wrap checkboxes and radiobuttons in their own form field types with access to the child collections

src/UglyToad.PdfPig.Tests/Integration/AcroFormsBasicFieldsTests.cs

@@ -43,16 +43,15 @@
             }
         }
 
-        //[Fact]
+        [Fact]
-        //public void GetFormFieldsByPage()
+        public void GetFormFieldsByPage()
-        //{
+        {
-        //    using (var document = PdfDocument.Open(GetFilename(), ParsingOptions.LenientParsingOff))
+            using (var document = PdfDocument.Open(GetFilename(), ParsingOptions.LenientParsingOff))
-        //    {
+            {
-        //        var form = document.GetForm();
+                var form = document.GetForm();
-        //        var fields = form.GetFieldsForPage(1).ToList();
+                var fields = form.GetFieldsForPage(1).ToList();
-        //        var page = document.GetPage(1).ExperimentalAccess.GetAnnotations().ToList();
+                Assert.Equal(18, fields.Count);
-        //        Assert.Equal(16, fields.Count);
+            }
-        //    }
+        }
-        //}
     }
 }

src/UglyToad.PdfPig.Tests/PublicApiScannerTests.cs

@@ -41,6 +41,7 @@
             {
                 "UglyToad.PdfPig.AcroForms.Fields.AcroButtonFieldFlags",
                 "UglyToad.PdfPig.AcroForms.Fields.AcroCheckboxField",
+                "UglyToad.PdfPig.AcroForms.Fields.AcroCheckboxesField",
                 "UglyToad.PdfPig.AcroForms.Fields.AcroChoiceFieldFlags",
                 "UglyToad.PdfPig.AcroForms.Fields.AcroChoiceOption",
                 "UglyToad.PdfPig.AcroForms.Fields.AcroComboBoxField",
@@ -50,6 +51,7 @@
                 "UglyToad.PdfPig.AcroForms.Fields.AcroListBoxField",
                 "UglyToad.PdfPig.AcroForms.Fields.AcroNonTerminalField",
                 "UglyToad.PdfPig.AcroForms.Fields.AcroPushButtonField",
+                "UglyToad.PdfPig.AcroForms.Fields.AcroRadioButtonField",
                 "UglyToad.PdfPig.AcroForms.Fields.AcroRadioButtonsField",
                 "UglyToad.PdfPig.AcroForms.Fields.AcroSignatureField",
                 "UglyToad.PdfPig.AcroForms.Fields.AcroTextField",

src/UglyToad.PdfPig/AcroForms/AcroForm.cs

@@ -2,6 +2,7 @@
 {
     using System;
     using System.Collections.Generic;
+    using System.Linq;
     using Fields;
     using Tokens;
     using Util.JetBrains.Annotations;
@@ -39,7 +40,7 @@
         /// <summary>
         /// Create a new <see cref="AcroForm"/>.
         /// </summary>
-        public AcroForm(DictionaryToken dictionary, SignatureFlags signatureFlags, bool needAppearances, 
+        public AcroForm(DictionaryToken dictionary, SignatureFlags signatureFlags, bool needAppearances,
             IReadOnlyDictionary<IndirectReference, AcroFieldBase> fields)
         {
             Dictionary = dictionary ?? throw new ArgumentNullException(nameof(dictionary));
@@ -64,6 +65,11 @@
                 {
                     yield return field.Value;
                 }
+                else if (field.Value is AcroNonTerminalField parent
+                && parent.Children.Any(x => x.PageNumber == pageNumber))
+                {
+                    yield return field.Value;
+                }
             }
         }
 

src/UglyToad.PdfPig/AcroForms/AcroFormFactory.cs

@@ -19,6 +19,15 @@
     /// </summary>
     internal class AcroFormFactory
     {
+        private static readonly HashSet<NameToken> InheritableFields = new HashSet<NameToken>
+        {
+            NameToken.Ft,
+            NameToken.Ff,
+            NameToken.V,
+            NameToken.Dv,
+            NameToken.Aa
+        };
+
         private readonly IPdfTokenScanner tokenScanner;
         private readonly IFilterProvider filterProvider;
 
