Move git specific stuff out of diff editor plugin

Move it to the git plugin.

Change-Id: I8151573ed50df70776f7ebf0475dd41fb84fae83
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

13 files changed, 370 insertions, 186 deletions

diff --git a/src/plugins/diffeditor/descriptionwidgetwatcher.cpp b/src/plugins/diffeditor/descriptionwidgetwatcher.cpp
new file mode 100644
index 0000000000..0e310cfbcd
--- /dev/null
+++ b/src/plugins/diffeditor/descriptionwidgetwatcher.cpp
@@ -0,0 +1,78 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 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 "descriptionwidgetwatcher.h"
+#include "diffeditor.h"
+#include "diffeditorcontroller.h"
+
+#include <coreplugin/editormanager/documentmodel.h>
+#include <coreplugin/editormanager/editormanager.h>
+#include <texteditor/texteditor.h>
+
+using namespace Core;
+
+namespace DiffEditor {
+
+DescriptionWidgetWatcher::DescriptionWidgetWatcher(DiffEditorController *controller)
+    : QObject(controller), m_document(controller->document())
+{
+    const QList<IEditor *> editors = DocumentModel::editorsForDocument(controller->document());
+    for (auto *editor : editors) {
+        if (TextEditor::TextEditorWidget *widget = descriptionWidget(editor))
+            m_widgets.append(widget);
+    }
+
+    connect(EditorManager::instance(), &EditorManager::editorOpened,
+            [this](IEditor *editor) {
+        if (TextEditor::TextEditorWidget *widget = descriptionWidget(editor)) {
+            m_widgets.append(widget);
+            emit descriptionWidgetAdded(widget);
+        }
+    });
+
+    connect(EditorManager::instance(), &EditorManager::editorAboutToClose,
+            [this](IEditor *editor) {
+        if (TextEditor::TextEditorWidget *widget = descriptionWidget(editor)) {
+            emit descriptionWidgetRemoved(widget);
+            m_widgets.removeAll(widget);
+        }
+    });
+}
+
+QList<TextEditor::TextEditorWidget *> DescriptionWidgetWatcher::descriptionWidgets() const
+{
+    return m_widgets;
+}
+
+TextEditor::TextEditorWidget *DescriptionWidgetWatcher::descriptionWidget(Core::IEditor *editor) const
+{
+    if (Internal::DiffEditor *diffEditor = qobject_cast<Internal::DiffEditor *>(editor)) {
+        if (diffEditor->document() == m_document)
+            return diffEditor->descriptionWidget();
+    }
+    return nullptr;
+}
+
+} // namespace DiffEditor
diff --git a/src/plugins/diffeditor/descriptionwidgetwatcher.h b/src/plugins/diffeditor/descriptionwidgetwatcher.h
new file mode 100644
index 0000000000..46988260fe
--- /dev/null
+++ b/src/plugins/diffeditor/descriptionwidgetwatcher.h
@@ -0,0 +1,60 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 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 "diffeditor_global.h"
+
+#include <QObject>
+
+namespace Core {
+class IDocument;
+class IEditor;
+}
+namespace TextEditor { class TextEditorWidget; }
+
+namespace DiffEditor {
+
+class DiffEditorController;
+
+class DIFFEDITOR_EXPORT DescriptionWidgetWatcher : public QObject
+{
+    Q_OBJECT
+public:
+    explicit DescriptionWidgetWatcher(DiffEditorController *controller);
+    QList<TextEditor::TextEditorWidget *> descriptionWidgets() const;
+
+signals:
+    void descriptionWidgetAdded(TextEditor::TextEditorWidget *editor);
+    void descriptionWidgetRemoved(TextEditor::TextEditorWidget *editor);
+
+private:
+    TextEditor::TextEditorWidget *descriptionWidget(Core::IEditor *editor) const;
+
+    QList<TextEditor::TextEditorWidget *> m_widgets;
+    Core::IDocument *m_document = nullptr;
+};
+
+} // namespace DiffEditor
diff --git a/src/plugins/diffeditor/diffeditor.cpp b/src/plugins/diffeditor/diffeditor.cpp
index d3654d5439..6288f2405b 100644
--- a/src/plugins/diffeditor/diffeditor.cpp
+++ b/src/plugins/diffeditor/diffeditor.cpp
@@ -81,22 +81,11 @@ public:
 
     virtual QSize sizeHint() const override;
 
