Help: Cleanly separate different viewer backends

Removes the conditional compilation of the text browser vs web kit,
cleans up the code, and enables us to provide and test other backends
(WebEngine? Native?)
Adds runtime switch for testing the text browser variant by setting
environment variable QTC_FORCE_TEXTBROWSER (for now)

Change-Id: I8cc9bb373438d37c8194e433224314caa0b617bd
Reviewed-by: Eike Ziller <[email protected]>

1 files changed, 440 insertions, 0 deletions

diff --git a/src/plugins/help/textbrowserhelpviewer.cpp b/src/plugins/help/textbrowserhelpviewer.cpp
new file mode 100644
index 00000000000..746f556c011
--- /dev/null
+++ b/src/plugins/help/textbrowserhelpviewer.cpp
@@ -0,0 +1,440 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of Qt Creator.
+**
+** 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 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+****************************************************************************/
+
+#include "textbrowserhelpviewer.h"
+
+#include "helpconstants.h"
+#include "localhelpmanager.h"
+
+#include <coreplugin/find/findplugin.h>
+#include <utils/hostosinfo.h>
+
+#include <QApplication>
+#include <QClipboard>
+#include <QContextMenuEvent>
+#include <QHelpEngine>
+#include <QKeyEvent>
+#include <QMenu>
+#include <QVBoxLayout>
+
+using namespace Help;
+using namespace Help::Internal;
+
+// -- HelpViewer
+
+TextBrowserHelpViewer::TextBrowserHelpViewer(qreal zoom, QWidget *parent)
+    : HelpViewer(parent)
+    , m_textBrowser(new TextBrowserHelpWidget(zoom, this))
+{
+    QVBoxLayout *layout = new QVBoxLayout;
+    setLayout(layout);
+    layout->setContentsMargins(0, 0, 0, 0);
+    layout->addWidget(m_textBrowser, 10);
+    QPalette p = palette();
+    p.setColor(QPalette::Inactive, QPalette::Highlight,
+        p.color(QPalette::Active, QPalette::Highlight));
+    p.setColor(QPalette::Inactive, QPalette::HighlightedText,
+        p.color(QPalette::Active, QPalette::HighlightedText));
+    setPalette(p);
+
+    // ???
+    QFont font = viewerFont();
+    font.setPointSize(int(font.pointSize() + zoom));
+    setViewerFont(font);
+
+    connect(m_textBrowser, SIGNAL(sourceChanged(QUrl)), this, SIGNAL(titleChanged()));
+    connect(m_textBrowser, SIGNAL(forwardAvailable(bool)), this, SIGNAL(forwardAvailable(bool)));
+    connect(m_textBrowser, SIGNAL(backwardAvailable(bool)), this, SIGNAL(backwardAvailable(bool)));
+}
+
+TextBrowserHelpViewer::~TextBrowserHelpViewer()
+{
+}
+
+QFont TextBrowserHelpViewer::viewerFont() const
+{
+    const QHelpEngineCore &engine = LocalHelpManager::helpEngine();
+    return qvariant_cast<QFont>(engine.customValue(QLatin1String("font"),
+        qApp->font()));
+}
+
+void TextBrowserHelpViewer::setViewerFont(const QFont &newFont)
+{
+    if (font() != newFont) {
+        m_textBrowser->forceFont = true;
+        m_textBrowser->setFont(newFont);
+        m_textBrowser->forceFont = false;
+    }
+}
+
+void TextBrowserHelpViewer::scaleUp()
+{
+    m_textBrowser->scaleUp();
+}
+
+void TextBrowserHelpViewer::scaleDown()
+{
+    m_textBrowser->scaleDown();
+}
+
+void TextBrowserHelpViewer::resetScale()
+{
+    if (m_textBrowser->zoomCount != 0) {
+        m_textBrowser->forceFont = true;
+        m_textBrowser->zoomOut(m_textBrowser->zoomCount);
+        m_textBrowser->forceFont = false;
+    }
+    m_textBrowser->zoomCount = 0;
+}
+
+qreal TextBrowserHelpViewer::scale() const
+{
+    return m_textBrowser->zoomCount;
+}
+
+QString TextBrowserHelpViewer::title() const
+{
+    return m_textBrowser->documentTitle();
+}
+
+void TextBrowserHelpViewer::setTitle(const QString &title)
+{
+    m_textBrowser->setDocumentTitle(title);
+}
+
+QUrl TextBrowserHelpViewer::source() const
+{
+    return m_textBrowser->source();
+}
+
+void TextBrowserHelpViewer::setSource(const QUrl &url)
+{
+    const QString &string = url.toString();
+    if (url.isValid() && string != QLatin1String("help")) {
+        if (launchWithExternalApp(url))
+            return;
+
+        QUrl resolvedUrl;
+        if (url.scheme() == QLatin1String("http"))
+            resolvedUrl = url;
+
+        if (!resolvedUrl.isValid()) {
