Methods - UNC-Project-Open-AAC/OS-DPI GitHub Wiki

Methods

The Methods component determines which access method(s) will be compatible with the user interface (UI). Direct and indirect access methods are usable in the OS-DPI.

  • Direct access - eye-gaze, pointing, and mouse. As the designer, you decide which direct access method to simulate. The OS-DPI does not distinguish between eye-gaze and pressing (using a mouse). Both eye-gaze and pressing methods can be simulated using the pre-loaded mouse method.

  • Indirect access - scanning with a switch. Scanning may be the option that a designer would like to simulate with the OS-DPI. Switch scanning works by connecting one or more switches to a communication device. The AAC user will activate the switch using whatever part of their body they can control with ease. They then select what they want to say by activating the switch to control a scanning Pattern on the screen. The OS-DPI can recognize any switch that is connected to a device.

The Methods panel has pre-loaded both direct and indirect access methods. Switch, Pointer dwell, and Mouse are default Methods as they are commonly used AAC access methods. However, the designer can decide which method(s) to activate, how to name them, and how many will be active at a time. There is no limit on how many methods are loaded into the design.

The method that has the blue "Active" box checked will be activated. Multiple methods can be active at the same time.

How to Implement Methods

First, you will need to decide the access methods you are intending to simulate.

Direct Selection Methods

Does the intended user use direct selection?

Follow along with this UI example created by the Project Open team. The intended user for this design utilizes direct selection (mouse) as their access method.

  1. In the Methods tab, select Mouse.
  2. Check the Active box.
  3. You may change the name to anything you like.
  4. You may also edit the Pointer Handler components to change the debounce time to faster or slower. This will require the user to touch and hold (or click and hold) on an icon/button to respond. In the UI example above, all Pointer Handler debounce times are the same.
  5. Decide what you want the mouse to do by adding and editing Pointer Handlers. Click Add --> Pointer Handler.
  • The first Pointer Handler in the example UI signals "Pointer down". This registers as a mouse click or finger press in the OS-DPI. The response is set to "Activate" so that the icon or button is selected and activated when pressed.
  • The second Pointer Handler in the example UI signals "Pointer enter". When the mouse cursor enters into the perimeter of the icon, the cue (which is set to yellow overlay) is activated and the icon turns yellow.
  • The last Pointer Handler in the example UI signals "Pointer leave". When the mouse cursor leaves the perimeter of the icon, the cue is cleared.
  1. Add a Timer Handler. Click Add --> ** Timer Handler**.
  • In our example, the signal is set to Timer Complete so that when the user has hovered over the intended icon or button, the timer handler will signal the dwell time threshold has been met and the icon or button can be activated.

Does the intended user use direct selection with a specified dwell time?

Follow along with this UI example created by the Project Open team. The intended user for this design utilizes direct selection (eye gaze) as their access method.

  1. In the Methods tab, select Pointer dwell. This method will activate icons by hovering over the icon for the determined dwell time.
  2. Check the Active box.
  3. You may change the name to anything you like.
  4. You may also edit the Pointer Handler components to change the debounce time to faster or slower. This will require the user to hover over the icon or button to respond. In the UI example above, all Pointer Handler debounce times are the same.
  5. Decide what you want the pointer to do.
  • The first Pointer Handler in the example UI signals "Pointer enter". This registers as a mouse click in the OS-DPI, as the OS-DPI does not distinguish between mouse clicking and eye gaze selection. The response is set to "cue" and "start timer" so that the yellow overlay cue appears and the timer for the dwell starts counting.
  • The second Pointer Handler in the example UI signals "Pointer leave". When the mouse cursor leaves the perimeter of the icon, the cue is cleared.
  • The third Pointer Handler in the example UI signals "Pointer down". This allows the user (or designer) to press down on the mouse to activate an icon.
  • Lastly, this design has a Timer Handler component.

Indirect Selection Methods

Does the intended user utilize scanning?

Follow along with this UI example created by the Project Open team. The intended user for this design utilizes indirect selection with scanning row by row as their access method.

  1. In the Methods tab, select 2 switch. This Method allows the designer to designate which keys (or series of keys) will activate a button, or sections of buttons through scanning patterns. The default name is "2 switch" but can be renamed to anything you choose.
  2. Decide how you want the scanning Patterns to be handled. This means that the designer decides which keys will cycle through the scanning pattern. The OS-DPI has two Key Handlers as a default in this Method.
  • The first Key Handler signal in the example UI has the signal set to "Key Up" and the Keys to perform this function are set to Space and Right Arrow. These can be customized according to your design.
  • The second Key Handler signal in the example UI also has the signal set to "Key Up" but always for the Left Arrow Keys to perform this function too. Each of these Key designations can be customized according to your design.

Components you may add