Display events and errors with `xcb-errors`

2 files changed, 37 insertions, 14 deletions

diff --git a/Makefile b/Makefile
index da5c16d..e01374a 100644
--- a/Makefile
+++ b/Makefile
@@ -8,7 +8,7 @@ DEPS = \
 	xcb-icccm \
 	xcb-xrm \
 	xcb-ewmh \
-	xcb-event \
+	xcb-errors \
 	"xcb-randr >= 1.5" \
 	"glib-2.0 >= 2.44" \
 	gio-2.0
diff --git a/x11.c b/x11.c
index b8e105b..d2eb233 100644
--- a/x11.c
+++ b/x11.c
@@ -7,8 +7,8 @@
 #include <xcb/xcb_aux.h>
 #include <xcb/xcb_icccm.h>
 #include <xcb/xcb_xrm.h>
-#include <xcb/xcb_event.h>
 #include <xcb/randr.h>
+#include <xcb/xcb_errors.h>
 
 #include "x11.h"
 #include "log.h"
@@ -20,6 +20,7 @@ struct Window {
     xcb_screen_t *screen;
     xcb_connection_t *connection;
     xcb_xrm_database_t *database;
+    xcb_errors_context_t *errors;
     xcb_drawable_t window;
     xcb_visualtype_t *visual_type;
     cairo_surface_t *surface;
@@ -65,21 +66,32 @@ static gboolean xcb_source_dispatch(GSource *source, GSourceFunc callback, gpoin
     g_assert_nonnull(callback);
     g_assert_nonnull(data);
 
+    Window *win = (Window *)data;
+
     do {
         switch (xsource->event->response_type & ~0x80) {
             case 0: {
                 xcb_generic_error_t *error = (xcb_generic_error_t *)xsource->event;
 
-                // TODO: This code crashes the program, so we should handle the errors
-                log_warning("Xcb event loop error '%s' [type %d]",
-                            xcb_event_get_error_label(error->response_type),
-                            error->response_type);
+                const char *extension;
+                const char *name  = xcb_errors_get_name_for_error(win->errors, error->error_code, &extension);
+                const char *major = xcb_errors_get_name_for_major_code(win->errors, error->major_code);
+                const char *minor = xcb_errors_get_name_for_minor_code(win->errors, error->major_code, error->minor_code);
+
+                // TODO: Handle errors instead of aborting
+                log_error("Xcb error '%s' [extension=%s, major=%s, minor=%s, resource=%u, sequence=%u]",
+                          name,
+                          extension ? extension : "none",
+                          major,
+                          minor ? minor : "none",
+                          (unsigned int)error->resource_id,
+                          (unsigned int)error->sequence);
                 break;
             }
 
             case XCB_EXPOSE: {
                 xcb_expose_event_t *expose = (xcb_expose_event_t *)xsource->event;
-                log_debug("Processing event 'Expose' [type %d]", XCB_EXPOSE);
+                log_debug("Processing event 'Expose' [type=%d]", XCB_EXPOSE);
 
                 // Redraw
                 callback(data);
@@ -93,7 +105,7 @@ static gboolean xcb_source_dispatch(GSource *source, GSourceFunc callback, gpoin
 
             case XCB_PROPERTY_NOTIFY: {
                 xcb_property_notify_event_t *property = (xcb_property_notify_event_t *)xsource->event;
-                log_debug("Processing event 'PropertyNotify' [type %d]", XCB_PROPERTY_NOTIFY);
+                log_debug("Processing event 'PropertyNotify' [type=%d]", XCB_PROPERTY_NOTIFY);
 
                 if (property->atom == XCB_ATOM_RESOURCE_MANAGER) {
                     window_update_scale(data);
@@ -105,9 +117,13 @@ static gboolean xcb_source_dispatch(GSource *source, GSourceFunc callback, gpoin
             }
 
             default: {
-                log_debug("Ignoring event '%s' [type %d]",
-                          xcb_event_get_label(xsource->event->response_type),
-                          XCB_EVENT_RESPONSE_TYPE(xsource->event));
+                const char *extension;
+                const char *name = xcb_errors_get_name_for_xcb_event(win->errors, xsource->event, &extension);
+
+                log_debug("Ignoring event '%s' [extension=%s, type=%d]",
+                          name,
+                          extension ? extension : "none",
+                          xsource->event->response_type & 0x7f);
             }
         }
     } while ((xsource->event = xcb_poll_for_event(xsource->win->connection)) != NULL);
@@ -189,7 +205,7 @@ Window *window_create(void)
     win->x = win->y = 0;
 
     xcb_randr_select_input(win->connection,
-                           win->window,
+                           win->screen->root,
                            XCB_RANDR_NOTIFY_MASK_SCREEN_CHANGE |
                            XCB_RANDR_NOTIFY_MASK_OUTPUT_CHANGE |
                            XCB_RANDR_NOTIFY_MASK_OUTPUT_PROPERTY);
@@ -199,6 +215,8 @@ Window *window_create(void)
 
     window_update_scale(win);
 
+    g_assert(xcb_errors_context_new(win->connection, &win->errors) == 0);
+
     xcb_depth_iterator_t depth_iter = xcb_screen_allowed_depths_iterator(win->screen);
     while (depth_iter.rem) {
         xcb_visualtype_iterator_t visual_iter = xcb_depth_visuals_iterator(depth_iter.data);
@@ -224,7 +242,7 @@ found_visual:
                               | XCB_EVENT_MASK_BUTTON_RELEASE | XCB_EVENT_MASK_BUTTON_PRESS;
 
     xcb_colormap_t colormap = xcb_generate_id(win->connection);
-	xcb_create_colormap(win->connection, XCB_COLORMAP_ALLOC_NONE, colormap, win->screen->root, win->visual_type->visual_id);
+    xcb_create_colormap(win->connection, XCB_COLORMAP_ALLOC_NONE, colormap, win->screen->root, win->visual_type->visual_id);
     log_debug("Xcb colormap created (id %u)", colormap);
 
     const uint32_t value_list[] = {
@@ -269,11 +287,12 @@ found_visual:
                                             screen_size->height);
 
     g_assert_cmpint(cairo_surface_status(win->surface), ==, CAIRO_STATUS_SUCCESS);
+    log_debug("Cairo surface created");
 
     win->cr = cairo_create(win->surface);
     g_assert_cmpint(cairo_status(win->cr), ==, CAIRO_STATUS_SUCCESS);
+    log_debug("Cairo context created");
 
-    log_debug("Cairo initialized");
 
     attach_source(win);
     log_debug("Xcb event loop attached");
@@ -297,8 +316,11 @@ void window_update_scale(Window *win)
         g_free(dpi_value);
     } else {
         log_debug("Xrm query '%s' not found", dpi_res);
+
         win->dpi = 96.0;
+        // TODO: Should we actually calculate the dpi depending on the screen size?
         //win->dpi = (double)screen_size->height * 25.4 / (double)screen_size->mheight;
+
         log_debug("Fallback dpi value '%.2lf'", win->dpi);
     }
 }
@@ -386,6 +408,7 @@ void window_destroy(Window *win)
     cairo_destroy(win->cr);
     cairo_surface_destroy(win->surface);
 
+    xcb_errors_context_free(win->errors);
     xcb_xrm_database_free(win->database);
     xcb_disconnect(win->connection);
     g_free(win);