+            const QHelpEngineCore &engine = LocalHelpManager::helpEngine();
+            resolvedUrl = engine.findFile(url);
+        }
+
+        if (resolvedUrl.isValid()) {
+            m_textBrowser->setSource(resolvedUrl);
+            slotLoadFinished();
+            return;
+        }
+    }
+
+    m_textBrowser->setSource(url);
+    m_textBrowser->setHtml(string == Help::Constants::AboutBlank
+        ? HelpViewer::tr("<title>about:blank</title>")
+        : HelpViewer::tr("<html><head><meta http-equiv=\""
+            "content-type\" content=\"text/html; charset=UTF-8\"><title>Error 404...</title>"
+            "</head><body><div align=\"center\"><br/><br/><h1>The page could not be found</h1>"
+            "<br/><h3>\"%1\"</h3></div></body></html>")
+          .arg(url.toString()));
+
+    slotLoadFinished();
+}
+
+void TextBrowserHelpViewer::scrollToAnchor(const QString &anchor)
+{
+    m_textBrowser->scrollToAnchor(anchor);
+}
+
+void TextBrowserHelpViewer::setHtml(const QString &html)
+{
+    m_textBrowser->setHtml(html);
+}
+
+QString TextBrowserHelpViewer::selectedText() const
+{
+    return m_textBrowser->textCursor().selectedText();
+}
+
+bool TextBrowserHelpViewer::isForwardAvailable() const
+{
+    return m_textBrowser->isForwardAvailable();
+}
+
+bool TextBrowserHelpViewer::isBackwardAvailable() const
+{
+    return m_textBrowser->isBackwardAvailable();
+}
+
+void TextBrowserHelpViewer::setOpenInNewWindowActionVisible(bool visible)
+{
+    m_textBrowser->showOpenInNewWindowAction = visible;
+}
+
+bool TextBrowserHelpViewer::findText(const QString &text, Core::FindFlags flags,
+    bool incremental, bool fromSearch, bool *wrapped)
+{
+    if (wrapped)
+        *wrapped = false;
+    QTextDocument *doc = m_textBrowser->document();
+    QTextCursor cursor = m_textBrowser->textCursor();
+    if (!doc || cursor.isNull())
+        return false;
+
+    const int position = cursor.selectionStart();
+    if (incremental)
+        cursor.setPosition(position);
+
+    QTextDocument::FindFlags f = Core::textDocumentFlagsForFindFlags(flags);
+    QTextCursor found = doc->find(text, cursor, f);
+    if (found.isNull()) {
+        if ((flags & Core::FindBackward) == 0)
+            cursor.movePosition(QTextCursor::Start);
+        else
+            cursor.movePosition(QTextCursor::End);
+        found = doc->find(text, cursor, f);
+        if (!found.isNull() && wrapped)
+            *wrapped = true;
+    }
+
+    if (fromSearch) {
+        cursor.beginEditBlock();
+        m_textBrowser->viewport()->setUpdatesEnabled(false);
+
+        QTextCharFormat marker;
+        marker.setForeground(Qt::red);
+        cursor.movePosition(QTextCursor::Start);
+        m_textBrowser->setTextCursor(cursor);
+
+        while (m_textBrowser->find(text)) {
+            QTextCursor hit = m_textBrowser->textCursor();
+            hit.mergeCharFormat(marker);
+        }
+
+        m_textBrowser->viewport()->setUpdatesEnabled(true);
+        cursor.endEditBlock();
+    }
+
+    bool cursorIsNull = found.isNull();
+    if (cursorIsNull) {
+        found = m_textBrowser->textCursor();
+        found.setPosition(position);
+    }
+    m_textBrowser->setTextCursor(found);
+    return !cursorIsNull;
+}
+
+// -- public slots
+
+void TextBrowserHelpViewer::copy()
+{
+    m_textBrowser->copy();
+}
+
+void TextBrowserHelpViewer::stop()
+{
+}
+
+void TextBrowserHelpViewer::forward()
+{
+    m_textBrowser->forward();
+}
+
+void TextBrowserHelpViewer::backward()
+{
+    m_textBrowser->backward();
+}
+
+void TextBrowserHelpViewer::print(QPrinter *printer)
+{
+    m_textBrowser->print(printer);
+}
+
+// -- private
+
+TextBrowserHelpWidget::TextBrowserHelpWidget(int zoom, TextBrowserHelpViewer *parent)
+    : QTextBrowser(parent)
+    , zoomCount(zoom)
+    , forceFont(false)
+    , lastAnchor(QString())
+    , showOpenInNewWindowAction(true)
+    , m_parent(parent)
+{
+    installEventFilter(this);
+    document()->setDocumentMargin(8);
+}
+
+QVariant TextBrowserHelpWidget::loadResource(int type, const QUrl &name)
+{
+    QByteArray ba;
+    if (type < 4) {
