Help: Add litehtml based viewer backend

For CMake add litehtml installation path to CMAKE_PREFIX_PATH For qmake pass litehtml installation path via LITEHTML_INSTALL_DIR qmake variable Release build of litehtml is recommended. The litehtml backend is used by default when available, you can force QTextBrowser again with the environment variable "QTC_HELPVIEWER_BACKEND=textbrowser". Some things are not implemented yet: - Text search - Context menu - Shift-drag to extend existing selection Change-Id: I79f989e5fe2063de2e9832abbed19b24d7a1a1fe Reviewed-by: hjk <hjk@qt.io>
2019-07-29 15:30:58 +02:00
parent 7855c9bb80
commit 0efd65e07e
12 changed files with 2456 additions and 3 deletions
--- a/src/plugins/help/litehtmlhelpviewer.cpp
+++ b/src/plugins/help/litehtmlhelpviewer.cpp
@@ -0,0 +1,356 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** 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 The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#include "litehtmlhelpviewer.h"
+
+#include "localhelpmanager.h"
+
+#include <utils/algorithm.h>
+#include <utils/qtcassert.h>
+
+#include <QClipboard>
+#include <QGuiApplication>
+#include <QScrollBar>
+#include <QTimer>
+#include <QVBoxLayout>
+
+#include <QDebug>
+
+using namespace Help;
+using namespace Help::Internal;
+
+const int kMaxHistoryItems = 20;
+
+static QByteArray getData(const QUrl &url)
+{
+    // TODO: this is just a hack for Qt documentation
+    // which decides to use a simpler CSS if the viewer does not have JavaScript
+    // which was a hack to decide if we are viewing in QTextBrowser or QtWebEngine et al
+    QUrl actualUrl = url;
+    QString path = url.path(QUrl::FullyEncoded);
+    static const char simpleCss[] = "/offline-simple.css";
+    if (path.endsWith(simpleCss)) {
+        path.replace(simpleCss, "/offline.css");
+        actualUrl.setPath(path);
+    }
+    const LocalHelpManager::HelpData help = LocalHelpManager::helpData(actualUrl);
+
+    // TODO: this is a hack around for https://github.com/litehtml/litehtml/issues/91
+    QByteArray data = help.data;
+    if (actualUrl.path(QUrl::FullyEncoded).endsWith(".css"))
+        data.replace("inline-table", "inline");
+
+    return data;
+}
+
+LiteHtmlHelpViewer::LiteHtmlHelpViewer(QWidget *parent)
+    : HelpViewer(parent)
+    , m_viewer(new QLiteHtmlWidget)
+{
+    m_viewer->setResourceHandler([](const QUrl &url) { return getData(url); });
+    connect(m_viewer, &QLiteHtmlWidget::linkClicked, this, &LiteHtmlHelpViewer::setSource);
+    auto layout = new QVBoxLayout;
+    setLayout(layout);
+    layout->setContentsMargins(0, 0, 0, 0);
+    layout->addWidget(m_viewer, 10);
+    setFocusProxy(m_viewer);
+    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));
+    p.setColor(QPalette::Base, Qt::white);
+    p.setColor(QPalette::Text, Qt::black);
+    setPalette(p);
+}
+
+LiteHtmlHelpViewer::~LiteHtmlHelpViewer() = default;
+
+QFont LiteHtmlHelpViewer::viewerFont() const
+{
+    return m_viewer->defaultFont();
+}
+
+void LiteHtmlHelpViewer::setViewerFont(const QFont &newFont)
+{
+    m_viewer->setDefaultFont(newFont);
+}
+
+void LiteHtmlHelpViewer::scaleUp()
+{
+    // TODO
+}
+
+void LiteHtmlHelpViewer::scaleDown()
+{
+    // TODO
+}
+
+void LiteHtmlHelpViewer::resetScale()
+{
+    // TODO
+}
+
+qreal LiteHtmlHelpViewer::scale() const
+{
+    // TODO
+    return 1;
+}
+
+void LiteHtmlHelpViewer::setScale(qreal scale)
+{
+    // TODO
+}
+
