Question

最新Facebook的Android应用程序有一个非常漂亮的浮动评论窗口。在那里，用户可以关闭向上或向下滑动的窗口，使其非常易于使用。

我想在我的应用中实现类似的行为，但我不知道该怎么做。任何关于如何做到这一点的想法或线索都将非常感激。

Facebook应用的截图（抱歉，我截取屏幕截图的Facebook应用程序是日文） Swipe up Swipe down

Answer 1

我编写了一些与此结束/调整大小行为相匹配的代码，我不知道它是否可行，但我的代码基于Activity类。我要做的第一件事是创建一个活动并给它Transluscent主题以获得具有透明背景的活动。

在我的manifest.xml中：

<activity
    android:name=".PopupActivity"
    android:label="@string/title_activity_popup"
    <!-- Use Translucent theme to get transparent activity background 
     and NoTitleBar to avoid super old style title bar ;) -->
    android:theme="@android:style/Theme.Translucent.NoTitleBar">
</activity>

然后我创建一个简单的布局文件，其中包含textview（对应于Facebook tchatting部分）和一个视图（对应于Facebook“Write your msg”/“send smiley”选项卡）

我的布局/ activity_popup.xml：

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/base_popup_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="8dp"
    android:background="@android:color/darker_gray"
    android:layout_marginBottom="124dp">

    <TextView
        android:text="@string/hello_world"
        android:layout_width="match_parent"
        android:layout_height="200dp"
        android:background="@android:color/black"/>

    <View
        android:layout_width="match_parent"
        android:layout_height="80dp"
        android:layout_alignParentBottom="true"
        android:background="@android:color/holo_blue_dark"/>

</RelativeLayout>

最后我在PopupActivity类中处理触摸和移动事件，我使用onTouchListener在onTouch方法中提供回调。

<强> PopupActivity

public class PopupActivity extends Activity implements View.OnTouchListener{

    private RelativeLayout baseLayout;

    private int previousFingerPosition = 0;
    private int baseLayoutPosition = 0;
    private int defaultViewHeight;

    private boolean isClosing = false;
    private boolean isScrollingUp = false;
    private boolean isScrollingDown = false;

    @Override
    protected void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_popup);
        baseLayout = (RelativeLayout) findViewById(R.id.base_popup_layout);
        baseLayout.setOnTouchListener(this);
    }


    public boolean onTouch(View view, MotionEvent event) {

        // Get finger position on screen
        final int Y = (int) event.getRawY();

        // Switch on motion event type
        switch (event.getAction() & MotionEvent.ACTION_MASK) {

            case MotionEvent.ACTION_DOWN:
                // save default base layout height
                defaultViewHeight = baseLayout.getHeight();

                // Init finger and view position
                previousFingerPosition = Y;
                baseLayoutPosition = (int) baseLayout.getY();
                break;

            case MotionEvent.ACTION_UP:
                // If user was doing a scroll up
                if(isScrollingUp){
                    // Reset baselayout position
                    baseLayout.setY(0);
                    // We are not in scrolling up mode anymore
                    isScrollingUp = false;
                }

                // If user was doing a scroll down
                if(isScrollingDown){
                    // Reset baselayout position
                    baseLayout.setY(0);
                    // Reset base layout size
                    baseLayout.getLayoutParams().height = defaultViewHeight;
                    baseLayout.requestLayout();
                    // We are not in scrolling down mode anymore
                    isScrollingDown = false;
                }
                break;
            case MotionEvent.ACTION_MOVE:
                if(!isClosing){
                    int currentYPosition = (int) baseLayout.getY();

                    // If we scroll up
                    if(previousFingerPosition >Y){
                        // First time android rise an event for "up" move
                        if(!isScrollingUp){
                            isScrollingUp = true;
                        }

                    // Has user scroll down before -> view is smaller than it's default size -> resize it instead of change it position
                    if(baseLayout.getHeight()<defaultViewHeight){
                        baseLayout.getLayoutParams().height = baseLayout.getHeight() - (Y - previousFingerPosition);
                        baseLayout.requestLayout();
                    }
                    else {
                        // Has user scroll enough to "auto close" popup ?
                        if ((baseLayoutPosition - currentYPosition) > defaultViewHeight / 4) {
                            closeUpAndDismissDialog(currentYPosition);
                            return true;
                        }

                        //
                    }
                    baseLayout.setY(baseLayout.getY() + (Y - previousFingerPosition));

                }
                // If we scroll down
                else{

                    // First time android rise an event for "down" move
                    if(!isScrollingDown){
                        isScrollingDown = true;
                    }

                    // Has user scroll enough to "auto close" popup ?
                    if (Math.abs(baseLayoutPosition - currentYPosition) > defaultViewHeight / 2)
                    {
                        closeDownAndDismissDialog(currentYPosition);
                        return true;
                    }

                    // Change base layout size and position (must change position because view anchor is top left corner)
                    baseLayout.setY(baseLayout.getY() + (Y - previousFingerPosition));
                    baseLayout.getLayoutParams().height = baseLayout.getHeight() - (Y - previousFingerPosition);
                    baseLayout.requestLayout();
                }

                // Update position
                previousFingerPosition = Y;
            }
            break;
        }
        return true;
    }
}

