ECMAddQtDesignerPlugin: drop support for Qt < 5.9

Given ECM is released tighly bundled with KF, which itself requires
Qt 5.15 now, and no Linux distribution is known by repology.org which
ships older Qt, but current ECM, that support is considered of no more use.

1 files changed, 4 insertions, 41 deletions

diff --git a/modules/ECMAddQtDesignerPlugin.cmake b/modules/ECMAddQtDesignerPlugin.cmake
index e3360885..bce14786 100644
--- a/modules/ECMAddQtDesignerPlugin.cmake
+++ b/modules/ECMAddQtDesignerPlugin.cmake
@@ -442,44 +442,16 @@ macro(ecm_add_qtdesignerplugin target)
     endif()
 
     # Check deps
-    # peek at Qt5Core to learn about the version to decide whether Qt5UiPlugin is enough
-    if(NOT Qt5Core_FOUND)
-        find_package(Qt${QT_MAJOR_VERSION}Core QUIET CONFIG)
-    endif()
-    if(Qt5Core_VERSION VERSION_LESS "5.5.0")
-        set(_qtdesigner_tobefound TRUE)
-    elseif(Qt5Core_VERSION VERSION_LESS "5.9.0")
-        set(_qtdesigner_tobefound TRUE)
-        set(_qtuiplugin_tobefound TRUE)
-    else()
-        # Since Qt 5.9 only Qt5UiPlugin is needed
-        set(_qtuiplugin_tobefound TRUE)
-    endif()
-    if(NOT Qt5Designer_FOUND AND _qtdesigner_tobefound)
-        find_package(Qt${QT_MAJOR_VERSION}Designer QUIET CONFIG)
-        set_package_properties(Qt${QT_MAJOR_VERSION}Designer PROPERTIES
-            PURPOSE "Required to build Qt Designer plugins"
-            TYPE REQUIRED
-        )
-    endif()
-    if(NOT Qt5UiPlugin_FOUND AND _qtuiplugin_tobefound)
+    if(NOT Qt${QT_MAJOR_VERSION}UiPlugin_FOUND)
         find_package(Qt${QT_MAJOR_VERSION}UiPlugin QUIET CONFIG)
         set_package_properties(Qt${QT_MAJOR_VERSION}UiPlugin PROPERTIES
             PURPOSE "Required to build Qt Designer plugins"
             TYPE REQUIRED
         )
     endif()
-    if (Qt5Designer_FOUND)
-        set(_qtdesigner_tobefound FALSE)
-    endif()
-    if (Qt5UiPlugin_FOUND)
-        set(_qtuiplugin_tobefound FALSE)
-        # in some old versions Qt5UiPlugin does not set its _INCLUDE_DIRS variable. Fill it manually
-        get_target_property(Qt5UiPlugin_INCLUDE_DIRS Qt5::UiPlugin INTERFACE_INCLUDE_DIRECTORIES)
-    endif()
 
-    # setup plugin only if designer/uiplugin libs were found, as we do not abort hard the cmake run otherwise
-    if(NOT _qtdesigner_tobefound AND NOT _qtuiplugin_tobefound)
+    # setup plugin only if uiplugin lib was found, as we do not abort hard the cmake run otherwise
+    if (Qt${QT_MAJOR_VERSION}UiPlugin_FOUND)
         set(_generation_dir "${CMAKE_CURRENT_BINARY_DIR}/${target}_ECMQtDesignerPlugin")
         file(MAKE_DIRECTORY "${_generation_dir}")
         set(_rc_icon_dir "/${ARGS_NAME}/designer")
@@ -624,15 +596,6 @@ QList<QDesignerCustomWidgetInterface*> ${_collection_classname}::customWidgets()
 
         # setup plugin binary
         add_library(${target} MODULE ${_srcs})
-        if(Qt5UiPlugin_VERSION AND Qt5UiPlugin_VERSION VERSION_GREATER_EQUAL 5.9.0)
-            list(APPEND ARGS_LINK_LIBRARIES Qt5::UiPlugin)
-        else()
-            # For Qt <5.9 include dir variables needed
-            target_include_directories(${target}
-                PRIVATE ${Qt5UiPlugin_INCLUDE_DIRS}
-                PRIVATE ${Qt5Designer_INCLUDE_DIRS}
-            )
-        endif()
         if(NOT WIN32)
             # Since there are no libraries provided by this module,
             # there is no point including the build tree in RPath,
@@ -647,7 +610,7 @@ QList<QDesignerCustomWidgetInterface*> ${_collection_classname}::customWidgets()
                 OUTPUT_NAME ${ARGS_OUTPUT_NAME}
             )
         endif()
-        target_link_libraries(${target} ${ARGS_LINK_LIBRARIES})
+        target_link_libraries(${target} ${ARGS_LINK_LIBRARIES} Qt${QT_MAJOR_VERSION}::UiPlugin)
 
         if (DEFINED ARGS_COMPONENT)
             set(_component COMPONENT ${ARGS_COMPONENT})