Merge 49464d233e into 801bc76ce3

This avoids exhausting the buffer pool when multiple events that would
trigger redraws occur rapidly (for example: scrolling, resizing output).

include/swaynag/swaynag.h

@@ -90,6 +90,7 @@ struct swaynag {
 	struct wp_cursor_shape_manager_v1 *cursor_shape_manager;
 	struct wl_surface *surface;
 
+	bool needs_redraw;
 	uint32_t width;
 	uint32_t height;
 	int32_t scale;

sway/sway.5.scd

@@ -106,9 +106,9 @@ They are expected to be used with *bindsym* or at runtime through *swaymsg*(1).
 *border* none|normal|csd|pixel [<n>]
 	Set border style for focused window. _normal_ includes a border of
 	thickness _n_ and a title bar. _pixel_ is a border without title bar _n_
-	pixels thick. Default is _normal_ with border thickness 2. _csd_ is short
+	pixels thick. The title bar always shows in stacking or tabbed layouts.
-	for client-side-decorations, which allows the client to draw its own
+	_csd_ is short for client-side-decorations, which allows the client to draw
-	decorations.
+	its own decorations. Default is _normal_ with border thickness 2.
 
 *border* toggle
 	Cycles through the available border styles.

swaynag/render.c

@@ -235,12 +235,10 @@ static uint32_t render_to_cairo(cairo_t *cairo, struct swaynag *swaynag) {
 	}
 
 	int border = swaynag->type->bar_border_thickness;
-	if (max_height > swaynag->height) {
 	max_height += border;
-	}
 	cairo_set_source_u32(cairo, swaynag->type->border_bottom);
 	cairo_rectangle(cairo, 0,
-			swaynag->height - border,
+			max_height - border,
 			swaynag->width,
 			border);
 	cairo_fill(cairo);
@@ -252,6 +250,7 @@ void render_frame(struct swaynag *swaynag) {
 	if (!swaynag->run_display) {
 		return;
 	}
+	swaynag->needs_redraw = false;
 
 	cairo_surface_t *recorder = cairo_recording_surface_create(
 			CAIRO_CONTENT_COLOR_ALPHA, NULL);
@@ -262,17 +261,24 @@ void render_frame(struct swaynag *swaynag) {
 	cairo_paint(cairo);
 	cairo_restore(cairo);
 	uint32_t height = render_to_cairo(cairo, swaynag);
-	if (height != swaynag->height) {
+	if (swaynag->height == 0) {
+		// for first commit, set required size but do not attach a buffer
 		zwlr_layer_surface_v1_set_size(swaynag->layer_surface, 0, height);
 		zwlr_layer_surface_v1_set_exclusive_zone(swaynag->layer_surface,
 			height);
 		wl_surface_commit(swaynag->surface);
-		wl_display_roundtrip(swaynag->display);
+		goto cleanup;
-	} else {
+	}
+	if (height != swaynag->height) {
+		zwlr_layer_surface_v1_set_size(swaynag->layer_surface, 0, height);
+		zwlr_layer_surface_v1_set_exclusive_zone(swaynag->layer_surface,
+			height);
+	}
+
 	swaynag->current_buffer = get_next_buffer(swaynag->shm,
 		swaynag->buffers,
 		swaynag->width * swaynag->scale,
-				swaynag->height * swaynag->scale);
+		height * swaynag->scale);
 	if (!swaynag->current_buffer) {
 		sway_log(SWAY_DEBUG, "Failed to get buffer. Skipping frame.");
 		goto cleanup;
@@ -292,8 +298,6 @@ void render_frame(struct swaynag *swaynag) {
 	wl_surface_damage(swaynag->surface, 0, 0,
 		swaynag->width, swaynag->height);
 	wl_surface_commit(swaynag->surface);
-		wl_display_roundtrip(swaynag->display);
-	}
 
 cleanup:
 	cairo_surface_destroy(recorder);

swaynag/swaynag.c

@@ -47,7 +47,7 @@ static void swaynag_button_execute(struct swaynag *swaynag,
 		swaynag->run_display = false;
 	} else if (button->type == SWAYNAG_ACTION_EXPAND) {
 		swaynag->details.visible = !swaynag->details.visible;
-		render_frame(swaynag);
+		swaynag->needs_redraw = true;
 	} else {
 		pid_t pid = fork();
 		if (pid < 0) {
@@ -98,7 +98,7 @@ static void layer_surface_configure(void *data,
 	swaynag->width = width;
 	swaynag->height = height;
 	zwlr_layer_surface_v1_ack_configure(surface, serial);
-	render_frame(swaynag);
+	swaynag->needs_redraw = true;
 }
 
 static void layer_surface_closed(void *data,
@@ -122,7 +122,7 @@ static void surface_enter(void *data, struct wl_surface *surface,
 					swaynag_output->name);
 			swaynag->output = swaynag_output;
 			swaynag->scale = swaynag->output->scale;
-			render_frame(swaynag);
+			swaynag->needs_redraw = true;
 			break;
 		}
 	};
@@ -244,7 +244,7 @@ static void wl_pointer_button(void *data, struct wl_pointer *wl_pointer,
 				&& y < button_up.y + button_up.height
 				&& swaynag->details.offset > 0) {
 			swaynag->details.offset--;
-			render_frame(swaynag);
+			swaynag->needs_redraw = true;
 			return;
 		}
 
@@ -257,7 +257,7 @@ static void wl_pointer_button(void *data, struct wl_pointer *wl_pointer,
 				&& y < button_down.y + button_down.height
 				&& swaynag->details.offset < bot) {
 			swaynag->details.offset++;
-			render_frame(swaynag);
+			swaynag->needs_redraw = true;
 			return;
 		}
 	}
@@ -284,7 +284,7 @@ static void wl_pointer_axis(void *data, struct wl_pointer *wl_pointer,
 		swaynag->details.offset++;
 	}
 
-	render_frame(swaynag);
+	swaynag->needs_redraw = true;
 }
 
 static const struct wl_pointer_listener pointer_listener = {
@@ -327,7 +327,7 @@ static void output_scale(void *data, struct wl_output *output,
 		if (!swaynag_output->swaynag->cursor_shape_manager) {
 			update_all_cursors(swaynag_output->swaynag);
 		}
-		render_frame(swaynag_output->swaynag);
+		swaynag_output->swaynag->needs_redraw = true;
 	}
 }
 
@@ -503,9 +503,11 @@ void swaynag_setup(struct swaynag *swaynag) {
 void swaynag_run(struct swaynag *swaynag) {
 	swaynag->run_display = true;
 	render_frame(swaynag);
-	while (swaynag->run_display
+	while (wl_display_dispatch(swaynag->display) != -1
-			&& wl_display_dispatch(swaynag->display) != -1) {
+			&& swaynag->run_display) {
-		// This is intentionally left blank
+		if (swaynag->needs_redraw) {
+			render_frame(swaynag);
+		}
 	}
 }