status: optimize filtering when chars are being taken from input queue

src/actions.cpp

@@ -1879,15 +1879,16 @@ void ApplyFilter::Run()
 	using Global::wFooter;
 	
 	Filterable *f = dynamic_cast<Filterable *>(myScreen);
+	std::string filter = f->currentFilter();
 	
 	LockStatusbar();
 	Statusbar() << NC::fmtBold << "Apply filter: " << NC::fmtBoldEnd;
-	wFooter->setGetStringHelper(std::bind(StatusbarApplyFilterImmediately, f, _1));
-	wFooter->getString(f->currentFilter());
+	wFooter->setGetStringHelper(StatusbarApplyFilterImmediately(f, ToWString(filter)));
+	wFooter->getString(filter);
 	wFooter->setGetStringHelper(StatusbargetStringHelper);
 	UnlockStatusbar();
 	
-	std::string filter = f->currentFilter();
+	filter = f->currentFilter();
  	if (filter.empty())
 	{
 		myPlaylist->Items->clearFilterResults();

src/status.cpp

@@ -78,16 +78,23 @@ void StatusbargetStringHelper(const std::wstring &)
 	TraceMpdStatus();
 }
 
-void StatusbarApplyFilterImmediately(Filterable *f, const std::wstring &ws)
+void StatusbarApplyFilterImmediately::operator()(const std::wstring &ws)
 {
-	static std::wstring cmp;
-	if (cmp != ws)
+	// if input queue is not empty, we don't want to update filter since next
+	// character will be taken from queue immediately, trigering this function
+	// again and thus making it inefficient, so let's apply filter only if
+	// "real" user input arrived. however, we want to apply filter if ENTER
+	// is next in queue, so its effects will be seen.
+	if (wFooter->inputQueue().empty() || wFooter->inputQueue().front() == KEY_ENTER)
 	{
-		cmp = ws;
-		f->applyFilter(ToString(cmp));
-		myScreen->RefreshWindow();
+		if (m_ws != ws)
+		{
+			m_ws = ws;
+			m_f->applyFilter(ToString(m_ws));
+			myScreen->RefreshWindow();
+		}
+		TraceMpdStatus();
 	}
-	TraceMpdStatus();
 }
 
 void LockProgressbar()

src/status.h

@@ -46,7 +46,18 @@ void ShowMessage(const char *, ...) GNUC_PRINTF(1, 2);
 
 void StatusbarMPDCallback();
 void StatusbargetStringHelper(const std::wstring &);
-void StatusbarApplyFilterImmediately(Filterable *f, const std::wstring &ws);
+
+struct StatusbarApplyFilterImmediately
+{
+	StatusbarApplyFilterImmediately(Filterable *f, const std::wstring &filter)
+	: m_f(f), m_ws(filter) { }
+	
+	void operator()(const std::wstring &ws);
+	
+private:
+	Filterable *m_f;
+	std::wstring m_ws;
+};
 
 #endif
 

src/utility/string.cpp

@@ -174,6 +174,8 @@ std::string getEnclosedString(const std::string &s, char a, char b, size_t *pos)
 		// we want to set pos to char after b if possible
 		if (i < s.length())
 			++i;
+		else // we reached end of string and didn't encounter closing char
+			result.clear();
 	}
 	if (pos != 0)
 		*pos = i;

src/window.h

@@ -340,6 +340,9 @@ struct Window
 	/// Push single character into input queue, so it can get consumed by ReadKey
 	void pushChar(int ch);
 	
+	/// @return const reference to internal input queue
+	const std::queue<int> &inputQueue() { return m_input_queue; }
+	
 	/// Scrolls the window by amount of lines given in its parameter
 	/// @param where indicates how many lines it has to scroll
 	virtual void scroll(Where where);