OnboardingSupportFragment
public
abstract
class
OnboardingSupportFragment
extends Fragment
java.lang.Object | ||
↳ | androidx.fragment.app.Fragment | |
↳ | androidx.leanback.app.OnboardingSupportFragment |
An OnboardingSupportFragment 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:
onCreateBackgroundView(LayoutInflater, ViewGroup)
to provide the background view. Background view has the same size as the screen and the lowest z-order.onCreateContentView(LayoutInflater, ViewGroup)
to provide the contents view. The content view is located in the content area at the center of the screen.onCreateForegroundView(LayoutInflater, ViewGroup)
to 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:
getPageCount()
to provide the number of pages.getPageTitle(int)
to provide the title of the page.getPageDescription(int)
to provide the description of the page.
Note that the information is used in onCreateView(LayoutInflater, ViewGroup, Bundle)
, 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
setLogoResourceId(int)
to show the default logo animation. This method should be called inFragment.onCreateView(LayoutInflater, ViewGroup, Bundle)
. - If the logo animation is complex, then override
onCreateLogoAnimation()
and return theAnimator
object 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 overrideonPageChanged(int, int)
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
OnboardingSupportFragment must have access to an appropriate theme. Specifically, the fragment must
receive R.style.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
R.styleable.LeanbackOnboardingTheme_onboardingTheme
. If present, this theme will be used by OnboardingSupportFragment as an overlay to the Activity's theme. - Finally, custom subclasses of OnboardingSupportFragment may provide a theme through the
onProvideTheme()
method. 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.)
R.attr.onboardingTheme
R.attr.onboardingHeaderStyle
R.attr.onboardingTitleStyle
R.attr.onboardingDescriptionStyle
R.attr.onboardingNavigatorContainerStyle
R.attr.onboardingPageIndicatorStyle
R.attr.onboardingStartButtonStyle
R.attr.onboardingLogoStyle
Summary
Public constructors | |
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OnboardingSupportFragment()
|
Public methods | |
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final
int
|
getArrowBackgroundColor()
Returns the background color of the arrow if it's set through
|
final
int
|
getArrowColor()
Returns the color of the arrow if it's set through
|
final
int
|
getDescriptionViewTextColor()
Returns the text color of DescriptionView if it's set through
|
final
int
|
getDotBackgroundColor()
Returns the background color of the dot if it's set through
|
final
int
|
getIconResourceId()
Returns the resource id of the main icon. |
final
int
|
getLogoResourceId()
Returns the resource ID of the splash logo image. |
final
CharSequence
|
getStartButtonText()
Returns the start button text if it's set through
|
final
int
|
getTitleViewTextColor()
Returns the text color of TitleView if it's set through
|
View
|
onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
Called to have the fragment instantiate its user interface view. |
int
|
onProvideTheme()
Returns the theme used for styling the fragment. |
void
|
onSaveInstanceState(Bundle outState)
Called to ask the fragment to save its current dynamic state, so it can later be reconstructed in a new instance of its process is restarted. |
void
|
onViewCreated(View view, Bundle savedInstanceState)
Called immediately after |
void
|
setArrowBackgroundColor(int color)
Sets the background color of the arrow. |
void
|
setArrowColor(int color)
Sets the color of the arrow. |
void
|
setDescriptionViewTextColor(int color)
Sets the text color for DescriptionView. |
void
|
setDotBackgroundColor(int color)
Sets the background color of the dots. |
final
void
|
setIconResouceId(int resourceId)
Sets the resource id for the main icon. |
final
void
|
setLogoResourceId(int id)
Sets the resource ID of the splash logo image. |
void
|
setStartButtonText(CharSequence text)
Sets the text on the start button text. |
void
|
setTitleViewTextColor(int color)
Sets the text color for TitleView. |
Protected methods | |
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final
int
|
getCurrentPageIndex()
Returns the index of the current page. |
abstract
int
|
getPageCount()
Returns the page count. |
abstract
