VcsBase: Create common base diff editor controller

Reuse it in subversion and git plugins.
It makes subversion diff more asynchronous than before.
Make VcsBase plugin dependand on DiffEditor plugin.

Change-Id: Iafea2941b890a95a269362e022af2dc03cdea550
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/git/gitclient.cpp

@@ -43,7 +43,6 @@
 #include <coreplugin/idocument.h>
 #include <coreplugin/iversioncontrol.h>
 #include <coreplugin/vcsmanager.h>
-#include <coreplugin/progressmanager/progressmanager.h>
 
 #include <utils/algorithm.h>
 #include <utils/asconst.h>
@@ -54,9 +53,9 @@
 #include <utils/qtcprocess.h>
 #include <utils/synchronousprocess.h>
 #include <utils/temporaryfile.h>
-#include <utils/runextensions.h>
 
 #include <vcsbase/submitfilemodel.h>
+#include <vcsbase/vcsbasediffeditorcontroller.h>
 #include <vcsbase/vcsbaseeditor.h>
 #include <vcsbase/vcsbaseeditorconfig.h>
 #include <vcsbase/vcsbaseplugin.h>
@@ -112,138 +111,31 @@ const unsigned silentFlags = unsigned(VcsCommand::SuppressCommandLogging
                                       | VcsCommand::SuppressStdErr
                                       | VcsCommand::SuppressFailMessage);
 
-static void readPatch(QFutureInterface<QList<FileData>> &futureInterface,
+class GitDiffEditorController : public VcsBaseDiffEditorController
-                      const QString &patch)
-{
-    bool ok;
-    const QList<FileData> &fileDataList = DiffUtils::readPatch(patch, &ok);
-    futureInterface.reportResult(fileDataList);
-}
-
-/////////////////////////////////////
-
-class BaseController : public DiffEditorController
 {
     Q_OBJECT
 
 public:
-    BaseController(IDocument *document, const QString &dir);
+    GitDiffEditorController(IDocument *document, const QString &workingDirectory);
-    ~BaseController();
 
 protected:
-    void runCommand(const QList<QStringList> &args, QTextCodec *codec = 0);
+    void runCommand(const QList<QStringList> &args, QTextCodec *codec = nullptr);
-    virtual void processCommandOutput(const QString &output);
 
     QStringList addConfigurationArguments(const QStringList &args) const;
     QStringList addHeadWhenCommandInProgress() const;
-
-    void setStartupFile(const QString &startupFile) { m_startupFile = startupFile; }
-    QString startupFile() const { return m_startupFile; }
-    QString directory() const { return m_directory; }
-
-private:
-    void processDiff(const QString &patch);
-    void storeOutput(const QString &output);
-    void cancelReload();
-    void commandFinished(bool success);
-    void processingFinished();
-
-    const QString m_directory;
-    QString m_startupFile;
-    QString m_output;
-    QPointer<VcsCommand> m_command;
-    QFutureWatcher<QList<FileData>> m_processWatcher;
 };
 
-BaseController::BaseController(IDocument *document, const QString &dir) :
+GitDiffEditorController::GitDiffEditorController(IDocument *document, const QString &workingDirectory) :
-    DiffEditorController(document),
+    VcsBaseDiffEditorController(document, GitPlugin::client(), workingDirectory)
-    m_directory(dir),
-    m_command(0)
 {
-    connect(&m_processWatcher, &QFutureWatcher<QList<FileData>>::finished,
-            this, &BaseController::processingFinished);
 }
 
-BaseController::~BaseController()
+void GitDiffEditorController::runCommand(const QList<QStringList> &args, QTextCodec *codec)
 {
-    cancelReload();
+    VcsBaseDiffEditorController::runCommand(args, diffExecutionFlags(), codec);
 }
 
