: QGraphicsView(parent)

, _clearSelectionAction(Q_NULLPTR)

, _deleteSelectionAction(Q_NULLPTR)

, _scene(Q_NULLPTR)

{

setDragMode(QGraphicsView::ScrollHandDrag);

setRenderHint(QPainter::Antialiasing);

auto const &flowViewStyle = StyleCollection::flowViewStyle();

setBackgroundBrush(flowViewStyle.BackgroundColor);

setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

setTransformationAnchor(QGraphicsView::AnchorUnderMouse);

setCacheMode(QGraphicsView::CacheBackground);

setViewportUpdateMode(QGraphicsView::BoundingRectViewportUpdate);

//setViewport(new QGLWidget(QGLFormat(QGL::SampleBuffers)));

: FlowView(parent)

{

setScene(scene);

{

_scene = scene;

QGraphicsView::setScene(_scene);

// setup actions

delete _clearSelectionAction;

_clearSelectionAction = new QAction(QStringLiteral("Clear Selection"), this);

_clearSelectionAction->setShortcut(Qt::Key_Escape);

connect(_clearSelectionAction, &QAction::triggered, _scene, &QGraphicsScene::clearSelection);

addAction(_clearSelectionAction);

delete _deleteSelectionAction;

_deleteSelectionAction = new QAction(QStringLiteral("Delete Selection"), this);

_deleteSelectionAction->setShortcut(Qt::Key_Delete);

connect(_deleteSelectionAction, &QAction::triggered, this, &FlowView::deleteSelectedNodes);

addAction(_deleteSelectionAction);

{

if (itemAt(event->pos()))

{

QGraphicsView::contextMenuEvent(event);

return;

}

QMenu modelMenu;

auto skipText = QStringLiteral("skip me");

//Add filterbox to the context menu

auto *txtBox = new QLineEdit(&modelMenu);

txtBox->setPlaceholderText(QStringLiteral("Filter"));

txtBox->setClearButtonEnabled(true);

auto *txtBoxAction = new QWidgetAction(&modelMenu);

txtBoxAction->setDefaultWidget(txtBox);

modelMenu.addAction(txtBoxAction);

//Add result treeview to the context menu

auto *treeView = new QTreeWidget(&modelMenu);

treeView->header()->close();

auto *treeViewAction = new QWidgetAction(&modelMenu);

treeViewAction->setDefaultWidget(treeView);

modelMenu.addAction(treeViewAction);

QMap<QString, QTreeWidgetItem*> topLevelItems;

for (auto const &cat : _scene->registry().categories())

{

auto item = new QTreeWidgetItem(treeView);

item->setText(0, cat);

item->setData(0, Qt::UserRole, skipText);

topLevelItems[cat] = item;

}

for (auto const &assoc : _scene->registry().registeredModelsCategoryAssociation())

{

auto parent = topLevelItems[assoc.second];

auto item = new QTreeWidgetItem(parent);

item->setText(0, assoc.first);

item->setData(0, Qt::UserRole, assoc.first);

}

treeView->expandAll();

connect(treeView, &QTreeWidget::itemClicked, [&](QTreeWidgetItem *item, int)

{

QString modelName = item->data(0, Qt::UserRole).toString();

if (modelName == skipText)

{

return;

}

auto type = _scene->registry().create(modelName);

if (type)

{

auto& node = _scene->createNode(std::move(type));

QPoint pos = event->pos();

QPointF posView = this->mapToScene(pos);

node.nodeGraphicsObject().setPos(posView);

_scene->nodePlaced(node);

}

else

{

qDebug() << "Model not found";

}

modelMenu.close();

});

//Setup filtering

connect(txtBox, &QLineEdit::textChanged, [&](const QString &text)

{

for (auto& topLvlItem : topLevelItems)

{

for (int i = 0; i < topLvlItem->childCount(); ++i)

{

auto child = topLvlItem->child(i);

auto modelName = child->data(0, Qt::UserRole).toString();

const bool match = (modelName.contains(text, Qt::CaseInsensitive));

child->setHidden(!match);

}

}

});

// make sure the text box gets focus so the user doesn't have to click on it

txtBox->setFocus();

modelMenu.exec(event->globalPos());

{

QPoint delta = event->angleDelta();

if (delta.y() == 0)

{

event->ignore();

return;

}

double const d = delta.y() / std::abs(delta.y());

if (d > 0.0)

scaleUp();

else

scaleDown();

{

double const step = 1.2;

double const factor = std::pow(step, 1.0);

QTransform t = transform();

if (t.m11() > 2.0)

return;

scale(factor, factor);

{

double const step = 1.2;

double const factor = std::pow(step, -1.0);

scale(factor, factor);

{

// Delete the selected connections first, ensuring that they won't be

// automatically deleted when selected nodes are deleted (deleting a node

// deletes some connections as well)

for (QGraphicsItem * item : _scene->selectedItems())

{

if (auto c = qgraphicsitem_cast<ConnectionGraphicsObject*>(item))

_scene->deleteConnection(c->connection());

}

// Delete the nodes; this will delete many of the connections.

// Selected connections were already deleted prior to this loop, otherwise

// qgraphicsitem_cast<NodeGraphicsObject*>(item) could be a use-after-free

// when a selected connection is deleted by deleting the node.

for (QGraphicsItem * item : _scene->selectedItems())

{

if (auto n = qgraphicsitem_cast<NodeGraphicsObject*>(item))

_scene->removeNode(n->node());

}

{

switch (event->key())

{

case Qt::Key_Shift:

setDragMode(QGraphicsView::RubberBandDrag);

break;

default:

break;

}

QGraphicsView::keyPressEvent(event);

{

switch (event->key())

{

case Qt::Key_Shift:

setDragMode(QGraphicsView::ScrollHandDrag);

break;

default:

break;

}

QGraphicsView::keyReleaseEvent(event);

{

QGraphicsView::mousePressEvent(event);

if (event->button() == Qt::LeftButton)

{

_clickPos = mapToScene(event->pos());

}

{

QGraphicsView::mouseMoveEvent(event);

if (scene()->mouseGrabberItem() == nullptr && event->buttons() == Qt::LeftButton)

{

// Make sure shift is not being pressed

if ((event->modifiers() & Qt::ShiftModifier) == 0)

{

QPointF difference = _clickPos - mapToScene(event->pos());

setSceneRect(sceneRect().translated(difference.x(), difference.y()));

}

}

{

QGraphicsView::drawBackground(painter, r);

auto drawGrid =

[&](double gridStep)

{

QRect windowRect = rect();

QPointF tl = mapToScene(windowRect.topLeft());

QPointF br = mapToScene(windowRect.bottomRight());

double left = std::floor(tl.x() / gridStep - 0.5);

double right = std::floor(br.x() / gridStep + 1.0);

double bottom = std::floor(tl.y() / gridStep - 0.5);

double top = std::floor (br.y() / gridStep + 1.0);

// vertical lines

for (int xi = int(left); xi <= int(right); ++xi)

{

QLineF line(xi * gridStep, bottom * gridStep,

xi * gridStep, top * gridStep );

painter->drawLine(line);

}

// horizontal lines

for (int yi = int(bottom); yi <= int(top); ++yi)

{

QLineF line(left * gridStep, yi * gridStep,

right * gridStep, yi * gridStep );

painter->drawLine(line);

}

};

auto const &flowViewStyle = StyleCollection::flowViewStyle();

QBrush bBrush = backgroundBrush();

QPen pfine(flowViewStyle.FineGridColor, 1.0);

painter->setPen(pfine);

drawGrid(15);

QPen p(flowViewStyle.CoarseGridColor, 1.0);

painter->setPen(p);

drawGrid(150);

{

_scene->setSceneRect(this->rect());

QGraphicsView::showEvent(event);