From 5d946e37629b56be5b57931c1a3f0463dc8bd913 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Gr=C3=A4=C3=9Flin?= <mgraesslin@kde.org>
Date: Tue, 11 Aug 2015 13:50:35 +0200
Subject: [PATCH] Make X11_XCB a build dependency of X11 windowed backend

Let's rather not build the plugin if we don't have the dependency
then building it without OpenGL support. Simplifies the code a bit
and makes the backend overall more useful and goes along with e.g.
the Wayland one which has EGL also as a hard dependency for the
plugin.

REVIEW: 124697
---
 CMakeLists.txt                       |  2 +-
 backends/CMakeLists.txt              |  4 +++-
 backends/x11/CMakeLists.txt          |  5 +----
 backends/x11/x11windowed_backend.cpp | 13 -------------
 4 files changed, 5 insertions(+), 19 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c1b9c6c361..5687720dd9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -208,7 +208,7 @@ add_feature_info("XCB-ICCCM" XCB_ICCCM_FOUND "Required for building test applica
 
 find_package(X11_XCB)
 set_package_properties(X11_XCB PROPERTIES
-                       PURPOSE "Required for OpenGL support in X11 windowed backend of kwin_wayland"
+                       PURPOSE "Required for building X11 windowed backend of kwin_wayland"
                        TYPE OPTIONAL)
 
 ########### configure tests ###############
diff --git a/backends/CMakeLists.txt b/backends/CMakeLists.txt
index 809ac64edb..d3dc674bfe 100644
--- a/backends/CMakeLists.txt
+++ b/backends/CMakeLists.txt
@@ -6,4 +6,6 @@ if(HAVE_LIBHYBRIS)
     add_subdirectory(hwcomposer)
 endif()
 add_subdirectory(wayland)
-add_subdirectory(x11)
+if(X11_XCB_FOUND)
+    add_subdirectory(x11)
+endif()
diff --git a/backends/x11/CMakeLists.txt b/backends/x11/CMakeLists.txt
index 9ce72fad1a..9ac360768c 100644
--- a/backends/x11/CMakeLists.txt
+++ b/backends/x11/CMakeLists.txt
@@ -6,10 +6,7 @@ set(X11BACKEND_SOURCES
 )
 
 add_library(KWinWaylandX11Backend MODULE ${X11BACKEND_SOURCES})
-target_link_libraries(KWinWaylandX11Backend kwin)
-if(X11_XCB_FOUND)
-    target_link_libraries(KWinWaylandX11Backend X11::XCB)
-endif()
+target_link_libraries(KWinWaylandX11Backend kwin X11::XCB)
 
 install(
     TARGETS
diff --git a/backends/x11/x11windowed_backend.cpp b/backends/x11/x11windowed_backend.cpp
index 95a5b70ecf..74df134add 100644
--- a/backends/x11/x11windowed_backend.cpp
+++ b/backends/x11/x11windowed_backend.cpp
@@ -23,9 +23,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "logging.h"
 #include "wayland_server.h"
 #include "xcbutils.h"
-#if HAVE_X11_XCB
 #include "eglonxbackend.h"
-#endif
 #include <kwinxrenderutils.h>
 #include <QAbstractEventDispatcher>
 #include <QCoreApplication>
@@ -36,9 +34,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <KWayland/Server/surface_interface.h>
 // system
 #include <linux/input.h>
-#if HAVE_X11_XCB
 #include <X11/Xlib-xcb.h>
-#endif
 
 namespace KWin
 {
@@ -67,22 +63,16 @@ void X11WindowedBackend::init()
 {
     int screen = 0;
     xcb_connection_t *c = nullptr;
-#if HAVE_X11_XCB
     Display *xDisplay = XOpenDisplay(deviceIdentifier().constData());
     if (xDisplay) {
         c = XGetXCBConnection(xDisplay);
         XSetEventQueueOwner(xDisplay, XCBOwnsEventQueue);
         screen = XDefaultScreen(xDisplay);
     }
-#else
-    c = xcb_connect(deviceIdentifier().constData(), &screen);
-#endif
     if (c && !xcb_connection_has_error(c)) {
         m_connection = c;
         m_screenNumber = screen;
-#if HAVE_X11_XCB
         m_display = xDisplay;
-#endif
         for (xcb_screen_iterator_t it = xcb_setup_roots_iterator(xcb_get_setup(m_connection));
             it.rem;
             --screen, xcb_screen_next(&it)) {
@@ -325,10 +315,7 @@ Screens *X11WindowedBackend::createScreens(QObject *parent)
 
 OpenGLBackend *X11WindowedBackend::createOpenGLBackend()
 {
-#if HAVE_X11_XCB
     return  new EglOnXBackend(connection(), display(), rootWindow(), screenNumer(), window());
-#endif
-    return nullptr;
 }
 
 QPainterBackend *X11WindowedBackend::createQPainterBackend()