Use glfw 3.3 functions for the primary selection

Allows us to drop the dependency on xsel for systems with glfw 3.3

README.asciidoc

@@ -85,7 +85,8 @@ the following dependencies are installed first.
 * libpng
 * glew   >= 2.0 (not needed on macOS)
 * fontconfig (not needed on macOS)
-* xrdb and xsel (only on X11 based systems)
+* xrdb (only on X11 based systems)
+* xsel (only on X11 systems with glfw < 3.3)
 * ImageMagick (optional, needed to use the `kitty icat` tool to display images in the terminal)
 * gcc or clang (required only for building)
 * pkg-config (required only for building)

kitty/data-types.c

@@ -139,6 +139,7 @@ extern bool init_keys(PyObject *module);
 extern bool init_graphics(PyObject *module);
 extern bool init_shaders(PyObject *module);
 extern bool init_shaders_debug(PyObject *module);
+extern bool init_x11_funcs(PyObject *module);
 #ifdef __APPLE__
 extern int init_CoreText(PyObject *);
 extern bool init_cocoa(PyObject *module);
@@ -180,6 +181,7 @@ PyInit_fast_data_types(void) {
         if (!init_Face(m)) return NULL;
         if (!init_freetype_library(m)) return NULL;
         if (!init_fontconfig_library(m)) return NULL;
+        if (!init_x11_funcs(m)) return NULL;
 #endif
 
 #define OOF(n) #n, offsetof(Cell, n)

kitty/utils.py

@@ -163,8 +163,10 @@ def parse_color_set(raw):
 def get_primary_selection():
     if isosx:
         return ''  # There is no primary selection on OS X
-    # glfw has no way to get the primary selection
-    # https://github.com/glfw/glfw/issues/894
+    try:
+        from .fast_data_types import get_selection_x11
+        ans = (get_selection_x11() or b'').decode('utf-8', 'replace')
+    except ImportError:
         ans = subprocess.check_output(['xsel', '-p'], stderr=open(os.devnull, 'wb'), stdin=open(os.devnull, 'rb')).decode('utf-8')
         if ans:
             # Without this for some reason repeated pastes dont work
@@ -191,6 +193,10 @@ def set_primary_selection(text):
         return  # There is no primary selection on OS X
     if isinstance(text, str):
         text = text.encode('utf-8')
+    try:
+        from .fast_data_types import set_selection_x11
+        set_selection_x11(text)
+    except ImportError:
         p = subprocess.Popen(['xsel', '-i', '-p'], stdin=subprocess.PIPE, stdout=open(os.devnull, 'wb'), stderr=subprocess.STDOUT)
         p.stdin.write(text), p.stdin.close()
         p.wait()

kitty/x11.c

@@ -0,0 +1,49 @@
+/*
+ * x11.c
+ * Copyright (C) 2017 Kovid Goyal <kovid at kovidgoyal.net>
+ *
+ * Distributed under terms of the GPL3 license.
+ */
+
+#include <Python.h>
+#include <stdbool.h>
+#include <GLFW/glfw3.h>
+#if GLFW_VERSION_MAJOR > 3 || (GLFW_VERSION_MAJOR == 3 && GLFW_VERSION_MINOR > 2)
+#define HAS_X11_SELECTION
+#endif
+
+#ifdef HAS_X11_SELECTION
+#define GLFW_EXPOSE_NATIVE_X11
+#include <GLFW/glfw3native.h>
+
+static PyObject*
+get_selection_x11(PyObject *self) {
+    (void)(self);
+    return Py_BuildValue("y", glfwGetX11SelectionString());
+}
+
+static PyObject*
+set_selection_x11(PyObject *self, PyObject *args) {
+    (void)(self);
+    const char *data;
+    if (!PyArg_ParseTuple(args, "y", &data)) return NULL;
+    glfwSetX11SelectionString(data);
+    Py_RETURN_NONE;
+}
+
+static PyMethodDef sel_methods[] = {
+    {"get_selection_x11", (PyCFunction)get_selection_x11, METH_NOARGS, ""},
+    {"set_selection_x11", (PyCFunction)set_selection_x11, METH_VARARGS, ""},
+    {NULL, NULL, 0, NULL}        /* Sentinel */
+};
+
+
+#endif
+
+bool 
+init_x11_funcs(PyObject *module) { 
+#ifdef HAS_X11_SELECTION
+    if (PyModule_AddFunctions(module, sel_methods) != 0) return false;
+#endif
+    return true; 
+}