-void BaseController::cancelReload()
+QStringList GitDiffEditorController::addConfigurationArguments(const QStringList &args) const
-{
-    if (m_command) {
-        m_command->disconnect();
-        m_command->cancel();
-        m_command.clear();
-    }
-
-    if (m_processWatcher.future().isRunning()) {
-        m_processWatcher.future().cancel();
-        m_processWatcher.setFuture(QFuture<QList<FileData>>());
-    }
-    m_output = QString();
-}
-
-void BaseController::commandFinished(bool success)
-{
-    if (m_command)
-        m_command.clear();
-
-    if (!success) {
-        cancelReload();
-        reloadFinished(success);
-        return;
-    }
-
-    processCommandOutput(m_output);
-}
-
-void BaseController::runCommand(const QList<QStringList> &args, QTextCodec *codec)
-{
-    cancelReload();
-
-    m_command = new VcsCommand(directory(), GitPlugin::client()->processEnvironment());
-    m_command->setCodec(codec ? codec : EditorManager::defaultTextCodec());
-    connect(m_command.data(), &VcsCommand::stdOutText, this, &BaseController::storeOutput);
-    connect(m_command.data(), &VcsCommand::finished, this, &BaseController::commandFinished);
-    m_command->addFlags(diffExecutionFlags());
-
-    for (const QStringList &arg : args) {
-        QTC_ASSERT(!arg.isEmpty(), continue);
-
-        m_command->addJob(GitPlugin::client()->vcsBinary(), arg, GitPlugin::client()->vcsTimeoutS());
-    }
-
-    m_command->execute();
-}
-
-void BaseController::storeOutput(const QString &output)
-{
-    m_output = output;
-}
-
-void BaseController::processCommandOutput(const QString &output)
-{
-    processDiff(output);
-}
-
-void BaseController::processDiff(const QString &patch)
-{
-    m_processWatcher.setFuture(Utils::runAsync(&readPatch, patch));
-
-    Core::ProgressManager::addTask(m_processWatcher.future(),
-                                   tr("Processing diff"), "DiffEditor");
-}
-
-void BaseController::processingFinished()
-{
-    const QList<FileData> fileDataList = m_processWatcher.future().result();
-
-    setDiffFiles(fileDataList, directory(), startupFile());
-    reloadFinished(true);
-}
-
-QStringList BaseController::addConfigurationArguments(const QStringList &args) const
 {
     QTC_ASSERT(!args.isEmpty(), return args);
 
@@ -261,23 +153,23 @@ QStringList BaseController::addConfigurationArguments(const QStringList &args) c
     return realArgs;
 }
 
-QStringList BaseController::addHeadWhenCommandInProgress() const
+QStringList GitDiffEditorController::addHeadWhenCommandInProgress() const
 {
     // This is workaround for lack of support for merge commits and resolving conflicts,
     // we compare the current state of working tree to the HEAD of current branch
     // instead of showing unsupported combined diff format.
-    GitClient::CommandInProgress commandInProgress = GitPlugin::client()->checkCommandInProgress(directory());
+    GitClient::CommandInProgress commandInProgress = GitPlugin::client()->checkCommandInProgress(workingDirectory());
     if (commandInProgress != GitClient::NoCommand)
         return {HEAD};
     return QStringList();
 }
 
-class RepositoryDiffController : public BaseController
+class RepositoryDiffController : public GitDiffEditorController
 {
     Q_OBJECT
 public:
     RepositoryDiffController(IDocument *document, const QString &dir) :
-        BaseController(document, dir)
+        GitDiffEditorController(document, dir)
     { }
 
     void reload() override;
@@ -290,12 +182,12 @@ void RepositoryDiffController::reload()
     runCommand(QList<QStringList>() << addConfigurationArguments(args));
 }
 
-class FileDiffController : public BaseController
+class FileDiffController : public GitDiffEditorController
 {
     Q_OBJECT
 public:
     FileDiffController(IDocument *document, const QString &dir, const QString &fileName) :
-        BaseController(document, dir),
+        GitDiffEditorController(document, dir),
         m_fileName(fileName)
     { }
 
@@ -314,13 +206,13 @@ void FileDiffController::reload()
     runCommand(QList<QStringList>() << addConfigurationArguments(args));
 }
 
-class FileListDiffController : public BaseController
+class FileListDiffController : public GitDiffEditorController
 {
     Q_OBJECT
 public:
     FileListDiffController(IDocument *document, const QString &dir,
                            const QStringList &stagedFiles, const QStringList &unstagedFiles) :
-        BaseController(document, dir),
+        GitDiffEditorController(document, dir),
         m_stagedFiles(stagedFiles),
         m_unstagedFiles(unstagedFiles)
     { }
@@ -351,13 +243,13 @@ void FileListDiffController::reload()
         runCommand(argLists);
 }
 
