Remove support for CMake <3.22

This project no longer supports Ubuntu 20.04 and in turn the workarounds
for CMake 3.16 are no longer needed. The new minimum version is
determined by Ubuntu 22.04.

Author: leonlynch

CMakeLists.txt

@@ -5,7 +5,7 @@
 # See LICENSE file.
 ##############################################################################
 
-cmake_minimum_required(VERSION 3.16)
+cmake_minimum_required(VERSION 3.22)
 
 project(emv-utils
 	VERSION 0.3.1
@@ -15,15 +15,7 @@ project(emv-utils
 )
 
 # Determine whether this project is the top-level project
-if(${CMAKE_VERSION} VERSION_LESS "3.21")
-	get_directory_property(EMV_UTILS_HAS_PARENT PARENT_DIRECTORY)
-	if(NOT EMV_UTILS_HAS_PARENT)
-		set(EMV_UTILS_IS_TOP_LEVEL True)
-	endif()
-else()
-	# CMake >=3.21 provides <PROJECT-NAME>_IS_TOP_LEVEL
-	set(EMV_UTILS_IS_TOP_LEVEL ${emv-utils_IS_TOP_LEVEL})
-endif()
+set(EMV_UTILS_IS_TOP_LEVEL ${emv-utils_IS_TOP_LEVEL})
 
 # Configure compiler
 set(CMAKE_C_STANDARD 11)

cmake/Modules/FindIsoCodes.cmake

@@ -1,5 +1,5 @@
 ##############################################################################
-# Copyright 2021 Leon Lynch
+# Copyright 2021, 2026 Leon Lynch
 #
 # This file is licensed under the terms of the LGPL v2.1 license.
 # See LICENSE file.
@@ -13,7 +13,7 @@
 # IsoCodes_DOMAINS
 # IsoCodes_JSON_PATH
 
-cmake_minimum_required(VERSION 3.12) # For list(TRANSFORM...)
+cmake_minimum_required(VERSION 3.22)
 
 # Use PkgConfig to find iso-codes
 find_package(PkgConfig REQUIRED)

src/CMakeLists.txt

@@ -5,7 +5,7 @@
 # See LICENSE file.
 ##############################################################################
 
-cmake_minimum_required(VERSION 3.16)
+cmake_minimum_required(VERSION 3.22)
 
 # Check whether C99 length modifier 'z' is supported
 include(CheckCSourceRuns)

tests/CMakeLists.txt

@@ -1,11 +1,11 @@
 ##############################################################################
-# Copyright 2021-2025 Leon Lynch
+# Copyright 2021-2026 Leon Lynch
 #
 # This file is licensed under the terms of the LGPL v2.1 license.
 # See LICENSE file.
 ##############################################################################
 
-cmake_minimum_required(VERSION 3.16)
+cmake_minimum_required(VERSION 3.22)
 
 if (BUILD_TESTING)
 	add_library(emv_cardreader_emul OBJECT EXCLUDE_FROM_ALL emv_cardreader_emul.c)

tools/CMakeLists.txt

@@ -5,7 +5,7 @@
 # See LICENSE file.
 ##############################################################################
 
-cmake_minimum_required(VERSION 3.16)
+cmake_minimum_required(VERSION 3.22)
 
 # Build command line tools by default
 option(BUILD_EMV_DECODE "Build emv-decode" ON)

viewer/CMakeLists.txt

@@ -5,7 +5,7 @@
 # See LICENSE.gpl file.
 ##############################################################################
 
-cmake_minimum_required(VERSION 3.16)
+cmake_minimum_required(VERSION 3.22)
 
 project(emv-viewer
 	VERSION 0.3.1
@@ -15,15 +15,7 @@ project(emv-viewer
 )
 
 # Determine whether this project is the top-level project
-if(${CMAKE_VERSION} VERSION_LESS "3.21")
-	get_directory_property(EMV_VIEWER_HAS_PARENT PARENT_DIRECTORY)
-	if(NOT EMV_VIEWER_HAS_PARENT)
-		set(EMV_VIEWER_IS_TOP_LEVEL True)
-	endif()
-else()
-	# CMake >=3.21 provides <PROJECT-NAME>_IS_TOP_LEVEL
-	set(EMV_VIEWER_IS_TOP_LEVEL ${emv-viewer_IS_TOP_LEVEL})
-endif()
+set(EMV_VIEWER_IS_TOP_LEVEL ${emv-viewer_IS_TOP_LEVEL})
 
 # Configure compiler
 set(CMAKE_CXX_STANDARD 14)
@@ -160,15 +152,8 @@ if(QT_VERSION VERSION_LESS 5.15)
 	qt5_wrap_cpp(MOC_SRCS ${EMV_VIEWER_MOC_HEADERS})
 	qt5_add_resources(QRC_SRCS icons.qrc)
 
-	if(CMAKE_VERSION VERSION_LESS "3.18")
-		# CMake versions older than 3.18 cannot create alias targets for
-		# non-global imported targets and an alternative is to use INTERFACE
-		# linking instead
-		add_library(Qt::Widgets INTERFACE IMPORTED)
-		set_target_properties(Qt::Widgets PROPERTIES INTERFACE_LINK_LIBRARIES Qt5::Widgets)
-	else()
-		add_library(Qt::Widgets ALIAS Qt5::Widgets)
-	endif()
+	# Create alias targets for compatibility with newer Qt versions
+	add_library(Qt::Widgets ALIAS Qt5::Widgets)
 else()
 	# Qt-5.15 and Qt-6 provide these version-less commands
 	qt_wrap_ui(UI_SRCS emv-viewer-mainwindow.ui)