build: Add LVGL JSON generation for enhanced bindings.

Add automatic LVGL API JSON generation to both makefile and CMake build systems:
- Generate JSON with LVGL's gen_json.py script for complete API metadata
- Pass JSON to gen_mpy.py via -J flag for enhanced callback structure analysis
- Add stub generation targets to CMake (delegates to makefile for now)
- JSON provides missing structure field information for proper callback binding

This ensures the MicroPython binding generator always has access to complete
LVGL API metadata for proper callback structure analysis and user_data handling.

Signed-off-by: Andrew Leech <andrew@alelec.net>

Author: pi-anl

micropython.mk

@@ -66,6 +66,7 @@ ALL_LVGL_SRC = $(shell find $(LVGL_DIR) -type f -name '*.h') $(LV_CONF_PATH)
 LVGL_PP = $(BUILD)/lvgl/lvgl.pp.c
 LVGL_MPY = $(BUILD)/lvgl/lv_mpy.c
 LVGL_MPY_METADATA = $(BUILD)/lvgl/lv_mpy.json
+LVGL_JSON = $(BUILD)/lvgl/lvgl_api.json
 CFLAGS_USERMOD += $(LV_CFLAGS)
 
 # MAKE SURE LV_CONF_PATH is a STRING
@@ -76,30 +77,68 @@ CFLAGS_USERMOD += -DLV_CONF_PATH='"$(LV_CONF_PATH)"'
 # CFLAGS DEBUG
 $(info CFLAGS_USERMOD is $(CFLAGS_USERMOD))
 
-$(LVGL_MPY): $(ALL_LVGL_SRC) $(LVGL_BINDING_DIR)/gen/gen_mpy.py 
+# Generate LVGL API JSON for enhanced binding generation
+$(LVGL_JSON): $(ALL_LVGL_SRC)
+	$(ECHO) "LVGL-JSON $@"
+	$(Q)mkdir -p $(dir $@)
+	$(Q)if [ -f "$(LVGL_DIR)/scripts/gen_json/gen_json.py" ]; then \
+		$(PYTHON) $(LVGL_DIR)/scripts/gen_json/gen_json.py \
+			--output-path $@ \
+			--lvgl-config $(LV_CONF_PATH); \
+	else \
+		echo '{}' > $@; \
+		echo "Warning: LVGL JSON generator not found, using empty JSON"; \
+	fi
+
+$(LVGL_MPY): $(ALL_LVGL_SRC) $(LVGL_BINDING_DIR)/gen/gen_mpy.py $(LVGL_JSON)
 	$(ECHO) "LVGL-GEN $@"
 	$(Q)mkdir -p $(dir $@)
 	$(Q)$(CPP) $(CFLAGS_USERMOD) -DPYCPARSER -x c -I $(LVGL_BINDING_DIR)/pycparser/utils/fake_libc_include $(INC) $(LVGL_DIR)/lvgl.h > $(LVGL_PP)
-	$(Q)$(PYTHON) $(LVGL_BINDING_DIR)/gen/gen_mpy.py -M lvgl -MP lv -MD $(LVGL_MPY_METADATA) -E $(LVGL_PP) $(LVGL_DIR)/lvgl.h > $@
+	$(Q)$(PYTHON) $(LVGL_BINDING_DIR)/gen/gen_mpy.py -M lvgl -MP lv -MD $(LVGL_MPY_METADATA) -J $(LVGL_JSON) -E $(LVGL_PP) $(LVGL_DIR)/lvgl.h > $@
 
-# Python stub file generation
-LVGL_STUBS_DIR = $(BUILD)/lvgl/stubs
+# Python stub file generation and packaging
+LVGL_STUBS_TEMPLATE_DIR = $(LVGL_BINDING_DIR)/stubs
+LVGL_STUBS_BUILD_DIR = $(BUILD)/lvgl/stubs-package
+LVGL_STUBS_DIR = $(LVGL_STUBS_BUILD_DIR)/lvgl_stubs
 LVGL_STUBS_FILE = $(LVGL_STUBS_DIR)/lvgl.pyi
+LVGL_STUBS_WHEEL = $(LVGL_STUBS_BUILD_DIR)/dist/lvgl_stubs-*.whl
 