+QString LiteHtmlHelpViewer::title() const
+{
+    return m_viewer->title();
+}
+
+QUrl LiteHtmlHelpViewer::source() const
+{
+    return m_viewer->url();
+}
+
+void LiteHtmlHelpViewer::setSource(const QUrl &url)
+{
+    if (launchWithExternalApp(url))
+        return;
+    m_forwardItems.clear();
+    emit forwardAvailable(false);
+    if (m_viewer->url().isValid()) {
+        m_backItems.push_back(currentHistoryItem());
+        while (m_backItems.size() > kMaxHistoryItems) // this should trigger only once anyhow
+            m_backItems.erase(m_backItems.begin());
+        emit backwardAvailable(true);
+    }
+    setSourceInternal(url);
+}
+
+void LiteHtmlHelpViewer::setHtml(const QString &html)
+{
+    m_viewer->setUrl({"about:invalid"});
+    m_viewer->setHtml(html);
+}
+
+QString LiteHtmlHelpViewer::selectedText() const
+{
+    return m_viewer->selectedText();
+}
+
+bool LiteHtmlHelpViewer::isForwardAvailable() const
+{
+    return !m_forwardItems.empty();
+}
+
+bool LiteHtmlHelpViewer::isBackwardAvailable() const
+{
+    return !m_backItems.empty();
+}
+
+void LiteHtmlHelpViewer::addBackHistoryItems(QMenu *backMenu)
+{
+    int backCount = 0;
+    Utils::reverseForeach(m_backItems, [this, backMenu, &backCount](const HistoryItem &item) {
+        ++backCount;
+        auto action = new QAction(backMenu);
+        action->setText(item.title);
+        connect(action, &QAction::triggered, this, [this, backCount] { goBackward(backCount); });
+        backMenu->addAction(action);
+    });
+}
+
+void LiteHtmlHelpViewer::addForwardHistoryItems(QMenu *forwardMenu)
+{
+    int forwardCount = 0;
+    for (const HistoryItem &item : m_forwardItems) {
+        ++forwardCount;
+        auto action = new QAction(forwardMenu);
+        action->setText(item.title);
+        connect(action, &QAction::triggered, this, [this, forwardCount] {
+            goForward(forwardCount);
+        });
+        forwardMenu->addAction(action);
+    }
+}
+
+bool LiteHtmlHelpViewer::findText(
+    const QString &text, Core::FindFlags flags, bool incremental, bool fromSearch, bool *wrapped)
+{
+    // TODO
+    return false;
+}
+
+void LiteHtmlHelpViewer::copy()
+{
+    QGuiApplication::clipboard()->setText(selectedText());
+}
+
+void LiteHtmlHelpViewer::stop() {}
+
+void LiteHtmlHelpViewer::forward()
+{
+    goForward(1);
+}
+
+void LiteHtmlHelpViewer::backward()
+{
+    goBackward(1);
+}
+void LiteHtmlHelpViewer::goForward(int count)
+{
+    HistoryItem nextItem = currentHistoryItem();
+    for (int i = 0; i < count; ++i) {
+        QTC_ASSERT(!m_forwardItems.empty(), return );
+        m_backItems.push_back(nextItem);
+        nextItem = m_forwardItems.front();
+        m_forwardItems.erase(m_forwardItems.begin());
+    }
+    emit backwardAvailable(isBackwardAvailable());
+    emit forwardAvailable(isForwardAvailable());
+    setSourceInternal(nextItem.url, nextItem.vscroll);
+}
+
+void LiteHtmlHelpViewer::goBackward(int count)
+{
+    HistoryItem previousItem = currentHistoryItem();
+    for (int i = 0; i < count; ++i) {
+        QTC_ASSERT(!m_backItems.empty(), return );
+        m_forwardItems.insert(m_forwardItems.begin(), previousItem);
+        previousItem = m_backItems.back();
+        m_backItems.pop_back();
+    }
+    emit backwardAvailable(isBackwardAvailable());
+    emit forwardAvailable(isForwardAvailable());
+    setSourceInternal(previousItem.url, previousItem.vscroll);
+}
+
