qerrormessage.cpp

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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include "qerrormessage.h"
 
#include "qapplication.h"
#include "qcheckbox.h"
#include "qlabel.h"
#include "qlayout.h"
#if QT_CONFIG(messagebox)
#include "qmessagebox.h"
#endif
#include "qpushbutton.h"
#include "qstringlist.h"
#include "qtextedit.h"
#include "qdialog_p.h"
#include "qpixmap.h"
#include "qmetaobject.h"
#include "qthread.h"
#include "qset.h"
 
#include <queue>
 
#include <stdio.h>
#include <stdlib.h>
 
QT_BEGIN_NAMESPACE
 
using namespace Qt::StringLiterals;
 
class QErrorMessagePrivate : public QDialogPrivate
{
    Q_DECLARE_PUBLIC(QErrorMessage)
public:
    struct Message {
        QString content;
        QString type;
    };
 
    QPushButton * ok;
    QCheckBox * again;
    QTextEdit * errors;
    QLabel * icon;
    std::queue<Message> pending;
    QSet<QString> doNotShow;
    QSet<QString> doNotShowType;
    QString currentMessage;
    QString currentType;
 
    bool isMessageToBeShown(const QString &message, const QString &type) const;
    bool nextPending();
    void retranslateStrings();
 
    void setVisible(bool) override;
 
private:
    void initHelper(QPlatformDialogHelper *) override;
    void helperPrepareShow(QPlatformDialogHelper *) override;
};
 
 
void QErrorMessagePrivate::initHelper(QPlatformDialogHelper *helper)
{
    Q_Q(QErrorMessage);
    auto *messageDialogHelper = static_cast<QPlatformMessageDialogHelper *>(helper);
    QObject::connect(messageDialogHelper, &QPlatformMessageDialogHelper::checkBoxStateChanged, q,
        [this](Qt::CheckState state) {
            again->setCheckState(state);
        }
    );
    QObject::connect(messageDialogHelper, &QPlatformMessageDialogHelper::clicked, q,
        [this](QPlatformDialogHelper::StandardButton, QPlatformDialogHelper::ButtonRole) {
            Q_Q(QErrorMessage);
            q->accept();
        }
    );
}
 
void QErrorMessagePrivate::helperPrepareShow(QPlatformDialogHelper *helper)
{
    Q_Q(QErrorMessage);
    auto *messageDialogHelper = static_cast<QPlatformMessageDialogHelper *>(helper);
    QSharedPointer<QMessageDialogOptions> options = QMessageDialogOptions::create();
    options->setText(currentMessage);
    options->setWindowTitle(q->windowTitle());
    options->setText(QErrorMessage::tr("An error occurred"));
    options->setInformativeText(currentMessage);
    options->setStandardIcon(QMessageDialogOptions::Critical);
    options->setCheckBox(again->text(), again->checkState());
    messageDialogHelper->setOptions(options);
}
 
namespace {
class QErrorMessageTextView : public QTextEdit
{
public:
    QErrorMessageTextView(QWidget *parent)
        : QTextEdit(parent) { setReadOnly(true); }
 
    virtual QSize minimumSizeHint() const override;
    virtual QSize sizeHint() const override;
};
} // unnamed namespace
 
QSize QErrorMessageTextView::minimumSizeHint() const
{
    return QSize(50, 50);
}
 
QSize QErrorMessageTextView::sizeHint() const
{
    return QSize(250, 75);
}
 
static QErrorMessage * qtMessageHandler = nullptr;
 
static void deleteStaticcQErrorMessage() // post-routine
{
    if (qtMessageHandler) {
        delete qtMessageHandler;
        qtMessageHandler = nullptr;
    }
}
 
static bool metFatal = false;
 
static QString msgType2i18nString(QtMsgType t)
{
    static_assert(QtDebugMsg == 0);
    static_assert(QtWarningMsg == 1);
    static_assert(QtCriticalMsg == 2);
    static_assert(QtFatalMsg == 3);
    static_assert(QtInfoMsg == 4);
 
    // adjust the array below if any of the above fire...
 
    const char * const messages[] = {
        QT_TRANSLATE_NOOP("QErrorMessage", "Debug Message:"),
        QT_TRANSLATE_NOOP("QErrorMessage", "Warning:"),
        QT_TRANSLATE_NOOP("QErrorMessage", "Critical Error:"),
        QT_TRANSLATE_NOOP("QErrorMessage", "Fatal Error:"),
        QT_TRANSLATE_NOOP("QErrorMessage", "Information:"),
    };
    Q_ASSERT(size_t(t) < sizeof messages / sizeof *messages);
 
    return QCoreApplication::translate("QErrorMessage", messages[t]);
}
 
static QtMessageHandler originalMessageHandler = nullptr;
 
static void jump(QtMsgType t, const QMessageLogContext &context, const QString &m)
{
    const auto forwardToOriginalHandler = qScopeGuard([&] {
       if (originalMessageHandler)
            originalMessageHandler(t, context, m);
    });
 
    if (!qtMessageHandler)
        return;
 
    auto *defaultCategory = QLoggingCategory::defaultCategory();
    if (context.category && defaultCategory
        && qstrcmp(context.category, defaultCategory->categoryName()) != 0)
        return;
 
    QString rich = "<p><b>"_L1 + msgType2i18nString(t) + "</b></p>"_L1
                   + Qt::convertFromPlainText(m, Qt::WhiteSpaceNormal);
 
