Add FOLDER target property, for IDEs (#3796)

This work was started from a patch by Thomas Schiffer.
Thanks, Thomas!

See the newly added documentation of the FOLDER target
property for details.

Also added global properties, USE_FOLDERS and
PREDEFINED_TARGETS_FOLDER. See new docs here, too.

By default, the FOLDER target property is used to organize
targets into folders in IDEs that have support for such
organization.

This commit adds "solution folder" support to the Visual
Studio generators. Currently works with versions 7 through
10.

Also, use the new FOLDER property in the ExternalProject
test and in the CMake project itself.

1 files changed, 16 insertions, 0 deletions

diff --git a/Source/cmGlobalVisualStudio71Generator.cxx b/Source/cmGlobalVisualStudio71Generator.cxx
index 1191575..897c3a2 100644
--- a/Source/cmGlobalVisualStudio71Generator.cxx
+++ b/Source/cmGlobalVisualStudio71Generator.cxx
@@ -111,6 +111,13 @@ void cmGlobalVisualStudio71Generator
   OrderedTargetDependSet orderedProjectTargets(projectTargets);
 
   this->WriteTargetsToSolution(fout, root, orderedProjectTargets);
+
+  bool useFolderProperty = this->UseFolderProperty();
+  if (useFolderProperty)
+    {
+    this->WriteFolders(fout);
+    }
+
   // Write out the configurations information for the solution
   fout << "Global\n";
   // Write out the configurations for the solution
@@ -120,6 +127,15 @@ void cmGlobalVisualStudio71Generator
   // Write out the configurations for all the targets in the project
   this->WriteTargetConfigurations(fout, root, orderedProjectTargets);
   fout << "\tEndGlobalSection\n";
+
+  if (useFolderProperty)
+    {
+    // Write out project folders
+    fout << "\tGlobalSection(NestedProjects) = preSolution\n";
+    this->WriteFoldersContent(fout);
+    fout << "\tEndGlobalSection\n";
+    }
+
   // Write the footer for the SLN file
   this->WriteSLNFooter(fout);
 }