-class ProjectDiffController : public BaseController
+class ProjectDiffController : public GitDiffEditorController
 {
     Q_OBJECT
 public:
     ProjectDiffController(IDocument *document, const QString &dir,
                           const QStringList &projectPaths) :
-        BaseController(document, dir),
+        GitDiffEditorController(document, dir),
         m_projectPaths(projectPaths)
     { }
 
@@ -374,13 +266,13 @@ void ProjectDiffController::reload()
     runCommand(QList<QStringList>() << addConfigurationArguments(args));
 }
 
-class BranchDiffController : public BaseController
+class BranchDiffController : public GitDiffEditorController
 {
     Q_OBJECT
 public:
     BranchDiffController(IDocument *document, const QString &dir,
                          const QString &branch) :
-        BaseController(document, dir),
+        GitDiffEditorController(document, dir),
         m_branch(branch)
     { }
 
@@ -397,12 +289,12 @@ void BranchDiffController::reload()
     runCommand(QList<QStringList>() << addConfigurationArguments(args));
 }
 
-class ShowController : public BaseController
+class ShowController : public GitDiffEditorController
 {
     Q_OBJECT
 public:
     ShowController(IDocument *document, const QString &dir, const QString &id) :
-        BaseController(document, dir),
+        GitDiffEditorController(document, dir),
         m_id(id),
         m_state(Idle)
     { }
@@ -421,7 +313,7 @@ void ShowController::reload()
     // stage 1
     m_state = GettingDescription;
     const QStringList args = {"show", "-s", noColorOption, showFormatC, m_id};
-    runCommand(QList<QStringList>() << args, GitPlugin::client()->encoding(directory(), "i18n.commitEncoding"));
+    runCommand(QList<QStringList>() << args, GitPlugin::client()->encoding(workingDirectory(), "i18n.commitEncoding"));
     setStartupFile(VcsBasePlugin::source(document()));
 }
 
@@ -429,7 +321,7 @@ void ShowController::processCommandOutput(const QString &output)
 {
     QTC_ASSERT(m_state != Idle, return);
     if (m_state == GettingDescription) {
-        setDescription(GitPlugin::client()->extendedShowDescription(directory(), output));
+        setDescription(GitPlugin::client()->extendedShowDescription(workingDirectory(), output));
         // stage 2
         m_state = GettingDiff;
         const QStringList args = {"show", "--format=format:", // omit header, already generated
@@ -437,7 +329,7 @@ void ShowController::processCommandOutput(const QString &output)
         runCommand(QList<QStringList>() << addConfigurationArguments(args));
     } else if (m_state == GettingDiff) {
         m_state = Idle;
-        BaseController::processCommandOutput(output);
+        GitDiffEditorController::processCommandOutput(output);
     }
 }
 

src/plugins/subversion/subversionclient.cpp

@@ -30,6 +30,7 @@
 
 #include <vcsbase/vcscommand.h>
 #include <vcsbase/vcsbaseconstants.h>
+#include <vcsbase/vcsbasediffeditorcontroller.h>
 #include <vcsbase/vcsbaseeditor.h>
 #include <vcsbase/vcsbaseeditorconfig.h>
 #include <vcsbase/vcsbaseplugin.h>
@@ -167,46 +168,40 @@ QStringList SubversionClient::escapeFiles(const QStringList &files)
     return Utils::transform(files, &SubversionClient::escapeFile);
 }
 
-class DiffController : public DiffEditorController
+class SubversionDiffEditorController : public VcsBaseDiffEditorController
 {
     Q_OBJECT
 public:
-    DiffController(IDocument *document, const SubversionClient *client, const QString &directory);
+    SubversionDiffEditorController(IDocument *document,
+                                   const QString &workingDirectory);
 
     void setFilesList(const QStringList &filesList);
     void setChangeNumber(int changeNumber);
 
 protected:
     void reload() override;
-
+    void processCommandOutput(const QString &output) override;
-private slots:
-    void slotTextualDiffOutputReceived(const QString &contents);
 
 private:
-    QString getDescription() const;
+    void requestDescription();
-    void postCollectTextualDiffOutput();
+    void requestDiff();
-    QProcessEnvironment processEnvironment() const;
 
