From d3f1ab78138a1f9256ec02842799ed6cd1e3ec1e Mon Sep 17 00:00:00 2001
From: Peng Wu <pwu@redhat.com>
Date: Thu, 1 Feb 2018 18:52:16 -0500
Subject: [PATCH] xtext: Always use Pango to get correct glyph width on Unix

This should be slower but pango seems to be reasonably fast
on Unix though extremely slow on Windows.

https://bugzilla.redhat.com/show_bug.cgi?id=1536298
---
 src/fe-gtk/xtext.c | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/src/fe-gtk/xtext.c b/src/fe-gtk/xtext.c
index fef00c51..203bcd60 100644
--- a/src/fe-gtk/xtext.c
+++ b/src/fe-gtk/xtext.c
@@ -157,7 +157,10 @@ static char * gtk_xtext_get_word (GtkXText * xtext, int x, int y, textentry ** r
 #define EMPH_BOLD 2
 #define EMPH_HIDDEN 4
 static PangoAttrList *attr_lists[4];
+#ifdef G_OS_WIN32
+/* the fontwidths variable is used on Windows only. */
 static int fontwidths[4][128];
+#endif
 
 static PangoAttribute *
 xtext_pango_attr (PangoAttribute *attr)
@@ -170,7 +173,10 @@ xtext_pango_attr (PangoAttribute *attr)
 static void
 xtext_pango_init (GtkXText *xtext)
 {
-	int i, j;
+	int i;
+#ifdef G_OS_WIN32
+	int j;
+#endif
 	char buf[2] = "\000";
 
 	if (attr_lists[0])
@@ -202,6 +208,7 @@ xtext_pango_init (GtkXText *xtext)
 			break;
 		}
 
+#ifdef G_OS_WIN32
 		/* Now initialize fontwidths[i] */
 		pango_layout_set_attributes (xtext->layout, attr_lists[i]);
 		for (j = 0; j < 128; j++)
@@ -210,8 +217,14 @@ xtext_pango_init (GtkXText *xtext)
 			pango_layout_set_text (xtext->layout, buf, 1);
 			pango_layout_get_pixel_size (xtext->layout, &fontwidths[i][j], NULL);
 		}
+#endif
 	}
-	xtext->space_width = fontwidths[0][' '];
+
+	/* re-compute space_width without using fontwidths */
+	pango_layout_set_attributes (xtext->layout, attr_lists[0]);
+	buf[0] = ' ';
+	pango_layout_set_text (xtext->layout, buf, 1);
+	pango_layout_get_pixel_size (xtext->layout, &(xtext->space_width), NULL);
 }
 
 static void
@@ -289,8 +302,10 @@ static int
 backend_get_text_width_emph (GtkXText *xtext, guchar *str, int len, int emphasis)
 {
 	int width;
+#ifdef G_OS_WIN32
 	int deltaw;
 	int mbl;
+#endif
 
 	if (*str == 0)
 		return 0;
@@ -301,6 +316,8 @@ backend_get_text_width_emph (GtkXText *xtext, guchar *str, int len, int emphasis
 
 	width = 0;
 	pango_layout_set_attributes (xtext->layout, attr_lists[emphasis]);
+
+#ifdef G_OS_WIN32
 	while (len > 0)
 	{
 		mbl = charlen(str);
@@ -315,6 +332,12 @@ backend_get_text_width_emph (GtkXText *xtext, guchar *str, int len, int emphasis
 		str += mbl;
 		len -= mbl;
 	}
+#else
+	/* This code is slow on Windows,
+	   but it will get the correct width from pango on Linux. */
+	pango_layout_set_text (xtext->layout, str, len);
+	pango_layout_get_pixel_size (xtext->layout, &width, NULL);
+#endif
 
 	return width;
 }