Revert "Designer: Use QDesktopServices to show designer help"

This reverts commit 5f238adc4c652e6e1bb34752f201cf8e377cbc25
and commit 1d994b1471bd43d7003697b47e3f7d2ebfc808df

Reason for revert: Qt Assistant is enabled again

Change-Id: If28fdcf10686750a43e3cc88b5b846d69ec82cd5
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>
(cherry picked from commit a1caa657d8f2f561b52b39cf4355dd7b9d217f45)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

7 files changed, 275 insertions, 25 deletions

diff --git a/src/designer/src/designer/.prev_CMakeLists.txt b/src/designer/src/designer/.prev_CMakeLists.txt
index a95b2c0fa..0437ab492 100644
--- a/src/designer/src/designer/.prev_CMakeLists.txt
+++ b/src/designer/src/designer/.prev_CMakeLists.txt
@@ -9,6 +9,7 @@ qt_internal_add_app(designer
         ../../../shared/fontpanel/fontpanel.cpp ../../../shared/fontpanel/fontpanel.h
         ../../../shared/qttoolbardialog/qttoolbardialog.cpp ../../../shared/qttoolbardialog/qttoolbardialog.h ../../../shared/qttoolbardialog/qttoolbardialog.ui
         appfontdialog.cpp appfontdialog.h
+        assistantclient.cpp assistantclient.h
         designer_enums.h
         main.cpp
         mainwindow.cpp mainwindow.h
diff --git a/src/designer/src/designer/CMakeLists.txt b/src/designer/src/designer/CMakeLists.txt
index c60be4c8a..5de06465d 100644
--- a/src/designer/src/designer/CMakeLists.txt
+++ b/src/designer/src/designer/CMakeLists.txt
@@ -9,6 +9,7 @@ qt_internal_add_app(designer
         ../../../shared/fontpanel/fontpanel.cpp ../../../shared/fontpanel/fontpanel.h
         ../../../shared/qttoolbardialog/qttoolbardialog.cpp ../../../shared/qttoolbardialog/qttoolbardialog.h ../../../shared/qttoolbardialog/qttoolbardialog.ui
         appfontdialog.cpp appfontdialog.h
+        assistantclient.cpp assistantclient.h
         designer_enums.h
         main.cpp
         mainwindow.cpp mainwindow.h
diff --git a/src/designer/src/designer/assistantclient.cpp b/src/designer/src/designer/assistantclient.cpp
new file mode 100644
index 000000000..45fee4393
--- /dev/null
+++ b/src/designer/src/designer/assistantclient.cpp
@@ -0,0 +1,180 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt Designer of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "assistantclient.h"
+
+#include <QtCore/qstring.h>
+#include <QtCore/qprocess.h>
+#include <QtCore/qdir.h>
+#include <QtCore/qlibraryinfo.h>
+#include <QtCore/qdebug.h>
+#include <QtCore/qfileinfo.h>
+#include <QtCore/qobject.h>
+#include <QtCore/qtextstream.h>
+#include <QtCore/qcoreapplication.h>
+
+QT_BEGIN_NAMESPACE
+
+enum { debugAssistantClient = 0 };
+
+AssistantClient::AssistantClient() = default;
+
+AssistantClient::~AssistantClient()
+{
+    if (isRunning()) {
+        m_process->terminate();
+        m_process->waitForFinished();
+    }
+    delete m_process;
+}
+
+bool AssistantClient::showPage(const QString &path, QString *errorMessage)
+{
+    QString cmd = QStringLiteral("SetSource ");
+    cmd += path;
+    return sendCommand(cmd, errorMessage);
+}
+
+bool AssistantClient::activateIdentifier(const QString &identifier, QString *errorMessage)
+{
+    QString cmd = QStringLiteral("ActivateIdentifier ");
+    cmd += identifier;
+    return sendCommand(cmd, errorMessage);
+}
+
+bool AssistantClient::activateKeyword(const QString &keyword, QString *errorMessage)
+{
+    QString cmd = QStringLiteral("ActivateKeyword ");
+    cmd += keyword;
+    return sendCommand(cmd, errorMessage);
+}
+
+bool AssistantClient::sendCommand(const QString &cmd, QString *errorMessage)
+{
+    if (debugAssistantClient)
+        qDebug() << "sendCommand " << cmd;
+    if (!ensureRunning(errorMessage))
+        return false;
+    if (!m_process->isWritable() || m_process->bytesToWrite() > 0) {
+        *errorMessage = QCoreApplication::translate("AssistantClient", "Unable to send request: Assistant is not responding.");
+        return false;
+    }
+    QTextStream str(m_process);
+    str << cmd << QLatin1Char('\n') << Qt::endl;
+    return true;
+}
+
+bool AssistantClient::isRunning() const
+{
+    return m_process && m_process->state() != QProcess::NotRunning;
+}
+
+QString AssistantClient::binary()
+{
+    QString app = QLibraryInfo::path(QLibraryInfo::BinariesPath) + QDir::separator();
+#if !defined(Q_OS_MACOS)
+    app += QStringLiteral("assistant");
+#else
