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#include <QtGui>

#include "diagramscene.h"

#include "arrow.h"

//! [0]

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;

}

//! [0]

//! [1]

void DiagramScene::setLineColor(const QColor &color)

{

    myLineColor = color;

    if (isItemChange(Arrow::Type)) {

        Arrow *item =

            qgraphicsitem_cast<Arrow *>(selectedItems().first());

        item->setColor(myLineColor);

        update();

    }

}

//! [1]

//! [2]

void DiagramScene::setTextColor(const QColor &color)

{

    myTextColor = color;

    if (isItemChange(DiagramTextItem::Type)) {

        DiagramTextItem *item =

            qgraphicsitem_cast<DiagramTextItem *>(selectedItems().first());

        item->setDefaultTextColor(myTextColor);

    }

}

//! [2]

//! [3]

void DiagramScene::setItemColor(const QColor &color)

{

    myItemColor = color;

    if (isItemChange(DiagramItem::Type)) {

        DiagramItem *item =

            qgraphicsitem_cast<DiagramItem *>(selectedItems().first());

        item->setBrush(myItemColor);

    }

}

//! [3]

//! [4]

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);

    }

}

//! [4]

void DiagramScene::setMode(Mode mode)

{

    myMode = mode;

}

void DiagramScene::setItemType(DiagramItem::DiagramType type)

{

    myItemType = type;

}

//! [5]

void DiagramScene::editorLostFocus(DiagramTextItem *item)

{

    QTextCursor cursor = item->textCursor();

    cursor.clearSelection();

    item->setTextCursor(cursor);

    if (item->toPlainText().isEmpty()) {

        removeItem(item);

        item->deleteLater();

    }

}

//! [5]

//! [6]

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;

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

        case InsertLine:

            line = new QGraphicsLineItem(QLineF(mouseEvent->scenePos(),

                                        mouseEvent->scenePos()));

            line->setPen(QPen(myLineColor, 2));

            addItem(line);

            break;

//! [7] //! [8]

        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);

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

    default:

        ;

    }

    QGraphicsScene::mousePressEvent(mouseEvent);

}

//! [9]

//! [10]

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);

    }

}

//! [10]

//! [11]

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;

//! [11] //! [12]

        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();

        }

    }

//! [12] //! [13]

    line = 0;

    QGraphicsScene::mouseReleaseEvent(mouseEvent);

}

//! [13]

//! [14]

bool DiagramScene::isItemChange(int type)

{

    foreach (QGraphicsItem *item, selectedItems()) {

        if (item->type() == type)

            return true;

    }

    return false;

}

//! [14]