From 53db43c2b2a19a26b11d3b83a9090beab9236de5 Mon Sep 17 00:00:00 2001
From: Uli Schlachter <psychon@znc.in>
Date: Sun, 10 Feb 2019 18:22:31 +0100
Subject: [PATCH] Emit a "request" signal on selection acquire objects

This now creates a selection transfer object and requests Lua to reply
to the request via this object. However, so far no answer is possible.

Signed-off-by: Uli Schlachter <psychon@znc.in>
---
 objects/selection_transfer.c | 77 ++++++++++++++++++++++++++++++++----
 1 file changed, 70 insertions(+), 7 deletions(-)

diff --git a/objects/selection_transfer.c b/objects/selection_transfer.c
index 040aea61..a5574c7a 100644
--- a/objects/selection_transfer.c
+++ b/objects/selection_transfer.c
@@ -21,13 +21,29 @@
 
 #include "objects/selection_transfer.h"
 #include "common/luaobject.h"
+#include "common/atoms.h"
 #include "globalconf.h"
 
 #define REGISTRY_TRANSFER_TABLE_INDEX "awesome_selection_transfers"
 
+enum transfer_state {
+    TRANSFER_WAIT_FOR_DATA,
+    TRANSFER_DONE
+};
+
 typedef struct selection_transfer_t
 {
     LUA_OBJECT_HEADER
+    /** Reference in the special table to this object */
+    int ref;
+    /* Information from the xcb_selection_request_event_t */
+    xcb_window_t requestor;
+    xcb_atom_t selection;
+    xcb_atom_t target;
+    xcb_atom_t property;
+    xcb_timestamp_t time;
+    /* Current state of the transfer */
+    enum transfer_state state;
 } selection_transfer_t;
 
 static lua_class_t selection_transfer_class;
@@ -58,22 +74,69 @@ selection_transfer_reject(xcb_window_t requestor, xcb_atom_t selection,
     selection_transfer_notify(requestor, selection, target, XCB_NONE, time);
 }
 
-#include "common/atoms.h" /* TODO remove */
+static void
+transfer_done(lua_State *L, selection_transfer_t *transfer)
+{
+    transfer->state = TRANSFER_DONE;
+
+    lua_pushliteral(L, REGISTRY_TRANSFER_TABLE_INDEX);
+    lua_rawget(L, LUA_REGISTRYINDEX);
+    luaL_unref(L, -1, transfer->ref);
+    transfer->ref = LUA_NOREF;
+    lua_pop(L, 1);
+}
+
 void
 selection_transfer_begin(lua_State *L, int ud, xcb_window_t requestor,
         xcb_atom_t selection, xcb_atom_t target, xcb_atom_t property,
         xcb_timestamp_t time)
 {
-    /* TODO implement this */
-    xcb_change_property(globalconf.connection, XCB_PROP_MODE_REPLACE,
-            requestor, property, UTF8_STRING, 8, 5, "Test\n");
-    selection_transfer_notify(requestor, selection, target, property, time);
+    ud = luaA_absindex(L, ud);
+
+    /* Allocate a transfer object */
+    selection_transfer_t *transfer = (void *) selection_transfer_class.allocator(L);
+    transfer->requestor = requestor;
+    transfer->selection = selection;
+    transfer->target = target;
+    transfer->property = property;
+    transfer->time = time;
+    transfer->state = TRANSFER_WAIT_FOR_DATA;
+
+    /* Save the object in the registry */
+    lua_pushliteral(L, REGISTRY_TRANSFER_TABLE_INDEX);
+    lua_rawget(L, LUA_REGISTRYINDEX);
+    lua_pushvalue(L, -2);
+    transfer->ref = luaL_ref(L, -2);
+    lua_pop(L, 1);
+
+    /* Get the atom name */
+    xcb_get_atom_name_reply_t *reply = xcb_get_atom_name_reply(globalconf.connection,
+            xcb_get_atom_name_unchecked(globalconf.connection, target), NULL);
+    if (reply) {
+        lua_pushlstring(L, xcb_get_atom_name_name(reply),
+                xcb_get_atom_name_name_length(reply));
+        p_delete(&reply);
+    } else
+        lua_pushnil(L);
+
+    /* Emit the request signal with target and transfer object */
+    lua_pushvalue(L, -2);
+    luaA_object_emit_signal(L, ud, "request", 2);
+
+    /* Reject the transfer if Lua did not do anything */
+    if (transfer->state == TRANSFER_WAIT_FOR_DATA) {
+        selection_transfer_reject(requestor, selection, target, time);
+        transfer_done(L, transfer);
+    }
+
+    /* Remove the transfer object from the stack */
+    lua_pop(L, 1);
 }
 
 static bool
-selection_transfer_checker(selection_transfer_t *selection)
+selection_transfer_checker(selection_transfer_t *transfer)
 {
-    return true;
+    return transfer->state != TRANSFER_DONE;
 }
 
 void