public class

VerticalGridSupportFragment

extends BaseSupportFragment

 java.lang.Object

androidx.fragment.app.Fragment

androidx.leanback.app.BrandedSupportFragment

androidx.leanback.app.BaseSupportFragment

↳androidx.leanback.app.VerticalGridSupportFragment

Gradle dependencies

compile group: 'androidx.leanback', name: 'leanback', version: '1.2.0-alpha02'

  • groupId: androidx.leanback
  • artifactId: leanback
  • version: 1.2.0-alpha02

Artifact androidx.leanback:leanback:1.2.0-alpha02 it located at Google repository (https://maven.google.com/)

Androidx artifact mapping:

androidx.leanback:leanback com.android.support:leanback-v17

Androidx class mapping:

androidx.leanback.app.VerticalGridSupportFragment android.support.v17.leanback.app.VerticalGridSupportFragment

Overview

A fragment for creating leanback vertical grids.

Renders a vertical grid of objects given a VerticalGridPresenter and an ObjectAdapter.

Summary

Fields
from FragmentmPreviousWho
Constructors
publicVerticalGridSupportFragment()

Methods
protected java.lang.ObjectcreateEntranceTransition()

Create entrance transition.

public ObjectAdaptergetAdapter()

Returns the object adapter.

public VerticalGridPresentergetGridPresenter()

Returns the grid presenter.

public OnItemViewClickedListenergetOnItemViewClickedListener()

Returns the item clicked listener.

public ViewonCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)

Called to have the fragment instantiate its user interface view.

public voidonDestroyView()

Called when the view previously created by Fragment.onCreateView(LayoutInflater, ViewGroup, Bundle) has been detached from the fragment.

public voidonStart()

Called when the Fragment is visible to the user.

protected voidrunEntranceTransition(java.lang.Object entranceTransition)

Run entrance transition.

public voidsetAdapter(ObjectAdapter adapter)

Sets the object adapter for the fragment.

public voidsetGridPresenter(VerticalGridPresenter gridPresenter)

Sets the grid presenter.

public voidsetOnItemViewClickedListener(OnItemViewClickedListener listener)

Sets an item clicked listener.

public voidsetOnItemViewSelectedListener(OnItemViewSelectedListener listener)

Sets an item selection listener.

public voidsetSelectedPosition(int position)

Sets the selected item position.