CharSequence
|
getPageDescription(int pageIndex)
Returns the description of the given page. |
abstract
CharSequence
|
getPageTitle(int pageIndex)
Returns the title of the given page. |
final
boolean
|
isLogoAnimationFinished()
Returns whether the logo enter animation is finished. |
void
|
moveToNextPage()
Navigates to the next page. |
void
|
moveToPreviousPage()
Navigates to the previous page. |
abstract
View
|
onCreateBackgroundView(LayoutInflater inflater, ViewGroup container)
Called to have the inherited class create background view. |
abstract
View
|
onCreateContentView(LayoutInflater inflater, ViewGroup container)
Called to have the inherited class create content view. |
Animator
|
onCreateDescriptionAnimator()
Provides the entry animation for description view. |
Animator
|
onCreateEnterAnimation()
Called to have the inherited class create its enter animation. |
abstract
View
|
onCreateForegroundView(LayoutInflater inflater, ViewGroup container)
Called to have the inherited class create foreground view. |
Animator
|
onCreateLogoAnimation()
Called to have the inherited class create its own logo animation. |
Animator
|
onCreateTitleAnimator()
Provides the entry animation for title view. |
void
|
onFinishFragment()
Called when the onboarding flow finishes. |
void
|
onLogoAnimationFinished()
Called immediately after the logo animation is complete or no logo animation is specified. |
void
|
onPageChanged(int newPage, int previousPage)
Called when the page has been changed. |
final
void
|
startEnterAnimation(boolean force)
Called to start entrance transition. |
Inherited methods | |
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Public constructors
OnboardingSupportFragment
public OnboardingSupportFragment ()
Public methods
getArrowBackgroundColor
public final int getArrowBackgroundColor ()
Returns the background color of the arrow if it's set through
setArrowBackgroundColor(int)
. If no color was set, transparent is returned.
Returns | |
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int |
getArrowColor
public final int getArrowColor ()
Returns the color of the arrow if it's set through
setArrowColor(int)
. If no color was set, transparent is returned.
Returns | |
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int |
getDescriptionViewTextColor
public final int getDescriptionViewTextColor ()
Returns the text color of DescriptionView if it's set through
setDescriptionViewTextColor(int)
. If no color was set, transparent is returned.
Returns | |
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int |
getDotBackgroundColor
public final int getDotBackgroundColor ()
Returns the background color of the dot if it's set through
setDotBackgroundColor(int)
. If no color was set, transparent is returned.
Returns | |
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int |
getIconResourceId
public final int getIconResourceId ()
Returns the resource id of the main icon.
Returns | |
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int |
getLogoResourceId
public final int getLogoResourceId ()
Returns the resource ID of the splash logo image.
Returns | |
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int |
The resource ID of the splash logo image. |
getStartButtonText
public final CharSequence getStartButtonText ()
Returns the start button text if it's set through
setStartButtonText(CharSequence)
}. If no string was set, null is returned.
Returns | |
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CharSequence |
getTitleViewTextColor
public final int getTitleViewTextColor ()
Returns the text color of TitleView if it's set through
setTitleViewTextColor(int)
. If no color was set, transparent is returned.
Returns | |
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int |
onCreateView
public View onCreateView (LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
Called to have the fragment instantiate its user interface view.
This is optional, and non-graphical fragments can return null. This will be called between
onCreate(Bundle)
and onActivityCreated(Bundle)
.
A default View can be returned by calling Fragment(int)
in your
constructor. Otherwise, this method returns null.
It is recommended to only inflate the layout in this method and move
logic that operates on the returned View to onViewCreated(View, Bundle)
.
If you return a View from here, you will later be called in
onDestroyView()
when the view is being released.
