Re-add WebSnap class & included API in WebWindow for tab preview

1 files changed, 164 insertions, 0 deletions

diff --git a/src/websnap.cpp b/src/websnap.cpp
new file mode 100644
index 00000000..6440136e
--- /dev/null
+++ b/src/websnap.cpp
@@ -0,0 +1,164 @@
+/* ============================================================
+*
+* This file is a part of the rekonq project
+*
+* Copyright (C) 2009-2012 by Andrea Diamantini <adjam7 at gmail dot com>
+* Copyright (C) 2010 by Matthieu Gicquel <matgic78 at gmail dot com>
+*
+*
+* This program is free software; you can redistribute it and/or
+* modify it under the terms of the GNU General Public License as
+* published by the Free Software Foundation; either version 2 of
+* the License or (at your option) version 3 or any later version
+* accepted by the membership of KDE e.V. (or its successor approved
+* by the membership of KDE e.V.), which shall act as a proxy
+* defined in Section 14 of version 3 of the license.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*
+* ============================================================ */
+
+
+// Self Includes
+#include "websnap.h"
+#include "websnap.moc"
+
+// KDE Includes
+#include <KStandardDirs>
+
+// Qt Includes
+#include <QSize>
+#include <QFile>
+
+#include <QCryptographicHash>
+
+#include <QPainter>
+#include <QAction>
+
+#include <QWebFrame>
+#include <QWebSettings>
+
+
+WebSnap::WebSnap(const QUrl& url, QObject *parent)
+    : QObject(parent)
+    , m_url(url)
+{
+    // this to not register websnap history
+    m_page.settings()->setAttribute(QWebSettings::PrivateBrowsingEnabled, true);
+
+    // this to not let this page open other windows
+    m_page.settings()->setAttribute(QWebSettings::PluginsEnabled, false);
+    m_page.settings()->setAttribute(QWebSettings::JavascriptEnabled, false);
+
+    connect(&m_page, SIGNAL(loadFinished(bool)), this, SLOT(saveResult(bool)));
+
+    QMetaObject::invokeMethod(this, "load", Qt::QueuedConnection);
+}
+
+
+WebSnap::~WebSnap()
+{
+    m_page.action(QWebPage::Stop)->trigger();
+    m_page.deleteLater();
+}
+
+
+void WebSnap::load()
+{
+    m_page.mainFrame()->load(m_url);
+}
+
+
+
+QPixmap WebSnap::render(const QWebPage &page, int w, int h)
+{
+    // create the page image
+    QPixmap pageImage = QPixmap(w, h);
+    pageImage.fill(Qt::transparent);
+
+    // render it
+    QPainter p(&pageImage);
+    page.mainFrame()->render(&p, QWebFrame::ContentsLayer);
+    p.end();
+
+    return pageImage;
+}
+
+
+// NOTE
+// to render page preview in a safe way, you CANNOT work with scrollbars!
+// In fact, disabling temporarily them DOES NOT work without reloading a page
+// that is something we CANNOT do.
+QPixmap WebSnap::renderPagePreview(const QWebPage &page, int w, int h)
+{
+    // store actual viewportsize
+    QSize oldSize = page.viewportSize();
+
+    // prepare page
+    // NOTE: I saw some sites with strange CMS and with absurd content size width (eg: 8584553)
+    // This usually leads setViewportSize to crash :(
+    // So, ensure renderWidth is no more than 2000.
+    int renderWidth = page.mainFrame()->contentsSize().width();
+    if (renderWidth > 2000)
+        renderWidth = 2000;
+    int renderHeight = renderWidth * ((0.0 + h) / w);
+
+    page.setViewportSize(QSize(renderWidth, renderHeight));
+
+    // consider scrollbars and render the page
+    bool verticalScrollBarActive = !page.mainFrame()->scrollBarGeometry(Qt::Vertical).isEmpty();
+    if (verticalScrollBarActive)
+        renderWidth -= 15;
+
+    bool horizontalScrollBarActive = !page.mainFrame()->scrollBarGeometry(Qt::Horizontal).isEmpty();
+    if (horizontalScrollBarActive)
+        renderHeight -= 15;
+
+    QPixmap pageImage = WebSnap::render(page, renderWidth, renderHeight);
+
+    // resize image
+    pageImage = pageImage.scaled(w, h, Qt::KeepAspectRatioByExpanding, Qt::SmoothTransformation);
+
+    // restore page state
+    page.setViewportSize(oldSize);
+
+    return pageImage;
+}
+
+
+QString WebSnap::imagePathFromUrl(const QUrl &url)
+{
+    QByteArray name = url.toEncoded(QUrl::RemoveScheme | QUrl::RemoveUserInfo | QUrl::StripTrailingSlash);
+
+    QByteArray hashedName = QCryptographicHash::hash(name, QCryptographicHash::Md5).toHex();
+
+    return KStandardDirs::locateLocal("cache", QString("thumbs/") + hashedName + ".png", true);
+}
+
+
+void WebSnap::saveResult(bool ok)
+{
+    if (ok)
+    {
+        QPixmap image = renderPagePreview(m_page, defaultWidth, defaultHeight);
+        QString path = imagePathFromUrl(m_url);
+        QFile::remove(path);
+        image.save(path);
+    }
+
+    emit snapDone(ok);
+
+    this->deleteLater();
+}
+
+
+bool WebSnap::existsImage(const QUrl &u)
+{
+    return QFile::exists(imagePathFromUrl(u));
+}