ABCpdf .NET PDF Component Documentation - ZZ Elements StructureElementElement Constructor Function

StructureElementElement Function

Syntax

[C#]
StructureElementElement() StructureElementElement(Atom atom, IndirectObject host) StructureElementElement(IndirectObject obj) StructureElementElement(Element relation, CreationOptions options)
[Visual Basic]
StructureElementElement() StructureElementElement(atom As Atom, host As IndirectObject) StructureElementElement(obj As IndirectObject) StructureElementElement(relation As Element, options As CreationOptions)

Params

Name	Description
atom	The Atom to be assigned to this Element.
host	An IndirectObject. This can be any IndirectObject from the Soup but ideally should be one closely associated with the Atom.
obj	The IndirectObject to be assigned to this Element.
relation	An Element. This can be any Element in the Soup but ideally should be one closely associated with this Element.
options	Options related to creation. For example this allows you to determine whether the Element should be created using an IndirectObject rather than just an Atom. If not provided a default set of options is used.

Notes

Create a new StructureElementElement.

The different constructors allow different ways of creating an Element. Some are used for wrapping existing Atoms or IndirectObjects and others are for creating new ones.

The constructor taking a relation Element creates a new object in the document - it is typically the constructor you will want to use. Do not specify creation options unless you have very specific needs.

However for your first Element - one you can use as a relation for the others - you will need to wrap an existing IndirectObject inside an Element. For this you might use code of the following form "CatalogElement root = new CatalogElement(doc.ObjectSoup.Catalog)".

The parameterless constructor allows you to create an empty Element. By empty we mean it has no contents - no Atom within it. So before use an Atom must be Assigned or Created. In practice it is easiest to do this using one of the other constructors.

The atom and host constructor is used to wrap an existing Atom. It creates an Element and then Assigns the Atom to it. The result is a specialized Element which can be used to examine or modify the contents of the Atom.

The CreationOptions enumeration may take the following values:

Default - Default creation options for this particular type of Element.
Indirect - Create Element containing an IndirectObject.
Direct - Create Element containing an Atom.

Example

This code snippet is taken from Form1.cs line 294 in the AccessiblePDF example project.

if (table.Items.Count <= 1)
  continue; // too small
int index = 0;
StructureElementElement parent = null;
StructureElementElement tb = new StructureElementElement(document);
tb.EntryType = "StructElem";
tb.EntryS = "Table";
foreach (Row row in table.Items) {
  StructureElementElement tr = new StructureElementElement(document);
  tr.EntryType = "StructElem";
  tr.EntryS = "TR";
  tr.SetParent(tb);
  foreach (StructureElementElement item in row.Items) {
    if ((parent == null) && (item != null)) {
      Debug.Assert(item.EntryP is StructureTreeRootElement == false);
      parent = item.EntryP as StructureElementElement;
      index = parent.EntryK.IndexOf(item);
    }
    StructureElementElement td = new StructureElementElement(document);
    td.EntryType = "StructElem";
    td.EntryS = "TD";
    td.SetParent(tr);
    if (item != null)
      item.SetParent(td);
  }
}
tb.SetParent(parent, index);

If table.Items.Count <= 1 Then
  continue ' too small
End If
Dim index As Integer = 0
Dim parent As StructureElementElement = Nothing
Dim tb As New StructureElementElement(document)
tb.EntryType = "StructElem"
tb.EntryS = "Table"
For Each row As Row In table.Items
  Dim tr As New StructureElementElement(document)
  tr.EntryType = "StructElem"
  tr.EntryS = "TR"
  tr.SetParent(tb)
  For Each item As StructureElementElement In row.Items
    If (parent Is Nothing) AndAlso (item IsNot Nothing) Then
      Debug.Assert(TypeOf item.EntryP Is StructureTreeRootElement = False)
      parent = TryCast(item.EntryP, StructureElementElement)
      index = parent.EntryK.IndexOf(item)
    End If
    Dim td As New StructureElementElement(document)
    td.EntryType = "StructElem"
    td.EntryS = "TD"
    td.SetParent(tr)
    If item IsNot Nothing Then
      item.SetParent(td)
    End If
  Next item
Next row
tb.SetParent(parent, index)

This code snippet is taken from Form1.cs line 335 in the AccessiblePDF example project.

