Add option to define AcroForm fontSize. Fixes foliojs#1088

CHANGELOG.md

@@ -3,6 +3,7 @@
 ### Unreleased
 
 - Allow applying 'underline' and 'strike' text styling together on a text
+- Allow to specify the AcroForm text fontSize
 
 ### [v0.12.0] - 2021-04-04
 

docs/forms.md

@@ -62,6 +62,7 @@ a hex color, or a named CSS color value for that option.
 - `password` [_boolean_] - The text will be masked (_e.g._ with asterisks).
 - `noSpell` [_boolean_] - If set, text entered in the field is not spell-checked
 - `format` [_object_] - See the section on **Text Field Formatting** below.
+- `fontSize` [_number_] - Sets the fontSize (default or 0 means auto sizing)
 
 ```js
 doc.formText('leaf2', 10, 60, 200, 40, {

lib/mixins/acroform.js

@@ -333,8 +333,12 @@ export default {
     // add current font to field's resource dict (RD) if not the default acroform font
     if (this._acroform.defaultFont !== this._font.name) {
       options.DR = { Font: {} };
+
+      // Get the fontSize option. If not set use auto sizing
+      const fontSize = options.fontSize || 0;
+
       options.DR.Font[this._font.id] = this._font.ref();
-      options.DA = new String(`/${this._font.id} 0 Tf 0 g`);
+      options.DA = new String(`/${this._font.id} ${fontSize} Tf 0 g`);
     }
     return options;
   },

tests/unit/acroform.spec.js

@@ -222,6 +222,40 @@ describe('acroform', () => {
     expect(docData).toContainChunk(expected);
   });
 
+  test('font size', () => {
+    const expected = [
+      '11 0 obj',
+      '<<\n' +
+        '/fontSize 16\n' +
+        '/FT /Tx\n' +
+        '/DR <<\n' +
+        '/Font <<\n' +
+        '/F2 10 0 R\n' +
+        '>>\n' +
+        '>>\n' +
+        '/DA (/F2 16 Tf 0 g)\n' +
+        '/T (text)\n' +
+        '/Subtype /Widget\n' +
+        '/F 4\n' +
+        '/Type /Annot\n' +
+        '/Rect [20 752 70 772]\n' +
+        '/Border [0 0 0]\n' +
+        '/C [0 0 0]\n' +
+        '/FontSize 16\n' +
+        '>>',
+      'endobj'
+    ];
+    doc.registerFont('myfont1', 'tests/fonts/Roboto-Regular.ttf');
+    doc.initForm();
+    const docData = logData(doc);
+    let opts = {
+      fontSize: 16
+    };
+    doc.font('myfont1').formText('text', 20, 20, 50, 20, opts);
+    expect(docData.length).toBe(3);
+    expect(docData).toContainChunk(expected);
+  });
+
   test('field heirarchy', () => {
     const expected = [
       '13 0 obj',