Improves CMAKE, adds CI workflow, adds EVDEV pointer device support (#60

)

* Implements dist. independent dependency detection using pkg-config
Improves the cmake file

* Adds ci workflow that tests building the project in different environments using docker

* Adds support for evdev input pointer device to the example
Updates README

.github/workflows/build.yml

@@ -0,0 +1,62 @@
+name: Test building the project in different environments
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    strategy:
+      matrix:
+        os:
+          - { image: "debian:bullseye", dockerfile: "Dockerfile_DEBIAN" }
+          - { image: "debian:bookworm", dockerfile: "Dockerfile_DEBIAN" }
+          - { image: "ubuntu:20.04", dockerfile: "Dockerfile_DEBIAN" }
+          - { image: "ubuntu:22.04", dockerfile: "Dockerfile_DEBIAN" }
+          - { image: "rockylinux:8", dockerfile: "Dockerfile_RHEL" }
+          - { image: "rockylinux:9", dockerfile: "Dockerfile_RHEL" }
+          - { image: "oraclelinux:8", dockerfile: "Dockerfile_RHEL" }
+          - { image: "oraclelinux:9", dockerfile: "Dockerfile_RHEL" }
+      fail-fast: false
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+        with:
+          submodules: recursive
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v2
+
+      - name: Build the Docker image
+        run: |
+          docker build \
+            --build-arg BASE_OS=${{ matrix.os.image }} \
+            -f docker/${{ matrix.os.dockerfile }} \
+            -t test_${{ matrix.os.image }} .
+
+      - name: FBDEV Test building the project
+        run: |
+          sed -i "s/^#define LV_USE_LINUX_FBDEV.*$/#define LV_USE_LINUX_FBDEV 1/g" lv_conf.h && \
+          sed -i "s/^#define LV_USE_LINUX_DRM.*$/#define LV_USE_LINUX_DRM 0/g" lv_conf.h && \
+          sed -i "s/^#define LV_USE_SDL.*$/#define LV_USE_SDL 0/g" lv_conf.h && \
+          docker run --rm -v "$(pwd)":/workdir -t test_${{ matrix.os.image }} \
+          /bin/bash -ec "mkdir build/ && cd build/ && cmake .. && make -j && ldd ../bin/main"
+
+      - name: DRM Test building the project
+        run: |
+          sudo rm -Rf build/ bin/ && \
+          sed -i "s/^#define LV_USE_LINUX_FBDEV.*$/#define LV_USE_LINUX_FBDEV 0/g" lv_conf.h && \
+          sed -i "s/^#define LV_USE_LINUX_DRM.*$/#define LV_USE_LINUX_DRM 1/g" lv_conf.h && \
+          sed -i "s/^#define LV_USE_SDL.*$/#define LV_USE_SDL 0/g" lv_conf.h && \
+          docker run --rm -v "$(pwd)":/workdir -t test_${{ matrix.os.image }} \
+          /bin/bash -ec "mkdir build/ && cd build/ && cmake .. && make -j && ldd ../bin/main"
+
+      - name: SDL Test building the project
+        run: |
+          sudo rm -Rf build/ bin/ && \
+          sed -i "s/^#define LV_USE_LINUX_FBDEV.*$/#define LV_USE_LINUX_FBDEV 0/g" lv_conf.h && \
+          sed -i "s/^#define LV_USE_LINUX_DRM.*$/#define LV_USE_LINUX_DRM 0/g" lv_conf.h && \
+          sed -i "s/^#define LV_USE_SDL.*$/#define LV_USE_SDL 1/g" lv_conf.h && \
+          docker run --rm -v "$(pwd)":/workdir -t test_${{ matrix.os.image }} \
+          /bin/bash -ec "mkdir build/ && cd build/ && cmake .. && make -j && ldd ../bin/main"

CMakeLists.txt

@@ -8,17 +8,26 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(EXECUTABLE_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/bin)
 
 add_subdirectory(lvgl)
-target_include_directories(lvgl PUBLIC ${PROJECT_SOURCE_DIR})
-
 add_executable(main main.c mouse_cursor_icon.c)
 
-include(${CMAKE_CURRENT_LIST_DIR}/lvgl/tests/FindLibDRM.cmake)
-include_directories(${Libdrm_INCLUDE_DIRS})
-
-find_package(SDL2)
-find_package(SDL2_image)
-include_directories(${SDL2_INCLUDE_DIRS} ${SDL2_IMAGE_INCLUDE_DIRS})
-
-target_link_libraries(main lvgl lvgl::examples lvgl::demos lvgl::thorvg ${SDL2_LIBRARIES} ${SDL2_IMAGE_LIBRARIES} ${Libdrm_LIBRARIES} m pthread)
-add_custom_target (run COMMAND ${EXECUTABLE_OUTPUT_PATH}/main DEPENDS main)
+find_package(PkgConfig REQUIRED) # We use the platform independent pkg-config to find all the libs
+pkg_check_modules(LIBDRM REQUIRED libdrm)
+pkg_check_modules(SDL2 REQUIRED sdl2)
+pkg_check_modules(SDL2_image REQUIRED SDL2_image)
 
