Add a wrap() function to create a Connection object from a raw C pointer.

This is necessary to work with xcb_connection_t pointers obtained with a
ctype call to XGetXCBConnection() for making XCB calls on a previously
opened display, for example by GtkPython.

Signed-off-by: Eamon Walsh <ewalsh@tycho.nsa.gov>

3 files changed, 48 insertions, 1 deletions

diff --git a/src/conn.c b/src/conn.c
index ef19c16..6720e3b 100644
--- a/src/conn.c
+++ b/src/conn.c
@@ -46,6 +46,7 @@ xpybConn_create(PyObject *core_type)
     if (self->extcache == NULL)
 	goto err;
 
+    self->wrapped = 0;
     self->setup = NULL;
     self->events = NULL;
     self->events_len = 0;
@@ -189,7 +190,7 @@ xpybConn_dealloc(xpybConn *self)
     Py_CLEAR(self->setup);
     Py_CLEAR(self->extcache);
 
-    if (self->conn)
+    if (self->conn && !self->wrapped)
 	xcb_disconnect(self->conn);
 
     for (i = 0; i < self->events_len; i++)
diff --git a/src/conn.h b/src/conn.h
index bd98e0e..672f411 100644
--- a/src/conn.h
+++ b/src/conn.h
@@ -4,6 +4,7 @@
 typedef struct {
     PyObject_HEAD
     xcb_connection_t *conn;
+    int wrapped;
     PyObject *dict;
     int pref_screen;
     PyObject *core;
diff --git a/src/module.c b/src/module.c
index f97fc80..6ef4644 100644
--- a/src/module.c
+++ b/src/module.c
@@ -115,6 +115,46 @@ err:
 }
 
 static PyObject *
+xpyb_wrap(PyObject *self, PyObject *args)
+{
+    PyObject *obj;
+    void *raw;
+    xpybConn *conn;
+
+    /* Make sure core was set. */
+    if (xpybModule_core == NULL) {
+	PyErr_SetString(xpybExcept_base, "No core protocol object has been set.  Did you import xcb.xproto?");
+	return NULL;
+    }
+
+    /* Parse arguments and allocate new connection object */
+    if (!PyArg_ParseTuple(args, "O", &obj))
+	return NULL;
+
+    conn = xpybConn_create((PyObject *)xpybModule_core);
+    if (conn == NULL)
+	return NULL;
+
+    /* Get our pointer */
+    raw = PyLong_AsVoidPtr(obj);
+    if (!raw || PyErr_Occurred()) {
+	PyErr_SetString(xpybExcept_base, "Bad pointer value passed to wrap().");
+	goto err;
+    }
+
+    conn->conn = raw;
+    conn->wrapped = 1;
+
+    /* Load extensions */
+    if (xpybConn_setup(conn) < 0)
+	goto err;
+
+    return (PyObject *)conn;
+err:
+    Py_DECREF(conn);
+    return NULL;
+}
+static PyObject *
 xpyb_add_core(PyObject *self, PyObject *args)
 {
     PyTypeObject *value, *setup;
@@ -217,6 +257,11 @@ static PyMethodDef XCBMethods[] = {
       METH_VARARGS | METH_KEYWORDS,
       "Connects to the X server." },
 
+    { "wrap",
+      (PyCFunction)xpyb_wrap,
+      METH_VARARGS,
+      "Wraps an existing XCB connection pointer." },
+
     { "popcount",
       (PyCFunction)xpyb_popcount,
       METH_VARARGS,