+    app += QStringLiteral("Assistant.app/Contents/MacOS/Assistant");
+#endif
+
+#if defined(Q_OS_WIN)
+    app += QStringLiteral(".exe");
+#endif
+
+    return app;
+}
+
+void AssistantClient::readyReadStandardError()
+{
+     qWarning("%s: %s",
+              qPrintable(QDir::toNativeSeparators(m_process->program())),
+              m_process->readAllStandardError().constData());
+}
+
+void AssistantClient::processTerminated(int exitCode, QProcess::ExitStatus exitStatus)
+{
+    const QString binary = QDir::toNativeSeparators(m_process->program());
+    if (exitStatus != QProcess::NormalExit)
+        qWarning("%s: crashed.", qPrintable(binary));
+    else if (exitCode != 0)
+        qWarning("%s: terminated with exit code %d.", qPrintable(binary), exitCode);
+}
+
+bool AssistantClient::ensureRunning(QString *errorMessage)
+{
+    if (isRunning())
+        return true;
+
+    if (!m_process) {
+        m_process = new QProcess;
+        QObject::connect(m_process, QOverload<int, QProcess::ExitStatus>::of(&QProcess::finished),
+                         this, &AssistantClient::processTerminated);
+        QObject::connect(m_process, &QProcess::readyReadStandardError,
+                         this, &AssistantClient::readyReadStandardError);
+    }
+
+    const QString app = binary();
+    if (!QFileInfo(app).isFile()) {
+        *errorMessage = QCoreApplication::translate("AssistantClient", "The binary '%1' does not exist.").arg(app);
+        return false;
+    }
+    if (debugAssistantClient)
+        qDebug() << "Running " << app;
+    // run
+    QStringList args(QStringLiteral("-enableRemoteControl"));
+    m_process->start(app, args);
+    if (!m_process->waitForStarted()) {
+        *errorMessage = QCoreApplication::translate("AssistantClient", "Unable to launch assistant (%1).").arg(app);
+        return false;
+    }
+    return true;
+}
+
+QString AssistantClient::documentUrl(const QString &module, int qtVersion)
+{
+    if (qtVersion == 0)
+        qtVersion = QT_VERSION;
+    QString rc;
+    QTextStream(&rc) << "qthelp://org.qt-project." << module << '.'
+                     << (qtVersion >> 16) << ((qtVersion >> 8) & 0xFF) << (qtVersion & 0xFF)
+                     << '/' << module << '/';
+    return rc;
+}
+
+QString AssistantClient::designerManualUrl(int qtVersion)
+{
+    return documentUrl(QStringLiteral("qtdesigner"), qtVersion);
+}
+
+QString AssistantClient::qtReferenceManualUrl(int qtVersion)
+{
+    return documentUrl(QStringLiteral("qtdoc"), qtVersion);
+}
+
+QT_END_NAMESPACE
diff --git a/src/designer/src/designer/assistantclient.h b/src/designer/src/designer/assistantclient.h
new file mode 100644
index 000000000..94618662a
--- /dev/null
+++ b/src/designer/src/designer/assistantclient.h
@@ -0,0 +1,72 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt Designer of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef ASSISTANTCLIENT_H
+#define ASSISTANTCLIENT_H
+
+#include <QtCore/qprocess.h>
+
+QT_BEGIN_NAMESPACE
+
+class QString;
+
+class AssistantClient : public QObject
+{
+    Q_OBJECT
+
+public:
+    AssistantClient();
+    ~AssistantClient();
+
+    bool showPage(const QString &path, QString *errorMessage);
+    bool activateIdentifier(const QString &identifier, QString *errorMessage);
+    bool activateKeyword(const QString &keyword, QString *errorMessage);
+
+    bool isRunning() const;
+
+    static QString documentUrl(const QString &prefix, int qtVersion = 0);
+    // Root of the Qt Designer documentation
+    static QString designerManualUrl(int qtVersion = 0);
+    // Root of the Qt Reference documentation
+    static QString qtReferenceManualUrl(int qtVersion = 0);
+
+private slots:
+    void readyReadStandardError();
+    void processTerminated(int exitCode, QProcess::ExitStatus exitStatus);
+
+private:
+    static QString binary();
+    bool sendCommand(const QString &cmd, QString *errorMessage);
+    bool ensureRunning(QString *errorMessage);
+
+    QProcess *m_process = nullptr;
+};
+
+QT_END_NAMESPACE
+
+#endif // ASSISTANTCLIENT_H
diff --git a/src/designer/src/designer/designer.pro b/src/designer/src/designer/designer.pro
index cddef1fbc..6a925202a 100644
--- a/src/designer/src/designer/designer.pro
+++ b/src/designer/src/designer/designer.pro
@@ -33,6 +33,7 @@ HEADERS += \
     designer_enums.h \
     appfontdialog.h \
     preferencesdialog.h \
+    assistantclient.h \
     mainwindow.h
 
