From c2c9e874fa069bc24df0982505788ae14c3024f3 Mon Sep 17 00:00:00 2001
From: Julius Huelsmann <juliusHuelsmann@gmail.com>
Date: Sat, 6 Jun 2020 13:12:28 +0200
Subject: [PATCH] patch: focus

---
 config.def.h |  5 +++--
 st.h         |  2 +-
 x.c          | 44 ++++++++++++++++++++++++++++++--------------
 3 files changed, 34 insertions(+), 17 deletions(-)

diff --git a/config.def.h b/config.def.h
index b94b23c..577d1f1 100644
--- a/config.def.h
+++ b/config.def.h
@@ -85,7 +85,7 @@ char *termname = "st-256color";
 unsigned int tabspaces = 8;
 
 /* bg opacity */
-float alpha = 0.8;
+float alpha = 0.8, alphaUnfocused = 0.6;
 
 /* Terminal colors (16 first used in escape sequence) */
 static const char *colorname[] = {
@@ -123,9 +123,10 @@ static const char *colorname[] = {
  * foreground, background, cursor, reverse cursor
  */
 unsigned int defaultfg = 7;
-unsigned int defaultbg = 258;
+unsigned int defaultbg = 0;
 static unsigned int defaultcs = 256;
 static unsigned int defaultrcs = 257;
+unsigned int bg = 17, bgUnfocused = 16;
 
 /*
  * Default shape of cursor
diff --git a/st.h b/st.h
index 2c656af..b5f1cf6 100644
--- a/st.h
+++ b/st.h
@@ -122,4 +122,4 @@ extern char *termname;
 extern unsigned int tabspaces;
 extern unsigned int defaultfg;
 extern unsigned int defaultbg;
-extern float alpha;
+extern float alpha, alphaUnfocused;
diff --git a/x.c b/x.c
index 50da23c..a0c3223 100644
--- a/x.c
+++ b/x.c
@@ -254,6 +254,8 @@ static char *opt_line  = NULL;
 static char *opt_name  = NULL;
 static char *opt_title = NULL;
 
+static int focused = 0;
+
 static int oldbutton = 3; /* button event on startup: 3 = release */
 
 void
@@ -774,35 +776,38 @@ xloadcolor(int i, const char *name, Color *ncolor)
 	return XftColorAllocName(xw.dpy, xw.vis, xw.cmap, name, ncolor);
 }
 
+void
+xloadalpha(void)
+{
+	float const usedAlpha = focused ? alpha : alphaUnfocused;
+	if (opt_alpha) alpha = strtof(opt_alpha, NULL);
+	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)
 {
-	int i;
 	static int loaded;
 	Color *cp;
 
-	if (loaded) {
-		for (cp = dc.col; cp < &dc.col[dc.collen]; ++cp)
-			XftColorFree(xw.dpy, xw.vis, xw.cmap, cp);
-	} else {
-		dc.collen = MAX(LEN(colorname), 256);
-		dc.col = xmalloc(dc.collen * sizeof(Color));
+	if (!loaded) {
+		dc.collen = 1 + (defaultbg = MAX(LEN(colorname), 256));
+		dc.col = xmalloc((dc.collen) * sizeof(Color));
 	}
 
-	for (i = 0; i < dc.collen; i++)
+	for (int i = 0; i+1 < dc.collen; ++i)
 		if (!xloadcolor(i, NULL, &dc.col[i])) {
 			if (colorname[i])
 				die("could not allocate color '%s'\n", colorname[i]);
 			else
 				die("could not allocate color %d\n", i);
 		}
+	if (dc.collen) // cannot die, as the color is already loaded.
+		xloadcolor(focused ?bg :bgUnfocused, NULL, &dc.col[defaultbg]);
 
-	/* 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].pixel &= 0x00FFFFFF;
-	dc.col[defaultbg].pixel |= (unsigned char)(0xff * alpha) << 24;
+	xloadalpha();
 	loaded = 1;
 }
 
@@ -1747,12 +1752,22 @@ focus(XEvent *ev)
 		xseturgency(0);
 		if (IS_SET(MODE_FOCUS))
 			ttywrite("\033[I", 3, 0);
+		if (!focused) {
+			focused = 1;
+			xloadcols();
+			redraw();
+		}
 	} else {
 		if (xw.ime.xic)
 			XUnsetICFocus(xw.ime.xic);
 		win.mode &= ~MODE_FOCUSED;
 		if (IS_SET(MODE_FOCUS))
 			ttywrite("\033[O", 3, 0);
+		if (focused) {
+			focused = 0;
+			xloadcols();
+			redraw();
+		}
 	}
 }
 
@@ -2065,6 +2080,7 @@ run:
 	XSetLocaleModifiers("");
 	cols = MAX(cols, 1);
 	rows = MAX(rows, 1);
+	defaultbg = MAX(LEN(colorname), 256);
 	tnew(cols, rows);
 	xinit(cols, rows);
 	xsetenv();
-- 
2.27.0