Make libevdev and x11 optional dependencies...

...but at least one have to be satisfied for build

CMakeLists.txt

@@ -2,8 +2,6 @@ cmake_minimum_required(VERSION 3.6)
 
 project(xautoclick VERSION 0.34)
 
-find_package(X11 REQUIRED)
-
 include(CheckIncludeFile)
 check_include_file("unistd.h" HAVE_UNISTD)
 if(${HAVE_UNISTD})
@@ -11,20 +9,35 @@ if(${HAVE_UNISTD})
     # TODO add_compile_definitions(HAVE_UNISTD_H)
 endif()
 
+find_package(X11)
+if(X11_FOUND)
 add_library(x11clicker STATIC
     x11clicker.c
     x11clicker.h
 )
 target_link_libraries(x11clicker ${X11_LIBRARIES} ${X11_XTest_LIB})
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DHAVE_X11_CLICKER")
+list(APPEND CLICKERS x11clicker)
+endif()
 
-find_package(PkgConfig REQUIRED)
+find_package(PkgConfig)
+if(PKG_CONFIG_FOUND)
 pkg_check_modules(LIBEVDEV libevdev)
+if(LIBEVDEV_FOUND)
 add_library(udevclicker STATIC
     udevclicker.c
     udevclicker.h
 )
 target_include_directories(udevclicker PRIVATE ${LIBEVDEV_INCLUDE_DIRS})
 target_link_libraries(udevclicker ${LIBEVDEV_LIBRARIES})
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DHAVE_UDEV_CLICKER")
+list(APPEND CLICKERS udevclicker)
+endif(LIBEVDEV_FOUND)
+endif(PKG_CONFIG_FOUND)
+
+if(NOT clickers)
+    message(FATAL_ERROR "No clicker engines could be built.")
+endif()
 
 add_library(clicker STATIC
     clicker.c
@@ -37,7 +50,7 @@ add_library(clicker STATIC
     options.h
     osdep.h
 )
-target_link_libraries(clicker udevclicker x11clicker)
+target_link_libraries(clicker ${CLICKERS})
 
 add_executable(aautoclick
     guiascii.c

README.md

@@ -26,19 +26,31 @@ Currently, xAutoClick has GUI front-ends for X11/CLI, X11/FLTK, X11/GTK+ 3.0 and
 
 ## Compilation
 
+### Dependencies
+
 Dependency | Debian / Ubuntu
 -- | --
-CMake      | `cmake`
+CMake | `cmake`
+
+At least one of clicker engines
+
+X11 clicker engine | Debian / Ubuntu
+-- | --
+libxtst | `libxtst-dev`
+
+Udev clicker engine | Debian / Ubuntu
+-- | --
 libevdev   | `libevdev-dev`
-libxtst    | `libxtst-dev`
 pkg-config | `pkgconf` or `pkg-config`
 
-Optional | Debian / Ubuntu
+Optional GUI | Debian / Ubuntu
 -- | --
 FLTK | `libfltk1.3-dev`
 GTK3 | `libgtk-3-dev`
 Qt5  | `qtbase5-dev`
 
+### Build
+
 To prepare, run:
 
 ```sh
@@ -53,6 +65,16 @@ To build if all is fine (at least one GUI must be set to yes), run:
 cmake --build .
 ```
 
+### Install
+
+To install, run:
+
+```sh
+sudo cmake --build . --target install
+```
+
+### Run
+
 To run without installation, use one of compiled executables in `./build` according to:
 
 GUI | Executable
@@ -63,12 +85,6 @@ FLTK  | `fltkautoclick`
 GTK   | `gautoclick3`
 Qt    | `qt5autoclick`
 
-To install, run:
-
-```sh
-sudo cmake --build . --target install
-```
-
 ## Authors
 
 Core, ASCII, GTK1, GTK2, QT3, QT4, FLTK, Command Line, build system: [Ivo van Poorten](https://github.com/ivop) <ivop@euronet.nl> <ivop@free.fr>

clicker.c

@@ -21,8 +21,12 @@
 
 #include "clicker.h"
 
+#ifdef HAVE_UDEV_CLICKER
 #include "udevclicker.h"
+#endif
+#ifdef HAVE_X11_CLICKER
 #include "x11clicker.h"
+#endif
 
 #include <stdlib.h>
 
@@ -39,8 +43,12 @@ static clicker_t* clicker_create(clicker_type_t type) {
         return NULL;
 
     switch (type) {
+#ifdef HAVE_UDEV_CLICKER
     case CLICKER_UDEV: udev_clicker_init(clicker); break;
+#endif
+#ifdef HAVE_X11_CLICKER
     case CLICKER_X11: x11_clicker_init(clicker); break;
+#endif
     default: break;
     }