Discussion and conclusion around qt6_add_executable API

qt_add_executable_android.cmake

@@ -118,5 +118,103 @@ endfunction()
 # Pros: With CMake <= 3.18 users need to call only 1 function at the end of the scope
 #       instead of multiple depending on platform.
 #       Automatically called with >= 3.19.
+#       We can call qt_import_qml_plugins in the finalize function,
+#       to handle the static Qt example scenario.
 # Cons: User still needs to call function manually with CMake <= 3.18.
 #       Hard to say if 1 function taking one target will be enough.
+
+
+# =============================================================================================
+# During meeting discussed some additional approaches
+
+
+# =============================================================================================
+# Approach 5
+# Check for a specifically defined function, and call it as setup in-between the other behaviour
+function(qt6_add_executable target)
+    add_executable(${target})
+    # ....
+
+    if(DEFINED my_custom_setup_function)
+        my_custom_setup_function()
+    endif()
+
+    qt_android_generate_deployment_settings("${target}")
+    # ....
+endfunction()
+
+function(my_custom_setup_function target)
+    set_target_properties(foo PROPERTIES QT_ANDROID_PACKAGE_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/bla")
+endfunction()
+
+# Picks up the my_custom_setup_function provided by the project developer
+qt6_add_executable(target)
+
+# Pros: Works with older CMake versions.
+#       Doesn't require explicit call from user
+#       Doesn't pollute qt6_add_executable API
+# Cons: Only one function can be declared for the whole CMake project.
+#       Function implementor will have have to add target specific
+#       conditional scopes for each target they define.
+#       A function can't be undefined, so kinda pollutes the project.
+
+
+
+
+# =====================================================================================
+# Approach 6
+# Combination of approach 1.1 and other ideas
+# Split Target creation and linking to Qt into helper function.
+# Add new finalize function.
+# User either opts into finalizing to be done explicitly / manually.
+# or stays with the default behaviour.
+function(qt6_create_executable target)
+    if(ANDROID)
+        add_library("${target}" MODULE ${ARGN})
+    else()
+        add_executable("${target}" ${ARGN})
+    endif()
+    target_link_libraries("${target}" PRIVATE Qt::Core)
+endfunction()
+
+function(qt6_finalize_executable target)
+    if(ANDROID)
+        qt_android_generate_deployment_settings("${target}")
+        qt_android_add_apk_target("${target}")
+    endif()
+endfunction()
+
+function(qt6_add_executable target)
+    qt6_create_executable()
+    # If user didn't opt into customization, run the finalizer right now.
+    if(NOT arg_NEEDS_CUSTOMIZATION)
+        set_target_properties(${target} PROPERTIES _qt_needs_finalizer FALSE)
+        if(CMAKE_VERSION VERSION_GREATER_EQUAL "3.19")
+            cmake_language(EVAL CODE "cmake_language(DEFER CALL \"qt6_finalize_executable(${target})\")")
+        else()
+            qt6_finalize_executable(${target})
+        endif()
+    else()
+        # Can we issue a warning based on this in some way? Probably not without CMake >= 3.19, in which case
+        # it doesn't make sense?
+        set_target_properties(${target} PROPERTIES _qt_needs_finalizer TRUE)
+    endif()
+endfunction()
+
+# 1 No opt-in, finalizer automatically called.
+# With CMake >= 3.19 the finalizer will be called at the end of the scope
+# With CMake <= 3.18 the finalizer will be called inside qt6_add_executable.
+qt6_add_executable(target)
+
+# 2 User opted in, they will run it manually.
+qt6_add_executable(target NEEDS_CUSTOMIZATION)
+set_target_properties(foo PROPERTIES QT_ANDROID_PACKAGE_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/bla")
+qt6_finalize_executable()
+
+
+# Pros: Sensible defaults.
+#       Works with older CMake versions.
+#       Introducing a new option for opt in is compatible with existing API.
+#       Automatic finalization with CMake >= 3.19
+
+# It was decided to go with approach 6.