+void LiteHtmlHelpViewer::print(QPrinter *printer)
+{
+    // TODO
+}
+
+void LiteHtmlHelpViewer::setSourceInternal(const QUrl &url, Utils::optional<int> vscroll)
+{
+    slotLoadStarted();
+    QUrl currentUrlWithoutFragment = m_viewer->url();
+    currentUrlWithoutFragment.setFragment({});
+    QUrl newUrlWithoutFragment = url;
+    newUrlWithoutFragment.setFragment({});
+    m_viewer->setUrl(url);
+    if (currentUrlWithoutFragment != newUrlWithoutFragment)
+        m_viewer->setHtml(QString::fromUtf8(getData(url)));
+    if (vscroll)
+        m_viewer->verticalScrollBar()->setValue(*vscroll);
+    else
+        m_viewer->scrollToAnchor(url.fragment(QUrl::FullyEncoded));
+    slotLoadFinished();
+    emit titleChanged();
+}
+
+LiteHtmlHelpViewer::HistoryItem LiteHtmlHelpViewer::currentHistoryItem() const
+{
+    return {m_viewer->url(), m_viewer->title(), m_viewer->verticalScrollBar()->value()};
+}
+
+// -- private
+//void TextBrowserHelpWidget::contextMenuEvent(QContextMenuEvent *event)
+//{
+//    QMenu menu("", nullptr);
+
+//    QAction *copyAnchorAction = nullptr;
+//    const QUrl link(linkAt(event->pos()));
+//    if (!link.isEmpty() && link.isValid()) {
+//        QAction *action = menu.addAction(tr("Open Link"));
+//        connect(action, &QAction::triggered, this, [this, link]() {
+//            setSource(link);
+//        });
+//        if (m_parent->isActionVisible(HelpViewer::Action::NewPage)) {
+//            action = menu.addAction(QCoreApplication::translate("HelpViewer", Constants::TR_OPEN_LINK_AS_NEW_PAGE));
+//            connect(action, &QAction::triggered, this, [this, link]() {
+//                emit m_parent->newPageRequested(link);
+//            });
+//        }
+//        if (m_parent->isActionVisible(HelpViewer::Action::ExternalWindow)) {
+//            action = menu.addAction(QCoreApplication::translate("HelpViewer", Constants::TR_OPEN_LINK_IN_WINDOW));
+//            connect(action, &QAction::triggered, this, [this, link]() {
+//                emit m_parent->externalPageRequested(link);
+//            });
+//        }
+//        copyAnchorAction = menu.addAction(tr("Copy Link"));
+//    } else if (!textCursor().selectedText().isEmpty()) {
+//        connect(menu.addAction(tr("Copy")), &QAction::triggered, this, &QTextEdit::copy);
+//    } else {
+//        connect(menu.addAction(tr("Reload")), &QAction::triggered, this, &QTextBrowser::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) {
+//            auto keyEvent = static_cast<QKeyEvent *>(event);
+//            if (keyEvent->key() == Qt::Key_Slash) {
+//                keyEvent->accept();
+//                Core::Find::openFindToolBar(Core::Find::FindForwardDirection);
+//                return true;
+//            }
+//        } else if (event->type() == QEvent::ToolTip) {
+//            auto e = static_cast<const QHelpEvent *>(event);
+//            QToolTip::showText(e->globalPos(), linkAt(e->pos()));
+//            return true;
+//        }
+//    }
+//    return QTextBrowser::eventFilter(obj, event);
+//}
+
+//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;
+//    const QString link = linkAt(e->pos());
+//    if (m_parent->isActionVisible(HelpViewer::Action::NewPage)
+//            && (controlPressed || e->button() == Qt::MidButton) && !link.isEmpty()) {
+//        emit m_parent->newPageRequested(QUrl(link));
+//        return;
+//    }
+
+//    QTextBrowser::mouseReleaseEvent(e);
+//}