--- /dev/null
+#undef I3__FILE__
+#define I3__FILE__ "restore_layout.c"
+/*
+ * vim:ts=4:sw=4:expandtab
+ *
+ * i3 - an improved dynamic tiling window manager
+ * © 2009-2013 Michael Stapelberg and contributors (see also: LICENSE)
+ *
+ * restore_layout.c: Everything for restored containers that is not pure state
+ * parsing (which can be found in load_layout.c).
+ *
+ *
+ */
+#include "all.h"
+
+typedef struct placeholder_state {
+ /** The X11 placeholder window. */
+ xcb_window_t window;
+ /** The container to which this placeholder window belongs. */
+ Con *con;
+
+ /** Current size of the placeholder window (to detect size changes). */
+ Rect rect;
+
+ /** The pixmap to render on (back buffer). */
+ xcb_pixmap_t pixmap;
+ /** The graphics context for “pixmap”. */
+ xcb_gcontext_t gc;
+
+ TAILQ_ENTRY(placeholder_state) state;
+} placeholder_state;
+
+static TAILQ_HEAD(state_head, placeholder_state) state_head =
+ TAILQ_HEAD_INITIALIZER(state_head);
+
+static xcb_connection_t *restore_conn;
+
+static void restore_handle_event(int type, xcb_generic_event_t *event);
+
+/* Documentation for these functions can be found in src/main.c, starting at xcb_got_event */
+static void restore_xcb_got_event(EV_P_ struct ev_io *w, int revents) {
+}
+
+static void restore_xcb_prepare_cb(EV_P_ ev_prepare *w, int revents) {
+ xcb_flush(restore_conn);
+}
+
+static void restore_xcb_check_cb(EV_P_ ev_check *w, int revents) {
+ xcb_generic_event_t *event;
+
+ if (xcb_connection_has_error(restore_conn)) {
+ // TODO: figure out how to reconnect with libev
+ ELOG("connection has an error\n");
+ return;
+ }
+
+ while ((event = xcb_poll_for_event(restore_conn)) != NULL) {
+ if (event->response_type == 0) {
+ xcb_generic_error_t *error = (xcb_generic_error_t*)event;
+ DLOG("X11 Error received (probably harmless)! sequence 0x%x, error_code = %d\n",
+ error->sequence, error->error_code);
+ free(event);
+ continue;
+ }
+
+ /* Strip off the highest bit (set if the event is generated) */
+ int type = (event->response_type & 0x7F);
+
+ restore_handle_event(type, event);
+
+ free(event);
+ }
+}
+
+/*
+ * Opens a separate connection to X11 for placeholder windows when restoring
+ * layouts. This is done as a safety measure (users can xkill a placeholder
+ * window without killing their window manager) and for better isolation, both
+ * on the wire to X11 and thus also in the code.
+ *
+ */
+void restore_connect(void) {
+ int screen;
+ restore_conn = xcb_connect(NULL, &screen);
+ if (restore_conn == NULL || xcb_connection_has_error(restore_conn))
+ errx(EXIT_FAILURE, "Cannot open display\n");
+
+ struct ev_io *xcb_watcher = scalloc(sizeof(struct ev_io));
+ struct ev_check *xcb_check = scalloc(sizeof(struct ev_check));
+ struct ev_prepare *xcb_prepare = scalloc(sizeof(struct ev_prepare));
+
+ ev_io_init(xcb_watcher, restore_xcb_got_event, xcb_get_file_descriptor(restore_conn), EV_READ);
+ ev_io_start(main_loop, xcb_watcher);
+
+ ev_check_init(xcb_check, restore_xcb_check_cb);
+ ev_check_start(main_loop, xcb_check);
+
+ ev_prepare_init(xcb_prepare, restore_xcb_prepare_cb);
+ ev_prepare_start(main_loop, xcb_prepare);
+}
+
+static void update_placeholder_contents(placeholder_state *state) {
+ // TODO: introduce color configuration for placeholder windows.
+ xcb_change_gc(restore_conn, state->gc, XCB_GC_FOREGROUND, (uint32_t[]) { config.client.background });
+ xcb_poly_fill_rectangle(restore_conn, state->pixmap, state->gc, 1,
+ (xcb_rectangle_t[]) { { 0, 0, state->rect.width, state->rect.height } });
+
+ // TODO: make i3font functions per-connection, at least these two for now…?
