[译]playbackOverlayActivity 和 PlaybackOverlayFragment--Android TV 应用开发教程七

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PlaybackOverview1

本章仅介绍UI部分，下一章将介绍视频控制。我们将实现用于处理视频内容的UI。

PlaybackOverlayActivity＆PlaybackOverlayFragment

创建PlaybackOverlayActivity＆PlaybackOverlayFragment与以前介绍的相同。

创建PlaybackOverlayActivity

New → Activity → BlankActivity
Activity 名称: PlaybackOverlayActivity
Layout 名称: activity_playback_overlay
…
此PlaybackOverlayActivity将在res / layout文件夹中引用activity_playback_overlay.xml文件。 它包含2层：视图- 后面的VideoView和前面的PlaybackOverlayFragment。 VideoView是我们将播放视频内容的视图，PlaybackOverlayFragment将显示用于控制视频的UI，我们将在本章中重点介绍。 activity_playback_overlay.xml编写如下：

现在我们不需要对PlaybackOverlayActivity进行修改。

PlaybackOverlayFragment

创建PlaybackOverlayFragment：New -> Java Class -> Name: PlaybackOverlayFragment
这个PlaybackOverlayFragment是android.support.v17.leanback.app.PlaybackOverlayFragment的子类，它为我们提供了构建视频控制UI的组件。
它与VideoDetailsFragment非常相似，因此在适配器中设置行后，您只需要调用setAdapter(adapter)即可。 对于PlaybackOverlayFragment，我们需要将显示视频控制UI的“PlaybackControlsRow”的实例设置为适配器的第一行元素。

PlaybackOverview

我们来研究“PlaybackControlsRow”及其 Presenter,“PlaybackControlsRowPresenter”。 我们需要在每个实例中指定以下内容。

• PlaybackControlsRow
  PrimaryActionsAdapter - 它拥有主列的图标
  SecondaryActionsAdapter - 它拥有子行的图标

  请注意，PlaybackControlsRow类为我们提供了许多有用的视频控制默认图标。 我们只需要实例化它的内部类。

• PlaybackControlsRowPresenter
  DescriptionPresenter - 它是Presenter用于在PrimaryActions栏顶部显示项目详细信息。

  
  
  

  PlaybackOverview2
  
  

  上图解释了PlaybackControlsRow的内部构造 - PlaybackControlsRowpresenter。 PlaybackControlsRowPresenter的构造器接受DescriptionPresenter对象的参数，该对象决定了如何显示视频细节。 这一次，我们将重用DetailsDescriptionPresenter，我们在上一章中给出了在DetailsFragment中显示项目详细信息。 PlaybackControlsRow有2行内部设置动作，PrimaryActionsAdapter和SecondaryActionsAdapter。 我们可以在这些actionadapters中设置“动作”图标。 有关可用操作和这些图标，请参阅上述照片。
  PlaybackOverlayFragment的示例实现如下。

package com.corochann.androidtvapptutorial;

import android.content.Context;
import android.os.Bundle;
import android.support.v17.leanback.widget.ArrayObjectAdapter;
import android.support.v17.leanback.widget.ClassPresenterSelector;
import android.support.v17.leanback.widget.ControlButtonPresenterSelector;
import android.support.v17.leanback.widget.HeaderItem;
import android.support.v17.leanback.widget.ListRow;
import android.support.v17.leanback.widget.ListRowPresenter;
import android.support.v17.leanback.widget.PlaybackControlsRow;
import android.support.v17.leanback.widget.PlaybackControlsRowPresenter;
import android.util.Log;

public class PlaybackOverlayFragment extends android.support.v17.leanback.app.PlaybackOverlayFragment {

    private static final String TAG = PlaybackOverlayFragment.class.getSimpleName();

    private Movie mSelectedMovie;
    private PlaybackControlsRow mPlaybackControlsRow;
    private ArrayObjectAdapter mPrimaryActionAdapter;
    private ArrayObjectAdapter mSecondaryActionAdapter;

    private PlaybackControlsRow.PlayPauseAction mPlayPauseAction;
    private PlaybackControlsRow.RepeatAction mRepeatAction;
    private PlaybackControlsRow.ThumbsUpAction mThumbsUpAction;
    private PlaybackControlsRow.ThumbsDownAction mThumbsDownAction;
    private PlaybackControlsRow.ShuffleAction mShuffleAction;
    private PlaybackControlsRow.SkipNextAction mSkipNextAction;
    private PlaybackControlsRow.SkipPreviousAction mSkipPreviousAction;
    private PlaybackControlsRow.FastForwardAction mFastForwardAction;
    private PlaybackControlsRow.RewindAction mRewindAction;
    private PlaybackControlsRow.HighQualityAction mHighQualityAction;
    private PlaybackControlsRow.ClosedCaptioningAction mClosedCaptioningAction;
    private PlaybackControlsRow.MoreActions mMoreActions;


