[PATCH weston 2/3] clients: Require EGL_MIN_SWAP_INTERVAL to be 0 for subsurfaces

[Jonas Ådahl]

Warn and fail when trying to create sub surfaces when swap interval 0 is
not supported by the EGL platform.

Signed-off-by: Jonas Ådahl <jadahl at gmail.com>
---
 clients/nested.c      |  1 +
 clients/subsurfaces.c |  2 ++
 clients/window.c      | 19 +++++++++++++++++++
 3 files changed, 22 insertions(+)

diff --git a/clients/nested.c b/clients/nested.c
index f094237..696b727 100644
--- a/clients/nested.c
+++ b/clients/nested.c
@@ -970,6 +970,7 @@ ss_surface_init(struct nested_surface *surface)
 		window_add_subsurface(nested->window,
 				      nested,
 				      SUBSURFACE_SYNCHRONIZED);
+	assert(ss_surface->widget);
 
 	widget_set_use_cairo(ss_surface->widget, 0);
 
diff --git a/clients/subsurfaces.c b/clients/subsurfaces.c
index 833030f..e0a5010 100644
--- a/clients/subsurfaces.c
+++ b/clients/subsurfaces.c
@@ -500,6 +500,7 @@ triangle_create(struct window *window, struct egl_state *egl)
 	tri->egl = egl;
 	tri->widget = window_add_subsurface(window, tri,
 		int_to_mode(option_triangle_mode));
+	assert(tri->widget);
 	widget_set_use_cairo(tri->widget, 0);
 	widget_set_resize_handler(tri->widget, triangle_resize_handler);
 	widget_set_redraw_handler(tri->widget, triangle_redraw_handler);
@@ -737,6 +738,7 @@ demoapp_create(struct display *display)
 
 	app->subsurface = window_add_subsurface(app->window, app,
 		int_to_mode(option_red_mode));
+	assert(app->subsurface);
 	widget_set_redraw_handler(app->subsurface, sub_redraw_handler);
 	widget_set_resize_handler(app->subsurface, sub_resize_handler);
 
diff --git a/clients/window.c b/clients/window.c
index b45b499..beb28ca 100644
--- a/clients/window.c
+++ b/clients/window.c
@@ -2023,6 +2023,9 @@ window_create_tooltip(struct tooltip *tooltip)
 
 	tooltip->widget = window_add_subsurface(parent->window, tooltip, SUBSURFACE_DESYNCHRONIZED);
 
+	if (!tooltip->widget)
+		return -1;
+
 	extents = get_text_extents(display, tooltip);
 	widget_set_redraw_handler(tooltip->widget, tooltip_redraw_handler);
 	widget_set_allocation(tooltip->widget,
@@ -4844,6 +4847,22 @@ window_add_subsurface(struct window *window, void *data,
 	struct surface *surface;
 	struct wl_surface *parent;
 	struct wl_subcompositor *subcompo = window->display->subcompositor;
+	GLint min_swap_interval;
+
+	if (EGL_FALSE == eglGetConfigAttrib(window->display->dpy,
+					    window->display->argb_config,
+					    EGL_MIN_SWAP_INTERVAL,
+					    &min_swap_interval)) {
+		fprintf(stderr, "failed to add subsurface, couldn't retrieve "
+			"EGL_MIN_SWAP_INTERVAL\n");
+		return NULL;
+	}
+
+	if (min_swap_interval > 0) {
+		fprintf(stderr, "failed to add subsurface, no "
+			"EGLSwapInterval(0) support\n");
+		return NULL;
+	}
 
 	surface = surface_create(window);
 	surface->buffer_type = window_get_buffer_type(window);
-- 
2.1.0