Allow optional imports in qmldir files

This is useful for modules that select their imports at runtime using
qmlRegisterModuleImport(). We can list all possible variants as optional
imports so that tools can see what types might be available.

Task-number: QTBUG-87130
Change-Id: I8a37bdde79aef3619fd1f05e5ea6781d521afa88
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

1 files changed, 27 insertions, 15 deletions

diff --git a/src/qml/Qt6QmlMacros.cmake b/src/qml/Qt6QmlMacros.cmake
index 4bd457311a..0afd365948 100644
--- a/src/qml/Qt6QmlMacros.cmake
+++ b/src/qml/Qt6QmlMacros.cmake
@@ -63,6 +63,11 @@
 #   as version to forward the version the current module is being imported with,
 #   e.g. QtQuick/auto. (OPTIONAL)
 #
+# OPTIONAL_IMPORTS: List of other Qml Modules that this module may import at
+#   run-time. Those are not automatically imported by the QML engine when
+#   importing the current module, but rather serve as hints to tools like
+#   qmllint. Versions can be specified in the same as for IMPORT. (OPTIONAL)
+#
 # RESOURCE_EXPORT: In static builds, when Qml files are processed via the Qt
 #   Quick Compiler generate a separate static library that will be linked in
 #   as an Interface. Supply an output variable to perform any custom actions
@@ -109,6 +114,7 @@ function(qt6_add_qml_module target)
        SOURCES
        QML_FILES
        IMPORTS
+       OPTIONAL_IMPORTS
        DEPENDENCIES
     )
 
@@ -283,23 +289,29 @@ function(qt6_add_qml_module target)
         # plugins.qmltypes is actually generated.
         string(APPEND qmldir_file_contents "typeinfo plugins.qmltypes\n")
     endif()
-    foreach(import IN LISTS arg_IMPORTS)
-        string(FIND ${import} "/" slash_position REVERSE)
-        if (slash_position EQUAL -1)
-            string(APPEND qmldir_file_contents "import ${import}\n")
-        else()
-            string(SUBSTRING ${import} 0 ${slash_position} import_module)
-            math(EXPR slash_position "${slash_position} + 1")
-            string(SUBSTRING ${import} ${slash_position} -1 import_version)
-            if (import_version MATCHES "[0-9]+\\.[0-9]+" OR import_version MATCHES "[0-9]+")
-                string(APPEND qmldir_file_contents "import ${import_module} ${import_version}\n")
-            elseif (import_version MATCHES "auto")
-                string(APPEND qmldir_file_contents "import ${import_module} auto\n")
+
+    macro(_add_imports imports import_string)
+        foreach(import IN LISTS ${imports})
+            string(FIND ${import} "/" slash_position REVERSE)
+            if (slash_position EQUAL -1)
+                string(APPEND qmldir_file_contents "${import_string} ${import}\n")
             else()
-                message(FATAL_ERROR "Invalid module import version number. Expected 'VersionMajor', 'VersionMajor.VersionMinor' or 'auto'.")
+                string(SUBSTRING ${import} 0 ${slash_position} import_module)
+                math(EXPR slash_position "${slash_position} + 1")
+                string(SUBSTRING ${import} ${slash_position} -1 import_version)
+                if (import_version MATCHES "[0-9]+\\.[0-9]+" OR import_version MATCHES "[0-9]+")
+                    string(APPEND qmldir_file_contents "${import_string} ${import_module} ${import_version}\n")
+                elseif (import_version MATCHES "auto")
+                    string(APPEND qmldir_file_contents "${import_string} ${import_module} auto\n")
+                else()
+                    message(FATAL_ERROR "Invalid module ${import_string} version number. Expected 'VersionMajor', 'VersionMajor.VersionMinor' or 'auto'.")
+                endif()
             endif()
-        endif()
-    endforeach()
+        endforeach()
+    endmacro()
+
+    _add_imports(arg_IMPORTS "import")
+    _add_imports(arg_OPTIONAL_IMPORTS "optional import")
 
     foreach(dependency IN LISTS arg_DEPENDENCIES)
         string(FIND ${dependency} "/" slash_position REVERSE)