Activity跳转动画无缝衔接

1234.gif

activity_main.xml：

MainActivity：

public class MainActivity extends AppCompatActivity implements AdapterView.OnItemClickListener {
private static final String TAG = "MainActivity";

private GridView mGridView;
private GridAdapter mAdapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

mGridView = (GridView) findViewById(R.id.grid);
mGridView.setOnItemClickListener(this);
mAdapter = new GridAdapter();
mGridView.setAdapter(mAdapter);
}

@Override
public void onItemClick(AdapterView> adapterView, View view, int position, long id) {
Item item = (Item) adapterView.getItemAtPosition(position);

// Construct an Intent as normal
Intent intent = new Intent(this, DetailActivity.class);
intent.putExtra(DetailActivity.EXTRA_PARAM_ID, item.getId());

// BEGIN_INCLUDE(start_activity)
/**
* Now create an {@link android.app.ActivityOptions} instance using the
* {@link ActivityOptionsCompat#makeSceneTransitionAnimation(Activity, Pair[])} factory
* method.
*/
ActivityOptionsCompat activityOptiOns= ActivityOptionsCompat.makeSceneTransitionAnimation(
this,

// Now we provide a list of Pair items which contain the view we can transitioning
// from, and the name of the view it is transitioning to, in the launched activity
new Pair(view.findViewById(R.id.imageview_item),
DetailActivity.VIEW_NAME_HEADER_IMAGE),
new Pair(view.findViewById(R.id.textview_name),
DetailActivity.VIEW_NAME_HEADER_TITLE));

// Now we can start the Activity, providing the activity options as a bundle
ActivityCompat.startActivity(this, intent, activityOptions.toBundle());
// END_INCLUDE(start_activity)
}
}


GridAdapter :

private class GridAdapter extends BaseAdapter {

@Override
public int getCount() {
return Item.ITEMS.length;
}

@Override
public Item getItem(int position) {
return Item.ITEMS[position];
}

@Override
public long getItemId(int position) {
return getItem(position).getId();
}

@Override
public View getView(int position, View view, ViewGroup viewGroup) {
if (view == null) {
view = getLayoutInflater().inflate(R.layout.grid_item, viewGroup, false);
}

final Item item = getItem(position);

// Load the thumbnail image
ImageView image = (ImageView) view.findViewById(R.id.imageview_item);
Picasso.with(image.getContext()).load(item.getThumbnailUrl()).into(image);


// Set the TextView's contents
TextView name = (TextView) view.findViewById(R.id.textview_name);
name.setText(item.getName());

return view;
}
}


grid_item.xml

DetailActivity

public class DetailActivity extends Activity {

// Extra name for the ID parameter
public static final String EXTRA_PARAM_ID = "detail:_id";

// View name of the header image. Used for activity scene transitions
public static final String VIEW_NAME_HEADER_IMAGE = "detail:header:image";

// View name of the header title. Used for activity scene transitions
public static final String VIEW_NAME_HEADER_TITLE = "detail:header:title";

private ImageView mHeaderImageView;
private TextView mHeaderTitle;

private Item mItem;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.details);

// Retrieve the correct Item instance, using the ID provided in the Intent
mItem = Item.getItem(getIntent().getIntExtra(EXTRA_PARAM_ID, 0));

mHeaderImageView = (ImageView) findViewById(R.id.imageview_header);
mHeaderTitle = (TextView) findViewById(R.id.textview_title);

// BEGIN_INCLUDE(detail_set_view_name)
/**
* Set the name of the view's which will be transition to, using the static values above.
* This could be done in the layout XML, but exposing it via static variables allows easy
* querying from other Activities
*/
ViewCompat.setTransitionName(mHeaderImageView, VIEW_NAME_HEADER_IMAGE);
ViewCompat.setTransitionName(mHeaderTitle, VIEW_NAME_HEADER_TITLE);
// END_INCLUDE(detail_set_view_name)

loadItem();
}

private void loadItem() {
// Set the title TextView to the item's name and author
mHeaderTitle.setText(getString(R.string.image_header, mItem.getName(), mItem.getAuthor()));

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP && addTransitionListener()) {
// If we're running on Lollipop and we have added a listener to the shared element
// transition, load the thumbnail. The listener will load the full-size image when
// the transition is complete.
loadThumbnail();
} else {
// If all other cases we should just load the full-size image now
loadFullSizeImage();
}
}