-signals:
-    void requestBranchList();
-
 protected:
-    void mouseMoveEvent(QMouseEvent *e) override;
-    void mouseReleaseEvent(QMouseEvent *e) override;
-
     void setDisplaySettings(const DisplaySettings &ds) override;
     void setMarginSettings(const MarginSettings &ms) override;
 
-    bool findContentsUnderCursor(const QTextCursor &cursor);
-    void highlightCurrentContents();
-    void handleCurrentContents();
-
 private:
-    QTextCursor m_currentCursor;
     Core::IContext *m_context;
 };
 
@@ -153,68 +142,6 @@ void DescriptionEditorWidget::setMarginSettings(const MarginSettings &ms)
     TextEditorWidget::setMarginSettings(MarginSettings());
 }
 
-void DescriptionEditorWidget::mouseMoveEvent(QMouseEvent *e)
-{
-    if (e->buttons()) {
-        TextEditorWidget::mouseMoveEvent(e);
-        return;
-    }
-
-    Qt::CursorShape cursorShape;
-
-    const QTextCursor cursor = cursorForPosition(e->pos());
-    if (findContentsUnderCursor(cursor)) {
-        highlightCurrentContents();
-        cursorShape = Qt::PointingHandCursor;
-    } else {
-        setExtraSelections(OtherSelection, QList<QTextEdit::ExtraSelection>());
-        cursorShape = Qt::IBeamCursor;
-    }
-
-    TextEditorWidget::mouseMoveEvent(e);
-    viewport()->setCursor(cursorShape);
-}
-
-void DescriptionEditorWidget::mouseReleaseEvent(QMouseEvent *e)
-{
-    if (e->button() == Qt::LeftButton && !(e->modifiers() & Qt::ShiftModifier)) {
-        const QTextCursor cursor = cursorForPosition(e->pos());
-        if (findContentsUnderCursor(cursor)) {
-            handleCurrentContents();
-            e->accept();
-            return;
-        }
-    }
-
-    TextEditorWidget::mouseReleaseEvent(e);
-}
-
-bool DescriptionEditorWidget::findContentsUnderCursor(const QTextCursor &cursor)
-{
-    m_currentCursor = cursor;
-    return cursor.block().text() == Constants::EXPAND_BRANCHES;
-}
-
-void DescriptionEditorWidget::highlightCurrentContents()
-{
-    QTextEdit::ExtraSelection sel;
-    sel.cursor = m_currentCursor;
-    sel.cursor.select(QTextCursor::LineUnderCursor);
-    sel.format.setUnderlineStyle(QTextCharFormat::SingleUnderline);
-    const QColor textColor = TextEditorSettings::fontSettings().formatFor(C_TEXT).foreground();
-    sel.format.setUnderlineColor(textColor.isValid() ? textColor : palette().color(QPalette::Foreground));
-    setExtraSelections(TextEditorWidget::OtherSelection,
-                       QList<QTextEdit::ExtraSelection>() << sel);
-}
-
-void DescriptionEditorWidget::handleCurrentContents()
-{
-    m_currentCursor.select(QTextCursor::LineUnderCursor);
-    m_currentCursor.removeSelectedText();
-    m_currentCursor.insertText("Branches: Expanding...");
-    emit requestBranchList();
-}
-
 ///////////////////////////////// DiffEditor //////////////////////////////////
 
