window: Track and report input and opaque regions

We just set the input region to the bounding box of the window frame
and set the opaque region to be the opaque rectangle inside the window
if the child widget is opaque.

clients/gears.c

@@ -315,7 +315,6 @@ gears_create(struct display *display)
 	gears->d = display;
 	gears->window = window_create(display);
 	gears->widget = frame_create(gears->window, gears);
-	window_set_transparent(gears->window, 1);
 	window_set_title(gears->window, "Wayland Gears");
 
 	gears->display = display_get_egl_display(gears->d);

clients/terminal.c

@@ -2272,6 +2272,7 @@ terminal_create(struct display *display, int fullscreen)
 	terminal->window = window_create(display);
 	terminal->widget = frame_create(terminal->window, terminal);
 	window_set_title(terminal->window, "Wayland Terminal");
+	widget_set_transparent(terminal->widget, 0);
 
 	init_state_machine(&terminal->state_machine);
 	init_color_table(terminal);

clients/view.c

@@ -62,11 +62,6 @@ redraw_handler(struct widget *widget, void *data)
 	PopplerPage *page;
 	double width, height, doc_aspect, window_aspect, scale;
 
-	if (view->fullscreen)
-		window_set_transparent(view->window, 0);
-	else
-		window_set_transparent(view->window, 1);
-
 	widget_get_allocation(view->widget, &allocation);
 
 	surface = window_get_surface(view->window);

clients/window.c

@@ -85,6 +85,7 @@ struct display {
 	struct wl_list input_list;
 	struct wl_list output_list;
 	cairo_surface_t *active_frame, *inactive_frame, *shadow;
+	int frame_radius;
 	struct xkb_desc *xkb;
 	cairo_surface_t **pointer_surfaces;
 
@@ -111,6 +112,8 @@ struct window {
 	struct window *parent;
 	struct wl_surface *surface;
 	struct wl_shell_surface *shell_surface;
+	struct wl_region *input_region;
+	struct wl_region *opaque_region;
 	char *title;
 	struct rectangle allocation, saved_allocation, server_allocation;
 	struct rectangle pending_allocation;
@@ -152,6 +155,7 @@ struct widget {
 	widget_motion_handler_t motion_handler;
 	widget_button_handler_t button_handler;
 	void *user_data;
+	int opaque;
 };
 
 struct input {
@@ -827,6 +831,9 @@ window_attach_surface(struct window *window)
 		return;
 	}
 
+	wl_surface_set_input_region(window->surface, window->input_region);
+	wl_surface_set_opaque_region(window->surface, window->opaque_region);
+
 	wl_surface_damage(window->surface, 0, 0,
 			  window->allocation.width,
 			  window->allocation.height);
@@ -953,6 +960,11 @@ window_destroy(struct window *window)
 			input->focus_widget = NULL;
 	}
 
+	if (window->input_region)
+		wl_region_destroy(window->input_region);
+	if (window->opaque_region)
+		wl_region_destroy(window->opaque_region);
+
 	if (window->frame)
 		frame_destroy(window->frame);
 
@@ -1002,6 +1014,7 @@ widget_create(struct window *window, void *data)
 	widget->user_data = data;
 	widget->allocation = window->allocation;
 	wl_list_init(&widget->child_list);
+	widget->opaque = 0;
 
 	return widget;
 }
@@ -1063,6 +1076,12 @@ widget_set_allocation(struct widget *widget,
 	widget_set_size(widget, width, height);
 }
 
+void
+widget_set_transparent(struct widget *widget, int transparent)
+{
+	widget->opaque = !transparent;
+}
+
 void *
 widget_get_user_data(struct widget *widget)
 {
@@ -1140,7 +1159,9 @@ frame_resize_handler(struct widget *widget,
 	struct frame *frame = data;
 	struct widget *child = frame->child;
 	struct rectangle allocation;
+	struct display *display = widget->window->display;
 	int decoration_width, decoration_height;
+	int opaque_margin;
 
