OnboardingFragment
public abstract class OnboardingFragment extends Fragment
An OnboardingFragment provides a common and simple way to build onboarding screen for applications.
Building the screen
The view structure of onboarding screen is composed of the common parts and custom parts. The common parts are composed of icon, title, description and page navigator and the custom parts are composed of background, contents and foreground.To build the screen views, the inherited class should override:
onCreateBackgroundViewto provide the background view. Background view has the same size as the screen and the lowest z-order.onCreateContentViewto provide the contents view. The content view is located in the content area at the center of the screen.onCreateForegroundViewto provide the foreground view. Foreground view has the same size as the screen and the highest z-order
Each of these methods can return null if the application doesn't want to provide it.
Page information
The onboarding screen may have several pages which explain the functionality of the application. The inherited class should provide the page information by overriding the methods:getPageCountto provide the number of pages.getPageTitleto provide the title of the page.getPageDescriptionto provide the description of the page.
Note that the information is used in onCreateView, so should be initialized before calling super.onCreateView.
Animation
Onboarding screen has three kinds of animations: Logo Splash Animation When onboarding screen appears, the logo splash animation is played by default. The animation fades in the logo image, pauses in a few seconds and fades it out.In most cases, the logo animation needs to be customized because the logo images of applications are different from each other, or some applications may want to show their own animations.
The logo animation can be customized in two ways:
- The simplest way is to provide the logo image by calling
setLogoResourceIdto show the default logo animation. This method should be called inonCreateView. - If the logo animation is complex, then override
onCreateLogoAnimationand return theAnimatorobject to run.
If the inherited class provides neither the logo image nor the animation, the logo animation will be omitted.
Page enter animation After logo animation finishes, page enter animation starts, which causes the header section - title and description views to fade and slide in. Users can override the default fade + slide animation by overridingonCreateTitleAnimator&onCreateDescriptionAnimator. By default we don't animate the custom views but users can provide animation by overriding onCreateEnterAnimation. Page change animation When the page changes, the default animations of the title and description are played. The inherited class can override onPageChanged to start the custom animations.
Finishing the screen
If the user finishes the onboarding screen after navigating all the pages, onFinishFragment is called. The inherited class can override this method to show another fragment or activity, or just remove this fragment.
Theming
OnboardingFragment must have access to an appropriate theme. Specifically, the fragment must receive Theme_Leanback_Onboarding, or a theme whose parent is set to that theme. Themes can be provided in one of three ways:
- The simplest way is to set the theme for the host Activity to the Onboarding theme or a theme that derives from it.
- If the Activity already has a theme and setting its parent theme is inconvenient, the existing Activity theme can have an entry added for the attribute
LeanbackOnboardingTheme_onboardingTheme. If present, this theme will be used by OnboardingFragment as an overlay to the Activity's theme. - Finally, custom subclasses of OnboardingFragment may provide a theme through the
onProvideThememethod. This can be useful if a subclass is used across multiple Activities.
