PDF Viewer’s user interface elements

Top toolbar

The top toolbar shows the View mode, Bookmarks, Search, and More options buttons.
The view mode can be set by pressing the Continuous Pages button or Single Page (Page by Page) button.

The bookmark pane is expanded and collapsed by pressing the bookmark button.

The Search options are displayed by pressing the Search button.
The Undo, Redo, Save, and Print options are displayed after clicking the More options button.

Bottom toolbar

The Bottom toolbar is used for adding annotations such as text markups, ink and signatures. 

The buttons Back, Text markups, Shapes, Ink, (add) Text, SIgnature are displayed after pressing the Annotations button.

After pressing the signature button the signature pad will appear on which the signature can be drawn. After drawing the signature, the Done button should be pressed to add the drawn signature to the PDF. The Clear button should be pressed to redraw the signature. The Close button should be used to cancel signing.

NOTE: On saving the handwritten signatures are flattened, so that it cannot be modified (it is not preserved as ink annotation).

Text markups contains options such as highlighting text, underlining text, and strikethrough text.

Ink should be confirmed by pressing the Done button.

NOTE: On saving the annotations are flattened, so that they cannot be modified (they are not preserved as ink annotations).

Ink color and thickness can be adjusted.
Various shapes can be added.