    @Override
    public void onCreate(Bundle savedInstanceState) {
        Log.i(TAG, "onCreate");
        super.onCreate(savedInstanceState);

        mSelectedMovie = (Movie) getActivity().getIntent().getSerializableExtra(DetailsActivity.MOVIE);

        setBackgroundType(PlaybackOverlayFragment.BG_LIGHT);
        setFadingEnabled(true);

        setUpRows();
    }

    private ArrayObjectAdapter mRowsAdapter;

    private void setUpRows() {
        ClassPresenterSelector ps = new ClassPresenterSelector();

        PlaybackControlsRowPresenter playbackControlsRowPresenter;
        playbackControlsRowPresenter = new PlaybackControlsRowPresenter(new DetailsDescriptionPresenter());

        ps.addClassPresenter(PlaybackControlsRow.class, playbackControlsRowPresenter);
        ps.addClassPresenter(ListRow.class, new ListRowPresenter());
        mRowsAdapter = new ArrayObjectAdapter(ps);

        /*
         * Add PlaybackControlsRow to mRowsAdapter, which makes video control UI.
         * PlaybackControlsRow is supposed to be first Row of mRowsAdapter.
         */
        addPlaybackControlsRow();
        /* add ListRow to second row of mRowsAdapter */
        addOtherRows();

        setAdapter(mRowsAdapter);

    }

    private void addPlaybackControlsRow() {
        mPlaybackControlsRow = new PlaybackControlsRow(mSelectedMovie);
        mRowsAdapter.add(mPlaybackControlsRow);

        ControlButtonPresenterSelector presenterSelector = new ControlButtonPresenterSelector();
        mPrimaryActionsAdapter = new ArrayObjectAdapter(presenterSelector);
        mSecondaryActionsAdapter = new ArrayObjectAdapter(presenterSelector);
        mPlaybackControlsRow.setPrimaryActionsAdapter(mPrimaryActionsAdapter);
        mPlaybackControlsRow.setSecondaryActionsAdapter(mSecondaryActionsAdapter);
        
        Activity activity = getActivity();
        mPlayPauseAction = new PlaybackControlsRow.PlayPauseAction(activity);
        mRepeatAction = new PlaybackControlsRow.RepeatAction(activity);
        mThumbsUpAction = new PlaybackControlsRow.ThumbsUpAction(activity);
        mThumbsDownAction = new PlaybackControlsRow.ThumbsDownAction(activity);
        mShuffleAction = new PlaybackControlsRow.ShuffleAction(activity);
        mSkipNextAction = new PlaybackControlsRow.SkipNextAction(activity);
        mSkipPreviousAction = new PlaybackControlsRow.SkipPreviousAction(activity);
        mFastForwardAction = new PlaybackControlsRow.FastForwardAction(activity);
        mRewindAction = new PlaybackControlsRow.RewindAction(activity);
        mHighQualityAction = new PlaybackControlsRow.HighQualityAction(activity);
        mClosedCaptioningAction = new PlaybackControlsRow.ClosedCaptioningAction(activity);
        mMoreActions = new PlaybackControlsRow.MoreActions(activity);

        /* PrimaryAction setting */
        mPrimaryActionsAdapter.add(mSkipPreviousAction);
        mPrimaryActionsAdapter.add(mRewindAction);
        mPrimaryActionsAdapter.add(mPlayPauseAction);
        mPrimaryActionsAdapter.add(mFastForwardAction);
        mPrimaryActionsAdapter.add(mSkipNextAction);

        /* SecondaryAction setting */
        mSecondaryActionsAdapter.add(mThumbsUpAction);
        mSecondaryActionsAdapter.add(mThumbsDownAction);
        mSecondaryActionsAdapter.add(mRepeatAction);
        mSecondaryActionsAdapter.add(mShuffleAction);
        mSecondaryActionsAdapter.add(mHighQualityAction);
        mSecondaryActionsAdapter.add(mClosedCaptioningAction);
        mSecondaryActionsAdapter.add(mMoreActions);
    }

    private void addOtherRows() {
        ArrayObjectAdapter listRowAdapter = new ArrayObjectAdapter(new CardPresenter());
        Movie movie = new Movie();
        movie.setTitle("Title");
        movie.setStudio("studio");
        movie.setDescription("description");
        movie.setCardImageUrl("http://heimkehrend.raindrop.jp/kl-hacker/wp-content/uploads/2014/08/DSC02580.jpg");
        listRowAdapter.add(movie);
        listRowAdapter.add(movie);

        HeaderItem header = new HeaderItem(0, "OtherRows");
        mRowsAdapter.add(new ListRow(header, listRowAdapter));
    }

}

背景VideoView尚未实现，黑色。 但是我们可以看到视频控制UI已经完成了！

源代码在github上。下一篇来介绍控制类具体实现：视频控制最小化实现 – Android TV 应用开发教程八

我将在下一章继续使用这个UI实现视频控件。
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