APK: Handle Qt being configured with custom paths

cmake/modules/AndroidApk.cmake

@@ -115,6 +115,62 @@ endfunction()
 add_android_apk_extra_libs("${TARGET_PREFIX}${META_PROJECT_NAME}${TARGET_SUFFIX}")
 list_to_string("," "" "" "${ANDROID_APK_EXTRA_LIBS}" ANDROID_APK_EXTRA_LIBS)
 
+# query certain qmake variables
+foreach(QMAKE_VARIABLE QT_INSTALL_QML QT_INSTALL_PLUGINS QT_INSTALL_IMPORTS)
+    query_qmake_variable(${QMAKE_VARIABLE})
+endforeach()
+
+# define function to get a list of (existing) paths
+function(compose_dirs_for_android_apk)
+    # parse arguments
+    set(OPTIONAL_ARGS)
+    set(ONE_VALUE_ARGS OUTPUT_VARIABLE)
+    set(MULTI_VALUE_ARGS POSSIBLE_DIRS)
+    cmake_parse_arguments(ARGS "${OPTIONAL_ARGS}" "${ONE_VALUE_ARGS}" "${MULTI_VALUE_ARGS}" ${ARGN})
+
+    list(REMOVE_DUPLICATES ARGS_POSSIBLE_DIRS)
+    unset(DIRS)
+    foreach(POSSIBLE_DIR ${ARGS_POSSIBLE_DIRS})
+        if(IS_DIRECTORY "${POSSIBLE_DIR}")
+            list(APPEND DIRS "${POSSIBLE_DIR}")
+        endif()
+    endforeach()
+
+    list_to_string("," "" "" "${DIRS}" DIRS)
+    set("${ARGS_OUTPUT_VARIABLE}" "${DIRS}" PARENT_SCOPE)
+endfunction()
+
+# pick QML import paths from install prefix
+compose_dirs_for_android_apk(
+    OUTPUT_VARIABLE ANDROID_APK_QML_IMPORT_DIRS
+    POSSIBLE_DIRS
+        "${QT_INSTALL_IMPORTS}"
+        "${QT_INSTALL_QML}"
+        "${CMAKE_INSTALL_PREFIX}/lib/qt/imports"
+        "${CMAKE_INSTALL_PREFIX}/lib/imports"
+        "${CMAKE_INSTALL_PREFIX}/lib/qt/qml"
+        "${CMAKE_INSTALL_PREFIX}/lib/qml"
+)
+if(NOT ANDROID_APK_QML_IMPORT_DIRS)
+    message(WARNING "Unable to find QML import directories for making the APK.")
+endif()
+
+# pick extra plugins from install prefix
+compose_dirs_for_android_apk(
+    OUTPUT_VARIABLE ANDROID_APK_EXTRA_PLUGIN_DIRS
+    POSSIBLE_DIRS
+        "${QT_INSTALL_PLUGINS}"
+        "${QT_INSTALL_QML}"
+        "${CMAKE_INSTALL_PREFIX}/lib/qt/plugins"
+        "${CMAKE_INSTALL_PREFIX}/lib/plugins"
+        "${CMAKE_INSTALL_PREFIX}/lib/qt/qml"
+        "${CMAKE_INSTALL_PREFIX}/lib/qml"
+        "${CMAKE_INSTALL_PREFIX}/share"
+)
+if(NOT ANDROID_APK_EXTRA_PLUGIN_DIRS)
+    message(WARNING "Unable to find extra plugin directories for making the APK.")
+endif()
+
 # find template for deployment JSON
 find_template_file("android-deployment.json" QT_UTILITIES ANDROID_DEPLOYMENT_JSON_TEMPLATE_FILE)
 set(ANDROID_DEPLOYMENT_JSON_FILE "${CMAKE_CURRENT_BINARY_DIR}/android-deployment.json")

cmake/modules/QtLinkage.cmake

@@ -109,5 +109,19 @@ if(NOT DEFINED QT_LINKAGE_DETERMINED)
         endif()
     endmacro()
 
+    macro(query_qmake_variable QMAKE_VARIABLE)
+        get_target_property(QMAKE_BIN Qt5::qmake IMPORTED_LOCATION)
+        execute_process(
+            COMMAND "${QMAKE_BIN}" -query "${QMAKE_VARIABLE}"
+            RESULT_VARIABLE "${QMAKE_VARIABLE}_RESULT"
+            OUTPUT_VARIABLE "${QMAKE_VARIABLE}"
+        )
+        if(NOT "${${QMAKE_VARIABLE}_RESULT}" STREQUAL 0 OR "${${QMAKE_VARIABLE}}" STREQUAL "")
+            message(FATAL_ERROR "Unable to read qmake variable ${QMAKE_VARIABLE} via \"${QMAKE_BIN} -query ${QMAKE_VARIABLE}\"; output was \"${${QMAKE_VARIABLE}}\".")
+        endif()
+        string(REGEX REPLACE "\n$" "" "${QMAKE_VARIABLE}" "${${QMAKE_VARIABLE}}")
+        message(STATUS "qmake variable ${QMAKE_VARIABLE} is ${${QMAKE_VARIABLE}}")
+    endmacro()
+
     set(QT_LINKAGE_DETERMINED YES)
 endif(NOT DEFINED QT_LINKAGE_DETERMINED)

cmake/templates/android-deployment.json.in

@@ -9,9 +9,9 @@
    "target-architecture": "@CMAKE_ANDROID_ARCH_ABI@",
    "application-binary": "$<TARGET_FILE:@TARGET_PREFIX@@META_PROJECT_NAME@@TARGET_SUFFIX@>",
    "qml-root-path": "@CMAKE_CURRENT_SOURCE_DIR@",
-   "qml-import-paths": "@CMAKE_INSTALL_PREFIX@/lib/qml",
+   "qml-import-paths": "@ANDROID_APK_QML_IMPORT_DIRS@",
    "android-extra-libs": "@ANDROID_APK_EXTRA_LIBS@",
-   "android-extra-plugins": "@CMAKE_INSTALL_PREFIX@/share,@CMAKE_INSTALL_PREFIX@/lib/qml",
+   "android-extra-plugins": "@ANDROID_APK_EXTRA_PLUGIN_DIRS@",
    "android-package-source-directory": "@ANDROID_APK_SUBDIR@",
    "stdcpp-path":"@ANDROID_APK_CXX_STANDARD_LIBRARY@",
    "sdkBuildToolsRevision": "@ANDROID_APK_BUILD_TOOLS_VERSION@",