logic: background indexing (issue #175)

* allow hiding of indexing dialogs to browse loaded project while indexing
* show indexing status in status bar while indexing
* use different dialog views for different use cases to avoid state collisions
* fixed error label in status bar jittering while indexing
* show hand cursors for clickable elements in status bar
* indexing is not interrupted on pressing ESC while in hidden
* disable error table and error label while indexing
* refactored indexing messages
* forbid indexing and changing project while indexing
* don't show indexing status messages in status bar when indexing in the background
* allow tasks to run in the background

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src/lib_gui/qt/view/QtStatusBarView.cpp

@@ -15,10 +15,6 @@ QtStatusBarView::QtStatusBarView(ViewLayout* viewLayout)
 	mw->setStatusBar(sb);
 }
 
-QtStatusBarView::~QtStatusBarView()
-{
-}
-
 void QtStatusBarView::createWidgetWrapper()
 {
 }
@@ -60,3 +56,23 @@ void QtStatusBarView::showIdeStatus(const std::wstring& message)
 		}
 	);
 }
+
+void QtStatusBarView::showIndexingProgress(bool unknownProgress, size_t progressPercent)
+{
+	m_onQtThread(
+		[=]()
+		{
+			m_widget->showIndexingProgress(unknownProgress, progressPercent);
+		}
+	);
+}
+
+void QtStatusBarView::hideIndexingProgress()
+{
+	m_onQtThread(
+		[=]()
+		{
+			m_widget->hideIndexingProgress();
+		}
+	);
+}