[tools] Add system package manger with ncurses as example

examples/tools/README.md

@@ -29,3 +29,7 @@
 
 - Build [ROS packages inside their workspace](ros/rosenv/workspace) using the [fmt library from Conan Center](https://conan.io/center/recipes/fmt) and consuming them also as transitive dependencies.
 - Build a [ROS navigation package](ros/rosenv/navigation_ws) that sends goals to a mobile robot from a YAML file using the [yaml-cpp library from Conan Center](https://conan.io/center/recipes/yaml-cpp).
+
+### [tools.system](system)
+
+- Wrap a [system package](system/package_manager/) using Conan and [ncurses](https://invisible-island.net/ncurses/). [Docs](https://docs.conan.io/2/examples/tools/system/package_manager.html)

examples/tools/system/package_manager/ci_test_example.py

@@ -0,0 +1,27 @@
+from test.examples_tools import run
+import re
+import os
+import sys
+
+
+print("- Packaging system ncurses library using Conan -")
+
+if sys.platform != "linux":
+    print("INFO: Skipping test, only for Linux due to system requirements.")
+    sys.exit(0)
+
+confs = ["tools.system.package_manager:mode=install",
+         "tools.system.package_manager:sudo=true",
+         "tools.build:verbosity=verbose",
+         "tools.compilation:verbosity=verbose"]
+
+out = run("conan create . {}".format(" ".join(["-c " + conf for conf in confs])))
+
+assert "ncurses/system: System requirements"
+assert "package(): WARN: No files in this package" in out
+
+print("- Consuming Conan package ncurses/system -")
+
+out = run("conan build consumer/ --name=ncurses-version --version=0.1.0 {}".format(" ".join(["-c " + conf for conf in confs])))
+
+assert "Conan: Target declared 'ncurses::ncurses'" in out

examples/tools/system/package_manager/conanfile.py

@@ -0,0 +1,59 @@
+from conan import ConanFile
+from conan.tools.system import package_manager
+from conan.tools.gnu import PkgConfig
+from conan.errors import ConanInvalidConfiguration
+
+required_conan_version = ">=2.0"
+
+
+class SysNcursesConan(ConanFile):
+    name = "ncurses"
+    version = "system"
+    description = "A textual user interfaces that work across a wide variety of terminals"
+    topics = ("curses", "terminal", "toolkit")
+    homepage = "https://invisible-mirror.net/archives/ncurses/"
+    license = "MIT"
+    package_type = "shared-library"
+    settings = "os", "arch", "compiler", "build_type"
+
+    def package_id(self):
+        self.info.clear()
+
+    def validate(self):
+        supported_os = ["Linux", "Macos", "FreeBSD"]
+        if self.settings.os not in supported_os:
+            raise ConanInvalidConfiguration(f"{self.ref} wraps a system package only supported by {supported_os}.")
+
+    def system_requirements(self):
+        dnf = package_manager.Dnf(self)
+        dnf.install(["ncurses-devel"], update=True, check=True)
+
+        yum = package_manager.Yum(self)
+        yum.install(["ncurses-devel"], update=True, check=True)
+
+        apt = package_manager.Apt(self)
+        apt.install(["libncurses-dev"], update=True, check=True)
+
+        pacman = package_manager.PacMan(self)
+        pacman.install(["ncurses"], update=True, check=True)
+
+        zypper = package_manager.Zypper(self)
+        zypper.install(["ncurses"], update=True, check=True)
+
+        brew = package_manager.Brew(self)
+        brew.install(["ncurses"], update=True, check=True)
+
+        pkg = package_manager.Pkg(self)
+        pkg.install(["ncurses"], update=True, check=True)
+
+    def package_info(self):
+        self.cpp_info.bindirs = []
+        self.cpp_info.includedirs = []
+        self.cpp_info.libdirs = []
+
+        self.cpp_info.set_property("cmake_file_name", "Curses")
+        self.cpp_info.set_property("cmake_target_name", "Curses::Curses")
+        self.cpp_info.set_property("cmake_additional_variables_prefixes", ["CURSES",])
+
+        pkg_config = PkgConfig(self, 'ncurses')
+        pkg_config.fill_cpp_info(self.cpp_info, is_system=True)

examples/tools/system/package_manager/consumer/CMakeLists.txt

@@ -0,0 +1,9 @@
+cmake_minimum_required(VERSION 3.15)
+project(ncurses_version C)
+
+find_package(Curses CONFIG REQUIRED)
+
+add_executable(${PROJECT_NAME} ncurses_version.c)
+target_link_libraries(${PROJECT_NAME} PRIVATE Curses::Curses)
+
+install(TARGETS ${PROJECT_NAME} DESTINATION bin)

examples/tools/system/package_manager/consumer/conanfile.py

@@ -0,0 +1,30 @@
+from conan import ConanFile
+from conan.tools.build import can_run
+from conan.tools.cmake import cmake_layout, CMake
+import os
+
+
+class AppNCursesVersionConan(ConanFile):
+    settings = "os", "compiler", "build_type", "arch"
+    generators = "CMakeDeps", "CMakeToolchain"
+    package_type = "application"
+    exports_sources = "CMakeLists.txt", "ncurses_version.c"
+
+    @property
+    def _supported_os(self):
+        return ["Linux", "Macos", "FreeBSD"]
+
+    def requirements(self):
+        if self.settings.os in _supported_os:
+            self.requires("ncurses/system")
+
+    def layout(self):
+        cmake_layout(self)
+
+    def build(self):
+        cmake = CMake(self)
+        cmake.configure()
+        cmake.build()
+
+        if self.settings.os in _supported_os:
+            self.run(os.path.join(self.build_folder, "ncurses_version"), env="conanrun")

examples/tools/system/package_manager/consumer/ncurses_version.c

@@ -0,0 +1,26 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <ncurses.h>
+
+
+int main(void) {
+    int max_y, max_x;
+    char message [256] = {0};
+
+    initscr();
+
+    start_color();
+    init_pair(1, COLOR_BLUE, COLOR_WHITE);
+    getmaxyx(stdscr, max_y, max_x);
+
+    snprintf(message, sizeof(message), "Conan 2.x Examples - Installed ncurses version: %s\n", curses_version());
+    attron(COLOR_PAIR(1));
+    mvprintw(max_y / 2, max_x / 2 - (strlen(message) / 2), "%s", message);
+    attroff(COLOR_PAIR(1));
+
+    refresh();
+
+    return EXIT_SUCCESS;
+}