overlay: add theme settings for colors and border width

adds theme settings like:
snapping.overlay.[region|edge].bg.color: #8080b380
snapping.overlay.[region|edge].border.color: #ffffff,#000000,#ffffff
snapping.overlay.[region|edge].border.width: 1

docs/labwc-theme.5.scd

@@ -208,6 +208,34 @@ elements are not listed here, but are supported.
 	Otherwise, an outlined rectangle is shown instead.
 	If software rendering is used, an outlined rectangle is always shown.
 
+*snapping.preview.region.bg.color*
+	Color of a filled rectangle shown as the preview when a window is snapped to
+	a region. Default is #8080b380.
+
+*snapping.preview.edge.bg.color*
+	Color of a filled rectangle shown as the preview when a window is snapped to
+	an edge. Default is #8080b380.
+
+*snapping.preview.region.border.width*
+	Border width of an outlined rectangle shown as the preview when a window is
+	snapped to a region. Inherits `osd.border.width` if not set.
+
+*snapping.preview.edge.border.width*
+	Border width of an outlined rectangle shown as the preview when a window is
+	snapped to an edge. Inherits `osd.border.width` if not set.
+
+*snapping.preview.region.border.color*
+	Color(s) of an outlined rectangle shown as the preview when a window is
+	snapped to a region. Possible value is a color or up to 3 colors separated
+	by commas (e.g. "#ffffff,#000000,#ffffff"). When multiple colors are
+	specified, a multi-line rectangle with each line having the specified color
+	is drawn. If not set, this inherits the on-screen-display theme
+	("[*osd.bg.color*],[*osd.label.text.color*],[*osd.bg.color*]").
+
+*snapping.preview.edge.border.color*
+	Color(s) of an outlined rectangle shown as the preview when a window is
+	snapped to an edge. See *snapping.preview.region.border.color* for details.
+
 *border.color*
 	Set both *window.active.border.color* and *window.inactive.border.color*.
 	This is obsolete, but supported for backward compatibility as some themes

docs/themerc

@@ -74,3 +74,9 @@ osd.workspace-switcher.boxes.height: 20
 
 snapping.preview.region.fill: yes
 snapping.preview.edge.fill: yes
+snapping.preview.region.bg.color: #8080b380
+snapping.preview.edge.bg.color: #8080b380
+snapping.preview.region.border.width: 1
+snapping.preview.edge.border.width: 1
+snapping.preview.region.border.color: #dddda6,#000000,#dddda6
+snapping.preview.edge.border.color: #dddda6,#000000,#dddda6

include/theme.h

@@ -83,6 +83,14 @@ struct theme {
 	bool snapping_preview_region_fill;
 	bool snapping_preview_edge_fill;
 
+	float snapping_preview_region_bg_color[4];
+	float snapping_preview_edge_bg_color[4];
+
+	int snapping_preview_region_border_width;
+	int snapping_preview_edge_border_width;
+	float snapping_preview_region_border_color[3][4];
+	float snapping_preview_edge_border_color[3][4];
+
 	/* textures */
 	struct lab_data_buffer *button_close_active_unpressed;
 	struct lab_data_buffer *button_maximize_active_unpressed;

src/overlay.c

@@ -6,7 +6,8 @@
 #include "view.h"
 
 static void
-create_overlay_rect(struct seat *seat, struct overlay_rect *rect, int fill)
+create_overlay_rect(struct seat *seat, struct overlay_rect *rect, int fill,
+		float bg_color[4], int border_width, float border_colors[3][4])
 {
 	struct server *server = seat->server;
 
@@ -18,20 +19,18 @@ create_overlay_rect(struct seat *seat, struct overlay_rect *rect, int fill)
 
 	if (rect->fill) {
 		/* Create a filled rectangle */
-		float color[4] = { 0.25, 0.25, 0.35, 0.5 };
 		rect->scene_rect = wlr_scene_rect_create(&server->scene->tree,
-			0, 0, color);
+			0, 0, bg_color);
 		rect->node = &rect->scene_rect->node;
 	} else {
 		/* Create outlines */
-		int line_width = server->theme->osd_border_width;
 		float *colors[3] = {
-			server->theme->osd_bg_color,
+			border_colors[0],
-			server->theme->osd_label_text_color,
+			border_colors[1],
-			server->theme->osd_bg_color
+			border_colors[2],
 		};
 		rect->pixman_rect = multi_rect_create(&server->scene->tree,
-			colors, line_width);
+			colors, border_width);
 		rect->node = &rect->pixman_rect->tree->node;
 	}
 
