From 69b6d27087895ddab63fd4d623bc6636adb79722 Mon Sep 17 00:00:00 2001
From: LordRusk <lordruskk@gmail.com>
Date: Thu, 26 Mar 2020 00:43:14 +0000
Subject: [PATCH] AlphaFocusHighlight patch instead of Alpha patch

---
 config.h |  3 ++-
 st.h     |  1 +
 x.c      | 44 ++++++++++++++++++++++++++++++--------------
 3 files changed, 33 insertions(+), 15 deletions(-)

diff --git a/config.h b/config.h
index 81804d5..3c87f46 100644
--- a/config.h
+++ b/config.h
@@ -91,7 +91,8 @@ char *termname = "st-256color";
 unsigned int tabspaces = 8;
 
 /* bg opacity */
-float alpha = 0.92;
+float alpha = 0.92;		//< alpha value used when the window is focused.
+float alphaUnfocussed = 0.8;	//< alpha value used when the focus is lost
 
 /* Terminal colors (16 first used in escape sequence) */
 static const char *colorname[] = {
diff --git a/st.h b/st.h
index 4504a30..3a06279 100644
--- a/st.h
+++ b/st.h
@@ -132,5 +132,6 @@ extern unsigned int tabspaces;
 extern unsigned int defaultfg;
 extern unsigned int defaultbg;
 extern float alpha;
+extern float alphaUnfocussed;
 extern MouseKey mkeys[];
 extern int ximspot_update_interval;
diff --git a/x.c b/x.c
index c09392b..de2d68f 100644
--- a/x.c
+++ b/x.c
@@ -4,6 +4,7 @@
 #include <limits.h>
 #include <locale.h>
 #include <signal.h>
+#include <stdbool.h>
 #include <sys/select.h>
 #include <time.h>
 #include <unistd.h>
@@ -261,6 +262,7 @@ static char *opt_io    = NULL;
 static char *opt_line  = NULL;
 static char *opt_name  = NULL;
 static char *opt_title = NULL;
+static bool focused = true;
 
 static int oldbutton = 3; /* button event on startup: 3 = release */
 
@@ -765,6 +767,20 @@ xloadcolor(int i, const char *name, Color *ncolor)
 	return XftColorAllocName(xw.dpy, xw.vis, xw.cmap, name, ncolor);
 }
 
+void
+xloadalpha(void)
+{
+    /* set alpha value of bg color */
+    if (opt_alpha)
+        alpha = strtof(opt_alpha, NULL);
+
+    float const usedAlpha = focused ? alpha : alphaUnfocussed;
+
+    dc.col[defaultbg].color.alpha = (unsigned short)(0xffff * usedAlpha);
+    dc.col[defaultbg].pixel &= 0x00FFFFFF;
+    dc.col[defaultbg].pixel |= (unsigned char)(0xff * usedAlpha) << 24;
+}
+
 void
 xloadcols(void)
 {
@@ -788,19 +804,9 @@ xloadcols(void)
 				die("could not allocate color %d\n", i);
 		}
 
-	/* set alpha value of bg color */
-	if (opt_alpha)
-		alpha = strtof(opt_alpha, NULL);
-	dc.col[defaultbg].color.alpha = (unsigned short)(0xffff * alpha);
-	dc.col[defaultbg].color.red =
-		((unsigned short)(dc.col[defaultbg].color.red * alpha)) & 0xff00;
-	dc.col[defaultbg].color.green =
-		((unsigned short)(dc.col[defaultbg].color.green * alpha)) & 0xff00;
-	dc.col[defaultbg].color.blue =
-		((unsigned short)(dc.col[defaultbg].color.blue * alpha)) & 0xff00;
-	dc.col[defaultbg].pixel &= 0x00FFFFFF;
-	dc.col[defaultbg].pixel |= (unsigned char)(0xff * alpha) << 24;
-	loaded = 1;
+	xloadalpha();
+ 	loaded = 1;
+
 }
 
 int
@@ -1812,13 +1818,23 @@ focus(XEvent *ev)
 		XSetICFocus(xw.xic);
 		win.mode |= MODE_FOCUSED;
 		xseturgency(0);
-		if (IS_SET(MODE_FOCUS))
 			ttywrite("\033[I", 3, 0);
+		if (!focused) {
+			focused = true;
+			xloadalpha();
+			redraw();
+		}
 	} else {
 		XUnsetICFocus(xw.xic);
 		win.mode &= ~MODE_FOCUSED;
 		if (IS_SET(MODE_FOCUS))
 			ttywrite("\033[O", 3, 0);
+		if (focused) {
+			focused = false;
+			xloadalpha();
+			redraw();
+		}
+
 	}
 }