+        const QHelpEngineCore &engine = LocalHelpManager::helpEngine();
+        ba = engine.fileData(name);
+        if (name.toString().endsWith(QLatin1String(".svg"), Qt::CaseInsensitive)) {
+            QImage image;
+            image.loadFromData(ba, "svg");
+            if (!image.isNull())
+                return image;
+        }
+    }
+    return ba;
+}
+
+bool TextBrowserHelpWidget::hasAnchorAt(const QPoint &pos)
+{
+    lastAnchor = anchorAt(pos);
+    if (lastAnchor.isEmpty())
+        return false;
+
+    lastAnchor = source().resolved(lastAnchor).toString();
+    if (lastAnchor.at(0) == QLatin1Char('#')) {
+        QString src = source().toString();
+        int hsh = src.indexOf(QLatin1Char('#'));
+        lastAnchor = (hsh >= 0 ? src.left(hsh) : src) + lastAnchor;
+    }
+    return true;
+}
+
+void TextBrowserHelpWidget::openLink(bool newPage)
+{
+    if (lastAnchor.isEmpty())
+        return;
+    if (newPage)
+        OpenPagesManager::instance().createPage(lastAnchor);
+    else
+        CentralWidget::instance()->setSource(lastAnchor);
+    lastAnchor.clear();
+}
+
+void TextBrowserHelpWidget::scaleUp()
+{
+    if (zoomCount < 10) {
+        zoomCount++;
+        forceFont = true;
+        zoomIn();
+        forceFont = false;
+    }
+}
+
+void TextBrowserHelpWidget::scaleDown()
+{
+    if (zoomCount > -5) {
+        zoomCount--;
+        forceFont = true;
+        zoomOut();
+        forceFont = false;
+    }
+}
+
+void TextBrowserHelpWidget::openLink()
+{
+    openLink(false);
+}
+
+void TextBrowserHelpWidget::openLinkInNewPage()
+{
+    openLink(true);
+}
+
+void TextBrowserHelpWidget::contextMenuEvent(QContextMenuEvent *event)
+{
+    QMenu menu(QLatin1String(""), 0);
+
+    QUrl link;
+    QAction *copyAnchorAction = 0;
+    if (hasAnchorAt(event->pos())) {
+        link = anchorAt(event->pos());
+        if (link.isRelative())
+            link = source().resolved(link);
+        menu.addAction(tr("Open Link"), this, SLOT(openLink()));
+        if (showOpenInNewWindowAction)
+            menu.addAction(tr("Open Link as New Page"), this, SLOT(openLinkInNewPage()));
+
+        if (!link.isEmpty() && link.isValid())
+            copyAnchorAction = menu.addAction(tr("Copy Link"));
+    } else if (!textCursor().selectedText().isEmpty()) {
+        menu.addAction(tr("Copy"), this, SLOT(copy()));
+    } else {
+        menu.addAction(tr("Reload"), this, SLOT(reload()));
+    }
+
+    if (copyAnchorAction == menu.exec(event->globalPos()))
+        QApplication::clipboard()->setText(link.toString());
+}
+
+bool TextBrowserHelpWidget::eventFilter(QObject *obj, QEvent *event)
+{
+    if (obj == this) {
+        if (event->type() == QEvent::FontChange) {
+            if (!forceFont)
+                return true;
+        } else if (event->type() == QEvent::KeyPress) {
+            QKeyEvent *keyEvent = static_cast<QKeyEvent *>(event);
+            if (keyEvent->key() == Qt::Key_Slash) {
+                keyEvent->accept();
+                Core::FindPlugin::instance()->openFindToolBar(Core::FindPlugin::FindForwardDirection);
+                return true;
+            }
+        }
+    }
+    return QTextBrowser::eventFilter(obj, event);
+}
+
+void TextBrowserHelpWidget::wheelEvent(QWheelEvent *e)
+{
+    if (e->modifiers() == Qt::ControlModifier) {
+        e->accept();
+        e->delta() > 0 ? scaleUp() : scaleDown();
+    } else {
+        QTextBrowser::wheelEvent(e);
+    }
+}
+
+void TextBrowserHelpWidget::mousePressEvent(QMouseEvent *e)
+{
+    if (Utils::HostOsInfo::isLinuxHost() && m_parent->handleForwardBackwardMouseButtons(e))
+        return;
+    QTextBrowser::mousePressEvent(e);
+}
+
+void TextBrowserHelpWidget::mouseReleaseEvent(QMouseEvent *e)
+{
+    if (!Utils::HostOsInfo::isLinuxHost() && m_parent->handleForwardBackwardMouseButtons(e))
+        return;
+
+    bool controlPressed = e->modifiers() & Qt::ControlModifier;
+    if ((controlPressed && hasAnchorAt(e->pos())) ||
+        (e->button() == Qt::MidButton && hasAnchorAt(e->pos()))) {
+        openLinkInNewPage();
+        return;
+    }
+
+    QTextBrowser::mouseReleaseEvent(e);
+}