patch: alpha

Allow dwm to have translucent bars, while keeping all the text on it
opaque, just like the alpha patch for st.

By default dwm might make windows' borders transparent when using
composit window manager (e.g. xcompmgr, picom).  Alpha patch allows to
make borders opaque.  If all you want is to make borders opaque, you
don't care about statusbar opacity and/or have problems applying alpha
patch, then you might use fixborders patch instead.

1 files changed, 54 insertions, 6 deletions

diff --git a/dwm.c b/dwm.c
index 53b393e..fb6153c 100644
--- a/dwm.c
+++ b/dwm.c
@@ -56,6 +56,8 @@
 #define TAGMASK                 ((1 << LENGTH(tags)) - 1)
 #define TEXTW(X)                (drw_fontset_getwidth(drw, (X)) + lrpad)
 
+#define OPAQUE                  0xffU
+
 /* enums */
 enum { CurNormal, CurResize, CurMove, CurLast }; /* cursor */
 enum { SchemeNorm, SchemeSel }; /* color schemes */
@@ -231,6 +233,7 @@ static Monitor *wintomon(Window w);
 static int xerror(Display *dpy, XErrorEvent *ee);
 static int xerrordummy(Display *dpy, XErrorEvent *ee);
 static int xerrorstart(Display *dpy, XErrorEvent *ee);
+static void xinitvisual(void);
 static void zoom(const Arg *arg);
 
 /* variables */
@@ -266,6 +269,10 @@ static Display *dpy;
 static Drw *drw;
 static Monitor *mons, *selmon;
 static Window root, wmcheckwin;
+static int useargb = 0;
+static Visual *visual;
+static int depth;
+static Colormap cmap;
 
 /* configuration, allows nested code to access above variables */
 #include "config.h"
@@ -1558,7 +1565,8 @@ setup(void)
 	sw = DisplayWidth(dpy, screen);
 	sh = DisplayHeight(dpy, screen);
 	root = RootWindow(dpy, screen);
-	drw = drw_create(dpy, screen, root, sw, sh);
+	xinitvisual();
+	drw = drw_create(dpy, screen, root, sw, sh, visual, depth, cmap);
 	if (!drw_fontset_create(drw, fonts, LENGTH(fonts)))
 		die("no fonts could be loaded.");
 	lrpad = drw->fonts->h;
@@ -1585,8 +1593,9 @@ setup(void)
 	cursor[CurMove] = drw_cur_create(drw, XC_fleur);
 	/* init appearance */
 	scheme = ecalloc(LENGTH(colors), sizeof(Clr *));
+	unsigned int alphas[] = {borderalpha, baralpha, OPAQUE};
 	for (i = 0; i < LENGTH(colors); i++)
-		scheme[i] = drw_scm_create(drw, colors[i], 3);
+		scheme[i] = drw_scm_create(drw, colors[i], alphas, 3);
 	/* init bars */
 	updatebars();
 	updatestatus();
@@ -1821,16 +1830,18 @@ updatebars(void)
 	Monitor *m;
 	XSetWindowAttributes wa = {
 		.override_redirect = True,
-		.background_pixmap = ParentRelative,
+		.background_pixel = 0,
+		.border_pixel = 0,
+		.colormap = cmap,
 		.event_mask = ButtonPressMask|ExposureMask
 	};
 	XClassHint ch = {"dwm", "dwm"};
 	for (m = mons; m; m = m->next) {
 		if (m->barwin)
 			continue;
-		m->barwin = XCreateWindow(dpy, root, m->wx, m->by, m->ww, bh, 0, DefaultDepth(dpy, screen),
-				CopyFromParent, DefaultVisual(dpy, screen),
-				CWOverrideRedirect|CWBackPixmap|CWEventMask, &wa);
+		m->barwin = XCreateWindow(dpy, root, m->wx, m->by, m->ww, bh, 0, depth,
+				InputOutput, visual,
+				CWOverrideRedirect|CWBackPixel|CWBorderPixel|CWColormap|CWEventMask, &wa);
 		XDefineCursor(dpy, m->barwin, cursor[CurNormal]->cursor);
 		XMapRaised(dpy, m->barwin);
 		XSetClassHint(dpy, m->barwin, &ch);
@@ -2129,6 +2140,43 @@ xerrorstart(Display *dpy, XErrorEvent *ee)
 }
 
 void
+xinitvisual(void)
+{
+	XVisualInfo *infos;
+	XRenderPictFormat *fmt;
+	int nitems;
+	int i;
+
+	XVisualInfo tpl = {
+		.screen = screen,
+		.depth = 32,
+		.class = TrueColor
+	};
+	long masks = VisualScreenMask | VisualDepthMask | VisualClassMask;
+
+	infos = XGetVisualInfo(dpy, masks, &tpl, &nitems);
+	visual = NULL;
+	for(i = 0; i < nitems; i++) {
+		fmt = XRenderFindVisualFormat(dpy, infos[i].visual);
+		if (fmt->type == PictTypeDirect && fmt->direct.alphaMask) {
+			visual = infos[i].visual;
+			depth = infos[i].depth;
+			cmap = XCreateColormap(dpy, root, visual, AllocNone);
+			useargb = 1;
+			break;
+		}
+	}
+
+	XFree(infos);
+
+	if (!visual) {
+		visual = DefaultVisual(dpy, screen);
+		depth = DefaultDepth(dpy, screen);
+		cmap = DefaultColormap(dpy, screen);
+	}
+}
+
+void
 zoom(const Arg *arg)
 {
 	Client *c = selmon->sel;