DiffEditor: Share "failed" state among multiple views

Change-Id: Id049ce8eafcb21d5e60fae17c47df8657c0e5779
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/diffeditor/diffeditordocument.h

@@ -46,6 +46,12 @@ public:
 
     DiffEditorController *controller() const;
 
+    enum State {
+        LoadOK,
+        Reloading,
+        LoadFailed
+    };
+
     QString makePatch(int fileIndex, int chunkIndex,
                       bool revert, bool addPrefix = false,
                       const QString &overriddenFileName = QString()) const;
@@ -76,7 +82,7 @@ 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; }
+    State state() const { return m_state; }
     void beginReload();
     void endReload(bool success);
 
@@ -100,7 +106,7 @@ private:
     int m_contextLineCount;
     bool m_isContextLineCountForced;
     bool m_ignoreWhitespace;
-    bool m_isReloading = false;
+    State m_state = LoadOK;
 
     friend class ::DiffEditor::DiffEditorController;
 };