Add widgets download API

This patch adds a QWebEngineDownloadItem class to the widget API
and extends QWebEngineProfile with a signal to notify about initiated
downloads, similar to the QML API.

[ChangeLog][QtWebEngineWidgets] Add widgets download API

Change-Id: I532de640934e1e93d63dfc347efb4113cb4a3d66
Reviewed-by: Jocelyn Turcotte <jturcotte@woboq.com>

1 files changed, 302 insertions, 0 deletions

diff --git a/src/webenginewidgets/api/qwebenginedownloaditem.cpp b/src/webenginewidgets/api/qwebenginedownloaditem.cpp
new file mode 100644
index 000000000..f97b25431
--- /dev/null
+++ b/src/webenginewidgets/api/qwebenginedownloaditem.cpp
@@ -0,0 +1,302 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtWebEngine module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qwebenginedownloaditem.h"
+
+#include "qwebenginedownloaditem_p.h"
+#include "qwebengineprofile_p.h"
+
+QT_BEGIN_NAMESPACE
+
+static inline QWebEngineDownloadItem::DownloadState toDownloadState(int state)
+{
+    switch (state) {
+    case BrowserContextAdapterClient::DownloadInProgress:
+        return QWebEngineDownloadItem::DownloadInProgress;
+    case BrowserContextAdapterClient::DownloadCompleted:
+        return QWebEngineDownloadItem::DownloadCompleted;
+    case BrowserContextAdapterClient::DownloadCancelled:
+        return QWebEngineDownloadItem::DownloadCancelled;
+    case BrowserContextAdapterClient::DownloadInterrupted:
+        return QWebEngineDownloadItem::DownloadInterrupted;
+    default:
+        Q_UNREACHABLE();
+        return QWebEngineDownloadItem::DownloadCancelled;
+    }
+}
+
+/*!
+    \class QWebEngineDownloadItem
+    \brief The QWebEngineDownloadItem class provides information about a download.
+
+    \since 5.5
+
+    \inmodule QtWebEngineWidgets
+
+    QWebEngineDownloadItem stores the state of a download to be used to manage requested downloads.
+*/
+
+QWebEngineDownloadItemPrivate::QWebEngineDownloadItemPrivate(QWebEngineProfilePrivate *p, const QUrl &url)
+    : profile(p)
+    , downloadFinished(false)
+    , downloadId(-1)
+    , downloadState(QWebEngineDownloadItem::DownloadCancelled)
+    , downloadUrl(url)
+    , totalBytes(-1)
+    , receivedBytes(0)
+{
+}
+
+QWebEngineDownloadItemPrivate::~QWebEngineDownloadItemPrivate()
+{
+    profile->downloadDestroyed(downloadId);
+}
+
+void QWebEngineDownloadItemPrivate::update(const BrowserContextAdapterClient::DownloadItemInfo &info)
+{
+    Q_Q(QWebEngineDownloadItem);
+
+    Q_ASSERT(downloadState != QWebEngineDownloadItem::DownloadRequested);
+
+    if (info.state != downloadState) {
+        downloadState = toDownloadState(info.state);
+        Q_EMIT q->stateChanged(downloadState);
+    }
+
+    if (info.receivedBytes != receivedBytes || info.totalBytes != totalBytes) {
+        receivedBytes = info.receivedBytes;
+        totalBytes = info.totalBytes;
+        Q_EMIT q->downloadProgress(receivedBytes, totalBytes);
+    }
+
+    downloadFinished = downloadState != QWebEngineDownloadItem::DownloadInProgress;
+
+    if (downloadFinished)
+        Q_EMIT q->finished();
+}
+
+/*!
+    Accepts the current download request, which will start the download.
+
+    \sa finished(), stateChanged()
+*/
+
+void QWebEngineDownloadItem::accept()
+{
+    Q_D(QWebEngineDownloadItem);
+
+    if (d->downloadState != QWebEngineDownloadItem::DownloadRequested)
+        return;
+
+    d->downloadState = QWebEngineDownloadItem::DownloadInProgress;
+    Q_EMIT stateChanged(d->downloadState);
+}
+
+/*!
+    Cancels the current download.
+
+    \sa finished(), stateChanged()
+*/
+
+void QWebEngineDownloadItem::cancel()
+{
+    Q_D(QWebEngineDownloadItem);
+
+    QWebEngineDownloadItem::DownloadState state = d->downloadState;
+
+    if (state == QWebEngineDownloadItem::DownloadCompleted
+            || state == QWebEngineDownloadItem::DownloadCancelled)
+        return;
+
+    d->downloadState = QWebEngineDownloadItem::DownloadCancelled;
+    Q_EMIT stateChanged(d->downloadState);
