DetailsFragmentBackgroundController
public class DetailsFragmentBackgroundController
Controller for DetailsFragment parallax background and embedded video play.
The parallax background drawable is made of two parts: cover drawable (by default FitWidthBitmapDrawable) above the details overview row and bottom drawable (by default ColorDrawable) below the details overview row. While vertically scrolling rows, the size of cover drawable and bottom drawable will be updated and the cover drawable will by default perform a parallax shift using PROPERTY_VERTICAL_OFFSET.
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* Cover Drawable *
* (FitWidthBitmapDrawable)*
* *
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* DetailsOverviewRow *
* *
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* Bottom Drawable *
* (ColorDrawable) *
* Related *
* Content *
***************************enableParallax and/or setupVideoPlayback explicitly. The PlaybackGlue is automatically play when fragment starts and pause when fragment stops. When video is ready to play, cover drawable will be faded out. Example:
DetailsFragmentBackgroundController mController = new DetailsFragmentBackgroundController(this); public void onCreate(Bundle savedInstance) { super.onCreate(savedInstance); MediaPlayerGlue player = new MediaPlayerGlue(..); player.setUrl(...); mController.enableParallax(); mController.setupVideoPlayback(player); } static class MyLoadBitmapTask extends ... { WeakReferencemFragmentRef; MyLoadBitmapTask(MyFragment fragment) { mFragmentRef = new WeakReference(fragment); } protected void onPostExecute(Bitmap bitmap) { MyFragment fragment = mFragmentRef.get(); if (fragment != null) { fragment.mController.setCoverBitmap(bitmap); } } } public void onStart() { new MyLoadBitmapTask(this).execute(url); } public void onStop() { mController.setCoverBitmap(null); }
To customize cover drawable and/or bottom drawable, app should call enableParallax. If app supplies a custom cover Drawable, it should not call setCoverBitmap. If app supplies a custom bottom Drawable, it should not call setSolidColor.
To customize playback fragment, app should override onCreateVideoFragment and onCreateGlueHost.
Summary
Public constructors |
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Creates a DetailsFragmentBackgroundController for a DetailsFragment. |
Public methods |
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boolean |
Precondition allows user navigate to video fragment using DPAD. |
void |
Enables default parallax background using a |
void |
enableParallax(Enables parallax background using a custom cover drawable at top and a custom bottom drawable. |
final Fragment |
Adds or gets fragment for rendering video in DetailsFragment. |
final Drawable |
Returns the drawable at bottom. |
final Bitmap |
Returns Bitmap set by |
final Drawable |
Returns the cover drawable at top. |
final int |
Returns Default parallax offset in pixels for bitmap moving vertically. |
final PlaybackGlue |
Returns current PlaybackGlue or null if not set or cleared. |
final @ColorInt int |
Returns color set by |
PlaybackGlueHost |
Creates a PlaybackGlueHost to host PlaybackGlue. |
Fragment |
Creates a Fragment to host |
final void |
setCoverBitmap(Bitmap bitmap)Convenient method to set Bitmap in cover drawable. |
final void |
setParallaxDrawableMaxOffset(int offset)Sets default parallax offset in pixels for bitmap moving vertically. |
final void |
setSolidColor(@ColorInt int color)Convenient method to set color in bottom drawable. |
void |
setupVideoPlayback(@NonNull PlaybackGlue playbackGlue)Enable video playback and set proper |
final void |
Switch to rows fragment. |
final void |
Switch to video fragment, note that this method is not affected by result of |
Public constructors
public DetailsFragmentBackgroundController(DetailsFragment fragment)
Creates a DetailsFragmentBackgroundController for a DetailsFragment. Note that each DetailsFragment can only associate with one DetailsFragmentBackgroundController.
| Parameters | |
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DetailsFragment fragment |
The DetailsFragment to control background and embedded video playing. |
| Throws | |
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java.lang.IllegalStateException |
If fragment was already associated with another controller. |
Public methods
public boolean canNavigateToVideoFragment()
Precondition allows user navigate to video fragment using DPAD. Default implementation returns true if PlaybackGlue is not null. Subclass may override, e.g. only allow navigation when isPrepared is true. Note this method does not block app calls switchToVideo.
| Returns | |
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boolean |
True allow to navigate to video fragment. |
public void enableParallax()
Enables default parallax background using a FitWidthBitmapDrawable as cover drawable and ColorDrawable as bottom drawable. A vertical parallax movement will be applied to the FitWidthBitmapDrawable. App may use setSolidColor and setCoverBitmap to change the content of bottom drawable and cover drawable. This method must be called before setupVideoPlayback.
| Throws | |
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java.lang.IllegalStateException |
If |
| See also | |
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setCoverBitmap |
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setSolidColor |
public void enableParallax(
@NonNull Drawable coverDrawable,
@NonNull Drawable bottomDrawable,
@Nullable ParallaxTarget.PropertyValuesHolderTarget coverDrawableParallaxTarget
)
Enables parallax background using a custom cover drawable at top and a custom bottom drawable. This method must be called before setupVideoPlayback.
