feat: implement window opacity control with inc/dec/toggle support ✨

config.conf

@@ -178,6 +178,12 @@ bind=SUPER,o,toggleoverlay,
 bind=SUPER+SHIFT,I,restore_minimized
 bind=ALT,z,toggle_scratchpad
 
+# window opacity control
+bind=SUPER,equal,inc_opacity,0.1
+bind=SUPER,minus,dec_opacity,0.1
+bind=SUPER+SHIFT,o,toggle_opacity,
+bind=SUPER+SHIFT,c,clear_custom_opacity,
+
 # scroller layout
 bind=ALT,e,set_proportion,1.0
 bind=ALT,x,switch_proportion_preset,

src/animation/client.h

@@ -1044,10 +1044,17 @@ void client_set_focused_opacity_animation(Client *c) {
 		return;
 	}
 
+	float opacity =
+		c == selmon->sel ? c->focused_opacity : c->unfocused_opacity;
+
+	if (c->custom_opacity > 0.0f) {
+		opacity = c->custom_opacity;
+	}
+
 	c->opacity_animation.duration = animation_duration_focus;
 	memcpy(c->opacity_animation.target_border_color, border_color,
 		   sizeof(c->opacity_animation.target_border_color));
-	c->opacity_animation.target_opacity = c->focused_opacity;
+	c->opacity_animation.target_opacity = opacity;
 	c->opacity_animation.time_started = get_now_in_ms();
 	if (c->opacity_animation.running) {
 		memcpy(c->opacity_animation.initial_border_color,
@@ -1070,6 +1077,13 @@ void client_set_unfocused_opacity_animation(Client *c) {
 	// Start border color animation to unfocused
 	float *border_color = get_border_color(c);
 
+	float opacity =
+		c == selmon->sel ? c->focused_opacity : c->unfocused_opacity;
+
+	if (c->custom_opacity > 0.0f) {
+		opacity = c->custom_opacity;
+	}
+
 	if (!animations) {
 		setborder_color(c);
 		return;
@@ -1079,7 +1093,7 @@ void client_set_unfocused_opacity_animation(Client *c) {
 	memcpy(c->opacity_animation.target_border_color, border_color,
 		   sizeof(c->opacity_animation.target_border_color));
 	// Start opacity animation to unfocused
-	c->opacity_animation.target_opacity = c->unfocused_opacity;
+	c->opacity_animation.target_opacity = opacity;
 	c->opacity_animation.time_started = get_now_in_ms();
 
 	if (c->opacity_animation.running) {
@@ -1103,6 +1117,13 @@ void client_set_unfocused_opacity_animation(Client *c) {
 bool client_apply_focus_opacity(Client *c) {
 	// Animate focus transitions (opacity + border color)
 	float *border_color = get_border_color(c);
+	float opacity =
+		c == selmon->sel ? c->focused_opacity : c->unfocused_opacity;
+
+	if (c->custom_opacity > 0.0f) {
+		opacity = c->custom_opacity;
+	}
+
 	if (c->isfullscreen) {
 		c->opacity_animation.running = false;
 		client_set_opacity(c, 1);
@@ -1122,8 +1143,6 @@ bool client_apply_focus_opacity(Client *c) {
 
 		float percent =
 			animation_fade_in && !c->nofadein ? opacity_eased_progress : 1.0;
-		float opacity =
-			c == selmon->sel ? c->focused_opacity : c->unfocused_opacity;
 
 		float target_opacity =
 			percent * (1.0 - fadein_begin_opacity) + fadein_begin_opacity;
@@ -1168,16 +1187,16 @@ bool client_apply_focus_opacity(Client *c) {
 		}
 	} else if (c == selmon->sel) {
 		c->opacity_animation.running = false;
-		c->opacity_animation.current_opacity = c->focused_opacity;
+		c->opacity_animation.current_opacity = opacity;
 		memcpy(c->opacity_animation.current_border_color, border_color,
 			   sizeof(c->opacity_animation.current_border_color));
-		client_set_opacity(c, c->focused_opacity);
+		client_set_opacity(c, opacity);
 	} else {
 		c->opacity_animation.running = false;
-		c->opacity_animation.current_opacity = c->unfocused_opacity;
+		c->opacity_animation.current_opacity = opacity;
 		memcpy(c->opacity_animation.current_border_color, border_color,
 			   sizeof(c->opacity_animation.current_border_color));
-		client_set_opacity(c, c->unfocused_opacity);
+		client_set_opacity(c, opacity);
 	}
 
