feat(wayland): add Wayland support (#51)

* fix(wayland) Rebase master to get the latest changes

* chore(wayland) adjust example code

* chore(wayland) align with driver, wait only if the cycle was fully completed

* feat(wayland) Simplify CMakeLists file

Use external scripts to obtain the selected backend in lv_conf.h
Generate wayland protocol via a shell script instead of CMake

* fix(wayland) - Remove test script

* doc(wayland) Update documentation

Remove the step that tells to edit the CMakeLists.txt file
and manually enable the option to select the backend

* feat(wayland) Move wayland display init and runloop to a separate file

Solve merge conflit with the main branch

* fix(wayland) Re-apply the delay timer execution only until the next timer fires up

* fix(wayland) adjust CI

* fix(wayland) fix CI

.github/workflows/build.yml

@@ -41,7 +41,7 @@ jobs:
           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"
+          /bin/bash -ec "cmake -B build -S . && make -j -C build && ldd bin/lvglsim"
 
       - name: DRM Test building the project
         run: |
@@ -50,7 +50,7 @@ jobs:
           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"
+          /bin/bash -ec "cmake -B build -S . && make -j -C build && ldd bin/lvglsim"
 
       - name: SDL Test building the project
         run: |
@@ -59,4 +59,5 @@ jobs:
           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"
+          /bin/bash -ec "cmake -B build -S . && make -j -C build && ldd bin/lvglsim"
+

CMakeLists.txt

@@ -1,33 +1,67 @@
 cmake_minimum_required(VERSION 3.10)
 project(lvgl)
 
-set(CMAKE_C_STANDARD 99)#C99 # lvgl officially support C99 and above
-set(CMAKE_CXX_STANDARD 17)#C17
-set(CMAKE_CXX_STANDARD_REQUIRED ON)
+foreach(BACKEND_NAME "SDL" "LINUX_DRM" "LINUX_FBDEV" "X11" "WAYLAND")
+    execute_process(COMMAND "scripts/backend_conf.sh" ${BACKEND_NAME} OUTPUT_VARIABLE IS_BACKEND_ENABLED)
+    set("LV_USE_${BACKEND_NAME}" ${IS_BACKEND_ENABLED})
+endforeach()
 
-set(EXECUTABLE_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/bin)
+# Uncomment if the program needs debugging
+#set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O0 -ggdb")
 
+set(CMAKE_C_STANDARD 99) # LVGL officially supports C99 and above
+set(CMAKE_CXX_STANDARD 17) #C17
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(EXECUTABLE_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/bin)
 add_subdirectory(lvgl)
-add_executable(main main.c mouse_cursor_icon.c)
+target_include_directories(lvgl PUBLIC ${PROJECT_SOURCE_DIR})
 
-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)
+if (LV_USE_LINUX_DRM)
 
