如何使用奇巧过渡框架何时实现backstack [英] How to implement a backstack when using the KitKat Transitions Framework

问题描述

我现在用的是新奇巧转换在Android API 。我创建使用两种布局两个场景的对象。我是从动画场景1 到场景2 在片段 。我想自动移回previous 场景当用户presses后退按钮。

I am using the new KitKat Transitions API on Android. I have created two Scene objects using two layouts. I animate from Scene 1 to Scene 2 inside a Fragment. I want to automatically move back to the previous Scene when the user presses the back button.

有某种在使用转换，内置backstack机制还是我必须推出自己的？

Is there some kind of built-in backstack mechanism when using Transitions, or do I have to roll my own?

这是很容易调用 TransitionManager.go（SCENE1），但我真的不希望实施 onBack pressed（ ）听众在我所有的片段具有场景动画。

It is easy enough to call TransitionManager.go(scene1), but I really do not want to implement an onBackPressed() listener in all my fragments that have Scene animations.

推荐答案

我最终轧制我自己的解决方案。

I ended up rolling my own solution.

让你的活动实现这个

public interface SceneBackstackHandler {

    public void addBackstackListener(BackstackListener listener);

    public void removeBackstackListener(BackstackListener listener);

    public void removeAllBackstackListeners();

    public interface BackstackListener {
        public boolean onBackPressed();
    }
}

活动

private final Object mBackstackListenerLock = new Object();
private List<BackstackListener> mBackstackListeners = new ArrayList<>();

@Override
public void onBackPressed() {
    synchronized (mBackstackListenerLock) {
        for (BackstackListener mBackstackListener : mBackstackListeners) {
            if (mBackstackListener.onBackPressed()) {
                // handled by fragment
                return;
            }
        }
        super.onBackPressed();
    }
}

@Override
protected void onPause() {
    super.onPause();
    removeAllBackstackListeners();
}

@Override
public void addBackstackListener(BackstackListener listener) {
    synchronized (mBackstackListenerLock) {
        mBackstackListeners.add(listener);
    }
}

@Override
public void removeBackstackListener(BackstackListener listener) {
    synchronized (mBackstackListenerLock) {
        mBackstackListeners.remove(listener);
    }
}

@Override
public void removeAllBackstackListeners() {
    synchronized (mBackstackListenerLock) {
        mBackstackListeners.clear();
    }
}

儿童片段：

public class MySceneFragment extends Fragment
        implements SceneBackstackHandler.BackstackListener {

    private Scene mCurrentScene;

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        mBackstackHandler = (SceneBackstackHandler) activity;
        mBackstackHandler.addBackstackListener(this);
    }

    @Override
    public void onDetach() {
        super.onDetach();
        mBackstackHandler.removeBackstackListener(this);
    }

    @Override
    public boolean onBackPressed() {
        if (mCurrentScene != null && mCurrentScene.equals(mMyScene)) {
            removeMyScene();
            return true;
        }
        return false;
    }

    private void changeScene(Scene scene) {
        TransitionManager.go(scene);
        mCurrentScene = scene;
    }
}

这篇关于如何使用奇巧过渡框架何时实现backstack的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！