ContrastRatioChecker (veraPDF WCAG Validation 1.20.1 API)

java.lang.Object
- org.verapdf.wcag.algorithms.semanticalgorithms.ContrastRatioChecker

public class ContrastRatioChecker
extends Object

Constructor Summary

Constructors
Constructor Description

ContrastRatioChecker()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`checkDocument(IDocument document, String pdfName)`
`void`	`checkSemanticTree(ITree tree, String pdfName)`	Traverses the document semantic tree and updates contrast ratio parameter of it's nodes.
`double`	`getContrastRatio(double first, double second)`	Determines contrast ratio of two color based on their relative luminance.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - ContrastRatioChecker
```
public ContrastRatioChecker()
```
- Method Detail
  - checkSemanticTree
```
public void checkSemanticTree(ITree tree,
                              String pdfName)
```
    Traverses the document semantic tree and updates contrast ratio parameter of it's nodes. Uses pdf document associated with the tree to determine contrast ratio by rendering it's pages.
    
    Parameters:
    
    tree - tree with nodes to update with calculated contrast ratio
    
    pdfName - String path to the pdf document associated with given tree
  - checkDocument
```
public void checkDocument(IDocument document,
                          String pdfName)
```
  - getContrastRatio
```
public double getContrastRatio(double first,
                               double second)
```
    Determines contrast ratio of two color based on their relative luminance. The resulting contrast ratio ranges from 1.0 to 21.0
    
    Parameters:
    
    first - relative luminance of the first color
    
    second - relative luminance of the first color
    
    Returns:
    
    contrast ratio of the given colors