from BaseSupportFragmentgetProgressBarManager, onCreate, onEntranceTransitionEnd, onEntranceTransitionPrepare, onEntranceTransitionStart, onViewCreated, prepareEntranceTransition, startEntranceTransition
from BrandedSupportFragmentgetBadgeDrawable, getSearchAffordanceColor, getSearchAffordanceColors, getTitle, getTitleView, getTitleViewAdapter, installTitleView, isShowingTitle, onInflateTitleView, onPause, onResume, onSaveInstanceState, setBadgeDrawable, setOnSearchClickedListener, setSearchAffordanceColor, setSearchAffordanceColors, setTitle, setTitleView, showTitle, showTitle
from Fragmentdump, equals, getActivity, getAllowEnterTransitionOverlap, getAllowReturnTransitionOverlap, getArguments, getChildFragmentManager, getContext, getDefaultViewModelCreationExtras, getDefaultViewModelProviderFactory, getEnterTransition, getExitTransition, getFragmentManager, getHost, getId, getLayoutInflater, getLayoutInflater, getLifecycle, getLoaderManager, getParentFragment, getParentFragmentManager, getReenterTransition, getResources, getRetainInstance, getReturnTransition, getSavedStateRegistry, getSharedElementEnterTransition, getSharedElementReturnTransition, getString, getString, getTag, getTargetFragment, getTargetRequestCode, getText, getUserVisibleHint, getView, getViewLifecycleOwner, getViewLifecycleOwnerLiveData, getViewModelStore, hashCode, hasOptionsMenu, instantiate, instantiate, isAdded, isDetached, isHidden, isInLayout, isMenuVisible, isRemoving, isResumed, isStateSaved, isVisible, onActivityCreated, onActivityResult, onAttach, onAttach, onAttachFragment, onConfigurationChanged, onContextItemSelected, onCreateAnimation, onCreateAnimator, onCreateContextMenu, onCreateOptionsMenu, onDestroy, onDestroyOptionsMenu, onDetach, onGetLayoutInflater, onHiddenChanged, onInflate, onInflate, onLowMemory, onMultiWindowModeChanged, onOptionsItemSelected, onOptionsMenuClosed, onPictureInPictureModeChanged, onPrepareOptionsMenu, onPrimaryNavigationFragmentChanged, onRequestPermissionsResult, onStop, onViewStateRestored, postponeEnterTransition, postponeEnterTransition, registerForActivityResult, registerForActivityResult, registerForContextMenu, requestPermissions, requireActivity, requireArguments, requireContext, requireFragmentManager, requireHost, requireParentFragment, requireView, setAllowEnterTransitionOverlap, setAllowReturnTransitionOverlap, setArguments, setEnterSharedElementCallback, setEnterTransition, setExitSharedElementCallback, setExitTransition, setHasOptionsMenu, setInitialSavedState, setMenuVisibility, setReenterTransition, setRetainInstance, setReturnTransition, setSharedElementEnterTransition, setSharedElementReturnTransition, setTargetFragment, setUserVisibleHint, shouldShowRequestPermissionRationale, startActivity, startActivity, startActivityForResult, startActivityForResult, startIntentSenderForResult, startPostponedEnterTransition, toString, unregisterForContextMenu
from java.lang.Objectclone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructors

public VerticalGridSupportFragment()

Methods

public void setGridPresenter(VerticalGridPresenter gridPresenter)

Sets the grid presenter.

public VerticalGridPresenter getGridPresenter()

Returns the grid presenter.

public void setAdapter(ObjectAdapter adapter)

Sets the object adapter for the fragment.

public ObjectAdapter getAdapter()

Returns the object adapter.

public void setOnItemViewSelectedListener(OnItemViewSelectedListener listener)

Sets an item selection listener.

public void setOnItemViewClickedListener(OnItemViewClickedListener listener)

Sets an item clicked listener.

public OnItemViewClickedListener getOnItemViewClickedListener()

Returns the item clicked listener.

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 Fragment.onCreate(Bundle) and Fragment.onViewCreated(View, Bundle).

A default View can be returned by calling Fragment.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 Fragment.onViewCreated(View, Bundle).

If you return a View from here, you will later be called in Fragment.onDestroyView() when the view is being released.

Parameters:

inflater: The LayoutInflater object that can be used to inflate any views in the fragment,
container: 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: If non-null, this fragment is being re-constructed from a previous saved state as given here.

Returns:

Return the View for the fragment's UI, or null.

public void onStart()

Called when the Fragment is visible to the user. This is generally tied to of the containing Activity's lifecycle.

public void onDestroyView()

Called when the view previously created by Fragment.onCreateView(LayoutInflater, ViewGroup, Bundle) has been detached from the fragment. The next time the fragment needs to be displayed, a new view will be created. This is called after Fragment.onStop() and before Fragment.onDestroy(). It is called regardless of whether Fragment.onCreateView(LayoutInflater, ViewGroup, Bundle) returned a non-null view. Internally it is called after the view's state has been saved but before it has been removed from its parent.

public void setSelectedPosition(int position)

Sets the selected item position.

protected java.lang.Object createEntranceTransition()

Create entrance transition. Subclass can override to load transition from resource or construct manually. Typically app does not need to override the default transition that browse and details provides.

protected void runEntranceTransition(java.lang.Object entranceTransition)

Run entrance transition. Subclass may use TransitionManager to perform go(Scene) or beginDelayedTransition(). App should not override the default implementation of browse and details fragment.