+target_include_directories(lvgl PUBLIC ${PROJECT_SOURCE_DIR})
+target_include_directories(lvgl PRIVATE ${SDL2_INCLUDE_DIRS})
+target_include_directories(lvgl PRIVATE ${SDL2_IMAGE_INCLUDE_DIRS})
+target_include_directories(lvgl PRIVATE ${LIBDRM_INCLUDE_DIRS})
+
+target_link_libraries(main PRIVATE lvgl) # Add '-static' if you want a standalone binary
+target_link_libraries(main PRIVATE lvgl::examples)
+target_link_libraries(main PRIVATE lvgl::demos)
+target_link_libraries(main PRIVATE lvgl::thorvg)
+target_link_libraries(main PRIVATE ${SDL2_LIBRARIES})
+target_link_libraries(main PRIVATE ${SDL2_IMAGE_LIBRARIES})
+target_link_libraries(main PRIVATE ${LIBDRM_LIBRARIES})
+target_link_libraries(main PRIVATE m)
+target_link_libraries(main PRIVATE pthread)
+
+add_custom_target(run COMMAND ${EXECUTABLE_OUTPUT_PATH}/main DEPENDS main)

README.md

@@ -11,6 +11,9 @@ resolution of 800x480.
 Check out this blog post for a step by step tutorial:
 https://blog.lvgl.io/2018-01-03/linux_fb
 
+## Build dependencies
+Check the [Dockerfiles](docker/) for the build dependencies.  
+
 ## Clone the project
 
 Clone the LVGL Framebuffer Demo project and its related sub modules.
@@ -70,6 +73,11 @@ The following variables are supported.
 
 - `LV_LINUX_FBDEV_DEVICE` - override default (`/dev/fb0`) framebuffer device node.
 
+
+### EVDEV touchscreen/mouse pointer device
+
+- `LV_LINUX_EVDEV_POINTER_DEVICE` - override default (`/dev/input/by-id/my-mouse-or-touchscreen`) input device
+
 ### DRM/KMS
 
 - `LV_LINUX_DRM_CARD` - override default (`/dev/dri/card0`) card.

docker/Dockerfile_DEBIAN

@@ -0,0 +1,16 @@
+ARG BASE_OS
+FROM "$BASE_OS"
+
+RUN DEBIAN_FRONTEND="noninteractive" apt-get update
+
+# Build tools
+RUN DEBIAN_FRONTEND="noninteractive" apt-get install -y make cmake build-essential
+
+# Required for LV_USE_SDL
+RUN DEBIAN_FRONTEND="noninteractive" apt-get install -y libsdl2-dev libsdl2-image-dev
+
+# Required for LV_USE_LINUX_DRM linux-headers-generic provides an included header file
+RUN DEBIAN_FRONTEND="noninteractive" apt-get install -y libdrm-dev linux-headers-generic
+
+RUN mkdir /workdir
+WORKDIR /workdir

docker/Dockerfile_RHEL

@@ -0,0 +1,31 @@
+ARG BASE_OS
+FROM "$BASE_OS"
+
+RUN dnf makecache --refresh
+RUN dnf -y install 'dnf-command(config-manager)'
+RUN dnf repolist --all
+
+# Rocky 8
+RUN dnf config-manager --set-enabled powertools || true
+
+# Oracle 8
+RUN dnf config-manager --set-enabled ol8_codeready_builder || true
+
+# Rocky/Oracle 9+
+RUN dnf config-manager --set-enabled crb || true
+
+RUN dnf -y install epel-release
+RUN dnf makecache --refresh
+
+# Build tools
+RUN dnf -y groupinstall "Development Tools"
+RUN dnf -y install cmake
+
+# Required for LV_USE_SDL
+RUN dnf -y install SDL2-devel SDL2_image-devel
+
+# Required for LV_USE_LINUX_DRM
+RUN dnf -y install libdrm-devel
+
+RUN mkdir /workdir
+WORKDIR /workdir

main.c

@@ -11,12 +11,34 @@ static const char *getenv_default(const char *name, const char *dflt)
     return getenv(name) ? : dflt;
 }
 
+#if LV_USE_EVDEV
+static void lv_linux_init_input_pointer(lv_display_t *disp)
+{
+    // Enables a pointer (touchscreen/mouse) input device
+    // Use 'evtest' to find the correct input device. /dev/input/by-id/ is recommeded if possible
+    // Use /dev/input/by-id/my-mouse-or-touchscreen or /dev/input/eventX
+    const char *input_device = getenv_default("LV_LINUX_EVDEV_POINTER_DEVICE", "/dev/input/by-id/my-mouse-or-touchscreen");
+    lv_indev_t *touch = lv_evdev_create(LV_INDEV_TYPE_POINTER, input_device); 
+    lv_indev_set_display(touch, disp);
+
+    // Disable this if you want no cursor
+    LV_IMAGE_DECLARE(mouse_cursor_icon); /*Declare the image source.*/
+    lv_obj_t * cursor_obj = lv_image_create(lv_screen_active()); /*Create an image object for the cursor */
+    lv_image_set_src(cursor_obj, &mouse_cursor_icon); /*Set the image source*/
+    lv_indev_set_cursor(touch, cursor_obj); /*Connect the image  object to the driver*/
+}
+#endif
+
 #if LV_USE_LINUX_FBDEV
 static void lv_linux_disp_init(void)
 {
     const char *device = getenv_default("LV_LINUX_FBDEV_DEVICE", "/dev/fb0");
     lv_display_t * disp = lv_linux_fbdev_create();
-
+
+    #if LV_USE_EVDEV
+    lv_linux_init_input_pointer(disp);
+    #endif
+
     lv_linux_fbdev_set_file(disp, device);
 }
 #elif LV_USE_LINUX_DRM
@@ -25,6 +47,10 @@ static void lv_linux_disp_init(void)
     const char *device = getenv_default("LV_LINUX_DRM_CARD", "/dev/dri/card0");
     lv_display_t * disp = lv_linux_drm_create();
 
+    #if LV_USE_EVDEV
+    lv_linux_init_input_pointer(disp);
+    #endif
+
     lv_linux_drm_set_file(disp, device, -1);
 }
 #elif LV_USE_SDL