paraviewpluginsexternal: add support for external plugins

Fixes #39.

CMakeLists.txt

@@ -32,6 +32,7 @@ function (superbuild_find_projects var)
   set(projects
     cxx11
     paraview
+    paraviewpluginsexternal
     python)
 
   option(USE_NONFREE_COMPONENTS "Enable the non-free parts of the superbuild" OFF)

README.md

@@ -137,6 +137,21 @@ This directory may then be copied to a non-networked machine and pointed at
 using the `superbuild_download_location` variable (or placed in the default
 location).
 
+## External plugins
+
+The superbuild supports building more plugins into ParaView using the
+`paraviewexternalplugins` project. As an example, to build two external
+plugins `a` and `b`, the following settings should be used:
+
+  * `enable_paraviewexternalplugins:BOOL=ON`: Enables building using external
+    plugins.
+  * `paraview_PLUGINS_EXTERNAL:STRING=a;b`: The list of plugins to build.
+  * `paraview_PLUGIN_a_PATH:PATH=/path/to/plugin/a`: The path to plugin `a`'s
+    source directory. It must contain a `plugins.cmake` to be picked up by
+    ParaView.
+  * `paraview_PLUGIN_b_PATH:PATH=/path/to/plugin/b`: Same as above, but for
+    plugin `b`.
+
 ## CMake Variables
 
 ### Style Guide

cmake/ParaViewSuperbuildMacros.cmake

@@ -56,3 +56,39 @@ function (paraview_add_plugin _name)
     "${${_name}_arguments}"
     PARENT_SCOPE)
 endfunction ()
+
+function (paraview_add_plugins_external)
+  set(paraview_PLUGINS_EXTERNAL ""
+    CACHE STRING "List of plugins to build externally")
+
+  set(plugin_cmake_args)
+  set(plugin_paths)
+  foreach (plugin IN LISTS paraview_PLUGINS_EXTERNAL)
+    set("paraview_PLUGIN_${plugin}_PATH" ""
+      CACHE PATH "Path to the source directory of the ${name} plugin")
+    if (NOT EXISTS "${paraview_PLUGIN_${plugin}_PATH}")
+      message(FATAL_ERROR
+        "The path for the ${plugin} plugin does not exist: "
+        "${paraview_PLUGIN_${plugin}_PATH}.")
+    endif ()
+
+    list(APPEND plugin_cmake_args
+      "-DPARAVIEW_BUILD_PLUGIN_${plugin}:BOOL=ON")
+    list(APPEND plugin_paths
+      "${paraview_PLUGIN_${plugin}_PATH}")
+  endforeach ()
+
+  superbuild_add_dummy_project(paraviewpluginsexternal)
+
+  superbuild_add_extra_cmake_args(${plugin_cmake_args})
+
+  if (NOT superbuild_build_phase)
+    set_property(GLOBAL
+      PROPERTY
+        paraview_plugin_dirs_external "${plugin_paths}")
+  endif ()
+
+  set(paraviewpluginsexternal_arguments
+    "${paraviewpluginsexternal_arguments}"
+    PARENT_SCOPE)
+endfunction ()

projects/paraview.cmake

@@ -45,8 +45,11 @@ set(paraview_all_plugins
 if (superbuild_build_phase)
   get_property(paraview_plugins GLOBAL
     PROPERTY paraview_plugins)
+  get_property(paraview_plugin_dirs_external GLOBAL
+    PROPERTY paraview_plugin_dirs_external)
 
-  set(paraview_plugin_dirs)
+  set(paraview_plugin_dirs
+    "${paraview_plugin_dirs_external}")
   foreach (paraview_plugin IN LISTS paraview_plugins)
     if (${paraview_plugin}_enabled AND TARGET "${paraview_plugin}")
       set(plugin_source_dir "<SOURCE_DIR>")
@@ -111,6 +114,7 @@ superbuild_add_project(paraview
     xdmf3 ospray vrpn tbb netcdf
     paraviewusersguide paraviewgettingstartedguide
     paraviewtutorial paraviewtutorialdata paraviewweb
+    paraviewpluginsexternal
     ${paraview_all_plugins}
     ${paraviews_platform_dependencies}
     ${PARAVIEW_EXTERNAL_PROJECTS}

projects/paraviewpluginsexternal.cmake

+paraview_add_plugins_external()