 	return false;

src/config/parse_config.h

@@ -1083,6 +1083,16 @@ FuncType parse_func_name(char *func_name, Arg *arg, char *arg_value,
 	} else if (strcmp(func_name, "scroller_stack") == 0) {
 		func = scroller_stack;
 		(*arg).i = parse_direction(arg_value);
+	} else if (strcmp(func_name, "toggle_opacity") == 0) {
+		func = toggle_opacity;
+	} else if (strcmp(func_name, "inc_opacity") == 0) {
+		(*arg).f = atof(arg_value);
+		func = inc_opacity;
+	} else if (strcmp(func_name, "dec_opacity") == 0) {
+		(*arg).f = atof(arg_value);
+		func = dec_opacity;
+	} else if (strcmp(func_name, "clear_custom_opacity") == 0) {
+		func = clear_custom_opacity;
 	} else {
 		return NULL;
 	}

src/dispatch/bind_declare.h

@@ -69,4 +69,8 @@ int32_t setoption(const Arg *arg);
 int32_t disable_monitor(const Arg *arg);
 int32_t enable_monitor(const Arg *arg);
 int32_t toggle_monitor(const Arg *arg);
-int32_t scroller_stack(const Arg *arg);
+int32_t scroller_stack(const Arg *arg);
+int32_t toggle_opacity(const Arg *arg);
+int32_t inc_opacity(const Arg *arg);
+int32_t dec_opacity(const Arg *arg);
+int32_t clear_custom_opacity(const Arg *arg);

src/dispatch/bind_define.h

@@ -1672,4 +1672,64 @@ int32_t scroller_stack(const Arg *arg) {
 
 	arrange(selmon, false, false);
 	return 0;
-}
+}
+
+int32_t toggle_opacity(const Arg *arg) {
+	Client *c = selmon->sel;
+	if (!c)
+		return 0;
+
+	if (c->custom_opacity > 0.0f) {
+		c->custom_opacity = 0.0f;
+		client_set_opacity(c, c->focused_opacity);
+	} else {
+		c->custom_opacity = 1.0f;
+		client_set_opacity(c, 1.0f);
+	}
+	return 0;
+}
+
+int32_t inc_opacity(const Arg *arg) {
+	Client *c = selmon->sel;
+	if (!c)
+		return 0;
+
+	float value = CLAMP_FLOAT(arg->f, 0.01f, 1.0f);
+
+	if (c->custom_opacity == 0.0f) {
+		c->custom_opacity = c->focused_opacity;
+	}
+
+	float target = MIN(c->custom_opacity + value, 1.0f);
+	c->custom_opacity = target;
+	client_set_opacity(c, target);
+	return 0;
+}
+
+int32_t dec_opacity(const Arg *arg) {
+	Client *c = selmon->sel;
+
+	if (!c)
+		return 0;
+
+	float value = CLAMP_FLOAT(arg->f, 0.01f, 1.0f);
+
+	if (c->custom_opacity == 0.0f) {
+		c->custom_opacity = c->focused_opacity;
+	}
+
+	float target = MAX(c->custom_opacity - value, 0.01f);
+	c->custom_opacity = target;
+	client_set_opacity(c, target);
+	return 0;
+}
+
+int32_t clear_custom_opacity(const Arg *arg) {
+	Client *c = selmon->sel;
+	if (!c)
+		return 0;
+
+	c->custom_opacity = 0.0f;
+	client_set_opacity(c, c->focused_opacity);
+	return 0;
+}

src/mango.c

@@ -401,6 +401,7 @@ struct Client {
 	int32_t isunglobal;
 	float focused_opacity;
 	float unfocused_opacity;
+	float custom_opacity;
 	char oldmonname[128];
 	int32_t noblur;
 	double master_mfact_per, master_inner_per, stack_inner_per;
@@ -3741,6 +3742,7 @@ void init_client_properties(Client *c) {
 	c->fake_no_border = false;
 	c->focused_opacity = focused_opacity;
 	c->unfocused_opacity = unfocused_opacity;
+	c->custom_opacity = 0.0f;
 	c->nofocus = 0;
 	c->nofadein = 0;
 	c->nofadeout = 0;