+
+    // We directly cancel the download request if the user cancels
+    // before it even started, so no need to notify the profile here.
+    if (state == QWebEngineDownloadItem::DownloadInProgress)
+        d->profile->cancelDownload(d->downloadId);
+}
+
+/*!
+    Returns the download item's id.
+*/
+
+quint32 QWebEngineDownloadItem::id()
+{
+    Q_D(QWebEngineDownloadItem);
+    return d->downloadId;
+}
+
+/*!
+    \fn QWebEngineDownloadItem::finished()
+
+    This signal is emitted whenever the download finishes.
+
+    \sa state(), isFinished()
+*/
+
+/*!
+    \fn QWebEngineDownloadItem::stateChanged(DownloadState state)
+
+    This signal is emitted whenever the download's \a state changes.
+
+    \sa state(), QWebEngineDownloadItem::DownloadState
+*/
+
+/*!
+    \fn QWebEngineDownloadItem::downloadProgress(qint64 bytesReceived, qint64 bytesTotal)
+
+    This signal is emitted whenever the download's \a bytesReceived or
+    \a bytesTotal changes.
+
+    \sa totalBytes(), receivedBytes()
+*/
+
+/*!
+    \enum QWebEngineDownloadItem::DownloadState
+
+    This enum describes the state in which the download is in.
+
+    \value DownloadRequested The download has been requested, but has not been accepted yet.
+    \value DownloadInProgress The download is in progress.
+    \value DownloadCompleted The download completed successfully.
+    \value DownloadCancelled The download has been cancelled.
+    \value DownloadInterrupted The download has been interrupted (by the server or because of lost connectivity).
+*/
+
+/*!
+    Returns the download item's current state.
+
+    \sa QWebEngineDownloadItem::DownloadState
+*/
+
+QWebEngineDownloadItem::DownloadState QWebEngineDownloadItem::state()
+{
+    Q_D(QWebEngineDownloadItem);
+    return d->downloadState;
+}
+
+/*!
+    Returns the download's total size in bytes.
+
+    -1 means the size is unknown.
+*/
+
+qint64 QWebEngineDownloadItem::totalBytes()
+{
+    Q_D(QWebEngineDownloadItem);
+    return d->totalBytes;
+}
+
+/*!
+    Returns the download's bytes that have been received so far.
+
+    -1 means the size is unknown.
+*/
+
+qint64 QWebEngineDownloadItem::receivedBytes()
+{
+    Q_D(QWebEngineDownloadItem);
+    return d->receivedBytes;
+}
+
+/*!
+    Returns the download's origin url.
+*/
+
+QUrl QWebEngineDownloadItem::url()
+{
+    Q_D(QWebEngineDownloadItem);
+    return d->downloadUrl;
+}
+
+/*!
+    Returns the download's full target path where it is being downloaded to.
+
+    The path includes the file name. The default suggested path is the standard download location
+    and file name is deduced not to overwrite already existing files.
+*/
+
+QString QWebEngineDownloadItem::path()
+{
+    Q_D(QWebEngineDownloadItem);
+    return d->downloadPath;
+}
+
+/*!
+    Sets the download's full target path, where the file should be downloaded to.
+
+    The \a path should also include the file name. The download path can only be set in response
+    to the QWebEngineProfile::downloadRequested() signal before the download is accepted.
+    Past that point this function has no effect on the download item's state.
+*/
+void QWebEngineDownloadItem::setPath(QString path)
+{
+    Q_D(QWebEngineDownloadItem);
+    if (d->downloadState != QWebEngineDownloadItem::DownloadRequested) {
+        qWarning("Setting the download path is not allowed after the download has been accepted.");
+        return;
+    }
+
+    d->downloadPath = path;
+}
+
+/*!
+    Returns whether this download is finished (not in progress).
+
+    \sa finished(), state(),
+*/
+
+bool QWebEngineDownloadItem::isFinished()
+{
+    Q_D(QWebEngineDownloadItem);
+    return d->downloadFinished;
+}
+
+QWebEngineDownloadItem::QWebEngineDownloadItem(QWebEngineDownloadItemPrivate *p, QObject *parent)
+    : QObject(parent)
+    , d_ptr(p)
+{
+    p->q_ptr = this;
+}
+
+/*! \internal
+*/
+QWebEngineDownloadItem::~QWebEngineDownloadItem()
+{
+}
+
+QT_END_NAMESPACE