XFA - Don't display print-only elements

- partial fix for https://bugzilla.mozilla.org/show_bug.cgi?id=1716980.

src/core/xfa/template.js

@@ -69,6 +69,7 @@ import {
   fixDimensions,
   fixTextIndent,
   getFonts,
+  isPrintOnly,
   layoutClass,
   layoutText,
   measureToString,
@@ -298,6 +299,10 @@ class Area extends XFAObject {
       class: ["xfaArea"],
     };
 
+    if (isPrintOnly(this)) {
+      attributes.class.push("xfaPrintOnly");
+    }
+
     if (this.name) {
       attributes.xfaName = this.name;
     }
@@ -1136,12 +1141,19 @@ class ContentArea extends XFAObject {
       width: measureToString(this.w),
       height: measureToString(this.h),
     };
+
+    const classNames = ["xfaContentarea"];
+
+    if (isPrintOnly(this)) {
+      classNames.push("xfaPrintOnly");
+    }
+
     return HTMLResult.success({
       name: "div",
       children: [],
       attributes: {
         style,
-        class: ["xfaContentarea"],
+        class: classNames,
         id: this[$uid],
       },
     });
@@ -1511,6 +1523,9 @@ class Draw extends XFAObject {
     if (this.font) {
       classNames.push("xfaFont");
     }
+    if (isPrintOnly(this)) {
+      classNames.push("xfaPrintOnly");
+    }
 
     const attributes = {
       style,
@@ -2079,6 +2094,10 @@ class ExclGroup extends XFAObject {
       classNames.push(cl);
     }
 
+    if (isPrintOnly(this)) {
+      classNames.push("xfaPrintOnly");
+    }
+
     attributes.style = style;
     attributes.class = classNames;
 
@@ -2327,6 +2346,10 @@ class Field extends XFAObject {
       classNames.push("xfaFont");
     }
 
+    if (isPrintOnly(this)) {
+      classNames.push("xfaPrintOnly");
+    }
+
     const attributes = {
       style,
       id: this[$uid],