doc: Post-process all auto-generated SVG.

This removes the hardcoded foreground color and inherit it from
the browser and/or CSS stylesheet.

This commit only support the foreground colors, future changes could
extend it to support all standard colors.

tests/examples/CMakeLists.txt

@@ -71,7 +71,9 @@ ${LUA_PATH_}")
 set(LUA_COV_RUNNER env -u LUA_PATH_5_1 -u LUA_PATH_5_2 -u LUA_PATH_5_3 "LUA_PATH=${LUA_PATH_}" "AWESOME_THEMES_PATH=${TOP_SOURCE_DIR}/themes/" "SOURCE_DIRECTORY=${TOP_SOURCE_DIR}" ${LUA_COV_RUNNER})
 
 # The documentation images directory.
+set(RAW_IMAGE_DIR "${CMAKE_BINARY_DIR}/raw_images")
 set(IMAGE_DIR "${CMAKE_BINARY_DIR}/doc/images")
+file(MAKE_DIRECTORY "${RAW_IMAGE_DIR}")
 file(MAKE_DIRECTORY "${IMAGE_DIR}")
 
 # Escape potentially multiline strings to be part of the API doc.
@@ -221,6 +223,7 @@ function(run_test test_path namespace escaped_content)
 
     # Get the file name without the extension.
     get_filename_component(${test_path} TEST_FILE_NAME NAME)
+    set(RAW_IMAGE_PATH "${RAW_IMAGE_DIR}/AUTOGEN${namespace}_${TEST_FILE_NAME}")
     set(IMAGE_PATH "${IMAGE_DIR}/AUTOGEN${namespace}_${TEST_FILE_NAME}")
 
     # Read the code and turn it into an usage example.
@@ -231,12 +234,14 @@ function(run_test test_path namespace escaped_content)
 
     # Does the test generate an output image?
     if(tmp_content MATCHES "--DOC_GEN_IMAGE")
+        set(OUTPUT_RAW_IMAGE_PATH "${RAW_IMAGE_PATH}.svg")
         set(OUTPUT_IMAGE_PATH "${IMAGE_PATH}.svg")
         escape_string(
             "![Usage example](../images/AUTOGEN${namespace}_${TEST_FILE_NAME}.svg)\n"
             "${TEST_DOC_CONTENT}" TEST_DOC_CONTENT ""
         )
     else()
+        set(OUTPUT_RAW_IMAGE_PATH "")
         set(OUTPUT_IMAGE_PATH "")
     endif()
 
@@ -294,30 +299,44 @@ function(run_test test_path namespace escaped_content)
     STRING(REPLACE "/" "-" TARGET_NAME ${TARGET_NAME})
     set(EXAMPLE_DOC_TEST_TARGETS ${EXAMPLE_DOC_TEST_TARGETS} ${TARGET_NAME}
         PARENT_SCOPE)
-    add_custom_target(${TARGET_NAME}
+    add_custom_target(${TARGET_NAME}_RAW
-        COMMAND "${TOP_SOURCE_DIR}/tests/examples/runner.sh" "${expected_output_path}" ${LUA_COV_RUNNER} ${template} ${test_path} ${IMAGE_PATH}
+        COMMAND "${TOP_SOURCE_DIR}/tests/examples/runner.sh" "${expected_output_path}" ${LUA_COV_RUNNER} ${template} ${test_path} ${RAW_IMAGE_PATH}
         VERBATIM)
 
