Add support for child documents to docview framework.

Child documents are virtual documents corresponding to parts of their parent
document which can't be saved nor loaded independently of their parent and are
closed when the parent is closed.

This finally makes some use of wxDocument::m_documentParent field which was
always present in the docview code but never used before.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@68051 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/docview.cpp

@@ -122,8 +122,12 @@ wxString FindExtension(const wxString& path)
 wxDocument::wxDocument(wxDocument *parent)
 {
     m_documentModified = false;
-    m_documentParent = parent;
     m_documentTemplate = NULL;
+
+    m_documentParent = parent;
+    if ( parent )
+        parent->m_childDocuments.push_back(this);
+
     m_commandProcessor = NULL;
     m_savedYet = false;
 }
@@ -140,6 +144,9 @@ wxDocument::~wxDocument()
     if (GetDocumentManager())
         GetDocumentManager()->RemoveDocument(this);
 
+    if ( m_documentParent )
+        m_documentParent->m_childDocuments.remove(this);
+
     // Not safe to do here, since it'll invoke virtual view functions
     // expecting to see valid derived objects: and by the time we get here,
     // we've called destructors higher up.
@@ -151,6 +158,40 @@ bool wxDocument::Close()
     if ( !OnSaveModified() )
         return false;
 
+    // When the parent document closes, its children must be closed as well as
+    // they can't exist without the parent.
+
+    // As usual, first check if all children can be closed.
+    DocsList::const_iterator it = m_childDocuments.begin();
+    for ( DocsList::const_iterator end = m_childDocuments.end(); it != end; ++it )
+    {
+        if ( !(*it)->OnSaveModified() )
+        {
+            // Leave the parent document opened if a child can't close.
+            return false;
+        }
+    }
+
+    // Now that they all did, do close them: as m_childDocuments is modified as
+    // we iterate over it, don't use the usual for-style iteration here.
+    while ( !m_childDocuments.empty() )
+    {
+        wxDocument * const childDoc = m_childDocuments.front();
+
+        // This will call OnSaveModified() once again but it shouldn't do
+        // anything as the document was just saved or marked as not needing to
+        // be saved by the call to OnSaveModified() that returned true above.
+        if ( !childDoc->Close() )
+        {
+            wxFAIL_MSG( "Closing the child document unexpectedly failed "
+                        "after its OnSaveModified() returned true" );
+        }
+
+        // Delete the child document by deleting all its views.
+        childDoc->DeleteAllViews();
+    }
+
+
     return OnCloseDocument();
 }
 
@@ -231,6 +272,12 @@ void wxDocument::Modify(bool mod)
 
 wxDocManager *wxDocument::GetDocumentManager() const
 {
+    // For child documents we use the same document manager as the parent, even
+    // though we don't have our own template (as children are not opened/saved
+    // directly).
+    if ( m_documentParent )
+        return m_documentParent->GetDocumentManager();
+
     return m_documentTemplate ? m_documentTemplate->GetDocumentManager() : NULL;
 }
 
@@ -895,7 +942,7 @@ BEGIN_EVENT_TABLE(wxDocManager, wxEvtHandler)
     EVT_UPDATE_UI(wxID_REVERT, wxDocManager::OnUpdateFileRevert)
     EVT_UPDATE_UI(wxID_NEW, wxDocManager::OnUpdateFileNew)
     EVT_UPDATE_UI(wxID_SAVE, wxDocManager::OnUpdateFileSave)
-    EVT_UPDATE_UI(wxID_SAVEAS, wxDocManager::OnUpdateDisableIfNoDoc)
+    EVT_UPDATE_UI(wxID_SAVEAS, wxDocManager::OnUpdateFileSaveAs)
     EVT_UPDATE_UI(wxID_UNDO, wxDocManager::OnUpdateUndo)
     EVT_UPDATE_UI(wxID_REDO, wxDocManager::OnUpdateRedo)
 
@@ -1254,7 +1301,13 @@ void wxDocManager::OnUpdateFileNew(wxUpdateUIEvent& event)
 void wxDocManager::OnUpdateFileSave(wxUpdateUIEvent& event)
 {
     wxDocument * const doc = GetCurrentDocument();
-    event.Enable( doc && !doc->AlreadySaved() );
+    event.Enable( doc && !doc->IsChildDocument() && !doc->AlreadySaved() );
+}
+
+void wxDocManager::OnUpdateFileSaveAs(wxUpdateUIEvent& event)
+{
+    wxDocument * const doc = GetCurrentDocument();
+    event.Enable( doc && !doc->IsChildDocument() );
 }
 
 void wxDocManager::OnUpdateUndo(wxUpdateUIEvent& event)