8.7 实例：基于图片记录查询.txt

来自「qt的源代码」· 文本 代码 · 共 295 行

 class InformationWindow : public QDialog
 {
     Q_OBJECT
 public:
     InformationWindow(int id, QSqlRelationalTableModel *offices,QWidget *parent = 0);
     int id();
 signals:
     void imageChanged(int id, const QString &fileName); 
 private slots:
     void revert();
     void submit();
     void enableButtons(bool enable = true); 
private:
     void createButtons();
     int locationId;
     QString displayedImage;
     QComboBox *imageFileEditor;
     QLabel *locationText;
     QLabel *countryText;
     QTextEdit *descriptionEditor;
     QPushButton *closeButton;
     QPushButton *submitButton;
     QPushButton *revertButton;
     QDialogButtonBox *buttonBox;
     QDataWidgetMapper *mapper;
 };    
 InformationWindow::InformationWindow(int id, QSqlRelationalTableModel *offices,
                                      QWidget *parent)
     : QDialog(parent)
 {
     QLabel *locationLabel = new QLabel(tr("Location: "));
     QLabel *countryLabel = new QLabel(tr("Country: "));
     QLabel *descriptionLabel = new QLabel(tr("Description: "));
     QLabel *imageFileLabel = new QLabel(tr("Image file: "));
     createButtons();
     locationText = new QLabel;
     countryText = new QLabel;
     descriptionEditor = new QTextEdit; 
imageFileEditor = new QComboBox;
     imageFileEditor->setModel(offices->relationModel(1));  imageFileEditor->setModelColumn(offices->relationModel(1)->fieldIndex("file")）；
 mapper = new QDataWidgetMapper(this);
     mapper->setModel(offices);
     mapper->setSubmitPolicy(QDataWidgetMapper::ManualSubmit);
     mapper->setItemDelegate(new QSqlRelationalDelegate(mapper));
     mapper->addMapping(imageFileEditor, 1);
     mapper->addMapping(locationText, 2);
     mapper->addMapping(countryText, 3);
     mapper->addMapping(descriptionEditor, 4);
     mapper->setCurrentIndex(id);   
connect(descriptionEditor, SIGNAL(textChanged()),
             this, SLOT(enableButtons()));
     connect(imageFileEditor, SIGNAL(currentIndexChanged(int)),
             this, SLOT(enableButtons()));
     QGridLayout *layout = new QGridLayout;
     layout->addWidget(locationLabel, 0, 0, Qt::AlignLeft | Qt::AlignTop);
     layout->addWidget(countryLabel, 1, 0, Qt::AlignLeft | Qt::AlignTop);
     layout->addWidget(imageFileLabel, 2, 0, Qt::AlignLeft | Qt::AlignTop);
     layout->addWidget(descriptionLabel, 3, 0, Qt::AlignLeft | Qt::AlignTop);
     layout->addWidget(locationText, 0, 1);
     layout->addWidget(countryText, 1, 1);
     layout->addWidget(imageFileEditor, 2, 1);
     layout->addWidget(descriptionEditor, 3, 1);
     layout->addWidget(buttonBox, 4, 0, 1, 2);
     setLayout(layout);
     locationId = id;
     displayedImage = imageFileEditor->currentText();
     setWindowFlags(Qt::Window);
     enableButtons(false);
     setWindowTitle(tr("Trolltech Office: %1").arg(locationText->text()));
     resize(320, sizeHint().height());
 }          
 int InformationWindow::id()
 {
     return locationId;
 } 
 void InformationWindow::revert()
 {
     mapper->revert();
     enableButtons(false);
 } 
 void InformationWindow::submit()
 {
     QString newImage(imageFileEditor->currentText());
     if (displayedImage != newImage) {
         displayedImage = newImage;
         emit imageChanged(locationId, newImage);
     }
     mapper->submit();
     mapper->setCurrentIndex(locationId);
     enableButtons(false);
 } 
 void InformationWindow::createButtons()
 {
     closeButton = new QPushButton(tr("&Close"));
     revertButton = new QPushButton(tr("&Revert"));
     submitButton = new QPushButton(tr("&Submit"));
     closeButton->setDefault(true);
     connect(closeButton, SIGNAL(clicked()), this, SLOT(close()));
     connect(revertButton, SIGNAL(clicked()), this, SLOT(revert()));
     connect(submitButton, SIGNAL(clicked()), this, SLOT(submit())); 
 buttonBox = new QDialogButtonBox;
     buttonBox->addButton(submitButton, QDialogButtonBox::ResetRole);
     buttonBox->addButton(revertButton, QDialogButtonBox::ResetRole);
     buttonBox->addButton(closeButton, QDialogButtonBox::RejectRole);
 }    
 void InformationWindow::enableButtons(bool enable)
 {
     revertButton->setEnabled(enable);
     submitButton->setEnabled(enable);
 }   
 class View : public QGraphicsView
 {
     Q_OBJECT
 public:
     View(const QString &offices, const QString &images, QWidget *parent = 0);
 protected:
     void mouseReleaseEvent(QMouseEvent *event);
 private slots:
     void updateImage(int id, const QString &fileName); 
 private:
     void addItems();
     InformationWindow* findWindow(int id);
     void showInformation(ImageItem *image);
     QGraphicsScene *scene;
     QList<InformationWindow *> informationWindows; 
 QSqlRelationalTableModel *officeTable;
 }; 
 View::View(const QString &offices, const QString &images, QWidget *parent)
     : QGraphicsView(parent)
 {
     officeTable = new QSqlRelationalTableModel(this);
     officeTable->setTable(offices);
     officeTable->setRelation(1, QSqlRelation(images, "locationid", "file"));
     officeTable->select();  
scene = new QGraphicsScene(this);
