Don't update the editbox styling when it hasn't changed

The syntax highlighting isn't especially slow, but the stylesneeded
event seems to be sent repeatedly until the styles aren't changed, so it
was pointlessly reparsing and restyling the text on every idle event.

aegisub/src/subs_edit_ctrl.cpp

@@ -118,9 +118,9 @@ SubsTextEditCtrl::SubsTextEditCtrl(wxWindow* parent, wxSize wsize, long style, a
 		Bind(wxEVT_COMMAND_MENU_SELECTED, bind(&cmd::call, "edit/line/split/estimate", context), EDIT_MENU_SPLIT_ESTIMATE);
 	}
 
-	Bind(wxEVT_STC_STYLENEEDED, &SubsTextEditCtrl::UpdateCallTip, this);
+	Bind(wxEVT_STC_STYLENEEDED, std::bind(&SubsTextEditCtrl::UpdateStyle, this));
-
 	Bind(wxEVT_CONTEXT_MENU, &SubsTextEditCtrl::OnContextMenu, this);
+	Bind(wxEVT_IDLE, std::bind(&SubsTextEditCtrl::UpdateCallTip, this));
 
 	OPT_SUB("Subtitle/Edit Box/Font Face", &SubsTextEditCtrl::SetStyles, this);
 	OPT_SUB("Subtitle/Edit Box/Font Size", &SubsTextEditCtrl::SetStyles, this);
@@ -137,8 +137,7 @@ SubsTextEditCtrl::SubsTextEditCtrl(wxWindow* parent, wxSize wsize, long style, a
 	Subscribe("Karaoke Variable");
 
 	OPT_SUB("Subtitle/Highlight/Syntax", &SubsTextEditCtrl::UpdateStyle, this);
-	static wxStyledTextEvent evt;
+	OPT_SUB("App/Call Tips", &SubsTextEditCtrl::UpdateCallTip, this);
-	OPT_SUB("App/Call Tips", &SubsTextEditCtrl::UpdateCallTip, this, std::ref(evt));
 }
 
 SubsTextEditCtrl::~SubsTextEditCtrl() {
@@ -208,39 +207,43 @@ void SubsTextEditCtrl::SetStyles() {
 }
 
 void SubsTextEditCtrl::UpdateStyle() {
+	{
+		std::string text = GetTextRaw().data();
+		if (text == line_text) return;
+		line_text = move(text);
+	}
+	tokenized_line = agi::ass::TokenizeDialogueBody(line_text);
+
+	cursor_pos = -1;
+	UpdateCallTip();
+
 	StartStyling(0,255);
 
-	std::string text = GetTextRaw().data();
-
 	if (!OPT_GET("Subtitle/Highlight/Syntax")->GetBool()) {
-		SetStyling(text.size(), 0);
+		SetStyling(line_text.size(), 0);
 		return;
 	}
 
-	if (text.empty()) return;
+	if (line_text.empty()) return;
 
 	AssDialogue *diag = context ? context->selectionController->GetActiveLine() : 0;
 	bool template_line = diag && diag->Comment && diag->Effect.Lower().StartsWith("template");
 
-	auto tokens = agi::ass::TokenizeDialogueBody(text);
+	for (auto const& style_range : agi::ass::SyntaxHighlight(line_text, tokenized_line, template_line, spellchecker.get()))
-	for (auto const& style_range : agi::ass::SyntaxHighlight(text, tokens, template_line, spellchecker.get()))
 		SetStyling(style_range.length, style_range.type);
 }
 
-/// @brief Update call tip
+void SubsTextEditCtrl::UpdateCallTip() {
-void SubsTextEditCtrl::UpdateCallTip(wxStyledTextEvent &) {
-	UpdateStyle();
-
 	if (!OPT_GET("App/Call Tips")->GetBool()) return;
 
+	int pos = GetCurrentPos();
+	if (!pos == cursor_pos) return;
+	cursor_pos = pos;
+
 	if (!calltip_provider)
 		calltip_provider.reset(new agi::CalltipProvider);
 
-	std::string text = GetTextRaw().data();
+	agi::Calltip new_calltip = calltip_provider->GetCalltip(tokenized_line, line_text, pos);
-	auto tokens = agi::ass::TokenizeDialogueBody(text);
-	int pos = GetCurrentPos();
-
-	agi::Calltip new_calltip = calltip_provider->GetCalltip(tokens, text, GetCurrentPos());
 
 	if (new_calltip.text.empty()) {
 		CallTipCancel();
@@ -256,15 +259,15 @@ void SubsTextEditCtrl::UpdateCallTip(wxStyledTextEvent &) {
 	CallTipSetHighlight(new_calltip.highlight_start, new_calltip.highlight_end);
 }
 
-void SubsTextEditCtrl::SetTextTo(wxString text) {
+void SubsTextEditCtrl::SetTextTo(wxString const& text) {
 	SetEvtHandlerEnabled(false);
 	Freeze();
 
 	int from=0,to=0;
 	GetSelection(&from,&to);
 
+	line_text.clear();
 	SetText(text);
-	UpdateStyle();
 
 	// Restore selection
 	SetSelectionU(GetReverseUnicodePosition(from), GetReverseUnicodePosition(to));
@@ -290,7 +293,6 @@ void SubsTextEditCtrl::Paste() {
 	int sel_start = GetUnicodePosition(from + data.size());
 	SetSelectionStart(sel_start);
 	SetSelectionEnd(sel_start);
-	UpdateStyle();
 }
 
 void SubsTextEditCtrl::OnContextMenu(wxContextMenuEvent &event) {

aegisub/src/subs_edit_ctrl.h

@@ -47,6 +47,7 @@ namespace agi {
 	class CalltipProvider;
 	class SpellChecker;
 	struct Context;
+	namespace ass { struct DialogueToken; }
 }
 
 /// @class SubsTextEditCtrl
@@ -82,6 +83,16 @@ class SubsTextEditCtrl : public ScintillaTextCtrl {
 	/// Position of the currently show calltip
 	size_t calltip_position;
 
+	/// Cursor position which the current calltip is for
+	int cursor_pos;
+
+	/// The last seen line text, used to avoid reparsing the line for syntax
+	/// highlighting when possible
+	std::string line_text;
+
+	/// Tokenized version of line_text
+	std::vector<agi::ass::DialogueToken> tokenized_line;
+
 	void OnContextMenu(wxContextMenuEvent &);
 	void OnAddToDictionary(wxCommandEvent &event);
 	void OnUseSuggestion(wxCommandEvent &event);
@@ -94,7 +105,7 @@ class SubsTextEditCtrl : public ScintillaTextCtrl {
 	void Subscribe(std::string const& name);
 
 	void StyleSpellCheck();
-	void UpdateCallTip(wxStyledTextEvent &);
+	void UpdateCallTip();
 	void SetStyles();
 
 	void UpdateStyle();
@@ -115,7 +126,7 @@ public:
 	SubsTextEditCtrl(wxWindow* parent, wxSize size, long style, agi::Context *context);
 	~SubsTextEditCtrl();
 
-	void SetTextTo(wxString text);
+	void SetTextTo(wxString const& text);
 	void Paste();
 
 	DECLARE_EVENT_TABLE()