@@ -92,7 +101,7 @@
 
                 var fieldDictionary = DirectObjectFinder.Get<DictionaryToken>(fieldToken, tokenScanner);
 
-                var field = GetAcroField(fieldDictionary, catalog);
+                var field = GetAcroField(fieldDictionary, catalog, new List<DictionaryToken>(0));
 
                 fields[fieldReferenceToken.Data] = field;
             }
@@ -100,12 +109,15 @@
             return new AcroForm(acroDictionary, signatureFlags, needAppearances, fields);
         }
 
-        private AcroFieldBase GetAcroField(DictionaryToken fieldDictionary, Catalog catalog)
+        private AcroFieldBase GetAcroField(DictionaryToken fieldDictionary, Catalog catalog,
+            IReadOnlyList<DictionaryToken> parentDictionaries)
         {
-            fieldDictionary.TryGet(NameToken.Ft, out NameToken fieldType);
+            fieldDictionary = CreateInheritedDictionary(fieldDictionary, parentDictionaries);
-            fieldDictionary.TryGet(NameToken.Ff, out NumericToken fieldFlagsToken);
 
-            var kids = new List<DictionaryToken>();
+            fieldDictionary.TryGet(NameToken.Ft, tokenScanner, out NameToken fieldType);
+            fieldDictionary.TryGet(NameToken.Ff, tokenScanner, out NumericToken fieldFlagsToken);
+
+            var kids = new List<(bool hasParent, DictionaryToken dictionary)>();
 
             if (fieldDictionary.TryGetOptionalTokenDirect(NameToken.Kids, tokenScanner, out ArrayToken kidsToken))
             {
@@ -120,7 +132,8 @@
 
                     if (kidObject.Data is DictionaryToken kidDictionaryToken)
                     {
-                        kids.Add(kidDictionaryToken);
+                        var hasParent = kidDictionaryToken.TryGet(NameToken.Parent, out IndirectReferenceToken _);
+                        kids.Add((hasParent, kidDictionaryToken));
                     }
                     else
                     {
@@ -147,19 +160,26 @@
                 bounds = rectArray.ToRectangle();
             }
 
+            var newParentDictionaries = new List<DictionaryToken>(parentDictionaries) {fieldDictionary};
+
+            var children = new List<AcroFieldBase>(kids.Count);
+            foreach (var kid in kids)
+            {
+                if (!kid.hasParent)
+                {
+                    // Is a widget annotation dictionary.
+                    continue;
+                }
+
+                children.Add(GetAcroField(kid.dictionary, catalog, newParentDictionaries));
+            }
+
             var fieldFlags = (uint) (fieldFlagsToken?.Long ?? 0);
 
             AcroFieldBase result;
             if (fieldType == null)
             {
-                var children = new List<AcroFieldBase>();
+                result = new AcroNonTerminalField(fieldDictionary, "Non-Terminal Field", fieldFlags, information, AcroFieldType.Unknown, children);
-                foreach (var kid in kids)
-                {
-                    var kidField = GetAcroField(kid, catalog);
-                    children.Add(kidField);
-                }
-
-                result = new AcroNonTerminalField(fieldDictionary, "Non-Terminal Field", fieldFlags, information, children);
             }
             else if (fieldType == NameToken.Btn)
             {
@@ -167,10 +187,19 @@
 
                 if (buttonFlags.HasFlag(AcroButtonFieldFlags.Radio))
                 {
-                    var field = new AcroRadioButtonsField(fieldDictionary, fieldType, buttonFlags, information, 
+                    if (children.Count > 0)
-                        pageNumber, 
+                    {
-                        bounds);
+                        result = new AcroRadioButtonsField(fieldDictionary, fieldType, buttonFlags, information,
-                    result = field;
+                            children);
+                    }
+                    else
+                    {
+                        var field = new AcroRadioButtonField(fieldDictionary, fieldType, buttonFlags, information,
+                            pageNumber,
+                            bounds);
+                        
+                        result = field;
+                    }
                 }
                 else if (buttonFlags.HasFlag(AcroButtonFieldFlags.PushButton))
                 {
@@ -191,13 +220,21 @@
                         isChecked = !string.Equals(valueToken.Data, NameToken.Off, StringComparison.OrdinalIgnoreCase);
                     }
 
