Some random notes about Weitzboard

First of all, I wrote Weitzboard for myself (to use it in my lectures employing a Wacom tablet with a stylus attached to a laptop running Linux). It's perfectly fine with me if other people are using the program, but I won't provide any support or add features I don't need. (In particular, it doesn't make much sense to use Weitzboard without both a stylus and a keyboard.) However, if you think you've found a genuine bug, feel free to send me an e-mail.

Linux

You will need a fairly recent web browser and thus shouldn't use the one that comes with your distribution because it will most likely lag several versions behind.

Firefox on Linux

On Linux, I got the best results so far with Firefox. However, you'll need to set the environment variable MOZ_USE_XINPUT2 to 1 in order for the stylus to be handled properly. (An alternative is to switch to Wayland.)

Chrome on Linux

Chrome is otherwise fine, but currently (August 2025) it can't detect the eraser of a stylus. (On Wayland, I couldn't use Weitzboard with Chrome at all.)

Windows

A pen stroke which quickly follows a key press (when you for example changed the color) is sometimes suppressed by the operating system and doesn't reach the browser. This happens on laptops with a touchpad. (And it can even happen if the touchpad is disabled …) You can "fix" this by setting the touchpad sensitivity to the highest possible value.

Firefox on Windows

Firefox is my main web browser, but its pen handling on Windows is unfortunately not as mature as that of Chrome. The Weitzboard code contains a few workarounds, but for handwritten text with lots of small "squiggles" Firefox is still problematic. What might help a bit is to disable Windows Ink in the Wacom settings. (This can be done on a per-application basis.)

Chrome on Windows

On Windows, Chrome currently (August 2025) seems to be the best option.

Other browsers or operating systems

I don't care.

The mouse

In the intended setup for this program, no mouse is present. However, some browsers have the strange habit of sending fake mouse events even if only a stylus is used. This can potentially confuse Weitzboard. If you're sure you're not going to use a mouse, employ the ignoreMouse parameter.

Local use and kiosk mode

You don't need my server and a connection to the internet to use Weitzboard. You can download it once and then run it by just double-clicking the downloaded file. I recommend opening the file in kiosk mode.

Erasing

If your stylus doesn't have an eraser, you can simulate one by holding the Shift key while "drawing". You can typically map one of the stylus buttons to this key in the system settings for your tablet. (If your stylus doesn't have buttons either, you're out of luck. You'll have to press the real Shift key on your keyboard.)

Printing and PDF generation

Weitzboard hooks into the printing process and divides the content into pieces suitable for ISO 216 formats like A4. The idea is that you use your printing system to generate a PDF file. (But you can of course also print to paper.)

Customization

Some parameters of Weitzboard can be changed using the query string of the URL. Currently, these are

• strokeWidth (a float between 1 and 15 for the default stroke width – which can be changed with the + and - keys),
• backupInterval (an integer between 1 and 60 for the time in minutes between two automatic backup attempts),
• backupThreshold (an integer between 5 and 200 for the – approximate – number of new strokes which would warrant a new backup),
• undoStackSize (an integer between 5 and 500 for the maximal number of undo actions to remember),
• eraserSize (an integer between 0 and 5 for how "lenient" the eraser is),
• gridGray (an integer between 50 and 100 for the shade of gray of the background grid – where 100 means no grid at all),
• gridDistance (an integer between 20 and 200 for the distance, in pixels, between the thick grid lines),
• gridStrokeWidth (a float between 0.2 and 3 for the width of the thick grid lines),
• doNotCrop (if present, don't crop white space during printing),
• showScrollBar (if present, show the vertical scrollbar – which is hidden by default because it might interfer with the palm of you hand when drawing),
• ignoreMouse (if present, completely ignore mouse events),
• and debug (which might clutter the console).

Backups

Weitzboard tries to create automatic backups from time to time and it also attempts an "emergeny backup" if you leave the program without having saved your work. But it has to use IndexedDB which can sometimes be a bit slow. As a result, the "shutdown backup" can fail because the browser-initiated alert box blocks everything including database access. The moral of the story is twofold: First, don't rely solely on automatic backups. Second, use kiosk mode and press q to leave the program.

Errors

If a line you've drawn doesn't appear or if you experience other kinds of unexpected behavior, please have a look at your console and look for error messages. If you find something there, please copy it and send it to me. As any developer, I'm particularly interested in reproducible bugs with a clear explanation of what you were doing.

Prior art

The user interface of Weitzboard partly mimics the user interface of the Windows program Whiteboard by Jörn Loviscach which I've used for many years. (Note that you'll also find another browser-based whiteboard program if you follow this link. It has several features I don't need but which you might find alluring.)