-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)
+    find_package(PkgConfig REQUIRED)
+    pkg_check_modules(LIBDRM REQUIRED libdrm)
+
+    target_include_directories(lvgl PUBLIC ${LIBDRM_INCLUDE_DIRS})
+    add_executable(lvglsim main.c mouse_cursor_icon.c)
+    target_link_libraries(lvglsim lvgl lvgl::examples lvgl::demos lvgl::thorvg ${LIBDRM_LIBRARIES} m pthread)
+
+elseif (LV_USE_SDL)
+
+    find_package(PkgConfig REQUIRED)
+    pkg_check_modules(SDL2 REQUIRED sdl2)
+    pkg_check_modules(SDL2_image REQUIRED SDL2_image)
+
+    target_include_directories(lvgl PRIVATE ${SDL2_INCLUDE_DIRS})
+    target_include_directories(lvgl PRIVATE ${SDL2_IMAGE_INCLUDE_DIRS})
+    add_executable(lvglsim main.c mouse_cursor_icon.c)
+    target_link_libraries(lvglsim lvgl lvgl::examples lvgl::demos lvgl::thorvg ${SDL2_LIBRARIES} ${SDL2_IMAGE_LIBRARIES} m pthread)
+
+elseif (LV_USE_WAYLAND)
+
+    find_package(PkgConfig REQUIRED)
+    pkg_check_modules(wayland-client REQUIRED wayland-client)
+    pkg_check_modules(wayland-cursor REQUIRED wayland-cursor)
+    pkg_check_modules(xkbcommon REQUIRED xkbcommon)
+
+    # Wayland protocols
+    pkg_check_modules(WAYLAND_PROTOCOLS REQUIRED wayland-protocols>=1.25)
+    pkg_get_variable(WAYLAND_PROTOCOLS_BASE wayland-protocols pkgdatadir)
+
+    execute_process(COMMAND "scripts/gen_wl_protocols.sh" OUTPUT_VARIABLE WAYLAND_PROTOCOLS_SRC)
+
+    target_include_directories(lvgl PRIVATE ${PROJECT_SOURCE_DIR}
+                                            "${PROJECT_SOURCE_DIR}/wl_protocols")
+    add_executable(lvglsim main.c ${WAYLAND_PROTOCOLS_SRC} 
+        mouse_cursor_icon.c backends/wayland.c)
+    target_compile_definitions(lvglsim PRIVATE LV_CONF_INCLUDE_SIMPLE)
+    target_link_libraries(lvglsim lvgl lvgl::examples lvgl::demos lvgl::thorvg m
+        wayland-client wayland-cursor xkbcommon)
+
+else()
+
+    # No specific build steps required for FBDEV
+    add_executable(lvglsim main.c mouse_cursor_icon.c)
+    target_link_libraries(lvglsim lvgl lvgl::examples lvgl::demos lvgl::thorvg m pthread)
+endif()
+
+add_custom_target (run COMMAND ${EXECUTABLE_OUTPUT_PATH}/lvglsim DEPENDS lvglsim)

README.md

@@ -1,8 +1,8 @@
 # LVGL on top of Linux graphics stack
 
 Example project to use LVGL on top of Linux graphics stack.
-Currently supported backends are either legacy framebuffer
-(fbdev), modern DRM/KMS, or SDL2.
+Currently supported backends are legacy framebuffer
+(fbdev), modern DRM/KMS, Wayland or SDL2.
 
 By default, legacy framebuffer backend uses `/dev/fb0` device node,
 DRM/KMS backend uses '/dev/dri/card0' card node, SDL2 uses window
@@ -24,38 +24,47 @@ cd lv_port_linux/
 git submodule update --init --recursive
 ```
 
-## Select graphics backend (optional)
+## Select graphics backend
 
 To use legacy framebuffer (fbdev) support, adjust `lv_conf.h` as follows:
 ```
 #define LV_USE_LINUX_FBDEV	1
 #define LV_USE_LINUX_DRM	0
 #define LV_USE_SDL		0
+#define LV_USE_WAYLAND		0
 ```
 
 To use modern DRM/KMS support, adjust `lv_conf.h` as follows:
 ```
 #define LV_USE_LINUX_FBDEV	0
 #define LV_USE_LINUX_DRM	1
 #define LV_USE_SDL		0
+#define LV_USE_WAYLAND		0
 ```
 
 To use SDL2 support, adjust `lv_conf.h` as follows:
 ```
 #define LV_USE_LINUX_FBDEV	0
 #define LV_USE_LINUX_DRM	0
 #define LV_USE_SDL		1
+#define LV_USE_WAYLAND		0
+```
+
+
+To use wayland, adjust `lv_conf.h` as follows:
+```
+#define LV_USE_LINUX_FBDEV	0
+#define LV_USE_LINUX_DRM	0
+#define LV_USE_SDL		0
+#define LV_USE_WAYLAND		1
 ```
 
-## Build the project (cmake or Makefile)
 
 ### cmake
 
 ```
-mkdir build
-cd build 
-cmake ..
-make -j
+cmake -B build -S .
+make -C build -j
 ```
 
 ### Makefile
@@ -64,10 +73,25 @@ make -j
 make -j
 ```
 
+## Command line options
+
+Command line options are used to modify behavior of the demo, they take precedence over environment variables.
+
+### Wayland
+
+- `-f` - enters fullscreen on startup
+- `-m` - maximizes window on startup
+- `-w <window width>` - set the width of the window
+- `-h <window height>` - set the height of the window
+
+### SDL2
+
+- `-w <window width>` - set the width of the window
+- `-h <window height>` - set the height of the window
+
 ## Environment variables
 
-Environment variables can be set to modify behavior of the demo.
-The following variables are supported.
+Environment variables can be set to modify the behavior of the demo.
 
