module/i3: use our own copy of i3/ipc.h

The main advantage is when targeting sway/wayland instead of i3/x11;
sway doesn't package ipc.h. There *is* an ipc.h in the sway sources,
but it doesn't define e.g the header format, and has different names
for the constants.

modules/i3-ipc.h

@@ -0,0 +1,114 @@
+/*
+ * vim:ts=4:sw=4:expandtab
+ *
+ * i3 - an improved dynamic tiling window manager
+ * © 2009 Michael Stapelberg and contributors (see also: LICENSE)
+ *
+ * This public header defines the different constants and message types to use
+ * for the IPC interface to i3 (see docs/ipc for more information).
+ *
+ */
+#pragma once
+
+#include <stdint.h>
+
+typedef struct i3_ipc_header {
+    /* 6 = strlen(I3_IPC_MAGIC) */
+    char magic[6];
+    uint32_t size;
+    uint32_t type;
+} __attribute__((packed)) i3_ipc_header_t;
+
+/*
+ * Messages from clients to i3
+ *
+ */
+
+/** Never change this, only on major IPC breakage (don’t do that) */
+#define I3_IPC_MAGIC "i3-ipc"
+
+/** Deprecated: use I3_IPC_MESSAGE_TYPE_RUN_COMMAND */
+#define I3_IPC_MESSAGE_TYPE_COMMAND 0
+
+/** The payload of the message will be interpreted as a command */
+#define I3_IPC_MESSAGE_TYPE_RUN_COMMAND 0
+
+/** Requests the current workspaces from i3 */
+#define I3_IPC_MESSAGE_TYPE_GET_WORKSPACES 1
+
+/** Subscribe to the specified events */
+#define I3_IPC_MESSAGE_TYPE_SUBSCRIBE 2
+
+/** Requests the current outputs from i3 */
+#define I3_IPC_MESSAGE_TYPE_GET_OUTPUTS 3
+
+/** Requests the tree layout from i3 */
+#define I3_IPC_MESSAGE_TYPE_GET_TREE 4
+
+/** Request the current defined marks from i3 */
+#define I3_IPC_MESSAGE_TYPE_GET_MARKS 5
+
+/** Request the configuration for a specific 'bar' */
+#define I3_IPC_MESSAGE_TYPE_GET_BAR_CONFIG 6
+
+/** Request the i3 version */
+#define I3_IPC_MESSAGE_TYPE_GET_VERSION 7
+
+/** Request a list of configured binding modes. */
+#define I3_IPC_MESSAGE_TYPE_GET_BINDING_MODES 8
+
+/** Request the raw last loaded i3 config. */
+#define I3_IPC_MESSAGE_TYPE_GET_CONFIG 9
+
+/** Send a tick event to all subscribers. */
+#define I3_IPC_MESSAGE_TYPE_SEND_TICK 10
+
+/** Trigger an i3 sync protocol message via IPC. */
+#define I3_IPC_MESSAGE_TYPE_SYNC 11
+
+/*
+ * Messages from i3 to clients
+ *
+ */
+#define I3_IPC_REPLY_TYPE_COMMAND 0
+#define I3_IPC_REPLY_TYPE_WORKSPACES 1
+#define I3_IPC_REPLY_TYPE_SUBSCRIBE 2
+#define I3_IPC_REPLY_TYPE_OUTPUTS 3
+#define I3_IPC_REPLY_TYPE_TREE 4
+#define I3_IPC_REPLY_TYPE_MARKS 5
+#define I3_IPC_REPLY_TYPE_BAR_CONFIG 6
+#define I3_IPC_REPLY_TYPE_VERSION 7
+#define I3_IPC_REPLY_TYPE_BINDING_MODES 8
+#define I3_IPC_REPLY_TYPE_CONFIG 9
+#define I3_IPC_REPLY_TYPE_TICK 10
+#define I3_IPC_REPLY_TYPE_SYNC 11
+
+/*
+ * Events from i3 to clients. Events have the first bit set high.
+ *
+ */
+#define I3_IPC_EVENT_MASK (1UL << 31)
+
+/* The workspace event will be triggered upon changes in the workspace list */
+#define I3_IPC_EVENT_WORKSPACE (I3_IPC_EVENT_MASK | 0)
+
+/* The output event will be triggered upon changes in the output list */
+#define I3_IPC_EVENT_OUTPUT (I3_IPC_EVENT_MASK | 1)
+
+/* The output event will be triggered upon mode changes */
+#define I3_IPC_EVENT_MODE (I3_IPC_EVENT_MASK | 2)
+
+/* The window event will be triggered upon window changes */
+#define I3_IPC_EVENT_WINDOW (I3_IPC_EVENT_MASK | 3)
+
+/** Bar config update will be triggered to update the bar config */
+#define I3_IPC_EVENT_BARCONFIG_UPDATE (I3_IPC_EVENT_MASK | 4)
+
+/** The binding event will be triggered when bindings run */
+#define I3_IPC_EVENT_BINDING (I3_IPC_EVENT_MASK | 5)
+
+/** The shutdown event will be triggered when the ipc shuts down */
+#define I3_IPC_EVENT_SHUTDOWN (I3_IPC_EVENT_MASK | 6)
+
+/** The tick event will be sent upon a tick IPC message */
+#define I3_IPC_EVENT_TICK (I3_IPC_EVENT_MASK | 7)