From 5787ca4ae0f04acf96195ef3e5f1749a4497bb84 Mon Sep 17 00:00:00 2001
From: Thomas Goyne <plorkyeran@aegisub.org>
Date: Mon, 16 Sep 2013 10:43:21 -0700
Subject: [PATCH] Cache widths of strings in SetColumnWidths

---
 aegisub/src/base_grid.cpp | 45 ++++++++++++++++++++++++++++-----------
 1 file changed, 32 insertions(+), 13 deletions(-)

diff --git a/aegisub/src/base_grid.cpp b/aegisub/src/base_grid.cpp
index 0f903cc95..7d6a40909 100644
--- a/aegisub/src/base_grid.cpp
+++ b/aegisub/src/base_grid.cpp
@@ -34,16 +34,6 @@
 
 #include "config.h"
 
-#include <algorithm>
-#include <cmath>
-#include <iterator>
-#include <numeric>
-
-#include <wx/dcbuffer.h>
-#include <wx/kbdstate.h>
-#include <wx/menu.h>
-#include <wx/sizer.h>
-
 #include "base_grid.h"
 
 #include "include/aegisub/context.h"
@@ -64,6 +54,17 @@
 
 #include <libaegisub/of_type_adaptor.h>
 
+#include <algorithm>
+#include <cmath>
+#include <iterator>
+#include <numeric>
+#include <unordered_map>
+
+#include <wx/dcbuffer.h>
+#include <wx/kbdstate.h>
+#include <wx/menu.h>
+#include <wx/sizer.h>
+
 enum {
 	GRID_SCROLLBAR = 1730,
 	MENU_SHOW_COL = 1250 // Needs 15 IDs after this
@@ -86,6 +87,15 @@ static inline void set_difference(const S1 &src1, const S2 &src2, D &dst) {
 		std::inserter(dst, dst.begin()));
 }
 
+namespace std {
+	template <typename T>
+	struct hash<boost::flyweight<T>> {
+		size_t operator()(boost::flyweight<T> const& ss) const {
+			return hash<const void*>()(&ss.get());
+		}
+	};
+}
+
 BaseGrid::BaseGrid(wxWindow* parent, agi::Context *context, const wxSize& size, long style, const wxString& name)
 : wxWindow(parent, -1, wxDefaultPosition, size, style, name)
 , lineHeight(1) // non-zero to avoid div by 0
@@ -837,6 +847,15 @@ void BaseGrid::SetColumnWidths() {
 	if (!byFrame)
 		startLen = endLen = dc.GetTextExtent(to_wx(AssTime().GetAssFormated())).GetWidth();
 
+	std::unordered_map<boost::flyweight<std::string>, int> widths;
+	auto get_width = [&](boost::flyweight<std::string> const& str) -> int {
+		auto it = widths.find(str);
+		if (it != end(widths)) return it->second;
+		int width = dc.GetTextExtent(to_wx(str)).GetWidth();
+		widths[str] = width;
+		return width;
+	};
+
 	// O(n) widths
 	bool showMargin[3] = { false, false, false };
 	int styleLen = 0;
@@ -849,9 +868,9 @@ void BaseGrid::SetColumnWidths() {
 		AssDialogue *curDiag = GetDialogue(i);
 
 		maxLayer = std::max(maxLayer, curDiag->Layer);
-		actorLen = std::max(actorLen, dc.GetTextExtent(to_wx(curDiag->Actor)).GetWidth());
-		styleLen = std::max(styleLen, dc.GetTextExtent(to_wx(curDiag->Style)).GetWidth());
-		effectLen = std::max(effectLen, dc.GetTextExtent(to_wx(curDiag->Effect)).GetWidth());
+		actorLen = std::max(actorLen, get_width(curDiag->Actor));
+		styleLen = std::max(styleLen, get_width(curDiag->Style));
+		effectLen = std::max(effectLen, get_width(curDiag->Effect));
 
 		// Margins
 		for (int j = 0; j < 3; j++) {