 DiffEditor::DiffEditor()
@@ -296,8 +223,6 @@ void DiffEditor::setDocument(QSharedPointer<DiffEditorDocument> doc)
 
     m_document = doc;
 
-    connect(m_descriptionWidget, &DescriptionEditorWidget::requestBranchList,
-            m_document.data(), &DiffEditorDocument::requestMoreInformation);
     connect(m_document.data(), &DiffEditorDocument::documentChanged,
             this, &DiffEditor::documentHasChanged);
     connect(m_document.data(), &DiffEditorDocument::descriptionChanged,
diff --git a/src/plugins/diffeditor/diffeditor.pro b/src/plugins/diffeditor/diffeditor.pro
index e9cf72b7fe..5c8c904495 100644
--- a/src/plugins/diffeditor/diffeditor.pro
+++ b/src/plugins/diffeditor/diffeditor.pro
@@ -1,7 +1,9 @@
 DEFINES += DIFFEDITOR_LIBRARY
 include(../../qtcreatorplugin.pri)
 
-HEADERS += diffeditor_global.h \
+HEADERS += \
+        descriptionwidgetwatcher.h \
+        diffeditor_global.h \
         diffeditor.h \
         diffeditorconstants.h \
         diffeditorcontroller.h \
@@ -17,7 +19,9 @@ HEADERS += diffeditor_global.h \
         unifieddiffeditorwidget.h \
         diffeditoricons.h
 
-SOURCES += diffeditor.cpp \
+SOURCES += \
+        descriptionwidgetwatcher.cpp \
+        diffeditor.cpp \
         diffeditorcontroller.cpp \
         diffeditordocument.cpp \
         diffeditorfactory.cpp \
diff --git a/src/plugins/diffeditor/diffeditor.qbs b/src/plugins/diffeditor/diffeditor.qbs
index 1c190a8dd2..8d0a1a1820 100644
--- a/src/plugins/diffeditor/diffeditor.qbs
+++ b/src/plugins/diffeditor/diffeditor.qbs
@@ -14,6 +14,8 @@ QtcPlugin {
     ]
 
     files: [
+        "descriptionwidgetwatcher.cpp",
+        "descriptionwidgetwatcher.h",
         "diffeditor.cpp",
         "diffeditor.h",
         "diffeditor.qrc",
diff --git a/src/plugins/diffeditor/diffeditorconstants.h b/src/plugins/diffeditor/diffeditorconstants.h
index c44a5fb84d..e1c9870c98 100644
--- a/src/plugins/diffeditor/diffeditorconstants.h
+++ b/src/plugins/diffeditor/diffeditorconstants.h
@@ -41,7 +41,5 @@ const char UNIFIED_VIEW_ID[] = "DiffEditor.Unified";
 
 const char G_TOOLS_DIFF[] = "QtCreator.Group.Tools.Options";
 
-const char EXPAND_BRANCHES[] = "Branches: <Expand>";
-
 } // namespace Constants
 } // namespace DiffEditor
diff --git a/src/plugins/diffeditor/diffeditorcontroller.cpp b/src/plugins/diffeditor/diffeditorcontroller.cpp
index bb2738b985..2cf36902af 100644
--- a/src/plugins/diffeditor/diffeditorcontroller.cpp
+++ b/src/plugins/diffeditor/diffeditorcontroller.cpp
@@ -65,12 +65,6 @@ bool DiffEditorController::ignoreWhitespace() const
     return m_document->ignoreWhitespace();
 }
 
-QString DiffEditorController::revisionFromDescription() const
-{
-    // TODO: This is specific for git and does not belong here at all!
-    return m_document->description().mid(7, 12);
-}
-
 QString DiffEditorController::makePatch(int fileIndex, int chunkIndex,
                                         PatchOptions options) const
 {
@@ -105,18 +99,9 @@ void DiffEditorController::setDescription(const QString &description)
     m_document->setDescription(description);
 }
 