     scene->setSceneRect(0, 0, 465, 615);
     setScene(scene);
     addItems();
     QGraphicsPixmapItem *logo = scene->addPixmap(QPixmap(":/logo.png"));
     logo->setPos(30, 515);
     setMinimumSize(470, 620);
     setMaximumSize(470, 620);
     setWindowTitle(tr("Trolltech World Wide"));
 } 
 void View::addItems()
 {
     int officeCount = officeTable->rowCount();
     int imageOffset = 150;
     int leftMargin = 70;
     int topMargin = 40;
     for (int i = 0; i < officeCount; i++) {
         ImageItem *image;
         QGraphicsTextItem *label;
         QSqlRecord record = officeTable->record(i);
         int id = record.value("id").toInt();
         QString file = record.value("file").toString();
         QString location = record.value("location").toString();
         int columnOffset = ((i / 3) * 37);
         int x = ((i / 3) * imageOffset) + leftMargin + columnOffset;
         int y = ((i % 3) * imageOffset) + topMargin;
         image = new ImageItem(id, QPixmap(":/" + file));
         image->setData(0, i);
         image->setPos(x, y);
         scene->addItem(image);
         label = scene->addText(location);
         QPointF labelOffset((150 - label->boundingRect().width()) / 2, 120.0);
         label->setPos(QPointF(x, y) + labelOffset);
     }
 } 
 void View::mouseReleaseEvent(QMouseEvent *event)
 {
     if (QGraphicsItem *item = itemAt(event->pos())) {
         if (ImageItem *image = qgraphicsitem_cast<ImageItem *>(item))
             showInformation(image);
     }
     QGraphicsView::mouseReleaseEvent(event);
 } 
void View::showInformation(ImageItem *image)
 {
     int id = image->id();
     if (id < 0 || id >= officeTable->rowCount())
         return;
     InformationWindow *window = findWindow(id);
     if (window && window->isVisible()) {
         window->raise();
         window->activateWindow();
     } else if (window && !window->isVisible()) {
         window->show();
     } else {
         InformationWindow *window;
         window = new InformationWindow(id, officeTable, this);
         connect(window, SIGNAL(imageChanged(int, QString)),
                 this, SLOT(updateImage(int, QString)));
         window->move(pos() + QPoint(20, 40));
         window->show();
         informationWindows.append(window);
     }
 } 
 void View::updateImage(int id, const QString &fileName)
 {
     QList<QGraphicsItem *> items = scene->items();
     while(!items.empty()) {
         QGraphicsItem *item = items.takeFirst();
         if (ImageItem *image = qgraphicsitem_cast<ImageItem *>(item)) {
             if (image->id() == id){
                 image->setPixmap(QPixmap(":/" +fileName));
                 image->adjust();
                 break;
 }
         }
     }
 } 
 InformationWindow* View::findWindow(int id)
 {
     QList<InformationWindow*>::iterator i, beginning, end;
     beginning = informationWindows.begin();
     end = informationWindows.end();
     for (i = beginning; i != end; ++i) {
         InformationWindow *window = (*i);
         if (window && (window->id() == id))
             return window;
     }
     return 0;
 } 
 class ImageItem : public QObject, public QGraphicsPixmapItem
 {
     Q_OBJECT
 public:
     ImageItem(int id, const QPixmap &pixmap, QGraphicsItem *parent = 0,
               QGraphicsScene *scene = 0);
     void adjust();
     int id();
 protected:
     void hoverEnterEvent(QGraphicsSceneHoverEvent *event);
     void hoverLeaveEvent(QGraphicsSceneHoverEvent *event);
 private slots:
     void setFrame(int frame);
     void updateItemPosition();
 private:
     QTimeLine timeLine;
     int recordId;
     double z;
 }; 
 ImageItem::ImageItem(int id, const QPixmap &pixmap, QGraphicsItem *parent,
                      QGraphicsScene *scene)
     : QGraphicsPixmapItem(pixmap, parent, scene)
 {
     recordId = id;
     setAcceptsHoverEvents(true);
     timeLine.setDuration(150);
     timeLine.setFrameRange(0, 150);
     connect(&timeLine, SIGNAL(frameChanged(int)), this, SLOT(setFrame(int)));
     connect(&timeLine, SIGNAL(finished()), this, SLOT(updateItemPosition()));
     adjust();
 } 
void ImageItem::hoverEnterEvent(QGraphicsSceneHoverEvent * /*event*/)
 {
     timeLine.setDirection(QTimeLine::Forward);
     if (z != 1.0) {
         z = 1.0;
         updateItemPosition();
     }
     if (timeLine.state() == QTimeLine::NotRunning)
         timeLine.start();
 }
 void ImageItem::hoverLeaveEvent(QGraphicsSceneHoverEvent * /*event*/)
 {
     timeLine.setDirection(QTimeLine::Backward);
     if (z != 0.0)
         z = 0.0;
     if (timeLine.state() == QTimeLine::NotRunning)
         timeLine.start();
 } 
void ImageItem::setFrame(int frame)
 {
     adjust();
     QPointF center = boundingRect().center();
     translate(center.x(), center.y());
     scale(1 + frame / 330.0, 1 + frame / 330.0);
     translate(-center.x(), -center.y());
 } 
 void ImageItem::adjust()
 {
     QMatrix matrix;
     matrix.scale(150/ boundingRect().width(), 120/ boundingRect().height());
     setMatrix(matrix);
 }
 int ImageItem::id()
 {
     return recordId;
 }
 void ImageItem::updateItemPosition()
 {
     setZValue(z);
 }