theDoc.Read(src);
AccessibilityOperation op = new AccessibilityOperation(theDoc);
op.PageContents.AddPages();
op.MakeAccessible();
theDoc.Save(dst);
Structure tags = new Structure();
tags.Load(theDoc);
// reorder elements so that they go from top to bottom
StructureElementElement document = (StructureElementElement)tags.Root.EntryK[0];
KidArranger.SortTopToBottom(tags, document);
// determine what styles are used for headers and change tag type appropriately
List<StructureElementElement> elements = tags.FindElementsByType("P");
Dictionary<string, List<StructureElementElement>> styles = new Dictionary<string, List<StructureElementElement>>();
foreach (StructureElementElement element in elements) {
  string weight = null;
  if (!element.GetStyle().TryGetValue("font-weight", out weight))
    continue; // we are only interested in bold fonts
  int value = 0;
  if ((!int.TryParse(weight, out value)) || (value < 700))
    continue;
  string size = null;
  if (!element.GetStyle().TryGetValue("font-size", out size))
    continue;
  List<StructureElementElement> matches = null;
  if (!styles.TryGetValue(size, out matches)) {
    matches = new List<StructureElementElement>();
    styles[size] = matches;
  }
  matches.Add(element);
}
List<Style> headers = new List<Style>();
foreach (KeyValuePair<string, List<StructureElementElement>> pair in styles)
  headers.Add(new Style(pair.Key, pair.Value));
headers.Sort((i1, i2) => i1.Elements.Count.CompareTo(i2.Elements.Count));
for (int i = 0; i < headers.Count; i++) {
  if (i > 4)
    break; // limit the number of header levels
  string tag = "H" + (i + 1).ToString();
  foreach (StructureElementElement element in headers[i].Elements) {
    element.EntryS = tag;
  }
}
theDoc.Save(dst);

theDoc.Read(src)
Dim op As New AccessibilityOperation(theDoc)
op.PageContents.AddPages()
op.MakeAccessible()
theDoc.Save(dst)
Dim tags As [Structure] = New [Structure]()
tags.Load(theDoc)
' reorder elements so that they go from top to bottom
Dim document As StructureElementElement = CType(tags.Root.EntryK(0), StructureElementElement)
KidArranger.SortTopToBottom(tags, document)
' determine what styles are used for headers and change tag type appropriately
Dim elements As List(Of StructureElementElement) = tags.FindElementsByType("P")
Dim styles As New Dictionary(Of String, List(Of StructureElementElement))()
For Each element As StructureElementElement In elements
  Dim weight As String = Nothing
  If Not element.GetStyle().TryGetValue("font-weight", weight) Then
    Continue For ' we are only interested in bold fonts
  End If
  Dim value As Integer = 0
  If (Not Integer.TryParse(weight, value)) OrElse (value < 700) Then
    Continue For
  End If
  Dim size As String = Nothing
  If Not element.GetStyle().TryGetValue("font-size", size) Then
    Continue For
  End If
  Dim matches As List(Of StructureElementElement) = Nothing
  If Not styles.TryGetValue(size, matches) Then
    matches = New List(Of StructureElementElement)()
    styles(size) = matches
  End If
  matches.Add(element)
Next element
Dim headers As New List(Of Style)()
For Each pair As KeyValuePair(Of String, List(Of StructureElementElement)) In styles
  headers.Add(New Style(pair.Key, pair.Value))
Next pair
headers.Sort(Function(i1, i2) i1.Elements.Count.CompareTo(i2.Elements.Count))
For i As Integer = 0 To headers.Count - 1
  If i > 4 Then
    Exit For ' limit the number of header levels
  End If
  Dim tag As String = "H" & (i + 1).ToString()
  For Each element As StructureElementElement In headers(i).Elements
    element.EntryS = tag
  Next element
Next i
theDoc.Save(dst)

This code snippet is taken from Form1.cs line 406 in the AccessiblePDF example project.

list = new StructureElementElement(document);
list.EntryType = "StructElem";
list.EntryS = "L";
Debug.Assert(element.EntryP is StructureTreeRootElement == false);
StructureElementElement parent = element.EntryP as StructureElementElement;
Debug.Assert(parent != null);
int index = parent.EntryK.IndexOf(element);
list.SetParent(parent, index);

list = New StructureElementElement(document)
list.EntryType = "StructElem"
list.EntryS = "L"
Debug.Assert(TypeOf element.EntryP Is StructureTreeRootElement = False)
Dim parent As StructureElementElement = TryCast(element.EntryP, StructureElementElement)
Debug.Assert(parent IsNot Nothing)
Dim index As Integer = parent.EntryK.IndexOf(element)
list.SetParent(parent, index)

This code snippet is taken from Form1.cs line 435 in the AccessiblePDF example project.