Parameters | |
---|---|
inflater |
LayoutInflater : The LayoutInflater object that can be used to inflate
any views in the fragment, |
container |
ViewGroup : If non-null, this is the parent view that the fragment's
UI should be attached to. The fragment should not add the view itself,
but this can be used to generate the LayoutParams of the view. |
savedInstanceState |
Bundle : If non-null, this fragment is being re-constructed
from a previous saved state as given here. |
Returns | |
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View |
Return the View for the fragment's UI, or null. |
onProvideTheme
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.
Returns | |
---|---|
int |
The theme resource ID of the theme to use in this fragment, or -1 to use the host Activity's theme. |
onSaveInstanceState
public void onSaveInstanceState (Bundle outState)
Called to ask the fragment to save its current dynamic state, so it
can later be reconstructed in a new instance of its process is
restarted. If a new instance of the fragment later needs to be
created, the data you place in the Bundle here will be available
in the Bundle given to onCreate(Bundle)
,
onCreateView(LayoutInflater, ViewGroup, Bundle)
, and
onActivityCreated(Bundle)
.
This corresponds to Activity.onSaveInstanceState(Bundle)
and most of the discussion there
applies here as well. Note however: this method may be called
at any time before onDestroy()
. There are many situations
where a fragment may be mostly torn down (such as when placed on the
back stack with no UI showing), but its state will not be saved until
its owning activity actually needs to save its state.
Parameters | |
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outState |
Bundle : Bundle in which to place your saved state.
|
onViewCreated
public void onViewCreated (View view, Bundle savedInstanceState)
Called immediately after onCreateView(LayoutInflater, ViewGroup, Bundle)
has returned, but before any saved state has been restored in to the view.
This gives subclasses a chance to initialize themselves once
they know their view hierarchy has been completely created. The fragment's
view hierarchy is not however attached to its parent at this point.
Parameters | |
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view |
View : The View returned by onCreateView(LayoutInflater, ViewGroup, Bundle) . |
savedInstanceState |
Bundle : If non-null, this fragment is being re-constructed
from a previous saved state as given here.
|
setArrowBackgroundColor
public void setArrowBackgroundColor (int color)
Sets the background color of the arrow. If not set, the default color from attr
R.styleable.PagingIndicator_arrowBgColor
in the theme will be used.
Parameters | |
---|---|
color |
int : the color to use for arrow background
|
setArrowColor
public void setArrowColor (int color)
Sets the color of the arrow. This color will supersede the color set in the theme attribute
R.styleable.PagingIndicator_arrowColor
if provided. If none of these two are set, the
arrow will have its original bitmap color.
Parameters | |
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color |
int : the color to use for arrow background
|
setDescriptionViewTextColor
public void setDescriptionViewTextColor (int color)
Sets the text color for DescriptionView. If not set, the default textColor set in style
referenced by attr R.attr.onboardingDescriptionStyle
will be used.
Parameters | |
---|---|
color |
int : the color to use as the text color for DescriptionView
|
setDotBackgroundColor
public void setDotBackgroundColor (int color)
Sets the background color of the dots. If not set, the default color from attr
R.styleable.PagingIndicator_dotBgColor
in the theme will be used.
Parameters | |
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color |
int : the color to use for dot backgrounds
|
setIconResouceId
public final void setIconResouceId (int resourceId)
Sets the resource id for the main icon.
Parameters | |
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resourceId |
int |
setLogoResourceId
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.
Parameters | |
---|---|
id |
int : The resource ID of the logo image.
|
setStartButtonText
public void setStartButtonText (CharSequence text)
Sets the text on the start button text. If not set, the default text set in
R.styleable.LeanbackOnboardingTheme_onboardingStartButtonStyle
will be used.
Parameters | |
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text |
CharSequence : the start button text
|
setTitleViewTextColor
public void setTitleViewTextColor (int color)
Sets the text color for TitleView. If not set, the default textColor set in style
referenced by attr R.attr.onboardingTitleStyle
will be used.
Parameters | |
---|---|
color |
int : the color to use as the text color for TitleView
|
Protected methods
getCurrentPageIndex
protected final int getCurrentPageIndex ()
Returns the index of the current page.