-    const SubversionClient *m_client;
+    enum State { Idle, GettingDescription, GettingDiff };
-    QString m_workingDirectory;
+    State m_state;
     QStringList m_filesList;
     int m_changeNumber = 0;
 };
 
-DiffController::DiffController(IDocument *document, const SubversionClient *client, const QString &directory) :
+SubversionDiffEditorController::SubversionDiffEditorController(
-    DiffEditorController(document),
+        IDocument *document,
-    m_client(client),
+        const QString &workingDirectory)
-    m_workingDirectory(directory)
+    : VcsBaseDiffEditorController(document, SubversionPlugin::instance()->client(), workingDirectory)
+    , m_state(Idle)
 {
     forceContextLineCount(3); // SVN can not change that when using internal diff
 }
 
-QProcessEnvironment DiffController::processEnvironment() const
+void SubversionDiffEditorController::setFilesList(const QStringList &filesList)
-{
-    return m_client->processEnvironment();
-}
-
-void DiffController::setFilesList(const QStringList &filesList)
 {
     if (isReloading())
         return;
@@ -214,7 +209,7 @@ void DiffController::setFilesList(const QStringList &filesList)
     m_filesList = SubversionClient::escapeFiles(filesList);
 }
 
-void DiffController::setChangeNumber(int changeNumber)
+void SubversionDiffEditorController::setChangeNumber(int changeNumber)
 {
     if (isReloading())
         return;
@@ -222,33 +217,24 @@ void DiffController::setChangeNumber(int changeNumber)
     m_changeNumber = qMax(changeNumber, 0);
 }
 
-QString DiffController::getDescription() const
+void SubversionDiffEditorController::requestDescription()
 {
+    m_state = GettingDescription;
+
     QStringList args(QLatin1String("log"));
-    args << SubversionClient::addAuthenticationOptions(m_client->settings());
+    args << SubversionClient::addAuthenticationOptions(client()->settings());
     args << QLatin1String("-r");
     args << QString::number(m_changeNumber);
-    const SubversionResponse logResponse =
+    runCommand(QList<QStringList>() << args, VcsCommand::SshPasswordPrompt);
-            SubversionPlugin::instance()->runSvn(m_workingDirectory, args,
-                                                 m_client->vcsTimeoutS(),
-                                                 VcsCommand::SshPasswordPrompt);
-
-    if (logResponse.error)
-        return QString();
-
-    return logResponse.stdOut;
 }
 
-void DiffController::postCollectTextualDiffOutput()
+void SubversionDiffEditorController::requestDiff()
 {
-    auto command = new VcsCommand(m_workingDirectory, processEnvironment());
+    m_state = GettingDiff;
-    command->setCodec(EditorManager::defaultTextCodec());
-    connect(command, &VcsCommand::stdOutText, this, &DiffController::slotTextualDiffOutputReceived);
-//    command->addFlags(diffExecutionFlags());
 
     QStringList args;
     args << QLatin1String("diff");
-    args << m_client->addAuthenticationOptions(m_client->settings());
+    args << SubversionClient::addAuthenticationOptions(client()->settings());
     args << QLatin1String("--internal-diff");
     if (ignoreWhitespace())
         args << QLatin1String("-x") << QLatin1String("-uw");
@@ -258,40 +244,43 @@ void DiffController::postCollectTextualDiffOutput()
     } else {
         args << m_filesList;
     }
-
+    runCommand(QList<QStringList>() << args, 0);
-    command->addJob(m_client->vcsBinary(), args, m_client->vcsTimeoutS());
-    command->execute();
 }
 
-void DiffController::slotTextualDiffOutputReceived(const QString &contents)
+void SubversionDiffEditorController::reload()
 {
-    bool ok;
+    if (m_changeNumber) {
-    QList<FileData> fileDataList
+        requestDescription();
-            = DiffUtils::readPatch(contents, &ok);
+    } else {
-    setDiffFiles(fileDataList, m_workingDirectory);
+        requestDiff();
-
+    }
-    reloadFinished(true);
 }
 
