() - firstRect.left(), firstRect.height());

   245 }

   246 

   247 void LinearView::paintEvent(QPaintEvent *event)

   248 {

   249     QPainter painter(viewport());

   250 

   251     QRect updateRect = event->rect();

   252     QBrush background(Qt::black);

   253     QPen foreground(Qt::white);

   254 

   255     painter.fillRect(updateRect, background);

   256     painter.setPen(foreground);

   257 

   258     QModelIndex firstItem = itemAt(updateRect.left(), updateRect.top());

   259     if (!firstItem.isValid())

   260         firstItem = model()->index(0, 0, QModelIndex());

   261 

   262     QModelIndex lastItem = itemAt(updateRect.right(), updateRect.bottom());

   263     if (!lastItem.isValid())

   264         lastItem = model()->index(rows() - 1, 0, QModelIndex());

   265 

   266     int x = updateRect.left();

   267     //int top = updateRect.top();

   268     //int bottom = updateRect.bottom();

   269 

   270     int row = firstItem.row();

   271     QModelIndex index = model()->index(row, 0, QModelIndex());

   272     int value = model()->data(index, Qt::DisplayRole).toInt();

   273     int midPoint = viewport()->height()/2;

   274     int y2 = midPoint - int(value * midPoint/255.0);

   275 

   276     while (row <= lastItem.row()) {

   277 

   278         QModelIndex index = model()->index(row, 0, QModelIndex());

   279         int value = model()->data(index, Qt::DisplayRole).toInt();

   280 

   281         int y1 = y2;

   282         y2 = midPoint - int(value * midPoint/255.0);

   283 

   284         painter.drawLine(x-1, y1, x, y2);

   285         ++row; ++x;

   286     }

   287 }

   288 

   289 void LinearView::resizeEvent(QResizeEvent * /* event */)

   290 {

   291     updateGeometries();

   292 }

   293 

   294 void LinearView::updateGeometries()

   295 {

   296     if (viewport()->width() < rows()) {

   297         horizontalScrollBar()->setPageStep(viewport()->width());

   298         horizontalScrollBar()->setRange(0, rows() - viewport()->width() - 1);

   299     }

   300 }

   301 

   302 QSize LinearView::sizeHint() const

   303 {

   304     return QSize(rows(), 200);

   305 }

   306 

   307 int LinearView::rows(const QModelIndex &index) const

   308 {

   309     return model()->rowCount(model()->parent(index));

   310 }

   311 

   312 bool LinearView::isIndexHidden(const QModelIndex &index) const

   313 {

   314     return false;

   315 }