Implement putting clients onto specific workspaces ("assign" in the configfile)

This closes ticket #39

src/client.c

@@ -0,0 +1,133 @@
+/*
+ * vim:ts=8:expandtab
+ *
+ * i3 - an improved dynamic tiling window manager
+ *
+ * © 2009 Michael Stapelberg and contributors
+ *
+ * See file LICENSE for license information.
+ *
+ * client.c: holds all client-specific functions
+ *
+ */
+#include <stdlib.h>
+#include <string.h>
+
+#include <xcb/xcb.h>
+#include <xcb/xcb_icccm.h>
+
+#include "data.h"
+#include "i3.h"
+#include "xcb.h"
+#include "util.h"
+#include "queue.h"
+
+/*
+ * Removes the given client from the container, either because it will be inserted into another
+ * one or because it was unmapped
+ *
+ */
+void client_remove_from_container(xcb_connection_t *conn, Client *client, Container *container) {
+        CIRCLEQ_REMOVE(&(container->clients), client, clients);
+
+        SLIST_REMOVE(&(container->workspace->focus_stack), client, Client, focus_clients);
+
+        /* If the container will be empty now and is in stacking mode, we need to
+           unmap the stack_win */
+        if (CIRCLEQ_EMPTY(&(container->clients)) && container->mode == MODE_STACK) {
+                struct Stack_Window *stack_win = &(container->stack_win);
+                stack_win->rect.height = 0;
+                xcb_unmap_window(conn, stack_win->window);
+        }
+}
+
+/*
+ * Warps the pointer into the given client (in the middle of it, to be specific), therefore
+ * selecting it
+ *
+ */
+void client_warp_pointer_into(xcb_connection_t *conn, Client *client) {
+        int mid_x = client->rect.width / 2,
+            mid_y = client->rect.height / 2;
+        xcb_warp_pointer(conn, XCB_NONE, client->child, 0, 0, 0, 0, mid_x, mid_y);
+}
+
+/*
+ * Returns true if the client supports the given protocol atom (like WM_DELETE_WINDOW)
+ *
+ */
+static bool client_supports_protocol(xcb_connection_t *conn, Client *client, xcb_atom_t atom) {
+        xcb_get_property_cookie_t cookie;
+        xcb_get_wm_protocols_reply_t protocols;
+        bool result = false;
+
+        cookie = xcb_get_wm_protocols_unchecked(conn, client->child, atoms[WM_PROTOCOLS]);
+        if (xcb_get_wm_protocols_reply(conn, cookie, &protocols, NULL) != 1)
+                return false;
+
+        /* Check if the client’s protocols have the requested atom set */
+        for (uint32_t i = 0; i < protocols.atoms_len; i++)
+                if (protocols.atoms[i] == atom)
+                        result = true;
+
+        xcb_get_wm_protocols_reply_wipe(&protocols);
+
+        return result;
+}
+
+/*
+ * Kills the given window using WM_DELETE_WINDOW or xcb_kill_window
+ *
+ */
+void client_kill(xcb_connection_t *conn, Client *window) {
+        /* If the client does not support WM_DELETE_WINDOW, we kill it the hard way */
+        if (!client_supports_protocol(conn, window, atoms[WM_DELETE_WINDOW])) {
+                LOG("Killing window the hard way\n");
+                xcb_kill_client(conn, window->child);
+                return;
+        }
+
+        xcb_client_message_event_t ev;
+
+        memset(&ev, 0, sizeof(xcb_client_message_event_t));
+
+        ev.response_type = XCB_CLIENT_MESSAGE;
+        ev.window = window->child;
+        ev.type = atoms[WM_PROTOCOLS];
+        ev.format = 32;
+        ev.data.data32[0] = atoms[WM_DELETE_WINDOW];
+        ev.data.data32[1] = XCB_CURRENT_TIME;
+
+        LOG("Sending WM_DELETE to the client\n");
+        xcb_send_event(conn, false, window->child, XCB_EVENT_MASK_NO_EVENT, (char*)&ev);
+        xcb_flush(conn);
+}
+
+/*
+ * Checks if the given window class and title match the given client
+ * Window title is passed as "normal" string and as UCS-2 converted string for
+ * matching _NET_WM_NAME capable clients as well as those using legacy hints.
+ *
+ */
+bool client_matches_class_name(Client *client, char *to_class, char *to_title,
+                               char *to_title_ucs, int to_title_ucs_len) {
+        /* Check if the given class is part of the window class */
+        if (strcasestr(client->window_class, to_class) == NULL)
+                return false;
+
+        /* If no title was given, we’re done */
+        if (to_title == NULL)
+                return true;
+
+        if (client->name_len > -1) {
+                /* UCS-2 converted window titles */
+                if (memmem(client->name, (client->name_len * 2), to_title_ucs, (to_title_ucs_len * 2)) == NULL)
+                        return false;
+        } else {
+                /* Legacy hints */
+                if (strcasestr(client->name, to_title) == NULL)
+                        return false;
+        }
+
+        return true;
+}