XFA - Fix lot of layout issues

- I thought it was possible to rely on browser layout engine to handle layout stuff but it isn't possible
    - mainly because when a contentArea overflows, we must continue to layout in the next contentArea
    - when no more contentArea is available then we must go to the next page...
    - we must handle breakBefore and breakAfter which allows to "break" the layout to go to the next container
  - Sometimes some containers don't provide their dimensions so we must compute them in order to know where to put
    them in their parents but to compute those dimensions we need to layout the container itself...
  - See top of file layout.js for more explanations about layout.
  - fix few bugs in other places I met during my work on layout.

src/core/xfa/xhtml.js

@@ -17,6 +17,7 @@ import {
   $acceptWhitespace,
   $childrenToHTML,
   $content,
+  $extra,
   $nodeName,
   $onText,
   $text,
@@ -24,8 +25,8 @@ import {
   XmlObject,
 } from "./xfa_object.js";
 import { $buildXFAObject, NamespaceIds } from "./namespaces.js";
-import { getMeasurement } from "./utils.js";
-import { measureToString } from "./html_utils.js";
+import { fixTextIndent, getFonts, measureToString } from "./html_utils.js";
+import { getMeasurement, HTMLResult } from "./utils.js";
 
 const XHTML_NS_ID = NamespaceIds.xhtml.id;
 
@@ -79,14 +80,16 @@ const StyleMapping = new Map([
   ],
   ["xfa-spacerun", ""],
   ["xfa-tab-stops", ""],
-  ["font-size", value => measureToString(getMeasurement(value))],
+  ["font-size", value => measureToString(1 * getMeasurement(value))],
   ["letter-spacing", value => measureToString(getMeasurement(value))],
-  ["line-height", value => measureToString(getMeasurement(value))],
+  ["line-height", value => measureToString(0.99 * getMeasurement(value))],
   ["margin", value => measureToString(getMeasurement(value))],
   ["margin-bottom", value => measureToString(getMeasurement(value))],
   ["margin-left", value => measureToString(getMeasurement(value))],
   ["margin-right", value => measureToString(getMeasurement(value))],
   ["margin-top", value => measureToString(getMeasurement(value))],
+  ["text-indent", value => measureToString(getMeasurement(value))],
+  ["font-family", value => getFonts(value)],
 ]);
 
 const spacesRegExp = /\s+/g;
@@ -121,6 +124,8 @@ function mapStyle(styleStr) {
         newValue;
     }
   }
+
+  fixTextIndent(style);
   return style;
 }
 
@@ -162,16 +167,27 @@ class XhtmlObject extends XmlObject {
     }
   }
 
-  [$toHTML]() {
-    return {
+  [$toHTML](availableSpace) {
+    const children = [];
+    this[$extra] = {
+      children,
+    };
+
+    this[$childrenToHTML]({});
+
+    if (children.length === 0 && !this[$content]) {
+      return HTMLResult.EMPTY;
+    }
+
+    return HTMLResult.success({
       name: this[$nodeName],
       attributes: {
         href: this.href,
         style: mapStyle(this.style),
       },
-      children: this[$childrenToHTML]({}),
+      children,
       value: this[$content] || "",
-    };
+    });
   }
 }
 
@@ -193,10 +209,15 @@ class Body extends XhtmlObject {
     super(attributes, "body");
   }
 
-  [$toHTML]() {
-    const html = super[$toHTML]();
+  [$toHTML](availableSpace) {
+    const res = super[$toHTML](availableSpace);
+    const { html } = res;
+    if (!html) {
+      return HTMLResult.EMPTY;
+    }
+    html.name = "div";
     html.attributes.class = "xfaRich";
-    return html;
+    return res;
   }
 }
 
@@ -209,10 +230,10 @@ class Br extends XhtmlObject {
     return "\n";
   }
 
-  [$toHTML]() {
-    return {
+  [$toHTML](availableSpace) {
+    return HTMLResult.success({
       name: "br",
-    };
+    });
   }
 }
 
@@ -221,34 +242,39 @@ class Html extends XhtmlObject {
     super(attributes, "html");
   }
 
-  [$toHTML]() {
-    const children = this[$childrenToHTML]({});
+  [$toHTML](availableSpace) {
+    const children = [];
+    this[$extra] = {
+      children,
+    };
+
+    this[$childrenToHTML]({});
     if (children.length === 0) {
-      return {
+      return HTMLResult.success({
         name: "div",
         attributes: {
           class: "xfaRich",
           style: {},
         },
         value: this[$content] || "",
-      };
+      });
     }
 
     if (children.length === 1) {
       const child = children[0];
       if (child.attributes && child.attributes.class === "xfaRich") {
-        return child;
+        return HTMLResult.success(child);
       }
     }
 
-    return {
+    return HTMLResult.success({
       name: "div",
       attributes: {
         class: "xfaRich",
         style: {},
       },
       children,
-    };
+    });
   }
 }
 
@@ -274,6 +300,10 @@ class P extends XhtmlObject {
   constructor(attributes) {
     super(attributes, "p");
   }
+
+  [$text]() {
+    return super[$text]() + "\n";
+  }
 }
 
 class Span extends XhtmlObject {