    // ### work around text engine quirk
    if (rich.endsWith("</p>"_L1))
        rich.chop(4);
 
    if (!metFatal) {
        if (QThread::currentThread() == qApp->thread()) {
            qtMessageHandler->showMessage(rich);
        } else {
            QMetaObject::invokeMethod(qtMessageHandler,
                                      "showMessage",
                                      Qt::QueuedConnection,
                                      Q_ARG(QString, rich));
        }
        metFatal = (t == QtFatalMsg);
    }
}
 
 
QErrorMessage::QErrorMessage(QWidget * parent)
    : QDialog(*new QErrorMessagePrivate, parent)
{
    Q_D(QErrorMessage);
 
#if defined(Q_OS_MACOS)
    setWindowModality(parent ? Qt::WindowModal : Qt::ApplicationModal);
#endif
 
    d->icon = new QLabel(this);
    d->errors = new QErrorMessageTextView(this);
    d->again = new QCheckBox(this);
    d->ok = new QPushButton(this);
    QGridLayout * grid = new QGridLayout(this);
 
    connect(d->ok, SIGNAL(clicked()), this, SLOT(accept()));
 
    grid->addWidget(d->icon,   0, 0, Qt::AlignTop);
    grid->addWidget(d->errors, 0, 1);
    grid->addWidget(d->again,  1, 1, Qt::AlignTop);
    grid->addWidget(d->ok,     2, 0, 1, 2, Qt::AlignCenter);
    grid->setColumnStretch(1, 42);
    grid->setRowStretch(0, 42);
 
#if QT_CONFIG(messagebox)
    const auto iconSize = style()->pixelMetric(QStyle::PM_MessageBoxIconSize, nullptr, this);
    const auto icon = style()->standardIcon(QStyle::SP_MessageBoxInformation, nullptr, this);
    d->icon->setPixmap(icon.pixmap(QSize(iconSize, iconSize), devicePixelRatio()));
    d->icon->setAlignment(Qt::AlignHCenter | Qt::AlignTop);
#endif
    d->again->setChecked(true);
    d->ok->setFocus();
 
    d->retranslateStrings();
}
 
 
QErrorMessage::~QErrorMessage()
{
    if (this == qtMessageHandler) {
        qtMessageHandler = nullptr;
        QtMessageHandler currentMessagHandler = qInstallMessageHandler(nullptr);
        if (currentMessagHandler != jump)
            qInstallMessageHandler(currentMessagHandler);
        else
            qInstallMessageHandler(originalMessageHandler);
        originalMessageHandler = nullptr;
    }
}
 
 
void QErrorMessage::done(int a)
{
    Q_D(QErrorMessage);
    if (!d->again->isChecked()) {
        if (d->currentType.isEmpty()) {
            if (!d->currentMessage.isEmpty())
                d->doNotShow.insert(d->currentMessage);
        } else {
            d->doNotShowType.insert(d->currentType);
        }
    }
    d->currentMessage.clear();
    d->currentType.clear();
 
    QDialog::done(a);
 
    if (d->nextPending()) {
        show();
    } else {
        if (this == qtMessageHandler && metFatal)
            exit(1);
    }
}
 
 
QErrorMessage * QErrorMessage::qtHandler()
{
    if (!qtMessageHandler) {
        qtMessageHandler = new QErrorMessage(nullptr);
        qAddPostRoutine(deleteStaticcQErrorMessage); // clean up
        qtMessageHandler->setWindowTitle(QCoreApplication::applicationName());
        originalMessageHandler = qInstallMessageHandler(jump);
    }
    return qtMessageHandler;
}
 
 
bool QErrorMessagePrivate::isMessageToBeShown(const QString &message, const QString &type) const
{
    return !message.isEmpty()
        && (type.isEmpty() ? !doNotShow.contains(message) : !doNotShowType.contains(type));
}
 
bool QErrorMessagePrivate::nextPending()
{
    while (!pending.empty()) {
        QString message = std::move(pending.front().content);
        QString type = std::move(pending.front().type);
        pending.pop();
        if (isMessageToBeShown(message, type)) {
#ifndef QT_NO_TEXTHTMLPARSER
            errors->setHtml(message);
#else
            errors->setPlainText(message);
#endif
            currentMessage = std::move(message);
            currentType = std::move(type);
            again->setChecked(true);
            return true;
        }
    }
    return false;
}
 
 
void QErrorMessage::showMessage(const QString &message)
{
    showMessage(message, QString());
}
 
void QErrorMessage::showMessage(const QString &message, const QString &type)
{
    Q_D(QErrorMessage);
    if (!d->isMessageToBeShown(message, type))
        return;
    d->pending.push({message, type});
    if (!isVisible() && d->nextPending())
        show();
}
 
void QErrorMessagePrivate::setVisible(bool visible)
{
    Q_Q(QErrorMessage);
 
    if (canBeNativeDialog())
        setNativeDialogVisible(visible);
 
    // Update WA_DontShowOnScreen based on whether the native dialog was shown,
    // so that QDialog::setVisible(visible) below updates the QWidget state correctly,
    // but skips showing the non-native version.
    q->setAttribute(Qt::WA_DontShowOnScreen, nativeDialogInUse);
 
    QDialogPrivate::setVisible(visible);
}
 
void QErrorMessage::changeEvent(QEvent *e)
{
    Q_D(QErrorMessage);
    if (e->type() == QEvent::LanguageChange) {
        d->retranslateStrings();
    }
    QDialog::changeEvent(e);
}
 
void QErrorMessagePrivate::retranslateStrings()
{
    again->setText(QErrorMessage::tr("&Show this message again"));
    ok->setText(QErrorMessage::tr("&OK"));
}
 
QT_END_NAMESPACE
 
#include "moc_qerrormessage.cpp"