- Qt 5.5
- Qt Widgets
- Icons Example
- iconpreviewarea.cpp Example File
- Qt 5.5.1 Reference Documentation

# iconpreviewarea.cpp Example File

widgets/icons/iconpreviewarea.cpp

    /****************************************************************************
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    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the examples of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
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    #include <QtWidgets>

    #include "iconpreviewarea.h"

    IconPreviewArea::IconPreviewArea(QWidget *parent)
        : QWidget(parent)
    {
        QGridLayout *mainLayout = new QGridLayout;
        setLayout(mainLayout);

        stateLabels[0] = createHeaderLabel(tr("Off"));
        stateLabels[1] = createHeaderLabel(tr("On"));
        Q_ASSERT(NumStates == 2);

        modeLabels[0] = createHeaderLabel(tr("Normal"));
        modeLabels[1] = createHeaderLabel(tr("Active"));
        modeLabels[2] = createHeaderLabel(tr("Disabled"));
        modeLabels[3] = createHeaderLabel(tr("Selected"));
        Q_ASSERT(NumModes == 4);

        for (int j = 0; j < NumStates; ++j)
            mainLayout->addWidget(stateLabels[j], j + 1, 0);

        for (int i = 0; i < NumModes; ++i) {
            mainLayout->addWidget(modeLabels[i], 0, i + 1);

            for (int j = 0; j < NumStates; ++j) {
                pixmapLabels[i][j] = createPixmapLabel();
                mainLayout->addWidget(pixmapLabels[i][j], j + 1, i + 1);
            }
        }
    }

    void IconPreviewArea::setIcon(const QIcon &icon)
    {
        this->icon = icon;
        updatePixmapLabels();
    }

    void IconPreviewArea::setSize(const QSize &size)
    {
        if (size != this->size) {
            this->size = size;
            updatePixmapLabels();
        }
    }

    QLabel *IconPreviewArea::createHeaderLabel(const QString &text)
    {
        QLabel *label = new QLabel(tr("<b>%1</b>").arg(text));
        label->setAlignment(Qt::AlignCenter);
        return label;
    }

    QLabel *IconPreviewArea::createPixmapLabel()
    {
        QLabel *label = new QLabel;
        label->setEnabled(false);
        label->setAlignment(Qt::AlignCenter);
        label->setFrameShape(QFrame::Box);
        label->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
        label->setBackgroundRole(QPalette::Base);
        label->setAutoFillBackground(true);
        label->setMinimumSize(132, 132);
        return label;
    }

    void IconPreviewArea::updatePixmapLabels()
    {
        for (int i = 0; i < NumModes; ++i) {
            QIcon::Mode mode;
            if (i == 0) {
                mode = QIcon::Normal;
            } else if (i == 1) {
                mode = QIcon::Active;
            } else if (i == 2) {
                mode = QIcon::Disabled;
            } else {
                mode = QIcon::Selected;
            }

            for (int j = 0; j < NumStates; ++j) {
                QIcon::State state = (j == 0) ? QIcon::Off : QIcon::On;
                QPixmap pixmap = icon.pixmap(size, mode, state);
                pixmapLabels[i][j]->setPixmap(pixmap);
                pixmapLabels[i][j]->setEnabled(!pixmap.isNull());
            }
        }
    }