当用户滚动到足以关闭弹出窗口（即动画和完成活动）时，会调用两个小方法：

public void closeUpAndDismissDialog(int currentPosition){
    isClosing = true;
    ObjectAnimator positionAnimator = ObjectAnimator.ofFloat(baseLayout, "y", currentPosition, -baseLayout.getHeight());
    positionAnimator.setDuration(300);
    positionAnimator.addListener(new Animator.AnimatorListener()
    {
        . . .
        @Override
        public void onAnimationEnd(Animator animator)
        {
            finish();
        }
        . . .
    });
    positionAnimator.start();
}

public void closeDownAndDismissDialog(int currentPosition){
    isClosing = true;
    Display display = getWindowManager().getDefaultDisplay();
    Point size = new Point();
    display.getSize(size);
    int screenHeight = size.y;
    ObjectAnimator positionAnimator = ObjectAnimator.ofFloat(baseLayout, "y", currentPosition, screenHeight+baseLayout.getHeight());
    positionAnimator.setDuration(300);
    positionAnimator.addListener(new Animator.AnimatorListener()
     {
        . . .
        @Override
        public void onAnimationEnd(Animator animator)
        {
            finish();
        }
        . . .
    });
    positionAnimator.start();
}

使用所有这些代码，您应该能够启动全局匹配Facebook弹出行为的PopupActivity。它只是一个草稿类，还有很多工作要做：添加动画，处理关闭参数等等......

屏幕截图：

Screenshot of PopupActivity as written above

Answer 2

我认为您可以使用appcompat libarary中的 BottomSheetDialogFragment 组件。查看此文章以获取相关信息： https://medium.com/@nullthemall/new-bottomsheet-caab21aff19b#.gpu1l516z

你也可以从中获得有用的信息 documentaion

Answer 3

好吧，OP 标题要求浮动活动，但 OP 内容正在寻找一个浮动评论窗口，就像 Facebook 评论窗口一样。

因此，在这里这将由 DialogFragment 实现，它为我们提供了每当您向上或向下滑动时自动将对话框弹回其原始状态/窗口大小的行为。当对话框被轻轻滑动时（精确滑动的距离小于原始布局大小的一半），这种行为会保持不变。

剩下的就是如果它的大小小于原始窗口大小的一半，它就会关闭这个对话框；换句话说，如果它的滑动大于原始布局大小的一半。通过更改对话框窗口根布局的唯一 Y 位置，并且不更改窗口大小，因为这提供了奇怪的调整大小行为。

首先创建此样式以使对话框窗口具有透明背景：

<style name="NoBackgroundDialogTheme" parent="Theme.AppCompat.Light.Dialog">
    <item name="android:windowBackground">@null</item>
</style>

此样式将通过覆盖 getTheme() 方法应用于 DialogFragment。

这是自定义的 DialogFragment：


class MyDialogFragment : DialogFragment(), View.OnTouchListener {

    private var rootLayoutY: Int = 0
    private val rootLayout by lazy {
        requireView().findViewById<ConstraintLayout>(R.id.dialog_root)
    }

    private var oldY = 0
    private var baseLayoutPosition = 0
    private var defaultViewHeight = 0
    private var isScrollingUp = false
    private var isScrollingDown = false

    override fun getTheme(): Int {
        return R.style.NoBackgroundDialogTheme
    }

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        val view: View = inflater.inflate(
            R.layout.fragment_dialog_facebook_comment, container,
            false
        )
        view.setBackgroundResource(R.drawable.rounded_background)

        return view
    }

    override fun onStart() {
        super.onStart()
        // Making the dialog full screen
        dialog?.window?.setLayout(
            LinearLayout.LayoutParams.MATCH_PARENT,
            LinearLayout.LayoutParams.MATCH_PARENT
        )
    }

    @SuppressLint("ClickableViewAccessibility")
    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        rootLayout.setOnTouchListener(this)

        rootLayout.viewTreeObserver.addOnGlobalLayoutListener(object :
            OnGlobalLayoutListener {
            override fun onGlobalLayout() {
                rootLayout.viewTreeObserver
                    .removeOnGlobalLayoutListener(this)
                // save default base layout height
                defaultViewHeight = rootLayout.height
            }
        })

    }

    @SuppressLint("ClickableViewAccessibility")
    override fun onTouch(v: View?, event: MotionEvent?): Boolean {
        // Get finger position on screen
        val y = event!!.rawY.toInt()


        // Switch on motion event type
        when (event.action and MotionEvent.ACTION_MASK) {

            MotionEvent.ACTION_DOWN -> {

                // Init finger and view position
                oldY = y
                baseLayoutPosition = rootLayout.y.toInt()
            }

            MotionEvent.ACTION_UP -> {

                if (rootLayoutY >= defaultViewHeight / 2) {
                    dismiss()
                    return true
                }

                // If user was doing a scroll up
                if (isScrollingUp) {
                    // Reset baselayout position
                    rootLayout.y = 0f
                    // We are not in scrolling up mode anymore
                    isScrollingUp = false
                }

                // If user was doing a scroll down
                if (isScrollingDown) {
                    // Reset baselayout position
                    rootLayout.y = 0f
                    //  Reset base layout size
                    rootLayout.layoutParams.height = defaultViewHeight
                    rootLayout.requestLayout()
                    // We are not in scrolling down mode anymore
                    isScrollingDown = false
                }

            }

            MotionEvent.ACTION_MOVE -> {

                rootLayoutY = abs(rootLayout.y.toInt())

                // Change base layout size and position (must change position because view anchor is top left corner)
                rootLayout.y = rootLayout.y + (y - oldY)

                if (oldY > y) { // scrolling up
                    if (!isScrollingUp) isScrollingUp = true
                } else { // Scrolling down
                    if (!isScrollingDown) isScrollingDown = true
                }

                // Update y position
                oldY = y
            }
        }
        return true
    }


}

就我而言，对话框的根布局是 ConstraintLayout。

Android浮动活动，在滑动时关闭

3 个答案: