diagramscene.cpp Example File

graphicsview/diagramscene/diagramscene.cpp
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#include "diagramscene.h" #include "arrow.h" #include <QTextCursor> #include <QGraphicsSceneMouseEvent> DiagramScene::DiagramScene(QMenu *itemMenu, QObject *parent) : QGraphicsScene(parent) { myItemMenu = itemMenu; myMode = MoveItem; myItemType = DiagramItem::Step; line = 0; textItem = 0; myItemColor = Qt::white; myTextColor = Qt::black; myLineColor = Qt::black; } void DiagramScene::setLineColor(const QColor &color) { myLineColor = color; if (isItemChange(Arrow::Type)) { Arrow *item = qgraphicsitem_cast<Arrow *>(selectedItems().first()); item->setColor(myLineColor); update(); } } void DiagramScene::setTextColor(const QColor &color) { myTextColor = color; if (isItemChange(DiagramTextItem::Type)) { DiagramTextItem *item = qgraphicsitem_cast<DiagramTextItem *>(selectedItems().first()); item->setDefaultTextColor(myTextColor); } } void DiagramScene::setItemColor(const QColor &color) { myItemColor = color; if (isItemChange(DiagramItem::Type)) { DiagramItem *item = qgraphicsitem_cast<DiagramItem *>(selectedItems().first()); item->setBrush(myItemColor); } } void DiagramScene::setFont(const QFont &font) { myFont = font; if (isItemChange(DiagramTextItem::Type)) { QGraphicsTextItem *item = qgraphicsitem_cast<DiagramTextItem *>(selectedItems().first()); //At this point the selection can change so the first selected item might not be a DiagramTextItem if (item) item->setFont(myFont); } } void DiagramScene::setMode(Mode mode) { myMode = mode; } void DiagramScene::setItemType(DiagramItem::DiagramType type) { myItemType = type; } void DiagramScene::editorLostFocus(DiagramTextItem *item) { QTextCursor cursor = item->textCursor(); cursor.clearSelection(); item->setTextCursor(cursor); if (item->toPlainText().isEmpty()) { removeItem(item); item->deleteLater(); } } void DiagramScene::mousePressEvent(QGraphicsSceneMouseEvent *mouseEvent) { if (mouseEvent->button() != Qt::LeftButton) return; DiagramItem *item; switch (myMode) { case InsertItem: item = new DiagramItem(myItemType, myItemMenu); item->setBrush(myItemColor); addItem(item); item->setPos(mouseEvent->scenePos()); emit itemInserted(item); break; case InsertLine: line = new QGraphicsLineItem(QLineF(mouseEvent->scenePos(), mouseEvent->scenePos())); line->setPen(QPen(myLineColor, 2)); addItem(line); break; case InsertText: textItem = new DiagramTextItem(); textItem->setFont(myFont); textItem->setTextInteractionFlags(Qt::TextEditorInteraction); textItem->setZValue(1000.0); connect(textItem, SIGNAL(lostFocus(DiagramTextItem*)), this, SLOT(editorLostFocus(DiagramTextItem*))); connect(textItem, SIGNAL(selectedChange(QGraphicsItem*)), this, SIGNAL(itemSelected(QGraphicsItem*))); addItem(textItem); textItem->setDefaultTextColor(myTextColor); textItem->setPos(mouseEvent->scenePos()); emit textInserted(textItem); default: ; } QGraphicsScene::mousePressEvent(mouseEvent); } void DiagramScene::mouseMoveEvent(QGraphicsSceneMouseEvent *mouseEvent) { if (myMode == InsertLine && line != 0) { QLineF newLine(line->line().p1(), mouseEvent->scenePos()); line->setLine(newLine); } else if (myMode == MoveItem) { QGraphicsScene::mouseMoveEvent(mouseEvent); } } void DiagramScene::mouseReleaseEvent(QGraphicsSceneMouseEvent *mouseEvent) { if (line != 0 && myMode == InsertLine) { QList<QGraphicsItem *> startItems = items(line->line().p1()); if (startItems.count() && startItems.first() == line) startItems.removeFirst(); QList<QGraphicsItem *> endItems = items(line->line().p2()); if (endItems.count() && endItems.first() == line) endItems.removeFirst(); removeItem(line); delete line; if (startItems.count() > 0 && endItems.count() > 0 && startItems.first()->type() == DiagramItem::Type && endItems.first()->type() == DiagramItem::Type && startItems.first() != endItems.first()) { DiagramItem *startItem = qgraphicsitem_cast<DiagramItem *>(startItems.first()); DiagramItem *endItem = qgraphicsitem_cast<DiagramItem *>(endItems.first()); Arrow *arrow = new Arrow(startItem, endItem); arrow->setColor(myLineColor); startItem->addArrow(arrow); endItem->addArrow(arrow); arrow->setZValue(-1000.0); addItem(arrow); arrow->updatePosition(); } } line = 0; QGraphicsScene::mouseReleaseEvent(mouseEvent); } bool DiagramScene::isItemChange(int type) { foreach (QGraphicsItem *item, selectedItems()) { if (item->type() == type) return true; } return false; }