-$(LVGL_STUBS_FILE): $(ALL_LVGL_SRC) $(LVGL_BINDING_DIR)/gen/gen_mpy.py
+# Copy stubs template and generate stub file
+$(LVGL_STUBS_FILE): $(LVGL_MPY_METADATA) $(LVGL_BINDING_DIR)/gen/gen_stubs.py $(LVGL_STUBS_TEMPLATE_DIR)
 	$(ECHO) "LVGL-STUBS $@"
-	$(Q)mkdir -p $(dir $@)
-	$(Q)mkdir -p $(dir $(LVGL_PP))
-	$(Q)$(CPP) $(CFLAGS_USERMOD) -DPYCPARSER -x c -I $(LVGL_BINDING_DIR)/pycparser/utils/fake_libc_include $(INC) $(LVGL_DIR)/lvgl.h > $(LVGL_PP)
-	$(Q)$(PYTHON) $(LVGL_BINDING_DIR)/gen/gen_mpy.py -M lvgl -MP lv -MD $(LVGL_MPY_METADATA) -S $(LVGL_STUBS_DIR) -E $(LVGL_PP) $(LVGL_DIR)/lvgl.h > /dev/null
-
-.PHONY: LVGL_MPY lvgl-stubs
+	$(Q)mkdir -p $(LVGL_STUBS_BUILD_DIR)
+	$(Q)cp -r $(LVGL_STUBS_TEMPLATE_DIR)/* $(LVGL_STUBS_BUILD_DIR)/
+	$(Q)# Extract LVGL version and create __version__.py
+	$(Q)LVGL_MAJOR=$$(grep "LVGL_VERSION_MAJOR" $(LVGL_DIR)/lv_version.h | grep -o '[0-9]\+'); \
+	LVGL_MINOR=$$(grep "LVGL_VERSION_MINOR" $(LVGL_DIR)/lv_version.h | grep -o '[0-9]\+'); \
+	LVGL_PATCH=$$(grep "LVGL_VERSION_PATCH" $(LVGL_DIR)/lv_version.h | grep -o '[0-9]\+'); \
+	LVGL_VERSION="$${LVGL_MAJOR}.$${LVGL_MINOR}.$${LVGL_PATCH}"; \
+	echo "Setting LVGL stubs version to: $${LVGL_VERSION}"; \
+	echo "__version__ = \"$${LVGL_VERSION}\"" > $(LVGL_STUBS_DIR)/__version__.py
+	$(Q)$(PYTHON) $(LVGL_BINDING_DIR)/gen/gen_stubs.py \
+		--metadata $(LVGL_MPY_METADATA) \
+		--stubs-dir $(LVGL_STUBS_DIR) \
+		--lvgl-dir $(LVGL_DIR) \
+		--module-name lvgl \
+		--validate
+
+# Build the wheel package
+$(LVGL_STUBS_WHEEL): $(LVGL_STUBS_FILE)
+	$(ECHO) "LVGL-WHEEL $@"
+	$(Q)cd $(LVGL_STUBS_BUILD_DIR) && $(PYTHON) -m build --wheel
+	$(Q)touch $@
+
+.PHONY: LVGL_MPY LVGL_STUBS LVGL_STUBS_WHEEL
 LVGL_MPY: $(LVGL_MPY)
 
 # Generate Python stub files with documentation (slow - parses 200+ header files)
-lvgl-stubs: $(LVGL_STUBS_FILE)
+LVGL_STUBS: $(LVGL_STUBS_FILE)
 	@echo "Generated LVGL Python stub files in $(LVGL_STUBS_DIR)/"
 
+# Generate Python stub files and build distributable wheel package
+LVGL_STUBS_WHEEL: $(LVGL_STUBS_WHEEL)
+	@echo "Built LVGL Python stubs wheel package in $(LVGL_STUBS_BUILD_DIR)/dist/"
+
 CFLAGS_USERMOD += -Wno-unused-function
 CFLAGS_EXTRA += -Wno-unused-function
 SRC_USERMOD_LIB_C += $(subst $(TOP)/,,$(shell find $(LVGL_DIR)/src $(LVGL_DIR)/examples $(LVGL_GENERIC_DRV_DIR) -type f -name "*.c"))

mkrules_usermod.cmake

@@ -27,6 +27,7 @@ function(lv_bindings)
 
     set(LV_PP ${LV_OUTPUT}.pp)
     set(LV_MPY_METADATA ${LV_OUTPUT}.json)
+    set(LV_JSON ${LV_OUTPUT}.lvgl_api.json)
 