Source

/*
 * Copyright (C) 2014 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */
package androidx.leanback.app;

import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import androidx.leanback.R;
import androidx.leanback.transition.TransitionHelper;
import androidx.leanback.util.StateMachine.State;
import androidx.leanback.widget.BrowseFrameLayout;
import androidx.leanback.widget.ObjectAdapter;
import androidx.leanback.widget.OnChildLaidOutListener;
import androidx.leanback.widget.OnItemViewClickedListener;
import androidx.leanback.widget.OnItemViewSelectedListener;
import androidx.leanback.widget.Presenter;
import androidx.leanback.widget.Row;
import androidx.leanback.widget.RowPresenter;
import androidx.leanback.widget.VerticalGridPresenter;

/**
 * A fragment for creating leanback vertical grids.
 *
 * <p>Renders a vertical grid of objects given a {@link VerticalGridPresenter} and
 * an {@link ObjectAdapter}.
 */
public class VerticalGridSupportFragment extends BaseSupportFragment {
    static final String TAG = "VerticalGF";
    static final boolean DEBUG = false;

    private ObjectAdapter mAdapter;
    private VerticalGridPresenter mGridPresenter;
    VerticalGridPresenter.ViewHolder mGridViewHolder;
    OnItemViewSelectedListener mOnItemViewSelectedListener;
    private OnItemViewClickedListener mOnItemViewClickedListener;
    private Object mSceneAfterEntranceTransition;
    private int mSelectedPosition = -1;

    /**
     * State to setEntranceTransitionState(false)
     */
    final State STATE_SET_ENTRANCE_START_STATE = new State("SET_ENTRANCE_START_STATE") {
        @Override
        public void run() {
            setEntranceTransitionState(false);
        }
    };

    @Override
    void createStateMachineStates() {
        super.createStateMachineStates();
        mStateMachine.addState(STATE_SET_ENTRANCE_START_STATE);
    }

    @Override
    void createStateMachineTransitions() {
        super.createStateMachineTransitions();
        mStateMachine.addTransition(STATE_ENTRANCE_ON_PREPARED,
                STATE_SET_ENTRANCE_START_STATE, EVT_ON_CREATEVIEW);
    }

    /**
     * Sets the grid presenter.
     */
    public void setGridPresenter(VerticalGridPresenter gridPresenter) {
        if (gridPresenter == null) {
            throw new IllegalArgumentException("Grid presenter may not be null");
        }
        mGridPresenter = gridPresenter;
        mGridPresenter.setOnItemViewSelectedListener(mViewSelectedListener);
        if (mOnItemViewClickedListener != null) {
            mGridPresenter.setOnItemViewClickedListener(mOnItemViewClickedListener);
        }
    }

    /**
     * Returns the grid presenter.
     */
    public VerticalGridPresenter getGridPresenter() {
        return mGridPresenter;
    }

    /**
     * Sets the object adapter for the fragment.
     */
    public void setAdapter(ObjectAdapter adapter) {
        mAdapter = adapter;
        updateAdapter();
    }

    /**
     * Returns the object adapter.
     */
    public ObjectAdapter getAdapter() {
        return mAdapter;
    }

    final private OnItemViewSelectedListener mViewSelectedListener =
            new OnItemViewSelectedListener() {
        @Override
        public void onItemSelected(Presenter.ViewHolder itemViewHolder, Object item,
                RowPresenter.ViewHolder rowViewHolder, Row row) {
            int position = mGridViewHolder.getGridView().getSelectedPosition();
            if (DEBUG) Log.v(TAG, "grid selected position " + position);
            gridOnItemSelected(position);
            if (mOnItemViewSelectedListener != null) {
                mOnItemViewSelectedListener.onItemSelected(itemViewHolder, item,
                        rowViewHolder, row);
            }
        }
    };

    final private OnChildLaidOutListener mChildLaidOutListener =
            new OnChildLaidOutListener() {
        @Override
        public void onChildLaidOut(ViewGroup parent, View view, int position, long id) {
            if (position == 0) {
                showOrHideTitle();
            }
        }
    };