Returns | |
---|---|
int |
The index of the current page. |
getPageCount
protected abstract int getPageCount ()
Returns the page count.
Returns | |
---|---|
int |
The page count. |
getPageDescription
protected abstract CharSequence getPageDescription (int pageIndex)
Returns the description of the given page.
Parameters | |
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pageIndex |
int : The page index. |
Returns | |
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CharSequence |
The description of the page. |
getPageTitle
protected abstract CharSequence getPageTitle (int pageIndex)
Returns the title of the given page.
Parameters | |
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pageIndex |
int : The page index. |
Returns | |
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CharSequence |
The title of the page. |
isLogoAnimationFinished
protected final boolean isLogoAnimationFinished ()
Returns whether the logo enter animation is finished.
Returns | |
---|---|
boolean |
true if the logo enter transition is finished, false otherwise
|
moveToNextPage
protected void moveToNextPage ()
Navigates to the next page.
moveToPreviousPage
protected void moveToPreviousPage ()
Navigates to the previous page.
onCreateBackgroundView
protected abstract View onCreateBackgroundView (LayoutInflater inflater, 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(LayoutInflater, ViewGroup, Bundle)
.
Parameters | |
---|---|
inflater |
LayoutInflater : The LayoutInflater object that can be used to inflate the views, |
container |
ViewGroup : The parent view that the additional views are attached to.The fragment
should not add the view by itself. |
Returns | |
---|---|
View |
The background view for the onboarding screen, or null .
|
onCreateContentView
protected abstract View onCreateContentView (LayoutInflater inflater, 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(LayoutInflater, ViewGroup, Bundle)
.
The content view would be located at the center of the screen.
Parameters | |
---|---|
inflater |
LayoutInflater : The LayoutInflater object that can be used to inflate the views, |
container |
ViewGroup : The parent view that the additional views are attached to.The fragment
should not add the view by itself. |
Returns | |
---|---|
View |
The content view for the onboarding screen, or null .
|
onCreateDescriptionAnimator
protected Animator onCreateDescriptionAnimator ()
Provides the entry animation for description view. This allows users to override the default fade and slide animation. Returning null will disable the animation.
Returns | |
---|---|
Animator |
onCreateEnterAnimation
protected Animator onCreateEnterAnimation ()
Called to have the inherited class create its enter animation. The start animation runs after logo animation ends.
Returns | |
---|---|
Animator |
The Animator object which runs the page enter animation.
|
onCreateForegroundView
protected abstract View onCreateForegroundView (LayoutInflater inflater, 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(LayoutInflater, ViewGroup, Bundle)
.
This foreground view would have the highest z-order.
Parameters | |
---|---|
inflater |
LayoutInflater : The LayoutInflater object that can be used to inflate the views, |
container |
ViewGroup : The parent view that the additional views are attached to.The fragment
should not add the view by itself. |
Returns | |
---|---|
View |
The foreground view for the onboarding screen, or null .
|
onCreateLogoAnimation
protected Animator onCreateLogoAnimation ()
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(int)
.
If this returns null
, the logo animation is skipped.
Returns | |
---|---|
Animator |
The Animator object which runs the logo animation.
|
onCreateTitleAnimator
protected Animator onCreateTitleAnimator ()
Provides the entry animation for title view. This allows users to override the default fade and slide animation. Returning null will disable the animation.
Returns | |
---|---|
Animator |
onFinishFragment
protected void onFinishFragment ()
Called when the onboarding flow finishes.
onLogoAnimationFinished
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.
onPageChanged
protected void onPageChanged (int newPage, int previousPage)
Called when the page has been changed.
Parameters | |
---|---|
newPage |
int : The new page. |
previousPage |
int : The previous page.
|
startEnterAnimation
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.
Parameters | |
---|---|
force |
boolean : true if enter animation has to be performed regardless of whether it's
been done in the past, false otherwise
|