theDoc.Read(src);
AccessibilityOperation op = new AccessibilityOperation(theDoc);
op.PageContents.AddPages();
op.MakeAccessible();
theDoc.Save(dst);
Structure tags = new Structure();
tags.Load(theDoc);
// reorder elements so that they go from top to bottom
StructureElementElement document = (StructureElementElement)tags.Root.EntryK[0];
KidArranger.SortTopToBottom(tags, document);
// define structure hierarchy template
List<Heading> template = new List<Heading>();
template.Add(new Heading("Title ", "Part", 1));
template.Add(new Heading("Subheader ", "Sect", 2));
// detect and insert section item structure
List<StructureElementElement> elements = tags.FindElementsByType("P");
Stack<StructureElementElement> hierarchy = new Stack<StructureElementElement>();
foreach (StructureElementElement element in elements) {
  string text = element.EntryActualText.TrimStart();
  foreach (Heading item in template) {
    if (text.StartsWith(item.Match)) {
      while (hierarchy.Count >= item.Level)
        hierarchy.Pop();
      if (hierarchy.Count == item.Level - 1) {
        StructureElementElement heading = new StructureElementElement(document);
        heading.EntryType = "StructElem";
        heading.EntryS = item.Type;
        StructureElementElement parent = (StructureElementElement)element.EntryP;
        int index = parent.EntryK.IndexOf(element);
        heading.SetParent(hierarchy.Count > 0 ? hierarchy.Peek() : parent, index);
        hierarchy.Push(heading);
      }
      break;
    }
  }
  if (hierarchy.Count > 0)
    element.SetParent(hierarchy.Peek(), Int32.MaxValue);
}
theDoc.Save(dst);

theDoc.Read(src)
Dim op As New AccessibilityOperation(theDoc)
op.PageContents.AddPages()
op.MakeAccessible()
theDoc.Save(dst)
Dim tags As [Structure] = New [Structure]()
tags.Load(theDoc)
' reorder elements so that they go from top to bottom
Dim document As StructureElementElement = CType(tags.Root.EntryK(0), StructureElementElement)
KidArranger.SortTopToBottom(tags, document)
' define structure hierarchy template
Dim template As New List(Of Heading)()
template.Add(New Heading("Title ", "Part", 1))
template.Add(New Heading("Subheader ", "Sect", 2))
' detect and insert section item structure
Dim elements As List(Of StructureElementElement) = tags.FindElementsByType("P")
Dim hierarchy As New Stack(Of StructureElementElement)()
For Each element As StructureElementElement In elements
  Dim text As String = element.EntryActualText.TrimStart()
  For Each item As Heading In template
    If text.StartsWith(item.Match) Then
      Do While hierarchy.Count >= item.Level
        hierarchy.Pop()
      Loop
      If hierarchy.Count = item.Level - 1 Then
        Dim heading As New StructureElementElement(document)
        heading.EntryType = "StructElem"
        heading.EntryS = item.Type
        Dim parent As StructureElementElement = CType(element.EntryP, StructureElementElement)
        Dim index As Integer = parent.EntryK.IndexOf(element)
        heading.SetParent(If(hierarchy.Count > 0, hierarchy.Peek(), parent), index)
        hierarchy.Push(heading)
      End If
      Exit For
    End If
  Next item
  If hierarchy.Count > 0 Then
    element.SetParent(hierarchy.Peek(), Int32.MaxValue)
  End If
Next element
theDoc.Save(dst)

This code snippet is taken from TableDetection.cs line 171 in the AccessiblePDF example project.

_tags = tags;
_items = new List<StructureElementElement>();

_tags = tags
_items = New List(Of StructureElementElement)()

This code snippet is taken from TaggedPDF.cs line 61 in the AccessiblePDF example project.

_root = new StructureElementElement(root, _catalog);
DictAtom tree = _catalog.Resolve(Atom.GetItem(_root.Atom, "ParentTree")) as DictAtom;
_parentTree = new ParentTree(this, tree);

_root = New StructureElementElement(root, _catalog)
Dim tree As DictAtom = TryCast(_catalog.Resolve(Atom.GetItem(_root.Atom, "ParentTree")), DictAtom)
_parentTree = New ParentTree(Me, tree)

This code snippet is taken from TaggedPDF.cs line 69 in the AccessiblePDF example project.

List<StructureElementElement> items = new List<StructureElementElement>();
FindElementsByType(_root, items, type);
return items;

Dim items As New List(Of StructureElementElement)()
FindElementsByType(_root, items, type)
Return items