-void DiffEditorController::branchesReceived(const QString &branches)
-{
-    QString tmp = m_document->description();
-    tmp.replace(Constants::EXPAND_BRANCHES, branches);
-    m_document->setDescription(tmp);
-}
-
-void DiffEditorController::requestMoreInformation()
+QString DiffEditorController::description() const
 {
-    const QString rev = revisionFromDescription();
-    if (!rev.isEmpty())
-        emit requestInformationForCommit(rev);
+    return m_document->description();
 }
 
 /**
diff --git a/src/plugins/diffeditor/diffeditorcontroller.h b/src/plugins/diffeditor/diffeditorcontroller.h
index e5d5ca7418..4578a7f82a 100644
--- a/src/plugins/diffeditor/diffeditorcontroller.h
+++ b/src/plugins/diffeditor/diffeditorcontroller.h
@@ -51,8 +51,6 @@ public:
     int contextLineCount() const;
     bool ignoreWhitespace() const;
 
-    QString revisionFromDescription() const;
-
     enum PatchOption {
         NoOption = 0,
         Revert = 1,
@@ -65,13 +63,12 @@ public:
                                                  const QString &displayName);
     static DiffEditorController *controller(Core::IDocument *document);
 
-    void branchesReceived(const QString &branches);
     void requestChunkActions(QMenu *menu, int fileIndex, int chunkIndex);
     bool chunkExists(int fileIndex, int chunkIndex) const;
+    Core::IDocument *document() const;
 
 signals:
     void chunkActionsRequested(QMenu *menu, int fileIndex, int chunkIndex);
-    void requestInformationForCommit(const QString &revision);
 
 protected:
     // reloadFinished() should be called
@@ -84,14 +81,11 @@ protected:
                       const QString &baseDirectory = QString(),
                       const QString &startupFile = QString());
     void setDescription(const QString &description);
+    QString description() const;
     void forceContextLineCount(int lines);
-    Core::IDocument *document() const;
 
 private:
-    void requestMoreInformation();
-
     Internal::DiffEditorDocument *const m_document;
-
     bool m_isReloading = false;
 
     friend class Internal::DiffEditorDocument;
diff --git a/src/plugins/diffeditor/diffeditordocument.cpp b/src/plugins/diffeditor/diffeditordocument.cpp
index 0845f3ef03..224d63dc2b 100644
--- a/src/plugins/diffeditor/diffeditordocument.cpp
+++ b/src/plugins/diffeditor/diffeditordocument.cpp
@@ -69,11 +69,6 @@ void DiffEditorDocument::setController(DiffEditorController *controller)
     if (m_controller)
         m_controller->deleteLater();
     m_controller = controller;
-
-    if (m_controller) {
-        connect(this, &DiffEditorDocument::requestMoreInformation,
-                m_controller, &DiffEditorController::requestMoreInformation);
-    }
 }
 
 DiffEditorController *DiffEditorDocument::controller() const
diff --git a/src/plugins/diffeditor/diffeditordocument.h b/src/plugins/diffeditor/diffeditordocument.h
index 2a5293dfaf..a9dff53faa 100644
--- a/src/plugins/diffeditor/diffeditordocument.h
+++ b/src/plugins/diffeditor/diffeditordocument.h
@@ -90,7 +90,6 @@ signals:
     void temporaryStateChanged();
     void documentChanged();
     void descriptionChanged();
-    void requestMoreInformation();
 
 private:
     void beginReload();
diff --git a/src/plugins/git/gitclient.cpp b/src/plugins/git/gitclient.cpp
index f642f8ba7e..92803826d6 100644
--- a/src/plugins/git/gitclient.cpp
+++ b/src/plugins/git/gitclient.cpp
@@ -62,9 +62,14 @@
 #include <vcsbase/vcscommand.h>
 #include <vcsbase/vcsoutputwindow.h>
 
