qdoc: Reorganize Qdoc's Node class hierarchy

This is a significant refactoring of QDoc's Node class hierarchy,
which is meant to make maintenance of QDoc easier, and which will
enable further development of QDoc as a library and plugin.

Class DocumentNode is renamed to class PageNode, and it inherits
the Node base class instead of inheriting class Aggregate. Class
Aggregate inherits class PageNode instead of the Node base class.
IOW, class DocumentNode and class Aggregate have swapped places
in the class hierarchy, and DocumentNode has changed its name to
PageNode.

This makes the Node hierarchy more logical because:
1. Every entity that causes a documentation page to be written
is a PageNode.
2. Only those PageNodes that can have children are Aggregates.

Thus the HeaderFile subtype of the former DocumentNode has been
promoted to class HeaderNode, which is a subclass of Aggregate.
This makes sense because the old HeaderFile DocumentNode caused
a documentation page to be generated, and that documentation page
was very much like a class reference page. The \headerfile command
is not used a lot in the Qt documentation but there are some useful
cases, so it is worth making a subclass of Aggregate to handle them.
The HeaderNode is now processed very much like the ClassNode and the
NamespaceNode.

Developers should be advised that isDocumentNode() is now isPageNode(),
but isPageNode() can no longer be used to decide if an Aggregate* is
a PageNode* (DocumentNode*), because Aggregate is now a subclass of
PageNode. So a new convenience function is added: isTextPageNode(),
which returns true if your Node* is a PageNode but not an Aggregate.
IOW, isTextPageNode() returns true if the Node* is some kind of text
page that doesn't represent a C++ or QML declaration.

Class ExampleNode is a subclass of PageNode, not Aggregate. IOW, an
ExampleNode no longer has children. Instead, the example files and
example images that belong to the example are stored as string lists.
It seems to work, but there might be problems in help files I haven't
found yet.

Class CollectionNode is now a subclass of Node instead of LeafNode.
Class LeafNode is removed. All former subclasses of LeafNode are now
subclasses of Node.

This change also removes a lot of DITA bitrot.

Work remaining to be done:
1. Remove the remaining DITA bitrot.
2. Consider letting QmlProperty and JsProperty be instances of Property
and use the Genus value to distiguish them.
3. Also consider replacing QmlPropertyGroup and JsPropertyGroup with a
single PropertyGroup and use the Genus value to distinguish them.

This update also rearranges the parameters passed to the clang parser,
and it removes some diff conflict lines that got saved by mistake.

Change-Id: I918f83030c48d96db4a5588ab53458f221a5374e
Reviewed-by: Martin Smith <martin.smith@qt.io>
Reviewed-by: Paul Wicking <paul.wicking@qt.io>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/qdoc/helpprojectwriter.h b/src/qdoc/helpprojectwriter.h
index c84761d58..81e2a65c4 100644
--- a/src/qdoc/helpprojectwriter.h
+++ b/src/qdoc/helpprojectwriter.h
@@ -45,7 +45,7 @@ struct SubProject
 {
     QString title;
     QString indexTitle;
-    QHash<Node::NodeType, QSet<DocumentNode::DocSubtype> > selectors;
+    QHash<Node::NodeType, QSet<Node::NodeType> > selectors;
     bool sortPages;
     QString type;
     QHash<QString, const Node *> nodes;