| Parameters | |
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@NonNull Drawable coverDrawable |
Custom cover drawable shown at top. |
@NonNull Drawable bottomDrawable |
Drawable shown at bottom. |
@Nullable ParallaxTarget.PropertyValuesHolderTarget coverDrawableParallaxTarget |
Target to perform parallax effect within coverDrawable. Use null for no parallax movement effect. Example to move bitmap within FitWidthBitmapDrawable: new ParallaxTarget.PropertyValuesHolderTarget( coverDrawable, PropertyValuesHolder.ofInt( FitWidthBitmapDrawable.PROPERTY_VERTICAL_OFFSET, 0, -120)) |
| Throws | |
|---|---|
java.lang.IllegalStateException |
If |
public final Fragment findOrCreateVideoFragment()
Adds or gets fragment for rendering video in DetailsFragment. A subclass that overrides onCreateGlueHost should call this method to get a fragment for creating a PlaybackGlueHost.
| Returns | |
|---|---|
Fragment |
Fragment the added or restored fragment responsible for rendering video. |
| See also | |
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onCreateGlueHost |
public final Drawable getBottomDrawable()
Returns the drawable at bottom. Returns null if enableParallax is not called. By default it's a ColorDrawable.
| Returns | |
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Drawable |
The bottom drawable. |
public final Bitmap getCoverBitmap()
Returns Bitmap set by setCoverBitmap.
| Returns | |
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Bitmap |
Bitmap for cover drawable. |
public final Drawable getCoverDrawable()
Returns the cover drawable at top. Returns null if enableParallax is not called. By default it's a FitWidthBitmapDrawable.
| Returns | |
|---|---|
Drawable |
The cover drawable at top. |
public final int getParallaxDrawableMaxOffset()
Returns Default parallax offset in pixels for bitmap moving vertically. When 0, a default value would be used.
| Returns | |
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int |
Default parallax offset in pixels for bitmap moving vertically. |
| See also | |
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enableParallax |
public final PlaybackGlue getPlaybackGlue()
Returns current PlaybackGlue or null if not set or cleared.
| Returns | |
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PlaybackGlue |
Current PlaybackGlue or null |
public final @ColorInt int getSolidColor()
Returns color set by setSolidColor.
| Returns | |
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@ColorInt int |
Solid color used for bottom drawable. |
public PlaybackGlueHost onCreateGlueHost()
Creates a PlaybackGlueHost to host PlaybackGlue. App may override this if it overrides onCreateVideoFragment. This method must be called after calling Fragment super.onCreate(). When override this method, app may call findOrCreateVideoFragment to get or create a fragment.
| Returns | |
|---|---|
PlaybackGlueHost |
A new PlaybackGlueHost to host PlaybackGlue. |
public Fragment onCreateVideoFragment()
Creates a Fragment to host PlaybackGlue. Returns a new VideoFragment by default. App may override and return a different fragment and it also must override onCreateGlueHost.
| Returns | |
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Fragment |
A new fragment used in |
| See also | |
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onCreateGlueHost |
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setupVideoPlayback |
public final void setCoverBitmap(Bitmap bitmap)
Convenient method to set Bitmap in cover drawable. If app is not using default FitWidthBitmapDrawable, app should not use this method It's safe to call setCoverBitmap() before calling enableParallax.
| Parameters | |
|---|---|
Bitmap bitmap |
bitmap to set as cover. |
public final void setParallaxDrawableMaxOffset(int offset)
Sets default parallax offset in pixels for bitmap moving vertically. This method must be called before enableParallax.
| Parameters | |
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int offset |
Offset in pixels (e.g. 120). |
| See also | |
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enableParallax |
public final void setSolidColor(@ColorInt int color)
Convenient method to set color in bottom drawable. If app is not using default ColorDrawable, app should not use this method. It's safe to call setSolidColor() before calling enableParallax.
| Parameters | |
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@ColorInt int color |
color for bottom drawable. |
public void setupVideoPlayback(@NonNull PlaybackGlue playbackGlue)
Enable video playback and set proper PlaybackGlueHost. This method by default creates a VideoFragment and VideoFragmentGlueHost to host the PlaybackGlue. This method must be called after calling details Fragment super.onCreate(). This method can be called multiple times to replace existing PlaybackGlue or calling setupVideoPlayback(null) to clear. Note a typical PlaybackGlue subclass releases resources in onDetachedFromHost, when the PlaybackGlue subclass is not doing that, it's app's responsibility to release the resources.
| Parameters | |
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@NonNull PlaybackGlue playbackGlue |
The new PlaybackGlue to set as background or null to clear existing one. |
| See also | |
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onCreateVideoFragment |
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onCreateGlueHost |
public final void switchToVideo()
Switch to video fragment, note that this method is not affected by result of canNavigateToVideoFragment. If the method is called in DetailsFragment.onCreate() it will make video fragment to be initially focused once it is created.
Calling switchToVideo() in DetailsFragment.onCreate() will clear the activity enter transition and shared element transition.
If switchToVideo() is called after prepareEntranceTransition and before onEntranceTransitionEnd, it will be ignored.
If prepareEntranceTransition is called after switchToVideo(), an IllegalStateException will be thrown.