+#include <diffeditor/descriptionwidgetwatcher.h>
 #include <diffeditor/diffeditorconstants.h>
 #include <diffeditor/diffeditorcontroller.h>
 #include <diffeditor/diffutils.h>
+
+#include <texteditor/fontsettings.h>
+#include <texteditor/texteditorsettings.h>
+
 #include <utils/utilsicons.h>
 
 #include <QAction>
@@ -76,8 +81,9 @@
 #include <QMessageBox>
 #include <QPushButton>
 #include <QRegExp>
-#include <QTextCodec>
+#include <QTextBlock>
 #include <QToolButton>
+#include <QTextCodec>
 
 const char GIT_DIRECTORY[] = ".git";
 const char graphLogFormatC[] = "%h %d %an %s %ci";
@@ -112,6 +118,153 @@ const unsigned silentFlags = unsigned(VcsCommand::SuppressCommandLogging
                                       | VcsCommand::SuppressStdErr
                                       | VcsCommand::SuppressFailMessage);
 
+static QString branchesDisplay(const QString &prefix, QStringList *branches, bool *first)
+{
+    const int limit = 12;
+    const int count = branches->count();
+    int more = 0;
+    QString output;
+    if (*first)
+        *first = false;
+    else
+        output += QString(sizeof(BRANCHES_PREFIX) - 1, ' '); // Align
+    output += prefix + ": ";
+    // If there are more than 'limit' branches, list limit/2 (first limit/4 and last limit/4)
+    if (count > limit) {
+        const int leave = limit / 2;
+        more = count - leave;
+        branches->erase(branches->begin() + leave / 2 + 1, branches->begin() + count - leave / 2);
+        (*branches)[leave / 2] = "...";
+    }
+    output += branches->join(", ");
+    //: Displayed after the untranslated message "Branches: branch1, branch2 'and %n more'"
+    //  in git show.
+    if (more > 0)
+        output += ' ' + GitClient::tr("and %n more", 0, more);
+    return output;
+}
+
+class DescriptionWidgetDecorator : public QObject
+{
+    Q_OBJECT
+public:
+    DescriptionWidgetDecorator(DescriptionWidgetWatcher *watcher);
+
+    bool eventFilter(QObject *watched, QEvent *event) override;
+
+signals:
+    void branchListRequested();
+
+private:
+    bool checkContentsUnderCursor(const QTextCursor &cursor) const;
+    void highlightCurrentContents(TextEditor::TextEditorWidget *textEditor,
+                                  const QTextCursor &cursor);
+    void handleCurrentContents(const QTextCursor &cursor);
+    void addWatch(TextEditor::TextEditorWidget *widget);
+    void removeWatch(TextEditor::TextEditorWidget *widget);
+
+    DescriptionWidgetWatcher *m_watcher;
+    QHash<QObject *, TextEditor::TextEditorWidget *> m_viewportToTextEditor;
+};
+
+DescriptionWidgetDecorator::DescriptionWidgetDecorator(DescriptionWidgetWatcher *watcher)
+    : QObject(),
+      m_watcher(watcher)
+{
+    QList<TextEditor::TextEditorWidget *> widgets = m_watcher->descriptionWidgets();
+    for (auto *widget : widgets)
+        addWatch(widget);
+
+    connect(m_watcher, &DescriptionWidgetWatcher::descriptionWidgetAdded,
+            this, &DescriptionWidgetDecorator::addWatch);
+    connect(m_watcher, &DescriptionWidgetWatcher::descriptionWidgetRemoved,
+            this, &DescriptionWidgetDecorator::removeWatch);
+}
+
+bool DescriptionWidgetDecorator::eventFilter(QObject *watched, QEvent *event)
+{
+    TextEditor::TextEditorWidget *textEditor = m_viewportToTextEditor.value(watched);
+    if (!textEditor)
+        return QObject::eventFilter(watched, event);
+
+    if (event->type() == QEvent::MouseMove) {
+        QMouseEvent *mouseEvent = static_cast<QMouseEvent *>(event);
+        if (mouseEvent->buttons())
+            return QObject::eventFilter(watched, event);
+
+        Qt::CursorShape cursorShape;
+
+        const QTextCursor cursor = textEditor->cursorForPosition(mouseEvent->pos());
+        if (checkContentsUnderCursor(cursor)) {
+            highlightCurrentContents(textEditor, cursor);
+            cursorShape = Qt::PointingHandCursor;
+        } else {
+            textEditor->setExtraSelections(TextEditor::TextEditorWidget::OtherSelection,
+                                           QList<QTextEdit::ExtraSelection>());
+            cursorShape = Qt::IBeamCursor;
+        }
+
+        bool ret = QObject::eventFilter(watched, event);
+        textEditor->viewport()->setCursor(cursorShape);
+        return ret;
+    } else if (event->type() == QEvent::MouseButtonRelease) {
+        QMouseEvent *mouseEvent = static_cast<QMouseEvent *>(event);
+
+        if (mouseEvent->button() == Qt::LeftButton && !(mouseEvent->modifiers() & Qt::ShiftModifier)) {
+            const QTextCursor cursor = textEditor->cursorForPosition(mouseEvent->pos());
+            if (checkContentsUnderCursor(cursor)) {
+                handleCurrentContents(cursor);
+                return true;
+            }
+        }
+
+        return QObject::eventFilter(watched, event);
+    }
+    return QObject::eventFilter(watched, event);
+}
+
+bool DescriptionWidgetDecorator::checkContentsUnderCursor(const QTextCursor &cursor) const
+{
+    return cursor.block().text() == Constants::EXPAND_BRANCHES;
+}
+
+void DescriptionWidgetDecorator::highlightCurrentContents(
+        TextEditor::TextEditorWidget *textEditor, const QTextCursor &cursor)
+{
+    QTextEdit::ExtraSelection sel;
+    sel.cursor = cursor;
+    sel.cursor.select(QTextCursor::LineUnderCursor);
+    sel.format.setUnderlineStyle(QTextCharFormat::SingleUnderline);
+    const QColor textColor = TextEditor::TextEditorSettings::fontSettings().formatFor(TextEditor::C_TEXT).foreground();
+    sel.format.setUnderlineColor(textColor.isValid() ? textColor : textEditor->palette().color(QPalette::Foreground));
+    textEditor->setExtraSelections(TextEditor::TextEditorWidget::OtherSelection,
+                       QList<QTextEdit::ExtraSelection>() << sel);
+}
+
+void DescriptionWidgetDecorator::handleCurrentContents(const QTextCursor &cursor)
+{
+    QTextCursor copy = cursor;
+
+    copy.select(QTextCursor::LineUnderCursor);
+    copy.removeSelectedText();
+    copy.insertText("Branches: Expanding...");
+    emit branchListRequested();
+}
+
+void DescriptionWidgetDecorator::addWatch(TextEditor::TextEditorWidget *widget)
+{
+    m_viewportToTextEditor.insert(widget->viewport(), widget);
+    widget->viewport()->installEventFilter(this);
+}
+
+void DescriptionWidgetDecorator::removeWatch(TextEditor::TextEditorWidget *widget)
+{
+    widget->viewport()->removeEventFilter(this);
+    m_viewportToTextEditor.remove(widget->viewport());
+}
+
+///////////////////////////////
+
 class GitDiffEditorController : public VcsBaseDiffEditorController
 {
     Q_OBJECT
@@ -124,13 +277,75 @@ protected:
 
     QStringList addConfigurationArguments(const QStringList &args) const;
     QStringList addHeadWhenCommandInProgress() const;
+
+private:
+    void updateBranchList();
+
+    DescriptionWidgetWatcher m_watcher;
+    DescriptionWidgetDecorator m_decorator;
 };
 
