kmscon: add dummy session type

The dummy session is a very simply session implementation that simply
draws a black background. It will be used by each seat as fallback if no
other session is available. If we didn't do that, we wouldn't be able to
guarantee that the screen is cleared after a session is unregistered.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>

diff --git a/Makefile.am b/Makefile.am
index 90f4704..3f8f1a6 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -416,6 +416,8 @@ kmscon_SOURCES = \
        $(SHL_MISC) \
        src/kmscon_terminal.h \
        src/kmscon_terminal.c \
+       src/kmscon_dummy.h \
+       src/kmscon_dummy.c \
        src/kmscon_seat.h \
        src/kmscon_seat.c \
        src/kmscon_conf.h \

diff --git a/src/kmscon_dummy.c b/src/kmscon_dummy.c
new file mode 100644 (file)
index 0000000..94294d2
--- /dev/null
+++ b/src/kmscon_dummy.c
@@ -0,0 +1,148 @@
+/*
+ * kmscon - Dummy Session
+ *
+ * Copyright (c) 2012 David Herrmann <dh.herrmann@googlemail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/*
+ * Dummy Session
+ */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include "kmscon_dummy.h"
+#include "kmscon_seat.h"
+#include "log.h"
+#include "shl_dlist.h"
+
+#define LOG_SUBSYSTEM "dummy"
+
+struct display {
+       struct shl_dlist list;
+       struct uterm_display *disp;
+};
+
+struct kmscon_dummy {
+       struct kmscon_session *session;
+       struct shl_dlist displays;
+       bool active;
+};
+
+static void dummy_redraw(struct kmscon_dummy *dummy, struct display *d)
+{
+       struct uterm_mode *mode;
+       unsigned int w, h;
+
+       mode = uterm_display_get_current(d->disp);
+       w = uterm_mode_get_width(mode);
+       h = uterm_mode_get_height(mode);
+
+       uterm_display_fill(d->disp, 0, 0, 0, 0, 0, w, h);
+       uterm_display_swap(d->disp);
+}
+
+static void dummy_session_event(struct kmscon_session *session,
+                               unsigned int event, struct uterm_display *disp,
+                               void *data)
+{
+       struct kmscon_dummy *dummy = data;
+       struct display *d;
+       struct shl_dlist *iter;
+
+       switch (event) {
+       case KMSCON_SESSION_DISPLAY_NEW:
+               d = malloc(sizeof(*d));
+               if (!d) {
+                       log_error("cannot allocate memory for new display");
+                       break;
+               }
+               memset(d, 0, sizeof(*d));
+               d->disp = disp;
+               shl_dlist_link_tail(&dummy->displays, &d->list);
+               if (dummy->active)
+                       dummy_redraw(dummy, d);
+               break;
+       case KMSCON_SESSION_DISPLAY_GONE:
+               shl_dlist_for_each(iter, &dummy->displays) {
+                       d = shl_dlist_entry(iter, struct display, list);
+                       if (d->disp != disp)
+                               continue;
+
+                       shl_dlist_unlink(&d->list);
+                       free(d);
+                       break;
+               }
+               break;
+       case KMSCON_SESSION_ACTIVATE:
+               dummy->active = true;
+               shl_dlist_for_each(iter, &dummy->displays) {
+                       d = shl_dlist_entry(iter, struct display, list);
+                       dummy_redraw(dummy, d);
+               }
+               break;
+       case KMSCON_SESSION_DEACTIVATE:
+               dummy->active = false;
+               break;
+       case KMSCON_SESSION_UNREGISTER:
+               while (!shl_dlist_empty(&dummy->displays)) {
+                       d = shl_dlist_entry(dummy->displays.prev,
+                                           struct display, list);
+                       shl_dlist_unlink(&d->list);
+                       free(d);
+               }
+
+               free(dummy);
+               break;
+       }
+}
+
+int kmscon_dummy_register(struct kmscon_session **out,
+                         struct kmscon_seat *seat)
+{
+       struct kmscon_dummy *dummy;
+       int ret;
+
+       if (!out || !seat)
+               return -EINVAL;
+
+       dummy = malloc(sizeof(*dummy));
+       if (!dummy)
+               return -ENOMEM;
+       memset(dummy, 0, sizeof(*dummy));
+       shl_dlist_init(&dummy->displays);
+
+       ret = kmscon_seat_register_session(seat, &dummy->session,
+                                          dummy_session_event, dummy);
+       if (ret) {
+               log_error("cannot register session for dummy: %d", ret);
+               goto err_free;
+       }
+
+       *out = dummy->session;
+       log_debug("new dummy object %p", dummy);
+       return 0;
+
+err_free:
+       free(dummy);
+       return ret;
+}

diff --git a/src/kmscon_dummy.h b/src/kmscon_dummy.h
new file mode 100644 (file)
index 0000000..4fb1cee
--- /dev/null
+++ b/src/kmscon_dummy.h
@@ -0,0 +1,39 @@
+/*
+ * kmscon - Dummy Session
+ *
+ * Copyright (c) 2012 David Herrmann <dh.herrmann@googlemail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/*
+ * Dummy Session
+ */
+
+#ifndef KMSCON_DUMMY_H
+#define KMSCON_DUMMY_H
+
+#include <stdlib.h>
+#include "kmscon_seat.h"
+
+int kmscon_dummy_register(struct kmscon_session **out,
+                         struct kmscon_seat *seat);
+
+#endif /* KMSCON_DUMMY_H */