Add flag to compile CLI-only (fix aseprite#1279)

New cmake flag -DENABLE_UI=OFF can be used to turn off the GUI
and compile a CLI-only version of Aseprite.

Requested here too:
https://community.aseprite.org/t/1351

.travis.yml

@@ -5,6 +5,11 @@ compiler:
   - clang
   - gcc
 
+env:
+  matrix:
+    - ENABLE_UI=OFF
+    - ENABLE_UI=ON
+
 before_install:
   - sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test
   - sudo apt-get update -qq
@@ -14,7 +19,7 @@ before_install:
 before_script:
   - mkdir build
   - cd build
-  - cmake .. -DENABLE_TESTS=ON
+  - cmake .. -DENABLE_TESTS=ON -DENABLE_UI=$ENABLE_UI
 
 script:
   - "make"

CMakeLists.txt

@@ -79,16 +79,26 @@ option(ENABLE_BENCHMARKS  "Compile benchmarks" off)
 option(ENABLE_TRIAL_MODE  "Compile the trial version" off)
 option(ENABLE_STEAM       "Compile with Steam library" off)
 option(ENABLE_DEVMODE     "Compile vesion for developers" off)
+option(ENABLE_UI          "Compile UI (turn off to compile CLI-only version)" on)
 option(FULLSCREEN_PLATFORM "Enable fullscreen by default" off)
 set(CUSTOM_WEBSITE_URL "" CACHE STRING "Enable custom local webserver to check updates")
 
-if(APPLE)
-  # On OS X Allegro isn't supported anymore
+if(NOT ENABLE_UI)
+  # Without UI, don't use back-ends
   set(USE_ALLEG4_BACKEND off)
-  set(USE_SKIA_BACKEND on)
+  set(USE_SKIA_BACKEND off)
+  set(USE_NONE_BACKEND on)
 else()
-  option(USE_ALLEG4_BACKEND "Use Allegro 4 backend" on)
-  option(USE_SKIA_BACKEND   "Use Skia backend" off)
+  if(APPLE)
+    # On OS X Allegro isn't supported anymore
+    set(USE_ALLEG4_BACKEND off)
+    set(USE_SKIA_BACKEND on)
+    set(USE_NONE_BACKEND off)
+  else()
+    option(USE_ALLEG4_BACKEND "Use Allegro 4 backend" on)
+    option(USE_SKIA_BACKEND   "Use Skia backend" off)
+    set(USE_NONE_BACKEND off)
+  endif()
 endif()
 
 # Check valid gtk + libpng combination

src/CMakeLists.txt

@@ -53,28 +53,36 @@ if(NOT "${CUSTOM_WEBSITE_URL}" STREQUAL "")
 endif()
 
 ######################################################################
-# Full-version or trial-mode?
+# With static libcurl
 
 if(NOT USE_SHARED_CURL AND CURL_STATICLIB)
   add_definitions(-DCURL_STATICLIB)
 endif()
 
 ######################################################################
-# Full-version or trial-mode?
+# Special versions (full/trial, devmode, UI/CLI, etc.)
 
 if(NOT ENABLE_TRIAL_MODE)
-  add_definitions(-DENABLE_SAVE -DENABLE_DATA_RECOVERY)
+  add_definitions(-DENABLE_SAVE)
 else()
   add_definitions(-DENABLE_TRIAL_MODE)
 endif()
 
-######################################################################
-# Special developer mode
-
 if(ENABLE_DEVMODE)
   add_definitions(-DENABLE_DEVMODE)
 endif()
 
+if(ENABLE_UI)
+  add_definitions(-DENABLE_UI)
+endif()
+
+if(ENABLE_UI AND NOT ENABLE_TRIAL_MODE)
+  set(ENABLE_DATA_RECOVERY on)
+  add_definitions(-DENABLE_DATA_RECOVERY)
+else()
+  set(ENABLE_DATA_RECOVERY off)
+endif()
+
 ######################################################################
 # Aseprite Libraries (in preferred order to be built)
 
@@ -170,16 +178,23 @@ if(WIN32)
     main/settings.manifest)
 endif()
 
-add_executable(aseprite WIN32
-  main/main.cpp
-  ${win32_resources})
+add_executable(aseprite main/main.cpp ${win32_resources})
+if(WIN32 AND ENABLE_UI)
+  set_target_properties(aseprite PROPERTIES WIN32_EXECUTABLE true)
+endif()
 target_link_libraries(aseprite app-lib ${PLATFORM_LIBS})
 add_dependencies(aseprite copy_data)
 
-if(MSVC AND USE_SKIA_BACKEND)
-  # Add support to expand filename wildcards in argc/argv
-  set_target_properties(aseprite
-    PROPERTIES LINK_FLAGS "-LINK wsetargv.obj -ENTRY:\"wWinMainCRTStartup\"")
+if(MSVC)
+  if(USE_SKIA_BACKEND)
+    # Linking with "wsetargv.obj" to add support to expand filename
+    # wildcards in argc/argv.
+    set_target_properties(aseprite
+      PROPERTIES LINK_FLAGS "-LINK wsetargv.obj -ENTRY:\"wWinMainCRTStartup\"")
+  else()
+    set_target_properties(aseprite
+      PROPERTIES LINK_FLAGS "-LINK wsetargv.obj -ENTRY:\"wmainCRTStartup\"")
+  endif()
 endif()
 
 install(TARGETS aseprite