/**
* Load the item's thumbnail image into our {@link ImageView}.
*/
private void loadThumbnail() {
Picasso.with(mHeaderImageView.getContext())
.load(mItem.getThumbnailUrl())
.noFade()
.into(mHeaderImageView);
}

/**
* Load the item's full-size image into our {@link ImageView}.
*/
private void loadFullSizeImage() {
Picasso.with(mHeaderImageView.getContext())
.load(mItem.getPhotoUrl())
.noFade()
.noPlaceholder()
.into(mHeaderImageView);
}

/**
* Try and add a {@link Transition.TransitionListener} to the entering shared element
* {@link Transition}. We do this so that we can load the full-size image after the transition
* has completed.
*
* @return true if we were successful in adding a listener to the enter transition
*/
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
private boolean addTransitionListener() {
final Transition transition = getWindow().getSharedElementEnterTransition();

if (transition != null) {
// There is an entering shared element transition so add a listener to it
transition.addListener(new Transition.TransitionListener() {
@Override
public void onTransitionEnd(Transition transition) {
// As the transition has ended, we can now load the full-size image
loadFullSizeImage();

// Make sure we remove ourselves as a listener
transition.removeListener(this);
}

@Override
public void onTransitionStart(Transition transition) {
// No-op
}

@Override
public void onTransitionCancel(Transition transition) {
// Make sure we remove ourselves as a listener
transition.removeListener(this);
}

@Override
public void onTransitionPause(Transition transition) {
// No-op
}

@Override
public void onTransitionResume(Transition transition) {
// No-op
}
});
return true;
}

// If we reach here then we have not added a listener
return false;
}

}


details.xml

Item

public class Item {

private static final String LARGE_BASE_URL = "http://storage.googleapis.com/androiddevelopers/sample_data/activity_transition/large/";
private static final String THUMB_BASE_URL = "http://storage.googleapis.com/androiddevelopers/sample_data/activity_transition/thumbs/";

public static Item[] ITEMS = new Item[] {
new Item("Flying in the Light", "Romain Guy", "flying_in_the_light.jpg"),
new Item("Caterpillar", "Romain Guy", "caterpillar.jpg"),
new Item("Look Me in the Eye", "Romain Guy", "look_me_in_the_eye.jpg"),
new Item("Flamingo", "Romain Guy", "flamingo.jpg"),
new Item("Rainbow", "Romain Guy", "rainbow.jpg"),
new Item("Over there", "Romain Guy", "over_there.jpg"),
new Item("Jelly Fish 2", "Romain Guy", "jelly_fish_2.jpg"),
new Item("Lone Pine Sunset", "Romain Guy", "lone_pine_sunset.jpg"),
};

public static Item getItem(int id) {
for (Item item : ITEMS) {
if (item.getId() == id) {
return item;
}
}
return null;
}

private final String mName;
private final String mAuthor;
private final String mFileName;

Item(String name, String author, String fileName) {
mName = name;
mAuthor = author;
mFileName = fileName;
}

public int getId() {
return mName.hashCode() + mFileName.hashCode();
}

public String getAuthor() {
return mAuthor;
}

public String getName() {
return mName;
}

public String getPhotoUrl() {
return LARGE_BASE_URL + mFileName;
}

public String getThumbnailUrl() {
return THUMB_BASE_URL + mFileName;
}

}


SquareFrameLayout

public class SquareFrameLayout extends FrameLayout {

public SquareFrameLayout(Context context) {
super(context);
}

public SquareFrameLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}

public SquareFrameLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
final int widthSize = MeasureSpec.getSize(widthMeasureSpec);
final int heightSize = MeasureSpec.getSize(heightMeasureSpec);

if (widthSize == 0 && heightSize == 0) {
// If there are no constraints on size, let FrameLayout measure
super.onMeasure(widthMeasureSpec, heightMeasureSpec);

// Now use the smallest of the measured dimensions for both dimensions
final int minSize = Math.min(getMeasuredWidth(), getMeasuredHeight());
setMeasuredDimension(minSize, minSize);
return;
}

final int size;
if (widthSize == 0 || heightSize == 0) {
// If one of the dimensions has no restriction on size, set both dimensions to be the
// on that does
size = Math.max(widthSize, heightSize);
} else {
// Both dimensions have restrictions on size, set both dimensions to be the
// smallest of the two
size = Math.min(widthSize, heightSize);
}

final int newMeasureSpec = MeasureSpec.makeMeasureSpec(size, MeasureSpec.EXACTLY);
super.onMeasure(newMeasureSpec, newMeasureSpec);
}
}