 GitDiffEditorController::GitDiffEditorController(IDocument *document, const QString &workingDirectory) :
-    VcsBaseDiffEditorController(document, GitPlugin::client(), workingDirectory)
+    VcsBaseDiffEditorController(document, GitPlugin::client(), workingDirectory),
+    m_watcher(this),
+    m_decorator(&m_watcher)
 {
+    connect(&m_decorator, &DescriptionWidgetDecorator::branchListRequested,
+            this, &GitDiffEditorController::updateBranchList);
 }
 
+void GitDiffEditorController::updateBranchList()
+{
+    const QString revision = description().mid(7, 12);
+    if (revision.isEmpty())
+        return;
+
+    const QString workingDirectory = baseDirectory();
+    VcsCommand *command = GitPlugin::client()->vcsExec(
+                workingDirectory, {"branch", noColorOption, "-a", "--contains", revision}, nullptr,
+                false, 0, workingDirectory);
+    connect(command, &VcsCommand::stdOutText, [this](const QString &text) {
+        const QString remotePrefix = "remotes/";
+        const QString localPrefix = "<Local>";
+        const int prefixLength = remotePrefix.length();
+        QString output = BRANCHES_PREFIX;
+        QStringList branches;
+        QString previousRemote = localPrefix;
+        bool first = true;
+        for (const QString &branch : text.split('\n')) {
+            const QString b = branch.mid(2).trimmed();
+            if (b.isEmpty())
+                continue;
+            if (b.startsWith(remotePrefix)) {
+                const int nextSlash = b.indexOf('/', prefixLength);
+                if (nextSlash < 0)
+                    continue;
+                const QString remote = b.mid(prefixLength, nextSlash - prefixLength);
+                if (remote != previousRemote) {
+                    output += branchesDisplay(previousRemote, &branches, &first) + '\n';
+                    branches.clear();
+                    previousRemote = remote;
+                }
+                branches << b.mid(nextSlash + 1);
+            } else {
+                branches << b;
+            }
+        }
+        if (branches.isEmpty()) {
+            if (previousRemote == localPrefix)
+                output += tr("<None>");
+        } else {
+            output += branchesDisplay(previousRemote, &branches, &first);
+        }
+        const QString branchList = output.trimmed();
+        QString newDescription = description();
+        newDescription.replace(Constants::EXPAND_BRANCHES, branchList);
+        setDescription(newDescription);
+    });
+}
+
+///////////////////////////////
+
 void GitDiffEditorController::runCommand(const QList<QStringList> &args, QTextCodec *codec)
 {
     VcsBaseDiffEditorController::runCommand(args, diffExecutionFlags(), codec);
@@ -679,8 +894,6 @@ void GitClient::requestReload(const QString &documentId, const QString &source,
 
     connect(controller, &DiffEditorController::chunkActionsRequested,
             this, &GitClient::chunkActionsRequested, Qt::DirectConnection);
-    connect(controller, &DiffEditorController::requestInformationForCommit,
-            this, &GitClient::branchesForCommit);
 
     VcsBasePlugin::setSource(document, sourceCopy);
     EditorManager::activateEditorForDocument(document);
@@ -1379,76 +1592,6 @@ void GitClient::synchronousTagsForCommit(const QString &workingDirectory, const
     }
 }
 
