Class CarScreen

java.lang.Object

com.codename1.car.CarScreen

public abstract class CarScreen
extends Object

One screen of the in-car experience -- the unit of the head-unit back stack. A screen produces a single CarTemplate from onCreateTemplate(); the framework pulls it when the screen is pushed or invalidated. Conceptually equivalent to androidx.car.app.Screen; on CarPlay a screen corresponds to one pushed CPTemplate.

class AlbumsScreen extends CarScreen {
    protected CarTemplate onCreateTemplate() {
        CarListTemplate t = new CarListTemplate().setTitle("Albums");
        for (Album a : albums) {
            t.addRow(new CarRow(a.name).setImage(a.art)
                .setBrowsable(true)
                .setOnAction(ctx -> ctx.pushScreen(new TracksScreen(a))));
        }
        return t;
    }
}

Constructor Summary

Constructors

Constructor	Description
CarScreen()

Method Summary

Modifier and Type	Method	Description
final void	dispatchCreate()	Framework entry point -- dispatches the onCreate lifecycle callback.
final CarTemplate	dispatchCreateTemplate()	Framework entry point -- pulls the template, used by the platform CarBridge.
final void	dispatchDestroy()	Framework entry point -- dispatches the onDestroy lifecycle callback.
final void	dispatchPause()	Framework entry point -- dispatches the onPause lifecycle callback.
final void	dispatchResume()	Framework entry point -- dispatches the onResume lifecycle callback.
final void	finish()	Pops this screen off the stack (equivalent to getContext().popScreen() when this is the top screen).
final CarContext	getContext()	Returns the context this screen is attached to, or null if it has not been pushed yet.
final void	invalidate()	Rebuilds and re-renders this screen's template (after the model behind it changed).
protected void	onCreate()	Lifecycle hook invoked once, when the screen is first pushed onto the stack, before its template is built.
protected abstract CarTemplate	onCreateTemplate()	Builds the template to display for this screen.
protected void	onDestroy()	Lifecycle hook invoked when the screen is popped and discarded.
protected void	onPause()	Lifecycle hook invoked when the screen is covered by a pushed screen.
protected void	onResume()	Lifecycle hook invoked when the screen becomes the visible top of stack.

Methods inherited from class Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

CarScreen

public CarScreen()

Method Details

onCreateTemplate

protected abstract CarTemplate onCreateTemplate()

Builds the template to display for this screen. Called by the framework when the screen is pushed and again after invalidate(). Must return a non-null CarTemplate.

Returns

the template to render on the head unit

onCreate

protected void onCreate()

Lifecycle hook invoked once, when the screen is first pushed onto the stack, before its template is built. Default is a no-op.

onResume

protected void onResume()

Lifecycle hook invoked when the screen becomes the visible top of stack. Default is a no-op.

onPause

protected void onPause()

Lifecycle hook invoked when the screen is covered by a pushed screen. Default is a no-op.

onDestroy

protected void onDestroy()

Lifecycle hook invoked when the screen is popped and discarded. Default is a no-op.

getContext

public final CarContext getContext()

Returns the context this screen is attached to, or null if it has not been pushed yet.

Returns

the car context, or null

invalidate

public final void invalidate()

Rebuilds and re-renders this screen's template (after the model behind it changed). No-op when the screen is not currently attached or no head unit is connected.

finish

public final void finish()

Pops this screen off the stack (equivalent to getContext().popScreen() when this is the top screen). No-op when not attached.

dispatchCreateTemplate

public final CarTemplate dispatchCreateTemplate()

Framework entry point -- pulls the template, used by the platform CarBridge.

dispatchCreate

public final void dispatchCreate()

Framework entry point -- dispatches the onCreate lifecycle callback.

dispatchResume

public final void dispatchResume()

Framework entry point -- dispatches the onResume lifecycle callback.

dispatchPause

public final void dispatchPause()

Framework entry point -- dispatches the onPause lifecycle callback.

dispatchDestroy

public final void dispatchDestroy()

Framework entry point -- dispatches the onDestroy lifecycle callback.