@@ -49,9 +48,15 @@ void overlay_reconfigure(struct seat *seat)
 
 	struct theme *theme = seat->server->theme;
 	create_overlay_rect(seat, &seat->overlay.region_rect,
-		theme->snapping_preview_region_fill);
+		theme->snapping_preview_region_fill,
+		theme->snapping_preview_region_bg_color,
+		theme->snapping_preview_region_border_width,
+		theme->snapping_preview_region_border_color);
 	create_overlay_rect(seat, &seat->overlay.edge_rect,
-		theme->snapping_preview_edge_fill);
+		theme->snapping_preview_edge_fill,
+		theme->snapping_preview_edge_bg_color,
+		theme->snapping_preview_edge_border_width,
+		theme->snapping_preview_edge_border_color);
 }
 
 static void

src/theme.c

@@ -428,6 +428,16 @@ parse_hexstr(const char *hex, float *rgba)
 	rgba[2] *= rgba[3];
 }
 
+static void
+parse_hexstrs(const char *hexes, float colors[3][4])
+{
+	gchar **elements = g_strsplit(hexes, ",", -1);
+	for (int i = 0; elements[i] && i < 3; i++) {
+		parse_hexstr(elements[i], colors[i]);
+	}
+	g_strfreev(elements);
+}
+
 static enum lab_justification
 parse_justification(const char *str)
 {
@@ -524,6 +534,19 @@ theme_builtin(struct theme *theme)
 
 	theme->snapping_preview_region_fill = true;
 	theme->snapping_preview_edge_fill = true;
+
+	parse_hexstr("#8080b380", theme->snapping_preview_region_bg_color);
+	parse_hexstr("#8080b380", theme->snapping_preview_edge_bg_color);
+
+	/* inherit settings in post_processing() if not set elsewhere */
+	theme->snapping_preview_region_border_width = INT_MIN;
+	theme->snapping_preview_edge_border_width = INT_MIN;
+	memset(theme->snapping_preview_region_border_color, 0,
+		sizeof(theme->snapping_preview_region_border_color));
+	theme->snapping_preview_region_border_color[0][0] = FLT_MIN;
+	memset(theme->snapping_preview_edge_border_color, 0,
+		sizeof(theme->snapping_preview_edge_border_color));
+	theme->snapping_preview_edge_border_color[0][0] = FLT_MIN;
 }
 
 static void
@@ -725,6 +748,24 @@ entry(struct theme *theme, const char *key, const char *value)
 	if (match_glob(key, "snapping.preview.edge.fill")) {
 		theme->snapping_preview_edge_fill = parse_bool(value, true);
 	}
+	if (match_glob(key, "snapping.preview.region.bg.color")) {
+		parse_hexstr(value, theme->snapping_preview_region_bg_color);
+	}
+	if (match_glob(key, "snapping.preview.edge.bg.color")) {
+		parse_hexstr(value, theme->snapping_preview_edge_bg_color);
+	}
+	if (match_glob(key, "snapping.preview.region.border.width")) {
+		theme->snapping_preview_region_border_width = atoi(value);
+	}
+	if (match_glob(key, "snapping.preview.edge.border.width")) {
+		theme->snapping_preview_edge_border_width = atoi(value);
+	}
+	if (match_glob(key, "snapping.preview.region.border.color")) {
+		parse_hexstrs(value, theme->snapping_preview_region_border_color);
+	}
+	if (match_glob(key, "snapping.preview.edge.border.color")) {
+		parse_hexstrs(value, theme->snapping_preview_edge_border_color);
+	}
 }
 
 static void
@@ -982,6 +1023,14 @@ create_corners(struct theme *theme)
 	theme->corner_top_right_inactive_normal = rounded_rect(&ctx);
 }
 
+static void
+fill_colors_with_osd_theme(struct theme *theme, float colors[3][4])
+{
+	memcpy(colors[0], theme->osd_bg_color, sizeof(colors[0]));
+	memcpy(colors[1], theme->osd_label_text_color, sizeof(colors[1]));
+	memcpy(colors[2], theme->osd_bg_color, sizeof(colors[2]));
+}
+
 static void
 post_processing(struct theme *theme)
 {
@@ -1043,6 +1092,23 @@ post_processing(struct theme *theme)
 		theme->osd_window_switcher_width =
 			MIN(theme->osd_window_switcher_width, 100);
 	}
+
+	if (theme->snapping_preview_region_border_width == INT_MIN) {
+		theme->snapping_preview_region_border_width =
+			theme->osd_border_width;
+	}
+	if (theme->snapping_preview_edge_border_width == INT_MIN) {
+		theme->snapping_preview_edge_border_width =
+			theme->osd_border_width;
+	}
+	if (theme->snapping_preview_region_border_color[0][0] == FLT_MIN) {
+		fill_colors_with_osd_theme(theme,
+			theme->snapping_preview_region_border_color);
+	}
+	if (theme->snapping_preview_edge_border_color[0][0] == FLT_MIN) {
+		fill_colors_with_osd_theme(theme,
+			theme->snapping_preview_edge_border_color);
+	}
 }
 
 void