 ### Legacy framebuffer (fbdev)
 
@@ -84,19 +108,25 @@ The following variables are supported.
 
 ### SDL2
 
-- `LV_SDL_VIDEO_WIDTH` - width of SDL2 surface (default `800`).
-- `LV_SDL_VIDEO_HEIGHT` - height of SDL2 surface (default `480`).
+- `LV_SIM_WINDOW_WIDTH` - width of SDL2 surface (default `800`).
+- `LV_SIM_WINDOW_HEIGHT` - height of SDL2 surface (default `480`).
+
+### Wayland
+
+- `LV_SIM_WINDOW_WIDTH` - width of the window (default `800`).
+- `LV_SIM_WINDOW_HEIGHT` - height of the window (default `480`).
+
 
 ## Run the demo application
 
-### As root
+### FBDEV
 
-Normal users don't have access to `/dev/fb0` so use `sudo` (or see below) : 
+Unpriviledged users don't have access to the framebuffer device `/dev/fb0`
+`sudo` or `su` must be used.
 
 cmake:
 ```
-cd ../bin
-sudo main
+sudo ./bin/lvglsim
 ```
 
 Makefile:
@@ -105,23 +135,12 @@ cd build/bin/
 sudo main
 ```
 
-### Userland
-
-You can give a normal user access to the framebuffer by adding them to the `video` group : 
-
+Access to the framebuffer device can be granted by adding the unpriviledged user to the `video` group
 
 cmake:
 ```
 sudo adduser $USER video
 newgrp video
-cd ../bin
-./main
+./bin/lvglsim
 ```
 
-Makefile:
-```
-sudo adduser $USER video
-newgrp video
-cd build/bin/
-./main
-```

backends/interface.h

@@ -0,0 +1,6 @@
+
+/* Enters the run loop of the selected backend */
+void lv_linux_run_loop(void);
+
+/* Initializes the display */
+void lv_linux_disp_init(void);

backends/settings.h

@@ -0,0 +1,11 @@
+#include <stdbool.h>
+#include <stdint.h>
+
+/* Settings defined in main.c */
+
+extern uint16_t window_width;
+extern uint16_t window_height;
+
+extern bool fullscreen;
+extern bool maximize;
+

backends/wayland.c

@@ -0,0 +1,50 @@
+#include <unistd.h>
+#include <stdlib.h>
+
+#include "lvgl/lvgl.h"
+#include "settings.h"
+
+/* Currently, the wayland driver calls lv_timer_handler internaly */
+void lv_linux_run_loop(void)
+{
+
+    bool completed;
+
+    /* Handle LVGL tasks */
+    while (1) {
+
+        completed = lv_wayland_timer_handler();
+
+        if (completed) {
+            /* wait only if the cycle was completed */
+            usleep(LV_DEF_REFR_PERIOD * 1000);
+        }
+
+        /* Run until the last window closes */
+        if (!lv_wayland_window_is_open(NULL)) {
+            break;
+        }
+    }
+
+}
+
+void lv_linux_disp_init(void)
+{
+    lv_display_t *disp;
+    lv_group_t *g;
+
+    disp = lv_wayland_window_create(window_width, window_height,
+            "LVGL Simulator", NULL);
+
+    if (fullscreen) {
+            lv_wayland_window_set_fullscreen(disp, fullscreen);
+    } else if (maximize) {
+            lv_wayland_window_set_maximized(disp, maximize);
+    }
+
+    g = lv_group_create();
+    lv_group_set_default(g);
+    lv_indev_set_group(lv_wayland_get_keyboard(disp), g);
+    lv_indev_set_group(lv_wayland_get_pointeraxis(disp), g);
+
+}