Show progress indicator while reloading diff

Change-Id: Ieefdb885682f01e0e1c8cec90f4769e832650a0c
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/diffeditor/diffeditordocument.cpp

@@ -328,6 +328,7 @@ QString DiffEditorDocument::plainText() const
 void DiffEditorDocument::beginReload()
 {
     emit aboutToReload();
+    m_isReloading = true;
     const bool blocked = blockSignals(true);
     setDiffFiles(QList<FileData>(), QString());
     setDescription(QString());
@@ -336,6 +337,7 @@ void DiffEditorDocument::beginReload()
 
 void DiffEditorDocument::endReload(bool success)
 {
+    m_isReloading = false;
     emit reloadFinished(success);
 }
 

src/plugins/diffeditor/diffeditordocument.h

@@ -76,6 +76,7 @@ public:
     bool reload(QString *errorString, ReloadFlag flag, ChangeType type) override;
     OpenResult open(QString *errorString, const QString &fileName,
                     const QString &realFileName) override;
+    bool isReloading() const { return m_isReloading; }
 
     QString plainText() const;
 
@@ -101,6 +102,7 @@ private:
     int m_contextLineCount;
     bool m_isContextLineCountForced;
     bool m_ignoreWhitespace;
+    bool m_isReloading = false;
 
     friend class ::DiffEditor::DiffEditorController;
 };

src/plugins/diffeditor/diffeditorwidgetcontroller.cpp

@@ -38,6 +38,7 @@
 
 #include <cpaster/codepasterservice.h>
 
+#include <utils/progressindicator.h>
 #include <utils/qtcassert.h>
 
 #include <QDir>
@@ -56,11 +57,64 @@ DiffEditorWidgetController::DiffEditorWidgetController(QWidget *diffEditorWidget
     : QObject(diffEditorWidget)
     , m_diffEditorWidget(diffEditorWidget)
 {
+    m_timer.setSingleShot(true);
+    m_timer.setInterval(100);
+    connect(&m_timer, &QTimer::timeout, this, &DiffEditorWidgetController::showProgress);
 }
 
 void DiffEditorWidgetController::setDocument(DiffEditorDocument *document)
 {
+    if (!m_progressIndicator) {
+        m_progressIndicator = new Utils::ProgressIndicator(Utils::ProgressIndicator::Large);
+        m_progressIndicator->attachToWidget(m_diffEditorWidget);
+        m_progressIndicator->hide();
+    }
+
+    if (m_document == document)
+        return;
+
+    if (m_document) {
+        disconnect(m_document, &IDocument::aboutToReload, this, &DiffEditorWidgetController::scheduleShowProgress);
+        disconnect(m_document, &IDocument::reloadFinished, this, &DiffEditorWidgetController::hideProgress);
+    }
+
+    const bool wasRunning = m_document && m_document->isReloading();
+
     m_document = document;
+
+    if (m_document) {
+        connect(m_document, &IDocument::aboutToReload, this, &DiffEditorWidgetController::scheduleShowProgress);
+        connect(m_document, &IDocument::reloadFinished, this, &DiffEditorWidgetController::hideProgress);
+    }
+
+    const bool isRunning = m_document && m_document->isReloading();
+
+    if (wasRunning == isRunning)
+        return;
+
+    if (isRunning)
+        scheduleShowProgress();
+    else
+        hideProgress();
+}
+
+void DiffEditorWidgetController::scheduleShowProgress()
+{
+    m_timer.start();
+}
+
+void DiffEditorWidgetController::showProgress()
+{
+    m_timer.stop();
+    if (m_progressIndicator)
+        m_progressIndicator->show();
+}
+
+void DiffEditorWidgetController::hideProgress()
+{
+    m_timer.stop();
+    if (m_progressIndicator)
+        m_progressIndicator->hide();
 }
 
 void DiffEditorWidgetController::patch(bool revert)

src/plugins/diffeditor/diffeditorwidgetcontroller.h

@@ -29,11 +29,13 @@
 
 #include <QObject>
 #include <QTextCharFormat>
+#include <QTimer>
 
 QT_FORWARD_DECLARE_CLASS(QMenu)
 
 namespace Core { class IDocument; }
 namespace TextEditor { class FontSettings; }
+namespace Utils { class ProgressIndicator; }
 
 namespace DiffEditor {
 
@@ -74,12 +76,19 @@ private:
     bool setAndVerifyIndexes(QMenu *menu, int diffFileIndex, int chunkIndex);
     bool fileNamesAreDifferent() const;
 
+    void scheduleShowProgress();
+    void showProgress();
+    void hideProgress();
+
     QWidget *m_diffEditorWidget;
 
     DiffEditorDocument *m_document = nullptr;
 
     int m_contextMenuFileIndex = -1;
     int m_contextMenuChunkIndex = -1;
+
+    Utils::ProgressIndicator *m_progressIndicator = nullptr;
+    QTimer m_timer;
 };
 
 } // namespace Internal