-                    var field = new AcroCheckboxField(fieldDictionary, fieldType, buttonFlags, information, 
+                    if (children.Count > 0)
-                        valueToken,
+                    {
-                        isChecked,
+                        result = new AcroCheckboxesField(fieldDictionary, fieldType, buttonFlags, information,
-                        pageNumber,
+                            children);
-                        bounds);
+                    }
+                    else
+                    {
+                        var field = new AcroCheckboxField(fieldDictionary, fieldType, buttonFlags, information,
+                            valueToken,
+                            isChecked,
+                            pageNumber,
+                            bounds);
 
-                    result = field;
+                        result = field;
+                    }
                 }
             }
             else if (fieldType == NameToken.Tx)
@@ -403,6 +440,34 @@
                 pageNumber,
                 bounds);
         }
+        
+        private static DictionaryToken CreateInheritedDictionary(DictionaryToken fieldDictionary, IReadOnlyList<DictionaryToken> parents)
+        {
+            if (parents.Count == 0)
+            {
+                return fieldDictionary;
+            }
+
+            var inheritedDictionary = new Dictionary<NameToken, IToken>();
+            foreach (var parent in parents)
+            {
+                foreach (var kvp in parent.Data)
+                {
+                    var key = NameToken.Create(kvp.Key);
+                    if (InheritableFields.Contains(key))
+                    {
+                        inheritedDictionary[key] = kvp.Value;
+                    }
+                }
+            }
+
+            foreach (var kvp in fieldDictionary.Data)
+            {
+                inheritedDictionary[NameToken.Create(kvp.Key)] = kvp.Value;
+            }
+
+            return new DictionaryToken(inheritedDictionary);
+        }
 
         private static bool IsChoiceSelected(IReadOnlyList<string> selectedOptionNames, IReadOnlyList<int> selectedOptionIndices, int index, string name)
         {

src/UglyToad.PdfPig/AcroForms/Fields/AcroCheckboxesField.cs

@@ -0,0 +1,24 @@
+namespace UglyToad.PdfPig.AcroForms.Fields
+{
+    using System.Collections.Generic;
+    using Tokens;
+
+    /// <inheritdoc />
+    /// <summary>
+    /// A set of related checkboxes.
+    /// </summary>
+    public class AcroCheckboxesField : AcroNonTerminalField
+    {
+        /// <inheritdoc />
+        /// <summary>
+        /// Create a new <see cref="AcroCheckboxesField"/>.
+        /// </summary>
+        internal AcroCheckboxesField(DictionaryToken dictionary, string fieldType, AcroButtonFieldFlags fieldFlags,
+            AcroFieldCommonInformation information,
+            IReadOnlyList<AcroFieldBase> children) : 
+            base(dictionary, fieldType, (uint)fieldFlags, information, 
+                AcroFieldType.Checkboxes, children)
+        {
+        }
+    }
+}

src/UglyToad.PdfPig/AcroForms/Fields/AcroFieldType.cs

@@ -10,12 +10,20 @@
         /// </summary>
         PushButton,
         /// <summary>
+        /// A set of checkboxes.
+        /// </summary>
+        Checkboxes,
+        /// <summary>
         /// A checkbox which toggles between on and off states.
         /// </summary>
         Checkbox,
         /// <summary>
         /// A set of radio buttons.
         /// </summary>
+        RadioButtons,
+        /// <summary>
+        /// A single radio button, as part of a set or on its own.
+        /// </summary>
         RadioButton,
         /// <summary>
         /// A textbox allowing user input through the keyboard.
@@ -34,8 +42,8 @@
         /// </summary>
         Signature,
         /// <summary>
-        /// A field which acts as a container for other fields.
+        /// The field type wasn't specified.
         /// </summary>
-        NonTerminal
+        Unknown
     }
 }

