Support Hex String Default Appearances (#693)

* Support hexadecimal Default Appearance (#677)

* Add test for PDFAcroField.getDefaultAppearance

* Add test for PDFWidgetAnnotation.getDefaultAppearance

* Cleanup

Co-authored-by: Bj Tecu <[email protected]>

src/core/acroform/PDFAcroField.ts

@@ -87,7 +87,13 @@ class PDFAcroField {
   }
 
   getDefaultAppearance(): string | undefined {
-    return this.DA()?.asString() ?? '';
+    const DA = this.DA();
+
+    if (DA instanceof PDFHexString) {
+      return DA.decodeText();
+    }
+
+    return DA?.asString();
   }
 
   getFlags(): number {

src/core/annotation/PDFWidgetAnnotation.ts

@@ -45,7 +45,13 @@ class PDFWidgetAnnotation extends PDFAnnotation {
   }
 
   getDefaultAppearance(): string | undefined {
-    return this.DA()?.asString() ?? '';
+    const DA = this.DA();
+
+    if (DA instanceof PDFHexString) {
+      return DA.decodeText();
+    }
+
+    return DA?.asString();
   }
 
   getAppearanceCharacteristics(): AppearanceCharacteristics | undefined {

tests/core/acroform/PDFAcroField.spec.ts

@@ -0,0 +1,44 @@
+import {
+  PDFAcroTerminal,
+  PDFContext,
+  PDFString,
+  PDFHexString,
+} from 'src/index';
+
+describe(`PDFAcroField`, () => {
+  it(`returns undefined for missing (DAs)`, () => {
+    const context = PDFContext.create();
+
+    const dict = context.obj({
+      DA: null,
+    });
+    const dictRef = context.register(dict);
+    const field = PDFAcroTerminal.fromDict(dict, dictRef);
+
+    expect(field.getDefaultAppearance()).toBe(undefined);
+  });
+
+  it(`returns normal direct appearance strings (DAs)`, () => {
+    const context = PDFContext.create();
+
+    const dict = context.obj({
+      DA: PDFString.of('/ZaDb 10 Tf 0 g'),
+    });
+    const dictRef = context.register(dict);
+    const field = PDFAcroTerminal.fromDict(dict, dictRef);
+
+    expect(field.getDefaultAppearance()).toBe('/ZaDb 10 Tf 0 g');
+  });
+
+  it(`returns hexadecimal (non-standard) direct appearance strings (DAs)`, () => {
+    const context = PDFContext.create();
+
+    const dict = context.obj({
+      DA: PDFHexString.fromText('/ZaDb 10 Tf 0 g'),
+    });
+    const dictRef = context.register(dict);
+    const field = PDFAcroTerminal.fromDict(dict, dictRef);
+
+    expect(field.getDefaultAppearance()).toBe('/ZaDb 10 Tf 0 g');
+  });
+});

tests/core/annotation/PDFWidgetAnnotation.spec.ts

@@ -0,0 +1,40 @@
+import {
+  PDFWidgetAnnotation,
+  PDFContext,
+  PDFString,
+  PDFHexString,
+  PDFName,
+  PDFNull,
+} from 'src/index';
+
+describe(`PDFWidgetAnnotation`, () => {
+  it(`returns undefined for missing (DAs)`, () => {
+    const context = PDFContext.create();
+
+    const parentRef = context.nextRef();
+    const widget = PDFWidgetAnnotation.create(context, parentRef);
+    widget.dict.set(PDFName.of('DA'), PDFNull);
+
+    expect(widget.getDefaultAppearance()).toBe(undefined);
+  });
+
+  it(`returns normal direct appearance strings (DAs)`, () => {
+    const context = PDFContext.create();
+
+    const parentRef = context.nextRef();
+    const widget = PDFWidgetAnnotation.create(context, parentRef);
+    widget.dict.set(PDFName.of('DA'), PDFString.of('/ZaDb 10 Tf 0 g'));
+
+    expect(widget.getDefaultAppearance()).toBe('/ZaDb 10 Tf 0 g');
+  });
+
+  it(`returns hexadecimal (non-standard) direct appearance strings (DAs)`, () => {
+    const context = PDFContext.create();
+
+    const parentRef = context.nextRef();
+    const widget = PDFWidgetAnnotation.create(context, parentRef);
+    widget.dict.set(PDFName.of('DA'), PDFHexString.fromText('/ZaDb 10 Tf 0 g'));
+
+    expect(widget.getDefaultAppearance()).toBe('/ZaDb 10 Tf 0 g');
+  });
+});