-static QString branchesDisplay(const QString &prefix, QStringList *branches, bool *first)
-{
-    const int limit = 12;
-    const int count = branches->count();
-    int more = 0;
-    QString output;
-    if (*first)
-        *first = false;
-    else
-        output += QString(sizeof(BRANCHES_PREFIX) - 1, ' '); // Align
-    output += prefix + ": ";
-    // If there are more than 'limit' branches, list limit/2 (first limit/4 and last limit/4)
-    if (count > limit) {
-        const int leave = limit / 2;
-        more = count - leave;
-        branches->erase(branches->begin() + leave / 2 + 1, branches->begin() + count - leave / 2);
-        (*branches)[leave / 2] = "...";
-    }
-    output += branches->join(", ");
-    //: Displayed after the untranslated message "Branches: branch1, branch2 'and %n more'"
-    //  in git show.
-    if (more > 0)
-        output += ' ' + GitClient::tr("and %n more", 0, more);
-    return output;
-}
-
-void GitClient::branchesForCommit(const QString &revision)
-{
-    auto controller = qobject_cast<DiffEditorController *>(sender());
-    QString workingDirectory = controller->baseDirectory();
-    VcsCommand *command = vcsExec(
-                workingDirectory, {"branch", noColorOption, "-a", "--contains", revision}, nullptr,
-                false, 0, workingDirectory);
-    connect(command, &VcsCommand::stdOutText, controller, [controller](const QString &text) {
-        const QString remotePrefix = "remotes/";
-        const QString localPrefix = "<Local>";
-        const int prefixLength = remotePrefix.length();
-        QString output = BRANCHES_PREFIX;
-        QStringList branches;
-        QString previousRemote = localPrefix;
-        bool first = true;
-        for (const QString &branch : text.split('\n')) {
-            const QString b = branch.mid(2).trimmed();
-            if (b.isEmpty())
-                continue;
-            if (b.startsWith(remotePrefix)) {
-                const int nextSlash = b.indexOf('/', prefixLength);
-                if (nextSlash < 0)
-                    continue;
-                const QString remote = b.mid(prefixLength, nextSlash - prefixLength);
-                if (remote != previousRemote) {
-                    output += branchesDisplay(previousRemote, &branches, &first) + '\n';
-                    branches.clear();
-                    previousRemote = remote;
-                }
-                branches << b.mid(nextSlash + 1);
-            } else {
-                branches << b;
-            }
-        }
-        if (branches.isEmpty()) {
-            if (previousRemote == localPrefix)
-                output += tr("<None>");
-        } else {
-            output += branchesDisplay(previousRemote, &branches, &first);
-        }
-        controller->branchesReceived(output.trimmed());
-    });
-}
-
 bool GitClient::isRemoteCommit(const QString &workingDirectory, const QString &commit)
 {
     return !vcsFullySynchronousExec(
@@ -2110,7 +2253,7 @@ QString GitClient::extendedShowDescription(const QString &workingDirectory, cons
     // Empty line before headers and commit message
     const int emptyLine = modText.indexOf("\n\n");
     if (emptyLine != -1)
-        modText.insert(emptyLine, QString('\n') + DiffEditor::Constants::EXPAND_BRANCHES);
+        modText.insert(emptyLine, QString('\n') + Constants::EXPAND_BRANCHES);
 
     return modText;
 }
diff --git a/src/plugins/git/gitclient.h b/src/plugins/git/gitclient.h
index 206a3c7b7b..655b49c9e0 100644
--- a/src/plugins/git/gitclient.h
+++ b/src/plugins/git/gitclient.h
@@ -330,7 +330,6 @@ public:
 private:
     void finishSubmoduleUpdate();
     void chunkActionsRequested(QMenu *menu, int fileIndex, int chunkIndex);
-    void branchesForCommit(const QString &revision);
 
     void stage(DiffEditor::DiffEditorController *diffController,
                const QString &patch, bool revert);
diff --git a/src/plugins/git/gitconstants.h b/src/plugins/git/gitconstants.h
index 6d81196c32..d817fcda28 100644
--- a/src/plugins/git/gitconstants.h
+++ b/src/plugins/git/gitconstants.h
@@ -53,5 +53,7 @@ const char C_GITEDITORID[]  = "Git Editor";
 
 const int OBSOLETE_COMMIT_AGE_IN_DAYS = 90;
 
+const char EXPAND_BRANCHES[] = "Branches: <Expand>";
+
 } // namespace Constants
 } // namespace Git