-void DiffController::reload()
+void SubversionDiffEditorController::processCommandOutput(const QString &output)
 {
-    const QString description = m_changeNumber
+    QTC_ASSERT(m_state != Idle, return);
-            ? getDescription() : QString();
+    if (m_state == GettingDescription) {
-    postCollectTextualDiffOutput();
+        setDescription(output);
-    setDescription(description);
+
+        requestDiff();
+    } else if (m_state == GettingDiff) {
+        m_state = Idle;
+        VcsBaseDiffEditorController::processCommandOutput(output);
+    }
 }
 
-DiffController *SubversionClient::findOrCreateDiffEditor(const QString &documentId,
+SubversionDiffEditorController *SubversionClient::findOrCreateDiffEditor(const QString &documentId,
                                                          const QString &source,
                                                          const QString &title,
                                                          const QString &workingDirectory) const
 {
     IDocument *document = DiffEditorController::findOrCreateDocument(documentId, title);
-    DiffController *controller = qobject_cast<DiffController *>(
+    SubversionDiffEditorController *controller = qobject_cast<SubversionDiffEditorController *>(
                 DiffEditorController::controller(document));
     if (!controller)
-        controller = new DiffController(document, this, workingDirectory);
+        controller = new SubversionDiffEditorController(document, workingDirectory);
     VcsBasePlugin::setSource(document, source);
+    EditorManager::activateEditorForDocument(document);
     return controller;
 }
 
@@ -304,7 +293,7 @@ void SubversionClient::diff(const QString &workingDirectory, const QStringList &
             + QLatin1String(".Diff.") + VcsBaseEditor::getTitleId(workingDirectory, files);
     const QString title = vcsEditorTitle(vcsCmdString, documentId);
 
-    DiffController *controller = findOrCreateDiffEditor(documentId, workingDirectory, title,
+    SubversionDiffEditorController *controller = findOrCreateDiffEditor(documentId, workingDirectory, title,
                                                         workingDirectory);
     controller->setFilesList(files);
     controller->requestReload();
@@ -335,7 +324,7 @@ void SubversionClient::describe(const QString &workingDirectory, int changeNumbe
                                                         QStringList(),
                                                         QString::number(changeNumber));
 
-    DiffController *controller = findOrCreateDiffEditor(documentId, workingDirectory, title, workingDirectory);
+    SubversionDiffEditorController *controller = findOrCreateDiffEditor(documentId, workingDirectory, title, workingDirectory);
     controller->setChangeNumber(changeNumber);
     controller->requestReload();
 }

src/plugins/subversion/subversionclient.h

@@ -35,7 +35,7 @@ namespace Subversion {
 namespace Internal {
 
 class SubversionSettings;
-class DiffController;
+class SubversionDiffEditorController;
 
 class SubversionClient : public VcsBase::VcsBaseClient
 {
@@ -78,7 +78,7 @@ protected:
     Core::Id vcsEditorKind(VcsCommandTag cmd) const override;
 
 private:
-    DiffController *findOrCreateDiffEditor(const QString &documentId, const QString &source,
+    SubversionDiffEditorController *findOrCreateDiffEditor(const QString &documentId, const QString &source,
                                            const QString &title, const QString &workingDirectory) const;
 
     mutable Utils::FileName m_svnVersionBinary;

src/plugins/vcsbase/vcsbase.pro

@@ -27,7 +27,8 @@ HEADERS += vcsbase_global.h \
     vcsbaseclientsettings.h \
     vcsbaseeditorconfig.h \
     submitfieldwidget.h \
-    submiteditorwidget.h
+    submiteditorwidget.h \
+    vcsbasediffeditorcontroller.h
 
 SOURCES += vcsplugin.cpp \
     vcsbaseplugin.cpp \
@@ -54,7 +55,8 @@ SOURCES += vcsplugin.cpp \
     vcsbaseclientsettings.cpp \
     vcsbaseeditorconfig.cpp \
     submitfieldwidget.cpp \
-    submiteditorwidget.cpp
+    submiteditorwidget.cpp \
+    vcsbasediffeditorcontroller.cpp
 
