LayoutCollector

LayoutCollector constructor

Initializes an instance of this class.

public LayoutCollector(Document doc)
Parameter Type Description
doc Document The document to which this collector instance will be attached to.

Examples

Shows how to see the the ranges of pages that a node spans.

Document doc = new Document();
LayoutCollector layoutCollector = new LayoutCollector(doc);

// Call the "GetNumPagesSpanned" method to count how many pages the content of our document spans.
// Since the document is empty, that number of pages is currently zero.
Assert.AreEqual(doc, layoutCollector.Document);
Assert.AreEqual(0, layoutCollector.GetNumPagesSpanned(doc));

// Populate the document with 5 pages of content.
DocumentBuilder builder = new DocumentBuilder(doc);
builder.Write("Section 1");
builder.InsertBreak(BreakType.PageBreak);
builder.InsertBreak(BreakType.PageBreak);
builder.InsertBreak(BreakType.SectionBreakEvenPage);
builder.Write("Section 2");
builder.InsertBreak(BreakType.PageBreak);
builder.InsertBreak(BreakType.PageBreak);

// Before the layout collector, we need to call the "UpdatePageLayout" method to give us
// an accurate figure for any layout-related metric, such as the page count.
Assert.AreEqual(0, layoutCollector.GetNumPagesSpanned(doc));

layoutCollector.Clear();
doc.UpdatePageLayout();

Assert.AreEqual(5, layoutCollector.GetNumPagesSpanned(doc));

// We can see the numbers of the start and end pages of any node and their overall page spans.
NodeCollection nodes = doc.GetChildNodes(NodeType.Any, true);
foreach (Node node in nodes)
{
    Console.WriteLine($"->  NodeType.{node.NodeType}: ");
    Console.WriteLine(
        $"\tStarts on page {layoutCollector.GetStartPageIndex(node)}, ends on page {layoutCollector.GetEndPageIndex(node)}," +
        $" spanning {layoutCollector.GetNumPagesSpanned(node)} pages.");
}

// We can iterate over the layout entities using a LayoutEnumerator.
LayoutEnumerator layoutEnumerator = new LayoutEnumerator(doc);

Assert.AreEqual(LayoutEntityType.Page, layoutEnumerator.Type);

// The LayoutEnumerator can traverse the collection of layout entities like a tree.
// We can also apply it to any node's corresponding layout entity.
layoutEnumerator.Current = layoutCollector.GetEntity(doc.GetChild(NodeType.Paragraph, 1, true));

Assert.AreEqual(LayoutEntityType.Span, layoutEnumerator.Type);
Assert.AreEqual("¶", layoutEnumerator.Text);

See Also