adjusted cmake for install option and quiet imgui linking

Author: ZZBaron

CMakeLists.txt

@@ -1,12 +1,30 @@
 cmake_minimum_required(VERSION 3.20)
 project(ImGuiFileDialog)
 
+# Option to control installation (disabled by default if used as subproject)
+if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+    set(IGFD_INSTALL_DEFAULT ON)
+else()
+    set(IGFD_INSTALL_DEFAULT OFF)
+endif()
+
+option(IGFD_INSTALL "Install ImGuiFileDialog library and headers" ${IGFD_INSTALL_DEFAULT})
+
+find_package(imgui QUIET) # fails quietly if not found (imgui is the target name for vcpkg and nixpkgs).
+
 add_library(ImGuiFileDialog STATIC
     ImGuiFileDialog.cpp
     ImGuiFileDialog.h
     ImGuiFileDialogConfig.h
 )
 
+if(imgui_FOUND)
+    target_link_libraries(ImGuiFileDialog PUBLIC imgui::imgui)
+    message(STATUS "ImGuiFileDialog: Found imgui package, linking automatically")
+else()
+    message(STATUS "ImGuiFileDialog: imgui package not found - ensure ImGui is available in your project")
+endif()
+
 # Use generator expressions for proper include directory handling
 target_include_directories(ImGuiFileDialog
     PUBLIC
@@ -19,25 +37,27 @@ if(UNIX)
 endif()
 
 # Installation configuration
-include(GNUInstallDirs)
-
-# Install the library
-install(TARGETS ImGuiFileDialog
-    EXPORT ImGuiFileDialogTargets
-    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
-    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
-    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
-)
+if(IGFD_INSTALL)
+    include(GNUInstallDirs)
 
-# Install headers
-install(FILES 
-    ImGuiFileDialog.h 
-    ImGuiFileDialogConfig.h
-    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
-)
+    # Install the library
+    install(TARGETS ImGuiFileDialog
+       EXPORT ImGuiFileDialogTargets
+       ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+       LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+       RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+    )
+
+    # Install headers
+    install(FILES 
+       ImGuiFileDialog.h 
+       ImGuiFileDialogConfig.h
+       DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+    )
 
-# Install export targets
-install(EXPORT ImGuiFileDialogTargets
-    FILE ImGuiFileDialogConfig.cmake
-    DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/ImGuiFileDialog
-)
+    # Install export targets
+    install(EXPORT ImGuiFileDialogTargets
+       FILE ImGuiFileDialogConfig.cmake
+       DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/ImGuiFileDialog
+    )
+endif()