1 files changed, 91 insertions, 0 deletions
diff --git a/cmake/keymap.cmake b/cmake/keymap.cmake
new file mode 100644
index 0000000..b7039f3
--- /dev/null
+++ b/cmake/keymap.cmake
@@ -0,0 +1,91 @@
+
+get_property(cached_keymap_value CACHE KEYMAP PROPERTY VALUE)
+
+# There are actually 4 sources, the three user input sources, and the
+# previously used value (CACHED_KEYMAP). The previously used value has
+# precedence, and if we detect that the user is trying to change the
+# value we give him a warning about needing to clean the build
+# directory to be able to change keymaps.
+
+set(keymap_cli_argument ${cached_keymap_value}) # Either new or old
+if(keymap_cli_argument STREQUAL CACHED_KEYMAP)
+	# We already have a CACHED_KEYMAP so there is no new input on the CLI
+  unset(keymap_cli_argument)
+endif()
+
+set(keymap_app_cmake_lists ${KEYMAP})
+if(cached_keymap_value STREQUAL KEYMAP)
+	# The app build scripts did not set a default, The KEYMAP we are
+  # reading is the cached value from the CLI
+  unset(keymap_app_cmake_lists)
+endif()
+
+if(CACHED_KEYMAP)
+  # Warn the user if it looks like he is trying to change the keymap
+  # without cleaning first
+  if(keymap_cli_argument)
+	  if(NOT (CACHED_KEYMAP STREQUAL keymap_cli_argument))
+      message(WARNING "The build directory must be cleaned pristinely when changing keymaps")
+      # TODO: Support changing keymaps without requiring a clean build
+    endif()
+  endif()
+
+  set(KEYMAP ${CACHED_KEYMAP})
+elseif(keymap_cli_argument)
+	set(KEYMAP ${keymap_cli_argument})
+
+elseif(DEFINED ENV{KEYMAP})
+	set(KEYMAP $ENV{KEYMAP})
+
+elseif(keymap_app_cmake_lists)
+	set(KEYMAP ${keymap_app_cmake_lists})
+
+else()
+	set(KEYMAP default)
+	message(STATUS "KEYMAP defaulted to 'default'")
+endif()
+
+message(STATUS "Keymap: ${KEYMAP}")
+
+# Store the selected keymap in the cache
+set(CACHED_KEYMAP ${KEYMAP} CACHE STRING "Selected keymap")
+
+set(ZMK_APP_DIR ${CMAKE_CURRENT_SOURCE_DIR})
+
+list(APPEND KEYMAP_DIRS ${ZMK_APP_DIR}/keymaps)
+
+foreach(root ${BOARD_ROOT})
+	find_path(BOARD_DIR
+	    NAMES ${BOARD}_defconfig
+	    PATHS ${root}/boards/*/*
+	    NO_DEFAULT_PATH
+	    )
+    	if(BOARD_DIR)
+		list(APPEND KEYMAP_DIRS ${BOARD_DIR}/keymaps)
+	endif()
+
+	if(DEFINED SHIELD)
+		find_path(shields_refs_list
+		    NAMES ${SHIELD}.overlay
+		    PATHS ${root}/boards/shields/*
+		    NO_DEFAULT_PATH
+		    )
+		foreach(shield_path ${shields_refs_list})
+			list(APPEND KEYMAP_DIRS ${shield_path}/keymaps)
+		endforeach()
+	endif()
+endforeach()
+
+foreach(keymap_root ${KEYMAP_DIRS})
+	find_path(KEYMAP_DIR
+		NAMES ${KEYMAP}
+		PATHS ${keymap_root}/*/*
+		NO_DEFAULT_PATH
+	)
+
+	if (KEYMAP_DIR)
+		message(STATUS "Using keymap directory: ${KEYMAP_DIR}/${KEYMAP}/")
+		set(DTC_OVERLAY_FILE ${KEYMAP_DIR}/${KEYMAP}/keymap.overlay)
+		break()
+	endif()
+endforeach()