- Qt 5.5
- Qt SQL
- Drill Down Example
- view.cpp Example File
- Qt 5.5.1 Reference Documentation

# view.cpp Example File

drilldown/view.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the examples of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
    ** You may use this file under the terms of the BSD license as follows:
    **
    ** "Redistribution and use in source and binary forms, with or without
    ** modification, are permitted provided that the following conditions are
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    **   * Redistributions of source code must retain the above copyright
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    **     notice, this list of conditions and the following disclaimer in
    **     the documentation and/or other materials provided with the
    **     distribution.
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    **     contributors may be used to endorse or promote products derived
    **     from this software without specific prior written permission.
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    ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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    #include "informationwindow.h"
    #include "imageitem.h"
    #include "view.h"

    View::View(const QString &items, const QString &images, QWidget *parent)
        : QGraphicsView(parent)
    {
        itemTable = new QSqlRelationalTableModel(this);
        itemTable->setTable(items);
        itemTable->setRelation(1, QSqlRelation(images, "itemid", "file"));
        itemTable->select();

        scene = new QGraphicsScene(this);
        scene->setSceneRect(0, 0, 465, 365);
        setScene(scene);

        addItems();

        setMinimumSize(470, 370);
        setMaximumSize(470, 370);

        QLinearGradient gradient(QPointF(0, 0), QPointF(0, 370));
        gradient.setColorAt(0, QColor("#868482"));
        gradient.setColorAt(1, QColor("#5d5b59"));
        setBackgroundBrush(gradient);
    }

    void View::addItems()
    {
        int itemCount = itemTable->rowCount();

        int imageOffset = 150;
        int leftMargin = 70;
        int topMargin = 40;

        for (int i = 0; i < itemCount; i++) {
            ImageItem *image;
            QGraphicsTextItem *label;
            QSqlRecord record = itemTable->record(i);

            int id = record.value("id").toInt();
            QString file = record.value("file").toString();
            QString item = record.value("itemtype").toString();

            int columnOffset = ((i % 2) * 37);
            int x = ((i % 2) * imageOffset) + leftMargin + columnOffset;
            int y = ((i / 2) * imageOffset) + topMargin;

            image = new ImageItem(id, QPixmap(":/" + file));
            image->setData(0, i);
            image->setPos(x, y);
            scene->addItem(image);

            label = scene->addText(item);
            label->setDefaultTextColor(QColor("#d7d6d5"));
            QPointF labelOffset((120 - 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 >= itemTable->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, itemTable, 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;
    }