introduce client.placeholder color

docs/userguide

@@ -727,6 +727,9 @@ client.unfocused::
 	A client which is not the focused one of its container.
 client.urgent::
 	A client which has its urgency hint activated.
+client.placeholder::
+	Background and text color are used to draw placeholder window contents
+	(when restoring layouts). Border and indicator are ignored.
 
 You can also specify the color to be used to paint the background of the client
 windows. This color will be used to paint the window on top of which the client
@@ -749,6 +752,7 @@ client.focused          #4c7899 #285577 #ffffff #2e9ef4
 client.focused_inactive #333333 #5f676a #ffffff #484e50
 client.unfocused        #333333 #222222 #888888 #292d2e
 client.urgent           #2f343a #900000 #ffffff #900000
+client.placeholder      #000000 #0c0c0c #ffffff #000000
 ---------------------------------------------------------
 
 Note that for the window decorations, the color around the child window is the

include/config.h

@@ -180,6 +180,7 @@ struct Config {
         struct Colortriple focused_inactive;
         struct Colortriple unfocused;
         struct Colortriple urgent;
+        struct Colortriple placeholder;
     } client;
     struct config_bar {
         struct Colortriple focused;

src/config.c

@@ -456,6 +456,9 @@ void load_configuration(xcb_connection_t *conn, const char *override_configpath,
     INIT_COLOR(config.client.unfocused, "#333333", "#222222", "#888888", "#292d2e");
     INIT_COLOR(config.client.urgent, "#2f343a", "#900000", "#ffffff", "#900000");
 
+    /* border and indicator color are ignored for placeholder contents */
+    INIT_COLOR(config.client.placeholder, "#000000", "#0c0c0c", "#ffffff", "#000000");
+
     /* the last argument (indicator color) is ignored for bar colors */
     INIT_COLOR(config.bar.focused, "#4c7899", "#285577", "#ffffff", "#000000");
     INIT_COLOR(config.bar.unfocused, "#333333", "#222222", "#888888", "#000000");

src/restore_layout.c

@@ -100,8 +100,8 @@ void restore_connect(void) {
 }
 
 static void update_placeholder_contents(placeholder_state *state) {
-    // TODO: introduce color configuration for placeholder windows.
-    xcb_change_gc(restore_conn, state->gc, XCB_GC_FOREGROUND, (uint32_t[]) { config.client.background });
+    xcb_change_gc(restore_conn, state->gc, XCB_GC_FOREGROUND,
+                  (uint32_t[]) { config.client.placeholder.background });
     xcb_poly_fill_rectangle(restore_conn, state->pixmap, state->gc, 1,
             (xcb_rectangle_t[]) { { 0, 0, state->rect.width, state->rect.height } });
 
@@ -109,7 +109,7 @@ static void update_placeholder_contents(placeholder_state *state) {
     xcb_flush(restore_conn);
     xcb_aux_sync(restore_conn);
 
-    set_font_colors(state->gc, config.client.focused.background, 0);
+    set_font_colors(state->gc, config.client.placeholder.text, config.client.placeholder.background);
 
     Match *swallows;
     int n = 0;
@@ -168,8 +168,7 @@ static void open_placeholder_window(Con *con) {
                 true,
                 XCB_CW_BACK_PIXEL | XCB_CW_EVENT_MASK,
                 (uint32_t[]){
-                    // TODO: use the background color as background pixel to avoid flickering
-                    root_screen->white_pixel,
+                    config.client.placeholder.background,
                     XCB_EVENT_MASK_EXPOSURE | XCB_EVENT_MASK_STRUCTURE_NOTIFY,
                 });
         /* Set the same name as was stored in the layout file. While perhaps