3. What is LWUIT?
Lightweight User Interface Toolkit
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Advanced, lightweight UI library
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Compelling UI
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Consistent across different devices
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For today's handsets (and more ...)
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Portable
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MIDP, Blackberry, Android, CDC, SE, TV, ...
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Inspired by Swing
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Tools support
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4. LWUIT: Key Benefits
Easy Development and Deployment
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Rapid development
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Familiar API
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Clean & simple
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Easy deployment
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One jar, many devices
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Consistent & flexible
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Customizable, extensible
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“Filthy Rich” UI
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Brand-able
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5. LWUIT: Key Features
Rich Functionality
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Swing-like MVC
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Layouts
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Fonts
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Rich widgets
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HTML widget
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3D & SVG integration
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Touch screen support
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Animations & transitions
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7. Access Requirements for LWUIT
What needs to be there to support users with disabilities
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Needs to be operable from the keyboard (by
someone who can’t use a touchscreen)
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LWUIT already has full phone keyboard
operability
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Needs to support a variety of themes for folks
with poor vision – e.g. “high contrast”, “large
print”
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LWUIT already themeable
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Needs to support an accessibility API for
interoperability with assistive technologies
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8. Accessibility API requirements
Industry consensus on a “sufficient accessibility API”
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Expose detailed information about UI
components
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Role, state(s), boundary, name & desc.
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Min/max/current value of anything that takes a
value (e.g. slider)
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Text contents, attributes, boundary of all text on
the display
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Relationships of UI components with each other;
including tabular
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Fire events when things happen to UI
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9. Goals and Constraints
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Minimal impact on phones that aren't running
AT
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Minimal impact on LWUIT API (only add
something if we really need to)
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Run with existing LWUIT apps
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Minimal runtime impact for accessibility
metadata (e.g. name of icons, associating
labels with text fields)
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Support native AT, support Java AT
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10. Roles
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LWUIT base components mapped to ARIA
roles:
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Roles are determined by:
– If a “role” client property is assigned, then it overrides
everything else
– instanceof checks: e.g. if component is TextArea: its
role is TEXTBOX
– UIID checks: e.g. if the component is a Dialog, then if
its UIID is “Menu” its role is MENU (otherwise its role is
DIALOG)
– Hierarchy checks: e.g. if grandparent of a component
is a Tabs class then it is either a TAB or a TABPANEL
(according to class and UIID)
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11. Attributes or States
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LWUIT base components get some attributes
inherently
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The user can specify attributes in the
component's client properties. These will override
everything.
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Attributes are determined by base component
states. For example:
– aria-disabled – by isEnabled()
– aria-visible – by isVisible()
– aria-checked – by isSelected()
– aria-expanded, aria-setsize, aria-posinset, aria-
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13. Architecture – Event Bus
Application Event Bus AT
LWUIT App Handler AT
Broker app
Event Bus
LWUIT AT
app AT Handler Broker
●
The Event Bus listens on 2 TCP/IP ports, one
for ATs and one for applications
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The Bus opens an AppHandler/ATHandler
instance for each app/AT
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ATHandler listens to AT queries, and forward
relevant App events to the AT
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14. Architecture – AT
Application Event Bus AT
LWUIT App Handler AT
Broker app
Event Bus
LWUIT AT
app AT Handler Broker
●
ATBroker provides for AT developers event
listeners and query methods, and on the other
hand communicates with the Bus via TCP/IP
(Or IMC in the future)
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The AT can signal (via the ATBroker) to which
events it would like to listen
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15. Architecture – Application
Application Event Bus AT
LWUIT App Handler AT
Broker app
Event Bus
LWUIT AT
app AT Handler Broker
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The broker once started with Broker.init(),
starts polling the application UI.
●
Once a new Form comes up, it adds itself
(and helper objects) as listeners to all
components in the UI.
●
In additionWorkshop and Internationalchanges to the UI for
AEGIS it polls other Conference, Brussels
16. Packages
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accessibility.common – a common package
used by all 3 runtimes (AT/App/Bus) for a
unified way of serializing event objects.
Includes:
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AEvent – the base event class. Basically
serializes the event type and a queryId. AEvent
can also be a query or response (Considering
elaborating the class structure)
●
Other events: RegisterEvent (App/AT
identification), FocusEvent, ComponentQuery
(queries component states/children etc.),
StatesResponsesInternational Conference, Brussels queries)
AEGIS Workshop and (Returns component
17. Code Samples: Enabling Access
●
Making a LWUIT app accessible is very easy,
simply add to your midlet:
Broker.init(“App Name”);
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Notes:
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This should be added after the
Display.init(midlet) call.
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Your app should use the ATBroker project
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This applies to the prototype only, when the
accessibility technology will be integrated into
OJWC, There would be no need to explicitly
initialize the broker, it would be done by LWUIT.
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18. Code Samples: Custom Properties
●
Most ARIA properties are determined
automatically by the Broker.
●
However, some custom components may
require setting various properties
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Example: Let's say that we have a custom
component that needs to relay the information
that it has 6 items:
putClientProperty(Attribute.getAttName(Attribute.ARI
A_SETSIZE), 6);
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Notes:
●
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19. Code Samples: Setting names
●
Another way of adding accessibility info is by
using:
component.setLabelForComponent(Label
componentLabel);
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This was created in LWUIT for other uses.
●
It is especially useful for components that don’t
have a defined name (For example TextArea/Field
vs. Label/Button)
●
Example:
Label nameLabel = new Label(“Name:”);
TextField nameField = new TextField();
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20. Code Samples:
ListCellRenderers
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Work is needed for custom list cells
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Set the appropriate Role for the cell
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Set the appropriate Name, Description
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Ensure correct Selection, item count
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Example from ScrollDemo.java:
public Component
getListCellRendererComponent(List list, Object value,
int index, boolean isSelected) {
Contact person = (Contact) value;
name.setText(person.getName());
email.setText(person.getEmail());
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21. Code Samples: ListCellRenderers
public Component
getListCellRendererComponent(List list, Object
value, int index
boolean isSelected) {
Contact person = (Contact) value;
name.setText(person.getName());
email.setText(person.getEmail());
pic.setIcon(person.getPic());
putClientProperty(Attribute.ATT_NAMES[Attrib
ute.ROLE], new Integer(Role.LISTITEM));
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22. Code Samples: AT
●
Writing an assistive technology is also quite
easy.
●
First, initialize the ATBroker:
ATBroker.getInstance().init(midlet,"AT
Name");
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Implement the relevant Listener
●
For focus for example, implement
AFocusListener that gets called on its
focusGained method.
●
Other listeners:
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– AHierarchyListener, ADataChangeListener,
23. Code Samples: AT
import accessibility.at.AFocusListener;
import accessibility.at.ATBroker;
import accessibility.common.FocusEvent;
import javax.microedition.midlet.MIDlet;
import
javax.microedition.midlet.MIDletStateChangeEx
ception;
public class SimpleATMIDlet extends MIDlet
implements AFocusListener {
protected WorkshopstartApp() throws
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24. Monkey Application
Scans all UI components and provides details about them
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Demonstrates the ability
for AT to query entire UI
hierarchy
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Also a great accessibility
debugging tool
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