JPedal has the option to customize the GUI without any need for programming knowledge. The user may have interface options activated and deactivated in the properties file just by setting a flag to true for active, or false for inactive. If you wish to you may do this by editing the properties file. Alternatively, you can use the user interface to control the viewer GUI.
Using the Preferences Dialog
First, open the viewer and click on the Edit menu option then Preferences.
Once the Preferences window is open, select the "Menu" option and you should see something similar to this: (may vary due to different operating systems):
Each tab in this window handles a different section of the viewer as shown below.
The checkboxes represent items within these sections. A checkbox with a plus next to it may be expanded as it represents a menu with multiple children. When deselecting an item it will no longer be displayed, but the component it was originally on remains (as above).
To remove these you need to click on the button found beneath the checkbox tree for each section. (The button in the example above reads "Click here to hide Menu Bar".) This will remove an entire section regardless of the options selected within the tree. If you wish you may remove all the elements from the GUI, leaving just a panel.
To add back all the removed elements from the GUI, navigate to the folder where you saved the JPedal jar. Click on the .properities file and change the value back from false to true for the specific element.
The JPedal Viewer has a constructor which allows you to pass in your own component to display your pdfs on. Combine this with the ability to remove the user interface and you can add pdf viewing with ease. If you wish to use the user interface just keep them active and have a full viewer in your application with minimal code alterations.