[services] kernel-switcher: add opengl switcher, improve application output

services/kernel-switcher

@@ -17,6 +17,7 @@ from entropy.exceptions import DependenciesNotRemovable
 from entropy.i18n import _
 from entropy.client.interfaces import Client
 import entropy.dep
+import entropy.tools
 
 # equo modules
 from text_query import print_package_info
@@ -56,9 +57,29 @@ def _get_target_tag(etp_client, kernel_match):
 
 def _setup_kernel_symlink(target_tag):
     eselect_exec = "/usr/bin/eselect"
-    if os.access(eselect_exec, os.X_OK) and not etpUi['pretend']:
+    if os.access(eselect_exec, os.X_OK):
         subprocess.call((eselect_exec, "kernel", "set", target_tag))
 
+# removing and installing proprietary drivers might reset the selected
+# OpenGL implementation
+
+def _get_opengl_impl():
+    eselect_exec = "/usr/bin/eselect"
+    sts = 1
+    out = "xorg-x11"
+    if os.access(eselect_exec, os.X_OK) and not etpUi['pretend']:
+        sts, xout = entropy.tools.getstatusoutput("%s opengl show" % (
+            eselect_exec,))
+        if sts == 0:
+            out = xout
+    return out
+
+def _set_opengl_impl(opengl):
+    eselect_exec = "/usr/bin/eselect"
+    if os.access(eselect_exec, os.X_OK):
+        args = (eselect_exec, "opengl", "set", opengl)
+        subprocess.call(args)
+
 def _show_kernel_warnings(kernel_atom):
     print_info("%s %s" % (purple(kernel_atom), teal(_("has been installed."))))
     print_warning("%s: %s" % (red(_("Attention")),
@@ -124,12 +145,14 @@ def _switch_kernel(args):
         matches = [x for x in matches if x is not None]
         matches.append(kernel_match)
 
+        opengl = _get_opengl_impl()
         rc, other = install_packages(
             etp_client,
             atomsdata = matches,
             check_critical_updates = False
         )
-        if rc == 0:
+        if (rc == 0) and (not etpUi['pretend']):
+            _set_opengl_impl(opengl)
             _setup_kernel_symlink(target_tag)
             _show_kernel_warnings(kernel_atom)
         return rc