Improve checkbox rendering

DEVSIX-7426

Author: guustysebie

forms/src/main/java/com/itextpdf/forms/PdfAcroForm.java

@@ -27,10 +27,10 @@ This file is part of the iText (R) project.
 import com.itextpdf.forms.exceptions.FormsExceptionMessageConstant;
 import com.itextpdf.forms.fields.AbstractPdfFormField;
 import com.itextpdf.forms.fields.PdfFormAnnotation;
+import com.itextpdf.forms.fields.PdfFormAnnotationUtil;
 import com.itextpdf.forms.fields.PdfFormField;
-import com.itextpdf.forms.logs.FormsLogMessageConstants;
 import com.itextpdf.forms.fields.PdfFormFieldMergeUtil;
-import com.itextpdf.forms.fields.PdfFormAnnotationUtil;
+import com.itextpdf.forms.logs.FormsLogMessageConstants;
 import com.itextpdf.forms.xfa.XfaForm;
 import com.itextpdf.kernel.exceptions.PdfException;
 import com.itextpdf.kernel.geom.AffineTransform;
@@ -216,7 +216,7 @@ public void addField(PdfFormField field, PdfPage page, boolean replaceExisted) {
         if (!field.getPdfObject().containsKey(PdfName.T)) {
             throw new PdfException(FormsExceptionMessageConstant.FORM_FIELD_MUST_HAVE_A_NAME);
         }
-        
+
         if (!replaceExisted) {
             PdfFormFieldMergeUtil.mergeKidsWithSameNames(field, true);
         }
@@ -1085,6 +1085,14 @@ public void removeXfaForm() {
         }
     }
 
+    /**
+     * Put a key/value pair in the  dictionary and overwrites the previous value if it already exists.
+     *
+     * @param key   the key as pdf name
+     * @param value the value as pdf object
+     *
+     * @return this {@link PdfAcroForm} instance
+     */
     public PdfAcroForm put(PdfName key, PdfObject value) {
         getPdfObject().put(key, value);
         setModified();

forms/src/main/java/com/itextpdf/forms/fields/AbstractPdfFormField.java

@@ -40,10 +40,7 @@ This file is part of the iText (R) project.
 import com.itextpdf.kernel.pdf.PdfString;
 
 import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.HashSet;
 import java.util.List;
-import java.util.Set;
 
 /**
  * This class represents a single field or field group in an {@link com.itextpdf.forms.PdfAcroForm
@@ -55,16 +52,17 @@ This file is part of the iText (R) project.
  */
 public abstract class AbstractPdfFormField extends PdfObjectWrapper<PdfDictionary> {
 
-    private static final PdfName[] TERMINAL_FIELDS = new PdfName[]{PdfName.Btn, PdfName.Tx, PdfName.Ch, PdfName.Sig};
     /**
      * Size of text in form fields when font size is not explicitly set.
      */
-    static final int DEFAULT_FONT_SIZE = 12;
+    public static final int DEFAULT_FONT_SIZE = 12;
 
     /**
      * Minimal size of text in form fields.
      */
-    static final int MIN_FONT_SIZE = 4;
+    public static final int MIN_FONT_SIZE = 4;
+
+    private static final PdfName[] TERMINAL_FIELDS = new PdfName[] {PdfName.Btn, PdfName.Tx, PdfName.Ch, PdfName.Sig};
 
     /**
      * Index of font value in default appearance element.

forms/src/main/java/com/itextpdf/forms/fields/CheckBoxFormFieldBuilder.java

@@ -90,14 +90,14 @@ public PdfButtonFormField createCheckBox() {
         check.put(PdfName.V, new PdfName(PdfFormAnnotation.OFF_STATE_VALUE));
 
         if (getWidgetRectangle() != null) {
-            //TODO DEVSIX-7426 remove flag
+            //TODO DEVSIX-7443 remove flag
             if (ExperimentalFeatures.ENABLE_EXPERIMENTAL_CHECKBOX_RENDERING) {
                 check.getFirstFormAnnotation()
                         .drawCheckBoxAndSaveAppearanceExperimental(PdfFormAnnotation.ON_STATE_VALUE);
                 setPageToField(check);
                 return check;
             }
-            //TODO DEVSIX-7426 remove from here till end
+            //TODO DEVSIX-7443 remove from here till end
             if (getConformanceLevel() == null) {
                 check.getFirstFormAnnotation().drawCheckAppearance(getWidgetRectangle().getWidth(),
                         getWidgetRectangle().getHeight(), PdfFormAnnotation.ON_STATE_VALUE);