 	if (widget->window->type == TYPE_TOPLEVEL) {
 		decoration_width = 20 + frame->margin * 2;
@@ -1150,6 +1171,15 @@ frame_resize_handler(struct widget *widget,
 		allocation.y = 50 + frame->margin;
 		allocation.width = width - decoration_width;
 		allocation.height = height - decoration_height;
+
+		widget->window->input_region =
+			wl_compositor_create_region(display->compositor);
+		wl_region_add(widget->window->input_region,
+			      frame->margin, frame->margin,
+			      width - 2 * frame->margin,
+			      height - 2 * frame->margin);
+
+		opaque_margin = frame->margin + display->frame_radius;
 	} else {
 		decoration_width = 0;
 		decoration_height = 0;
@@ -1158,6 +1188,16 @@ frame_resize_handler(struct widget *widget,
 		allocation.y = 0;
 		allocation.width = width;
 		allocation.height = height;
+		opaque_margin = 0;
+	}
+
+	if (child->opaque) {
+		widget->window->opaque_region =
+			wl_compositor_create_region(display->compositor);
+		wl_region_add(widget->window->opaque_region,
+			      opaque_margin, opaque_margin,
+			      width - 2 * opaque_margin,
+			      height - 2 * opaque_margin);
 	}
 
 	widget_set_allocation(child, allocation.x, allocation.y,
@@ -2024,6 +2064,16 @@ idle_resize(struct task *task, uint32_t events)
 			      window->pending_allocation.width,
 			      window->pending_allocation.height);
 
+	if (window->input_region) {
+		wl_region_destroy(window->input_region);
+		window->input_region = NULL;
+	}
+
+	if (window->opaque_region) {
+		wl_region_destroy(window->opaque_region);
+		window->opaque_region = NULL;
+	}
+
 	if (widget->resize_handler)
 		widget->resize_handler(widget,
 				       widget->allocation.width,
@@ -2238,12 +2288,6 @@ window_set_close_handler(struct window *window,
 	window->close_handler = handler;
 }
 
-void
-window_set_transparent(struct window *window, int transparent)
-{
-	window->transparent = transparent;
-}
-
 void
 window_set_title(struct window *window, const char *title)
 {
@@ -2300,6 +2344,8 @@ window_create_internal(struct display *display, struct window *parent)
 	window->saved_allocation = window->allocation;
 	window->transparent = 1;
 	window->type = TYPE_TOPLEVEL;
+	window->input_region = NULL;
+	window->opaque_region = NULL;
 
 	if (display->dpy)
 #ifdef HAVE_CAIRO_EGL
@@ -2709,14 +2755,14 @@ display_handle_global(struct wl_display *display, uint32_t id,
 static void
 display_render_frame(struct display *d)
 {
-	int radius = 8;
 	cairo_t *cr;
 
+	d->frame_radius = 8;
 	d->shadow = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, 128, 128);
 	cr = cairo_create(d->shadow);
 	cairo_set_operator(cr, CAIRO_OPERATOR_OVER);
 	cairo_set_source_rgba(cr, 0, 0, 0, 1);
-	rounded_rect(cr, 16, 16, 112, 112, radius);
+	rounded_rect(cr, 16, 16, 112, 112, d->frame_radius);
 	cairo_fill(cr);
 	cairo_destroy(cr);
 	blur_surface(d->shadow, 64);
@@ -2726,7 +2772,7 @@ display_render_frame(struct display *d)
 	cr = cairo_create(d->active_frame);
 	cairo_set_operator(cr, CAIRO_OPERATOR_OVER);
 	cairo_set_source_rgba(cr, 0.8, 0.8, 0.4, 1);
-	rounded_rect(cr, 16, 16, 112, 112, radius);
+	rounded_rect(cr, 16, 16, 112, 112, d->frame_radius);
 	cairo_fill(cr);
 	cairo_destroy(cr);
 
@@ -2735,7 +2781,7 @@ display_render_frame(struct display *d)
 	cr = cairo_create(d->inactive_frame);
 	cairo_set_operator(cr, CAIRO_OPERATOR_OVER);
 	cairo_set_source_rgba(cr, 0.6, 0.6, 0.6, 1);
-	rounded_rect(cr, 16, 16, 112, 112, radius);
+	rounded_rect(cr, 16, 16, 112, 112, d->frame_radius);
 	cairo_fill(cr);
 	cairo_destroy(cr);
 }

clients/window.h

@@ -321,6 +321,8 @@ widget_set_allocation(struct widget *widget,
 void
 widget_set_size(struct widget *widget, int32_t width, int32_t height);
 void
+widget_set_transparent(struct widget *widget, int transparent);
+void
 widget_schedule_resize(struct widget *widget, int32_t width, int32_t height);
 
 void *

clients/wscreensaver.c

@@ -188,7 +188,6 @@ create_wscreensaver_instance(struct wscreensaver *screensaver,
 		return NULL;
 	}
 
-	window_set_transparent(mi->window, 0);
 	window_set_title(mi->window, progname);
 
 	if (screensaver->interface) {