-    if(NOT ${OUTPUT_IMAGE_PATH} STREQUAL "")
+    add_custom_target(${TARGET_NAME}
-        file(RELATIVE_PATH rel_output "${TOP_SOURCE_DIR}" "${OUTPUT_IMAGE_PATH}")
+        COMMAND "${TOP_SOURCE_DIR}/tests/examples/_postprocess.lua" ${OUTPUT_RAW_IMAGE_PATH} "${OUTPUT_IMAGE_PATH}"
+        VERBATIM
+        DEPENDS ${TARGET_NAME}_RAW "${TOP_SOURCE_DIR}/tests/examples/_postprocess.lua"
+    )
+
+
+    if(NOT ${OUTPUT_RAW_IMAGE_PATH} STREQUAL "")
+        file(RELATIVE_PATH rel_output "${TOP_SOURCE_DIR}" "${OUTPUT_RAW_IMAGE_PATH}")
         if(tmp_content MATCHES "--DOC_GEN_OUTPUT")
             add_custom_command(
-                COMMAND "${TOP_SOURCE_DIR}/tests/examples/runner.sh" "${expected_output_path}" ${LUA_COV_RUNNER} ${template} ${test_path} ${IMAGE_PATH} ${IGNORE_ERRORS}
+                COMMAND "${TOP_SOURCE_DIR}/tests/examples/runner.sh" "${expected_output_path}" ${LUA_COV_RUNNER} ${template} ${test_path} ${RAW_IMAGE_PATH} ${IGNORE_ERRORS}
                 # COMMENT "Running ${rel_test_path} (via ${rel_template}, generating ${rel_output})"
                 DEPENDS ${template} ${test_path}
-                OUTPUT  ${OUTPUT_IMAGE_PATH}
+                OUTPUT  ${OUTPUT_RAW_IMAGE_PATH}
                 OUTPUT  ${expected_output_path}
                 VERBATIM)
         else()
             add_custom_command(
-                COMMAND "${TOP_SOURCE_DIR}/tests/examples/runner.sh" "${expected_output_path}" ${LUA_COV_RUNNER} ${template} ${test_path} ${IMAGE_PATH} ${IGNORE_ERRORS}
+                COMMAND "${TOP_SOURCE_DIR}/tests/examples/runner.sh" "${expected_output_path}" ${LUA_COV_RUNNER} ${template} ${test_path} ${RAW_IMAGE_PATH} ${IGNORE_ERRORS}
                 # COMMENT "Running ${rel_test_path} (via ${rel_template}, generating ${rel_output})"
                 DEPENDS ${template} ${test_path}
-                OUTPUT  ${OUTPUT_IMAGE_PATH}
+                OUTPUT  ${OUTPUT_RAW_IMAGE_PATH}
                 VERBATIM)
         endif()
-        set(EXAMPLE_DOC_GENERATED_FILES ${OUTPUT_IMAGE_PATH} ${EXAMPLE_DOC_GENERATED_FILES}
+
-            PARENT_SCOPE)
+        add_custom_command(
+            COMMAND "${TOP_SOURCE_DIR}/tests/examples/_postprocess.lua" ${OUTPUT_RAW_IMAGE_PATH} "${OUTPUT_IMAGE_PATH}"
+            DEPENDS ${template} ${test_path} ${OUTPUT_RAW_IMAGE_PATH} "${TOP_SOURCE_DIR}/tests/examples/_postprocess.lua"
+            OUTPUT  "${OUTPUT_IMAGE_PATH}"
+            VERBATIM)
+
+        set(EXAMPLE_DOC_GENERATED_FILES "${OUTPUT_IMAGE_PATH}" ${EXAMPLE_DOC_GENERATED_FILES} PARENT_SCOPE)
+
     elseif(tmp_content MATCHES "--DOC_GEN_OUTPUT")
         add_custom_command(
             COMMAND "${TOP_SOURCE_DIR}/tests/examples/runner.sh" "${expected_output_path}" ${LUA_COV_RUNNER} ${template} ${test_path} "" ${IGNORE_ERRORS}
@@ -338,7 +357,8 @@ file(GLOB_RECURSE test_files FOLLOW_SYMLINKS LIST_DIRECTORIES false
 # Find and run all test files.
 foreach(file ${test_files})
     if ((NOT "${file}" MATCHES ".*/shims/.*")
-        AND (NOT "${file}" MATCHES ".*/template.lua"))
+        AND (NOT "${file}" MATCHES ".*/template.lua")
+        AND (NOT "${file}" MATCHES ".*/_.*[.]lua"))
 
         # Get the file name without the extension.
         get_filename_component(TEST_FILE_NAME ${file} NAME_WE)

tests/examples/_postprocess.lua

@@ -0,0 +1,66 @@
+#!/usr/bin/env lua
+
+-- This script takes `.svg` file generated by Cairo or Inkscape and
+-- replace hardcoded colors so they can be set using CSS or the
+-- web browser itself. This makes the accessibility mode work and
+-- allows themes to be created for the documentation.
+
+local input, output = ...
+
+-- The second 24bit is just the 32 bit converted to #010001 and back.
+local FOREGROUNDS = {
+    "rgb[(]0[.]5%%,0%%,0[.]5%%[)];",
+    "rgb[(]0[.]392157%%,0%%,0[.]392157%%[)];",
+    "#010001",
+}
+
+local CLASSES = {
+    stroke = "svg_stroke",
+    fill   = "svg_fill"
+}
+
+local i, o = io.open(input, "r"), io.open(output, "w")
+
+if (not i) or (not o) then return end
+
+local line, count = i:read("*line"), 0
+
+while line do
+    -- Deduplicate and concatenate the classes.
+    local classes = {}
+    local token_found = {}
+    local class_str = {}
+
+    for _, token in ipairs { "fill", "stroke" } do
+
+        for _, color in ipairs(FOREGROUNDS) do
+            line, count = line:gsub(token .. ":" .. color, token .. ":currentcolor;")
+
+            -- Add the CSS class.
+            if count > 0 then
+                classes[CLASSES[token]] = true
+            end
+
+            line, count = line:gsub(token .. ":" .. color, token .. ":currentcolor;")
+
+            -- Add the CSS class.
+            if count > 0 and not token_found[token] then
+                token_found[token] = true
+				table.insert(classes, CLASSES[token])
+            end
+        end
+    end
+
+    for class in pairs(classes) do
+        table.insert(class_str, class)
+    end
+
+    if #class_str > 0 then
+        line = line:gsub(' style="', ' class="' .. table.concat(class_str, ",") .. '" style="')
+    end
+
+    o:write(line .. "\n")
+    line = i:read("*line")
+end
+
+o:close()