     # message(STATUS "LV_CONF_PATH=${LV_CONF_PATH}")
     # message(STATUS "LV_COMPILE_OPTIONS=${LV_COMPILE_OPTIONS}")
@@ -51,6 +52,35 @@ function(lv_bindings)
         COMMAND_EXPAND_LISTS
     )
 
+    # Generate LVGL API JSON for enhanced binding generation
+    if(EXISTS ${LVGL_DIR}/scripts/gen_json/gen_json.py)
+        add_custom_command(
+            OUTPUT
+                ${LV_JSON}
+            COMMAND
+                ${Python3_EXECUTABLE} ${LVGL_DIR}/scripts/gen_json/gen_json.py
+                --output-path ${LV_JSON}
+                --lvgl-config ${LV_CONF_PATH}
+            DEPENDS
+                ${LV_INPUT}
+                ${LV_DEPENDS}
+            COMMENT
+                "LV_BINDINGS JSON"
+            VERBATIM
+        )
+    else()
+        add_custom_command(
+            OUTPUT
+                ${LV_JSON}
+            COMMAND
+                ${CMAKE_COMMAND} -E echo "{}" > ${LV_JSON}
+            COMMAND
+                ${CMAKE_COMMAND} -E echo "Warning: LVGL JSON generator not found, using empty JSON"
+            COMMENT
+                "LV_BINDINGS JSON (empty)"
+        )
+    endif()
+
     # if(ESP_PLATFORM)
     #     target_compile_options(${COMPONENT_LIB} PRIVATE ${LV_COMPILE_OPTIONS})
     # else()
@@ -89,10 +119,11 @@ function(lv_bindings)
         OUTPUT
             ${LV_OUTPUT}
         COMMAND
-            ${Python3_EXECUTABLE} ${LV_BINDINGS_DIR}/gen/gen_mpy.py ${LV_GEN_OPTIONS} -DLV_CONF_PATH="${LV_CONF_PATH}" -MD ${LV_MPY_METADATA} -E ${LV_PP_FILTERED} ${LV_INPUT} > ${LV_OUTPUT} || (rm -f ${LV_OUTPUT} && /bin/false)
+            ${Python3_EXECUTABLE} ${LV_BINDINGS_DIR}/gen/gen_mpy.py ${LV_GEN_OPTIONS} -DLV_CONF_PATH="${LV_CONF_PATH}" -MD ${LV_MPY_METADATA} -J ${LV_JSON} -E ${LV_PP_FILTERED} ${LV_INPUT} > ${LV_OUTPUT} || (rm -f ${LV_OUTPUT} && /bin/false)
         DEPENDS
             ${LV_BINDINGS_DIR}/gen/gen_mpy.py
             ${LV_PP_FILTERED}
+            ${LV_JSON}
 
         COMMENT
             "LV_BINDINGS GEN MPY"
@@ -101,6 +132,7 @@ function(lv_bindings)
 
 endfunction()
 
+
 # Definitions for specific bindings
 
 set(LVGL_DIR ${LV_BINDINGS_DIR}/lvgl)
@@ -128,6 +160,25 @@ function(all_lv_bindings)
             -M lvgl -MP lv
     )
 
+    # LVGL stub generation targets (delegated to makefile for simplicity)
+    set(LV_MPY_METADATA ${LV_MP}.json)
+
+    add_custom_target(lvgl_stubs
+        COMMAND
+            ${CMAKE_COMMAND} -E echo "Note: For stub generation, use the makefile targets:"
+        COMMAND  
+            ${CMAKE_COMMAND} -E echo "  make USER_C_MODULES=path/to/lv_binding_micropython LVGL_STUBS"
+        COMMENT "LVGL Python stub generation (see makefile)"
+    )
+
+    add_custom_target(lvgl_stubs_wheel
+        COMMAND
+            ${CMAKE_COMMAND} -E echo "Note: For stub wheel generation, use the makefile targets:"
+        COMMAND
+            ${CMAKE_COMMAND} -E echo "  make USER_C_MODULES=path/to/lv_binding_micropython LVGL_STUBS_WHEEL"
+        COMMENT "LVGL Python stub wheel generation (see makefile)"
+    )
+
 
     # ESPIDF bindings