SurfaceCallback
public interface SurfaceCallback
A callback for changes on the SurfaceContainer and its attributes.
Summary
Public methods |
|
|---|---|
default void |
@RequiresCarApi(value = 5)Provides information about a click event on the car screen. |
default void |
@RequiresCarApi(value = 2)Provides information about a fling touch event on the car screen. |
default void |
@RequiresCarApi(value = 2)Provides information about a scale touch event on the car screen. |
default void |
@RequiresCarApi(value = 2)Provides information about a scroll touch event on the car screen. |
default void |
onStableAreaChanged(@NonNull Rect stableArea)Indicates that the stable area provided by the host has changed. |
default void |
onSurfaceAvailable(@NonNull SurfaceContainer surfaceContainer)Provides a |
default void |
onSurfaceDestroyed(@NonNull SurfaceContainer surfaceContainer)Indicates that the |
default void |
onVisibleAreaChanged(@NonNull Rect visibleArea)Indicates that the visible area provided by the host has changed. |
Public methods
onClick
@RequiresCarApi(value = 5)
default void onClick(float x, float y)
Provides information about a click event on the car screen.
See androidx.car.app.navigation.model.NavigationTemplate class description for more details on how to receive this callback.
This method may not be called in some car systems.
| Parameters | |
|---|---|
float x |
x coordinate of the click in pixels |
float y |
y coordinate of the click in pixels |
onFling
@RequiresCarApi(value = 2)
default void onFling(float velocityX, float velocityY)
Provides information about a fling touch event on the car screen.
See androidx.car.app.navigation.model.NavigationTemplate class description for more details on how to receive this callback.
This method may not be called in some car systems.
| Parameters | |
|---|---|
float velocityX |
the velocity of this fling measured in pixels per second along the x axis |
float velocityY |
the velocity of this fling measured in pixels per second along the y axis |
onScale
@RequiresCarApi(value = 2)
default void onScale(float focusX, float focusY, float scaleFactor)
Provides information about a scale touch event on the car screen.
See androidx.car.app.navigation.model.NavigationTemplate class description for more details on how to receive this callback.
This method may not be called in some car systems.
| Parameters | |
|---|---|
float focusX |
x coordinate of the focal point in pixels. A negative value indicates that the focal point is unavailable. |
float focusY |
y coordinate of the focal point in pixels. A negative value indicates that the focal point is unavailable. |
float scaleFactor |
the scaling factor from the previous state to the current state during the scale event. This value is defined as (current state) / (previous state) |
onScroll
@RequiresCarApi(value = 2)
default void onScroll(float distanceX, float distanceY)
Provides information about a scroll touch event on the car screen.
See androidx.car.app.navigation.model.NavigationTemplate class description for more details on how to receive this callback.
| Parameters | |
|---|---|
float distanceX |
the distance in pixels along the X axis that has been scrolled since the last touch position during the scroll event |
float distanceY |
the distance in pixels along the Y axis that has been scrolled since the last touch position during the scroll event |
onStableAreaChanged
default void onStableAreaChanged(@NonNull Rect stableArea)
Indicates that the stable area provided by the host has changed.
The surface may be occluded for several reasons including status bar changes, overlays from other apps or dynamic UI within the template (also see onVisibleAreaChanged). The stable area is the visual area that accounts for these occlusions as if they were always present. If the app needs to show more persistent data that do not necessarily adjust based on these dynamic content changes, it should be bounded by this area.
onSurfaceAvailable
default void onSurfaceAvailable(@NonNull SurfaceContainer surfaceContainer)
Provides a SurfaceContainer from the host which is ready for drawing.
This method may be called multiple times if the surface changes characteristics. For instance, the size or DPI may change without the underlying surface being destroyed.
This method is guaranteed to be called before any other methods on this listener.
Important: every instance of android.view.Surface received through this method must be released by calling release.
| Parameters | |
|---|---|
@NonNull SurfaceContainer surfaceContainer |
the |
onSurfaceDestroyed
default void onSurfaceDestroyed(@NonNull SurfaceContainer surfaceContainer)
Indicates that the SurfaceContainer provided by the host will be destroyed after this callback.
| Parameters | |
|---|---|
@NonNull SurfaceContainer surfaceContainer |
the |
onVisibleAreaChanged
default void onVisibleAreaChanged(@NonNull Rect visibleArea)
Indicates that the visible area provided by the host has changed.
The surface may be occluded for several reasons including status bar changes, overlays from other apps or dynamic UI within a template. visibleArea is the area currently guaranteed to not be occluded by any other UI. If the app needs to show critical data, it should be bounded by this area.