Allow to build examples as standalone project

Create CMake config files which can be used from the very same CMake
project. These CMake config files simply do not create any targets,
controlled via the QT_NO_CREATE_TARGETS.

This patch also allows to build qtbase.git:examples as a standalone
project, against an already-built Qt.

Ran this:
  ag -s "QT " examples -l -0 | xargs -0 -n 1 .../util/cmake/pro2cmake.py --is-example

Task-number: QTBUG-74713
Change-Id: I44cce5a4048618b30f890c5b789592c227a8b47d
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

3 files changed, 40 insertions, 52 deletions

diff --git a/examples/widgets/tools/styleplugin/CMakeLists.txt b/examples/widgets/tools/styleplugin/CMakeLists.txt
index 630c3703f8..8ee575f8a6 100644
--- a/examples/widgets/tools/styleplugin/CMakeLists.txt
+++ b/examples/widgets/tools/styleplugin/CMakeLists.txt
@@ -1,4 +1,19 @@
 # Generated from styleplugin.pro.
 
+# special case begin
+cmake_minimum_required(VERSION 3.14)
+project(styleplugin LANGUAGES CXX)
+
+set(CMAKE_INCLUDE_CURRENT_DIR ON)
+
+set(CMAKE_AUTOMOC ON)
+set(CMAKE_AUTORCC ON)
+set(CMAKE_AUTOUIC ON)
+
+set(INSTALL_EXAMPLEDIR "examples")
+
+find_package(Qt5 COMPONENTS Widgets)
+# special case end
+
 add_subdirectory(stylewindow)
 add_subdirectory(plugin)
diff --git a/examples/widgets/tools/styleplugin/plugin/CMakeLists.txt b/examples/widgets/tools/styleplugin/plugin/CMakeLists.txt
index c311799d30..28c6ec07ab 100644
--- a/examples/widgets/tools/styleplugin/plugin/CMakeLists.txt
+++ b/examples/widgets/tools/styleplugin/plugin/CMakeLists.txt
@@ -1,32 +1,9 @@
-# Generated from plugin.pro.
+# special case begin
 
-#####################################################################
-## mplestyleplugin Module:
-#####################################################################
-
-add_qt_plugin(simplestyleplugin TYPE style # special case
-    SOURCES
-        simplestyle.cpp simplestyle.h
-        simplestyleplugin.cpp simplestyleplugin.h
-    LIBRARIES
-        Qt::Widgets
+add_library(simplestyleplugin MODULE
+    simplestyle.cpp simplestyle.h
+    simplestyleplugin.cpp simplestyleplugin.h
 )
+target_link_libraries(simplestyleplugin PUBLIC Qt::Widgets)
 
-#### Keys ignored in scope 1:.:plugin.pro:<NONE>:
-# CONFIG = "plugin" "install_ok"
-# EXAMPLE_FILES = "simplestyle.json"
-# INSTALLS = "target"
-# TEMPLATE = "lib"
-# target.path = "$$[QT_INSTALL_EXAMPLES]/widgets/tools/styleplugin/styles"
-
-## Scopes:
-#####################################################################
-
-#### Keys ignored in scope 3:.:plugin.pro:CONFIG(debug,release OR debug):
-# DESTDIR = "../debug/styles/"
-
-#### Keys ignored in scope 4:.:plugin.pro:CONFIG(release,release OR debug):
-# DESTDIR = "../release/styles/"
-
-#### Keys ignored in scope 5:.:plugin.pro:else:
-# DESTDIR = "../styles/"
+# special case end
diff --git a/examples/widgets/tools/styleplugin/stylewindow/CMakeLists.txt b/examples/widgets/tools/styleplugin/stylewindow/CMakeLists.txt
index a6d6a56874..3e3893ad03 100644
--- a/examples/widgets/tools/styleplugin/stylewindow/CMakeLists.txt
+++ b/examples/widgets/tools/styleplugin/stylewindow/CMakeLists.txt
@@ -1,31 +1,27 @@
 # Generated from stylewindow.pro.
 
-#####################################################################
-## styleplugin Binary:
-#####################################################################
+cmake_minimum_required(VERSION 3.14)
+project(styleplugin LANGUAGES CXX)
 
-add_qt_executable(styleplugin
-    GUI
-    OUTPUT_DIRECTORY "${INSTALL_EXAMPLESDIR}/widgets/tools/styleplugin"
-    INSTALL_DIRECTORY "${INSTALL_EXAMPLESDIR}/widgets/tools/styleplugin"
-    SOURCES
-        main.cpp
-        stylewindow.cpp stylewindow.h
-    LIBRARIES
-        Qt::Widgets
-)
+set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
-#### Keys ignored in scope 1:.:stylewindow.pro:<NONE>:
-# CONFIG = "install_ok"
+set(CMAKE_AUTOMOC ON)
+set(CMAKE_AUTORCC ON)
+set(CMAKE_AUTOUIC ON)
 
-## Scopes:
-#####################################################################
+set(INSTALL_EXAMPLEDIR "examples")
 
-#### Keys ignored in scope 3:.:stylewindow.pro:debug:
-# DESTDIR = "../debug/"
+find_package(Qt5 COMPONENTS Widgets)
 
-#### Keys ignored in scope 4:.:stylewindow.pro:release:
-# DESTDIR = "../release/"
+add_executable(styleplugin WIN32 MACOSX_BUNDLE
+    main.cpp
+    stylewindow.cpp stylewindow.h
+)
+target_link_libraries(styleplugin PUBLIC
+    Qt::Widgets
+)
 
-#### Keys ignored in scope 5:.:stylewindow.pro:else:
-# DESTDIR = "../"
+install(TARGETS styleplugin
+    RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
+    BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
+)