If the theme is provided in multiple ways, the onProvideTheme override has priority, followed by the Activity's theme. (Themes whose parent theme is already set to the onboarding theme do not need to set the onboardingTheme attribute; if set, it will be ignored.) onboardingThemeonboardingHeaderStyleonboardingTitleStyleonboardingDescriptionStyleonboardingNavigatorContainerStyleonboardingPageIndicatorStyleonboardingStartButtonStyleonboardingLogoStyle
Summary
Public constructors |
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Public methods |
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final @ColorInt int |
Returns the background color of the arrow if it's set through |
final @ColorInt int |
Returns the color of the arrow if it's set through |
final @ColorInt int |
Returns the text color of DescriptionView if it's set through |
final @ColorInt int |
Returns the background color of the dot if it's set through |
final int |
Returns the resource id of the main icon. |
final int |
Returns the resource ID of the splash logo image. |
final @Nullable CharSequence |
Returns the start button text if it's set through |
final @ColorInt int |
Returns the text color of TitleView if it's set through |
@Nullable View |
This method is deprecated. |
int |
Returns the theme used for styling the fragment. |
void |
This method is deprecated. |
void |
This method is deprecated. |
void |
Sets the background color of the arrow. |
void |
Sets the color of the arrow. |
void |
Sets the text color for DescriptionView. |
void |
Sets the background color of the dots. |
final void |
Sets the resource id for the main icon. |
final void |
Sets the resource ID of the splash logo image. |
void |
Sets the text on the start button text. |
void |
Sets the text color for TitleView. |
Protected methods |
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final int |
Returns the index of the current page. |
abstract int |
Returns the page count. |
abstract @Nullable CharSequence |
Returns the description of the given page. |
abstract @Nullable CharSequence |
Returns the title of the given page. |
final boolean |
Returns whether the logo enter animation is finished. |
void |
Navigates to the next page. |
void |
Navigates to the previous page. |
abstract @Nullable View |
Called to have the inherited class create background view. |
abstract @Nullable View |
Called to have the inherited class create content view. |
@NonNull Animator |
Provides the entry animation for description view. |
@Nullable Animator |
Called to have the inherited class create its enter animation. |
abstract @Nullable View |
Called to have the inherited class create foreground view. |
@Nullable Animator |
Called to have the inherited class create its own logo animation. |
@NonNull Animator |
Provides the entry animation for title view. |
void |
Called when the onboarding flow finishes. |
void |
Called immediately after the logo animation is complete or no logo animation is specified. |
void |
Called when the page has been changed. |
final void |
Called to start entrance transition. |
Inherited Constants |
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Inherited methods |
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Public constructors
Public methods
public final @ColorInt intgetArrowBackgroundColor()
Returns the background color of the arrow if it's set through setArrowBackgroundColor. If no color was set, transparent is returned.
public final @ColorInt intgetArrowColor()
Returns the color of the arrow if it's set through setArrowColor. If no color was set, transparent is returned.
public final @ColorInt intgetDescriptionViewTextColor()
Returns the text color of DescriptionView if it's set through setDescriptionViewTextColor. If no color was set, transparent is returned.
public final @ColorInt intgetDotBackgroundColor()
Returns the background color of the dot if it's set through setDotBackgroundColor. If no color was set, transparent is returned.
public final int getLogoResourceId()Returns the resource ID of the splash logo image.
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int |
The resource ID of the splash logo image. |
public final @Nullable CharSequencegetStartButtonText()
Returns the start button text if it's set through setStartButtonText}. If no string was set, null is returned.
public final @ColorInt intgetTitleViewTextColor()
Returns the text color of TitleView if it's set through setTitleViewTextColor. If no color was set, transparent is returned.
public @Nullable ViewonCreateView(
LayoutInflater inflater,
@Nullable ViewGroup container,
Bundle savedInstanceState
)
public int onProvideTheme()Returns the theme used for styling the fragment. The default returns -1, indicating that the host Activity's theme should be used.
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int |
The theme resource ID of the theme to use in this fragment, or -1 to use the host Activity's theme. |
public voidsetArrowBackgroundColor(@ColorInt int color)
Sets the background color of the arrow. If not set, the default color from attr PagingIndicator_arrowBgColor in the theme will be used.
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@ColorInt int color |
the color to use for arrow background |
public voidsetArrowColor(@ColorInt int color)
Sets the color of the arrow. This color will supersede the color set in the theme attribute PagingIndicator_arrowColor if provided. If none of these two are set, the arrow will have its original bitmap color.
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@ColorInt int color |
the color to use for arrow background |
public voidsetDescriptionViewTextColor(@ColorInt int color)
Sets the text color for DescriptionView. If not set, the default textColor set in style referenced by attr onboardingDescriptionStyle will be used.
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@ColorInt int color |
the color to use as the text color for DescriptionView |
public voidsetDotBackgroundColor(@ColorInt int color)
Sets the background color of the dots. If not set, the default color from attr PagingIndicator_dotBgColor in the theme will be used.
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@ColorInt int color |
the color to use for dot backgrounds |
public final void setLogoResourceId(int id)Sets the resource ID of the splash logo image. If the logo resource id set, the default logo splash animation will be played.
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int id |
The resource ID of the logo image. |
public voidsetStartButtonText(@Nullable CharSequence text)
Sets the text on the start button text. If not set, the default text set in LeanbackOnboardingTheme_onboardingStartButtonStyle will be used.
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@Nullable CharSequence text |
the start button text |
public voidsetTitleViewTextColor(@ColorInt int color)
Sets the text color for TitleView. If not set, the default textColor set in style referenced by attr onboardingTitleStyle will be used.
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@ColorInt int color |
the color to use as the text color for TitleView |
Protected methods
protected final int getCurrentPageIndex()Returns the index of the current page.
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int |
The index of the current page. |
protected abstract @Nullable CharSequencegetPageDescription(int pageIndex)
Returns the description of the given page.
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int pageIndex |
The page index. |
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@Nullable CharSequence |
The description of the page. |
protected abstract @Nullable CharSequencegetPageTitle(int pageIndex)
Returns the title of the given page.
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int pageIndex |
The page index. |
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@Nullable CharSequence |
The title of the page. |
protected final boolean isLogoAnimationFinished()Returns whether the logo enter animation is finished.
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boolean |
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protected abstract @Nullable ViewonCreateBackgroundView(
@NonNull LayoutInflater inflater,
@NonNull ViewGroup container
)
Called to have the inherited class create background view. This is optional and the fragment which doesn't have the background view can return null. This is called inside onCreateView.
| Parameters | |
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@NonNull LayoutInflater inflater |
The LayoutInflater object that can be used to inflate the views, |
@NonNull ViewGroup container |
The parent view that the additional views are attached to.The fragment should not add the view by itself. |
protected abstract @Nullable ViewonCreateContentView(
@NonNull LayoutInflater inflater,
@NonNull ViewGroup container
)
Called to have the inherited class create content view. This is optional and the fragment which doesn't have the content view can return null. This is called inside onCreateView.
The content view would be located at the center of the screen.
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@NonNull LayoutInflater inflater |
The LayoutInflater object that can be used to inflate the views, |
@NonNull ViewGroup container |
The parent view that the additional views are attached to.The fragment should not add the view by itself. |
protected @NonNull AnimatoronCreateDescriptionAnimator()
Provides the entry animation for description view. This allows users to override the default fade and slide animation. Returning null will disable the animation.
protected @Nullable AnimatoronCreateEnterAnimation()
Called to have the inherited class create its enter animation. The start animation runs after logo animation ends.
protected abstract @Nullable ViewonCreateForegroundView(
@NonNull LayoutInflater inflater,
@NonNull ViewGroup container
)
Called to have the inherited class create foreground view. This is optional and the fragment which doesn't need the foreground view can return null. This is called inside onCreateView.
This foreground view would have the highest z-order.
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@NonNull LayoutInflater inflater |
The LayoutInflater object that can be used to inflate the views, |
@NonNull ViewGroup container |
The parent view that the additional views are attached to.The fragment should not add the view by itself. |
protected @Nullable AnimatoronCreateLogoAnimation()
Called to have the inherited class create its own logo animation.
This is called only if the logo image resource ID is not set by setLogoResourceId. If this returns null, the logo animation is skipped.
protected @NonNull AnimatoronCreateTitleAnimator()
Provides the entry animation for title view. This allows users to override the default fade and slide animation. Returning null will disable the animation.
protected void onLogoAnimationFinished()Called immediately after the logo animation is complete or no logo animation is specified. This method can also be called when the activity is recreated, i.e. when no logo animation are performed. By default, this method will hide the logo view and start the entrance animation for this fragment. Overriding subclasses can provide their own data loading logic as to when the entrance animation should be executed.
protected void onPageChanged(int newPage, int previousPage)Called when the page has been changed.
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int newPage |
The new page. |
int previousPage |
The previous page. |
protected final void startEnterAnimation(boolean force)Called to start entrance transition. This can be called by subclasses when the logo animation and data loading is complete. If force flag is set to false, it will only start the animation if it's not already done yet. Otherwise, it will always start the enter animation. In both cases, the logo view will hide and the rest of fragment views become visible after this call.
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boolean force |
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