 RESOURCES += vcsbase.qrc
 

src/plugins/vcsbase/vcsbase.qbs

@@ -12,6 +12,7 @@ QtcPlugin {
     Depends { name: "TextEditor" }
     Depends { name: "ProjectExplorer" }
     Depends { name: "CppTools" }
+    Depends { name: "DiffEditor" }
 
     pluginRecommends: [
         "CodePaster"
@@ -53,6 +54,8 @@ QtcPlugin {
         "vcsbaseclientsettings.cpp",
         "vcsbaseclientsettings.h",
         "vcsbaseconstants.h",
+        "vcsbasediffeditorcontroller.cpp",
+        "vcsbasediffeditorcontroller.h",
         "vcsbaseeditor.cpp",
         "vcsbaseeditor.h",
         "vcsbaseeditorconfig.cpp",

src/plugins/vcsbase/vcsbase_dependencies.pri

@@ -8,6 +8,7 @@ QTC_PLUGIN_DEPENDS += \
     coreplugin \
     texteditor \
     projectexplorer \
-    cpptools
+    cpptools \
+    diffeditor
 QTC_PLUGIN_RECOMMENDS += \
     cpaster

src/plugins/vcsbase/vcsbasediffeditorcontroller.cpp

@@ -0,0 +1,195 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 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 "vcsbasediffeditorcontroller.h"
+#include "vcsbaseclient.h"
+#include "vcscommand.h"
+
+#include <coreplugin/editormanager/editormanager.h>
+#include <coreplugin/progressmanager/progressmanager.h>
+#include <diffeditor/diffutils.h>
+#include <utils/qtcassert.h>
+#include <utils/runextensions.h>
+
+#include <QPointer>
+
+using namespace DiffEditor;
+using namespace Core;
+
+namespace VcsBase {
+
+static void readPatch(QFutureInterface<QList<FileData>> &futureInterface,
+                      const QString &patch)
+{
+    bool ok;
+    const QList<FileData> &fileDataList = DiffUtils::readPatch(patch, &ok);
+    futureInterface.reportResult(fileDataList);
+}
+
+class VcsBaseDiffEditorControllerPrivate
+{
+public:
+    VcsBaseDiffEditorControllerPrivate(VcsBaseDiffEditorController *controller,
+                                       VcsBaseClientImpl *client,
+                                       const QString &workingDirectory);
+    ~VcsBaseDiffEditorControllerPrivate();
+
+    void processingFinished();
+    void processDiff(const QString &patch);
+    void cancelReload();
+    void commandFinished(bool success);
+
+    VcsBaseDiffEditorController *q;
+    VcsBaseClientImpl *m_client;
+    const QString m_directory;
+    QString m_startupFile;
+    QString m_output;
+    QPointer<VcsCommand> m_command;
+    QFutureWatcher<QList<FileData>> m_processWatcher;
+};
+
+VcsBaseDiffEditorControllerPrivate::VcsBaseDiffEditorControllerPrivate(VcsBaseDiffEditorController *controller,
+        VcsBaseClientImpl *client,
+        const QString &workingDirectory)
+    : q(controller)
+    , m_client(client)
+    , m_directory(workingDirectory)
+{
+    QObject::connect(&m_processWatcher, &QFutureWatcher<QList<FileData>>::finished, q,
+                     [this] () { processingFinished(); });
+}
+
+VcsBaseDiffEditorControllerPrivate::~VcsBaseDiffEditorControllerPrivate()
+{
+    cancelReload();
+}
+
+void VcsBaseDiffEditorControllerPrivate::processingFinished()
+{
+    const QList<FileData> fileDataList = m_processWatcher.future().result();
+
+    q->setDiffFiles(fileDataList, q->workingDirectory(), q->startupFile());
+    q->reloadFinished(true);
+}
+
+void VcsBaseDiffEditorControllerPrivate::processDiff(const QString &patch)
+{
+    m_processWatcher.setFuture(Utils::runAsync(&readPatch, patch));
+
+    ProgressManager::addTask(m_processWatcher.future(),
+                                   q->tr("Processing diff"), "DiffEditor");
+}
+
+void VcsBaseDiffEditorControllerPrivate::cancelReload()
+{
+    if (m_command) {
+        m_command->disconnect();
+        m_command->cancel();
+        m_command.clear();
+    }
+
+    if (m_processWatcher.future().isRunning()) {
+        m_processWatcher.future().cancel();
+        m_processWatcher.setFuture(QFuture<QList<FileData>>());
+    }
+    m_output = QString();
+}
+
+void VcsBaseDiffEditorControllerPrivate::commandFinished(bool success)
+{
+    if (m_command)
+        m_command.clear();
+
+    if (!success) {
+        cancelReload();
+        q->reloadFinished(success);
+        return;
+    }
+
+    q->processCommandOutput(m_output);
+}
+
+/////////////////////
+
+VcsBaseDiffEditorController::VcsBaseDiffEditorController(IDocument *document,
+                                                         VcsBaseClientImpl *client,
+                                                         const QString &workingDirectory)
+    : DiffEditorController(document)
+    , d(new VcsBaseDiffEditorControllerPrivate(this, client, workingDirectory))
+{
+}
+
+VcsBaseDiffEditorController::~VcsBaseDiffEditorController()
+{
+    delete d;
+}
+
+void VcsBaseDiffEditorController::runCommand(const QList<QStringList> &args, unsigned flags, QTextCodec *codec)
+{
+    d->cancelReload();
+
+    d->m_command = new VcsCommand(workingDirectory(), d->m_client->processEnvironment());
+    d->m_command->setCodec(codec ? codec : EditorManager::defaultTextCodec());
+    connect(d->m_command.data(), &VcsCommand::stdOutText, this,
+            [this] (const QString &output) { d->m_output = output; });
+    connect(d->m_command.data(), &VcsCommand::finished, this,
+            [this] (bool success) { d->commandFinished(success); });
+    d->m_command->addFlags(flags);
+
+    for (const QStringList &arg : args) {
+        QTC_ASSERT(!arg.isEmpty(), continue);
+
+        d->m_command->addJob(d->m_client->vcsBinary(), arg, d->m_client->vcsTimeoutS());
+    }
+
+    d->m_command->execute();
+}
+
+void VcsBaseDiffEditorController::processCommandOutput(const QString &output)
+{
+    d->processDiff(output);
+}
+
+VcsBaseClientImpl *VcsBaseDiffEditorController::client() const
+{
+    return d->m_client;
+}
+
+QString VcsBaseDiffEditorController::workingDirectory() const
+{
+    return d->m_directory;
+}
+
+void VcsBaseDiffEditorController::setStartupFile(const QString &startupFile)
+{
+    d->m_startupFile = startupFile;
+}
+
+QString VcsBaseDiffEditorController::startupFile() const
+{
+    return d->m_startupFile;
+}
+
+} // namespace VcsBase