+ xcb_flush(restore_conn);
+ xcb_aux_sync(restore_conn);
+
+ // TODO: actually represent the criteria, most likely just line by line from (0, 0)
+ set_font_colors(state->gc, config.client.focused.background, 0);
+ i3String *line = i3string_from_utf8("⌚");
+ int text_width = predict_text_width(line);
+ int x = (state->rect.width / 2) - (text_width / 2);
+ int y = (state->rect.height / 2) - (config.font.height / 2);
+ draw_text(line, state->pixmap, state->gc, x, y, text_width);
+ i3string_free(line);
+ xcb_flush(conn);
+ xcb_aux_sync(conn);
+}
+
+static void open_placeholder_window(Con *con) {
+ if (con_is_leaf(con)) {
+ xcb_window_t placeholder = create_window(
+ restore_conn,
+ con->rect,
+ XCB_COPY_FROM_PARENT,
+ XCB_COPY_FROM_PARENT,
+ XCB_WINDOW_CLASS_INPUT_OUTPUT,
+ XCURSOR_CURSOR_POINTER,
+ true,
+ XCB_CW_BACK_PIXEL | XCB_CW_EVENT_MASK,
+ (uint32_t[]){
+ // TODO: use the background color as background pixel to avoid flickering
+ root_screen->white_pixel,
+ XCB_EVENT_MASK_EXPOSURE | XCB_EVENT_MASK_STRUCTURE_NOTIFY,
+ });
+ // TODO: set window title from con->name
+ DLOG("Created placeholder window 0x%08x for leaf container %p / %s\n",
+ placeholder, con, con->name);
+
+ placeholder_state *state = scalloc(sizeof(placeholder_state));
+ state->window = placeholder;
+ state->con = con;
+ state->rect = con->rect;
+ state->pixmap = xcb_generate_id(restore_conn);
+ // TODO: get rid of hardcoded 24
+ xcb_create_pixmap(restore_conn, 24, state->pixmap,
+ state->window, state->rect.width, state->rect.height);
+ state->gc = xcb_generate_id(restore_conn);
+ xcb_create_gc(restore_conn, state->gc, state->pixmap, XCB_GC_GRAPHICS_EXPOSURES, (uint32_t[]){ 0 });
+ update_placeholder_contents(state);
+ TAILQ_INSERT_TAIL(&state_head, state, state);
+
+ /* create temporary id swallow to match the placeholder */
+ Match *temp_id = smalloc(sizeof(Match));
+ match_init(temp_id);
+ temp_id->id = placeholder;
+ TAILQ_INSERT_TAIL(&(con->swallow_head), temp_id, matches);
+ }
+
+ Con *child;
+ TAILQ_FOREACH(child, &(con->nodes_head), nodes) {
+ open_placeholder_window(child);
+ }
+ TAILQ_FOREACH(child, &(con->floating_head), floating_windows) {
+ open_placeholder_window(child);
+ }
+}
+
+/*
+ * Open placeholder windows for all children of parent. The placeholder window
+ * will vanish as soon as a real window is swallowed by the container. Until
+ * then, it exposes the criteria that must be fulfilled for a window to be
+ * swallowed by this container.
+ *
+ */
+void restore_open_placeholder_windows(Con *parent) {
+ Con *child;
+ TAILQ_FOREACH(child, &(parent->nodes_head), nodes) {
+ open_placeholder_window(child);
+ }
+ TAILQ_FOREACH(child, &(parent->floating_head), floating_windows) {
+ open_placeholder_window(child);
+ }
+
+ xcb_flush(restore_conn);
+}
+
+static void expose_event(xcb_expose_event_t *event) {
+ placeholder_state *state;
+ TAILQ_FOREACH(state, &state_head, state) {
+ if (state->window != event->window)
+ continue;
+
+ DLOG("refreshing window 0x%08x contents (con %p)\n", state->window, state->con);
+
+ /* Since we render to our pixmap on every change anyways, expose events
+ * only tell us that the X server lost (parts of) the window contents. We
+ * can handle that by copying the appropriate part from our pixmap to the
+ * window. */
+ xcb_copy_area(restore_conn, state->pixmap, state->window, state->gc,
+ event->x, event->y, event->x, event->y,
+ event->width, event->height);
+ xcb_flush(restore_conn);
+ return;
+ }
+
+ ELOG("Received ExposeEvent for unknown window 0x%08x\n", event->window);
+}
+
+/*
+ * Window size has changed. Update the width/height, then recreate the back
+ * buffer pixmap and the accompanying graphics context and force an immediate
+ * re-rendering.
+ *
+ */
+static void configure_notify(xcb_configure_notify_event_t *event) {
+ placeholder_state *state;
+ TAILQ_FOREACH(state, &state_head, state) {
+ if (state->window != event->window)
+ continue;
+
+ DLOG("ConfigureNotify: window 0x%08x has now width=%d, height=%d (con %p)\n",
+ state->window, event->width, event->height, state->con);
+
+ state->rect.width = event->width;
+ state->rect.height = event->height;
+
+ xcb_free_pixmap(restore_conn, state->pixmap);
+ xcb_free_gc(restore_conn, state->gc);
+
+ state->pixmap = xcb_generate_id(restore_conn);
+ // TODO: get rid of hardcoded 24
+ xcb_create_pixmap(restore_conn, 24, state->pixmap,
+ state->window, state->rect.width, state->rect.height);
+ state->gc = xcb_generate_id(restore_conn);
+ xcb_create_gc(restore_conn, state->gc, state->pixmap, XCB_GC_GRAPHICS_EXPOSURES, (uint32_t[]){ 0 });
+
+ update_placeholder_contents(state);
+ xcb_copy_area(restore_conn, state->pixmap, state->window, state->gc,
+ 0, 0, 0, 0, state->rect.width, state->rect.height);
+ xcb_flush(restore_conn);
+ return;
+ }
+
+ ELOG("Received ConfigureNotify for unknown window 0x%08x\n", event->window);
+}
+
+// TODO: this event loop is not taken care of in the floating event handler
+static void restore_handle_event(int type, xcb_generic_event_t *event) {
+ switch (type) {
+ case XCB_EXPOSE:
+ expose_event((xcb_expose_event_t*)event);
+ break;
+ case XCB_CONFIGURE_NOTIFY:
+ configure_notify((xcb_configure_notify_event_t*)event);
+ break;
+ default:
+ DLOG("Received unhandled X11 event of type %d\n", type);
+ break;
+ }
+}