 SOURCES += main.cpp \
@@ -49,6 +50,7 @@ SOURCES += main.cpp \
     versiondialog.cpp \
     appfontdialog.cpp \
     preferencesdialog.cpp \
+    assistantclient.cpp \
     mainwindow.cpp
 
 PRECOMPILED_HEADER=qdesigner_pch.h
diff --git a/src/designer/src/designer/qdesigner_actions.cpp b/src/designer/src/designer/qdesigner_actions.cpp
index 55e250283..4b98d6493 100644
--- a/src/designer/src/designer/qdesigner_actions.cpp
+++ b/src/designer/src/designer/qdesigner_actions.cpp
@@ -70,12 +70,9 @@
 
 #include <QtGui/qaction.h>
 #include <QtGui/qactiongroup.h>
-#include <QtGui/qcursor.h>
-#include <QtGui/qdesktopservices.h>
 #include <QtGui/qevent.h>
 #include <QtGui/qicon.h>
 #include <QtGui/qimage.h>
-#include <QtGui/qpainter.h>
 #include <QtGui/qpixmap.h>
 #include <QtGui/qscreen.h>
 #if defined(QT_PRINTSUPPORT_LIB) // Some platforms may not build QtPrintSupport
@@ -86,7 +83,9 @@
 #    define HAS_PRINTER
 #  endif
 #endif
+#include <QtGui/qpainter.h>
 #include <QtGui/qtransform.h>
+#include <QtGui/qcursor.h>
 
 #include <QtCore/qsize.h>
 #include <QtCore/qlibraryinfo.h>
@@ -988,32 +987,23 @@ QAction *QDesignerActions::minimizeAction() const
 
 void QDesignerActions::showDesignerHelp()
 {
-    showHelp("qtdesigner-manual.html");
+    QString url = AssistantClient::designerManualUrl();
+    url += QStringLiteral("qtdesigner-manual.html");
+    showHelp(url);
 }
 
 void QDesignerActions::helpRequested(const QString &manual, const QString &document)
 {
-    Q_UNUSED(manual);
-    showHelp(document);
+    QString url = AssistantClient::documentUrl(manual);
+    url += document;
+    showHelp(url);
 }
 
-bool QDesignerActions::showHelp(const QString &htmlFile)
+void QDesignerActions::showHelp(const QString &url)
 {
-    const int qtVersion = QT_VERSION;
-    QString url;
-    QTextStream(&url) << "https://doc.qt.io/qt-" << (qtVersion >> 16)
-// TODO: uncomment the line below just before Qt 6.0 release
-// we should have then https://doc.qt.io/qt-6.0/ link valid (like in case of 5.x series).
-// Currently it redirects to Qt 6 snapshot.
-//                      << "." << ((qtVersion >> 8) & 0xFF)
-                      << '/' << htmlFile;
-
-    return QDesktopServices::openUrl(QUrl(url));
-}
-
-bool QDesignerActions::showIdentifier(const QString &identifier)
-{
-    return showHelp(identifier.toLower() + ".html");
+    QString errorMessage;
+    if (!m_assistantClient.showPage(url, &errorMessage))
+        QMessageBox::warning(core()->topLevel(), tr("Assistant"), errorMessage);
 }
 
 void QDesignerActions::aboutDesigner()
@@ -1042,7 +1032,10 @@ void QDesignerActions::showWidgetSpecificHelp()
         return;
     }
 
-    showIdentifier(helpId);
+    QString errorMessage;
+    const bool rc = m_assistantClient.activateIdentifier(helpId, &errorMessage);
+    if (!rc)
+        QMessageBox::warning(core()->topLevel(), tr("Assistant"), errorMessage);
 }
 
 void QDesignerActions::updateCloseAction()
diff --git a/src/designer/src/designer/qdesigner_actions.h b/src/designer/src/designer/qdesigner_actions.h
index 715388b4e..4192a002b 100644
--- a/src/designer/src/designer/qdesigner_actions.h
+++ b/src/designer/src/designer/qdesigner_actions.h
@@ -29,6 +29,7 @@
 #ifndef QDESIGNER_ACTIONS_H
 #define QDESIGNER_ACTIONS_H
 
+#include "assistantclient.h"
 #include "qdesigner_settings.h"
 
 #include <QtCore/qobject.h>
@@ -142,8 +143,7 @@ private:
     bool saveFormAs(QDesignerFormWindowInterface *fw);
     void updateRecentFileActions();
     void addRecentFile(const QString &fileName);
-    bool showIdentifier(const QString &identifier);
-    bool showHelp(const QString &htmlFile);
+    void showHelp(const QString &help);
     void closePreview();
     QRect fixDialogRect(const QRect &rect) const;
     QString fixResourceFileBackupPath(QDesignerFormWindowInterface *fwi, const QDir& backupDir);
@@ -158,6 +158,7 @@ private:
     QDesignerWorkbench *m_workbench;
     QDesignerFormEditorInterface *m_core;
     QDesignerSettings m_settings;
+    AssistantClient m_assistantClient;
     QString m_openDirectory;
     QString m_saveDirectory;