src/plugins/vcsbase/vcsbasediffeditorcontroller.h

@@ -0,0 +1,62 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 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.
+**
+****************************************************************************/
+
+#pragma once
+
+#include "vcsbase_global.h"
+#include <diffeditor/diffeditorcontroller.h>
+
+namespace Core { class IDocument; }
+
+namespace VcsBase {
+
+class VcsBaseClientImpl;
+class VcsBaseDiffEditorControllerPrivate;
+
+class VCSBASE_EXPORT VcsBaseDiffEditorController : public DiffEditor::DiffEditorController
+{
+    Q_OBJECT
+
+public:
+    VcsBaseDiffEditorController(Core::IDocument *document,
+                                VcsBaseClientImpl *client,
+                                const QString &workingDirectory);
+    ~VcsBaseDiffEditorController();
+
+protected:
+    void runCommand(const QList<QStringList> &args, unsigned flags, QTextCodec *codec = nullptr);
+    virtual void processCommandOutput(const QString &output);
+
+    VcsBaseClientImpl *client() const;
+    QString workingDirectory() const;
+    void setStartupFile(const QString &startupFile);
+    QString startupFile() const;
+
+private:
+    friend class VcsBaseDiffEditorControllerPrivate;
+    VcsBaseDiffEditorControllerPrivate *d;
+};
+
+} //namespace VcsBase