    /**
     * Sets an item selection listener.
     */
    public void setOnItemViewSelectedListener(OnItemViewSelectedListener listener) {
        mOnItemViewSelectedListener = listener;
    }

    void gridOnItemSelected(int position) {
        if (position != mSelectedPosition) {
            mSelectedPosition = position;
            showOrHideTitle();
        }
    }

    void showOrHideTitle() {
        if (mGridViewHolder.getGridView().findViewHolderForAdapterPosition(mSelectedPosition)
                == null) {
            return;
        }
        if (!mGridViewHolder.getGridView().hasPreviousViewInSameRow(mSelectedPosition)) {
            showTitle(true);
        } else {
            showTitle(false);
        }
    }

    /**
     * Sets an item clicked listener.
     */
    public void setOnItemViewClickedListener(OnItemViewClickedListener listener) {
        mOnItemViewClickedListener = listener;
        if (mGridPresenter != null) {
            mGridPresenter.setOnItemViewClickedListener(mOnItemViewClickedListener);
        }
    }

    /**
     * Returns the item clicked listener.
     */
    public OnItemViewClickedListener getOnItemViewClickedListener() {
        return mOnItemViewClickedListener;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        ViewGroup root = (ViewGroup) inflater.inflate(R.layout.lb_vertical_grid_fragment,
                container, false);
        ViewGroup gridFrame = (ViewGroup) root.findViewById(R.id.grid_frame);
        installTitleView(inflater, gridFrame, savedInstanceState);
        getProgressBarManager().setRootView(root);

        ViewGroup gridDock = (ViewGroup) root.findViewById(R.id.browse_grid_dock);
        mGridViewHolder = mGridPresenter.onCreateViewHolder(gridDock);
        gridDock.addView(mGridViewHolder.view);
        mGridViewHolder.getGridView().setOnChildLaidOutListener(mChildLaidOutListener);

        mSceneAfterEntranceTransition = TransitionHelper.createScene(gridDock, new Runnable() {
            @Override
            public void run() {
                setEntranceTransitionState(true);
            }
        });

        updateAdapter();
        return root;
    }

    private void setupFocusSearchListener() {
        BrowseFrameLayout browseFrameLayout = (BrowseFrameLayout) getView().findViewById(
                R.id.grid_frame);
        browseFrameLayout.setOnFocusSearchListener(getTitleHelper().getOnFocusSearchListener());
    }

    @Override
    public void onStart() {
        super.onStart();
        setupFocusSearchListener();
    }

    @Override
    public void onDestroyView() {
        super.onDestroyView();
        mGridViewHolder.getGridView().swapAdapter(null, true);
        mGridViewHolder = null;
        mSceneAfterEntranceTransition = null;
    }

    /**
     * Sets the selected item position.
     */
    public void setSelectedPosition(int position) {
        mSelectedPosition = position;
        if(mGridViewHolder != null && mGridViewHolder.getGridView().getAdapter() != null) {
            mGridViewHolder.getGridView().setSelectedPositionSmooth(position);
        }
    }

    private void updateAdapter() {
        if (mGridViewHolder != null) {
            mGridPresenter.onBindViewHolder(mGridViewHolder, mAdapter);
            if (mSelectedPosition != -1) {
                mGridViewHolder.getGridView().setSelectedPosition(mSelectedPosition);
            }
        }
    }

    @Override
    protected Object createEntranceTransition() {
        return TransitionHelper.loadTransition(getContext(),
                R.transition.lb_vertical_grid_entrance_transition);
    }

    @Override
    protected void runEntranceTransition(Object entranceTransition) {
        TransitionHelper.runTransition(mSceneAfterEntranceTransition, entranceTransition);
    }

    void setEntranceTransitionState(boolean afterTransition) {
        mGridPresenter.setEntranceTransitionState(mGridViewHolder, afterTransition);
    }
}