src/UglyToad.PdfPig/AcroForms/Fields/AcroNonTerminalField.cs

@@ -19,9 +19,11 @@
         /// <summary>
         /// Create a new <see cref="AcroNonTerminalField"/>.
         /// </summary>
-        internal AcroNonTerminalField(DictionaryToken dictionary, string fieldType, uint fieldFlags, AcroFieldCommonInformation information,
+        internal AcroNonTerminalField(DictionaryToken dictionary, string fieldType, uint fieldFlags, 
+            AcroFieldCommonInformation information,
+            AcroFieldType acroFieldType,
             IReadOnlyList<AcroFieldBase> children) : 
-            base(dictionary, fieldType, fieldFlags, AcroFieldType.NonTerminal, information,
+            base(dictionary, fieldType, fieldFlags, acroFieldType, information,
                 null, null)
         {
             Children = children ?? throw new ArgumentNullException(nameof(children));

src/UglyToad.PdfPig/AcroForms/Fields/AcroRadioButtonField.cs

@@ -0,0 +1,30 @@
+namespace UglyToad.PdfPig.AcroForms.Fields
+{
+    using Geometry;
+    using Tokens;
+
+    /// <inheritdoc />
+    /// <summary>
+    /// A single radio button.
+    /// </summary>
+    public class AcroRadioButtonField : AcroFieldBase
+    {
+        /// <summary>
+        /// The <see cref="AcroButtonFieldFlags"/> which define the behaviour of this button type.
+        /// </summary>
+        public AcroButtonFieldFlags Flags { get; }
+
+        /// <inheritdoc />
+        /// <summary>
+        /// Create a new <see cref="AcroRadioButtonField"/>.
+        /// </summary>
+        public AcroRadioButtonField(DictionaryToken dictionary, string fieldType, AcroButtonFieldFlags fieldFlags,
+            AcroFieldCommonInformation information,
+            int? pageNumber,
+            PdfRectangle? bounds) :
+            base(dictionary, fieldType, (uint)fieldFlags, AcroFieldType.RadioButton, information, pageNumber, bounds)
+        {
+            Flags = fieldFlags;
+        }
+    }
+}

src/UglyToad.PdfPig/AcroForms/Fields/AcroRadioButtonsField.cs

@@ -1,13 +1,13 @@
 namespace UglyToad.PdfPig.AcroForms.Fields
 {
-    using Geometry;
+    using System.Collections.Generic;
     using Tokens;
 
     /// <inheritdoc />
     /// <summary>
     /// A set of radio buttons.
     /// </summary>
-    public class AcroRadioButtonsField : AcroFieldBase
+    public class AcroRadioButtonsField : AcroNonTerminalField
     {
         /// <summary>
         /// The <see cref="AcroButtonFieldFlags"/> which define the behaviour of this button type.
@@ -20,9 +20,8 @@
         /// </summary>
         public AcroRadioButtonsField(DictionaryToken dictionary, string fieldType, AcroButtonFieldFlags fieldFlags, 
             AcroFieldCommonInformation information,
-            int? pageNumber,
+            IReadOnlyList<AcroFieldBase> children) : 
-            PdfRectangle? bounds) : 
+            base(dictionary, fieldType, (uint)fieldFlags, information, AcroFieldType.RadioButtons, children)
-            base(dictionary, fieldType, (uint)fieldFlags, AcroFieldType.RadioButton, information, pageNumber, bounds)
         {
             Flags = fieldFlags;
         }