繁体   English   中英

使用 Android 检测长按

[英]Detecting a long press with Android

我目前正在使用

onTouchEvent(MotionEvent event){
}

检测用户何时按下我的 glSurfaceView 有没有一种方法可以检测何时进行了长按。 我猜如果我在开发文档中找不到太多内容,那么这将是某种解决方法。 类似于注册 ACTION_DOWN 并查看 ACTION_UP 之前的时间。

你如何使用opengl-es检测android上的长按?

GestureDetector是最好的解决方案。

这是一个有趣的选择。 在每个ACTION_DOWN 的onTouchEvent 中,安排一个 Runnable 在 1 秒内运行。 在每个ACTION_UPACTION_MOVE 上,取消预定的 Runnable。 如果ACTION_DOWN事件的取消发生不到 1,则 Runnable 将不会运行。

final Handler handler = new Handler(); 
Runnable mLongPressed = new Runnable() { 
    public void run() { 
        Log.i("", "Long press!");
    }   
};

@Override
public boolean onTouchEvent(MotionEvent event, MapView mapView){
    if(event.getAction() == MotionEvent.ACTION_DOWN)
        handler.postDelayed(mLongPressed, ViewConfiguration.getLongPressTimeout());
    if((event.getAction() == MotionEvent.ACTION_MOVE)||(event.getAction() == MotionEvent.ACTION_UP))
        handler.removeCallbacks(mLongPressed);
    return super.onTouchEvent(event, mapView);
}

试试这个:

final GestureDetector gestureDetector = new GestureDetector(new GestureDetector.SimpleOnGestureListener() {
    public void onLongPress(MotionEvent e) {
        Log.e("", "Longpress detected");
    }
});

public boolean onTouchEvent(MotionEvent event) {
    return gestureDetector.onTouchEvent(event);
};

我有一个检测点击、长点击和移动的代码。 这是上面给出的答案和我通过窥视每个文档页面所做的更改的相当组合。

//Declare this flag globally
boolean goneFlag = false;

//Put this into the class
final Handler handler = new Handler(); 
    Runnable mLongPressed = new Runnable() { 
        public void run() { 
            goneFlag = true;
            //Code for long click
        }   
    };

//onTouch code
@Override
    public boolean onTouch(View v, MotionEvent event) {
        switch (event.getAction()) {    
        case MotionEvent.ACTION_DOWN:
            handler.postDelayed(mLongPressed, 1000);
            //This is where my code for movement is initialized to get original location.
            break;
        case MotionEvent.ACTION_UP:
            handler.removeCallbacks(mLongPressed);
            if(Math.abs(event.getRawX() - initialTouchX) <= 2 && !goneFlag) {
                //Code for single click
                return false;
            }
            break;
        case MotionEvent.ACTION_MOVE:
            handler.removeCallbacks(mLongPressed);
            //Code for movement here. This may include using a window manager to update the view
            break;
        }
        return true;
    }

我确认它正在工作,因为我已经在我自己的应用程序中使用了它。

我创建了一个片段- 受实际 View 源的启发 - 可靠地检测具有自定义延迟的长按/按下。 但它在 Kotlin 中:

val LONG_PRESS_DELAY = 500

val handler = Handler()
var boundaries: Rect? = null

var onTap = Runnable {
    handler.postDelayed(onLongPress, LONG_PRESS_DELAY - ViewConfiguration.getTapTimeout().toLong())
}

var onLongPress = Runnable {

    // Long Press
}

override fun onTouch(view: View, event: MotionEvent): Boolean {
    when (event.action) {
        MotionEvent.ACTION_DOWN -> {
            boundaries = Rect(view.left, view.top, view.right, view.bottom)
            handler.postDelayed(onTap, ViewConfiguration.getTapTimeout().toLong())
        }
        MotionEvent.ACTION_UP, MotionEvent.ACTION_CANCEL -> {
            handler.removeCallbacks(onLongPress)
            handler.removeCallbacks(onTap)
        }
        MotionEvent.ACTION_MOVE -> {
            if (!boundaries!!.contains(view.left + event.x.toInt(), view.top + event.y.toInt())) {
                handler.removeCallbacks(onLongPress)
                handler.removeCallbacks(onTap)
            }
        }
    }
    return true
}

当您的意思是用户按下时,您的意思是点击吗? 点击是指用户按下然后立即抬起手指。 因此它包含两个 onTouch 事件。 您应该将 onTouchEvent 的使用保存在初始触摸或发布后发生的事情上。

因此,如果是点击,您应该使用 onClickListener。

您的回答是类似的:使用 onLongClickListener。

MSquare 的解决方案仅在您持有特定像素时才有效,但这对最终用户来说是不合理的期望,除非他们使用鼠标(他们不使用鼠标,他们使用手指)。

所以我为 DOWN 和 UP 动作之间的距离添加了一些阈值,以防中间有 MOVE 动作。

final Handler longPressHandler = new Handler();
Runnable longPressedRunnable = new Runnable() {
    public void run() {
        Log.e(TAG, "Long press detected in long press Handler!");
        isLongPressHandlerActivated = true;
    }
};

private boolean isLongPressHandlerActivated = false;

private boolean isActionMoveEventStored = false;
private float lastActionMoveEventBeforeUpX;
private float lastActionMoveEventBeforeUpY;

@Override
public boolean dispatchTouchEvent(MotionEvent event) {
    if(event.getAction() == MotionEvent.ACTION_DOWN) {
        longPressHandler.postDelayed(longPressedRunnable, 1000);
    }
    if(event.getAction() == MotionEvent.ACTION_MOVE || event.getAction() == MotionEvent.ACTION_HOVER_MOVE) {
        if(!isActionMoveEventStored) {
            isActionMoveEventStored = true;
            lastActionMoveEventBeforeUpX = event.getX();
            lastActionMoveEventBeforeUpY = event.getY();
        } else {
            float currentX = event.getX();
            float currentY = event.getY();
            float firstX = lastActionMoveEventBeforeUpX;
            float firstY = lastActionMoveEventBeforeUpY;
            double distance = Math.sqrt(
                    (currentY - firstY) * (currentY - firstY) + ((currentX - firstX) * (currentX - firstX)));
            if(distance > 20) {
                longPressHandler.removeCallbacks(longPressedRunnable);
            }
        }
    }
    if(event.getAction() == MotionEvent.ACTION_UP) {
        isActionMoveEventStored = false;
        longPressHandler.removeCallbacks(longPressedRunnable);
        if(isLongPressHandlerActivated) {
            Log.d(TAG, "Long Press detected; halting propagation of motion event");
            isLongPressHandlerActivated = false;
            return false;
        }
    }
    return super.dispatchTouchEvent(event);
}

这个想法是为将来执行长按创建一个Runnable ,但是这个执行可以因为点击或移动而被取消。

您还需要知道,何时消耗了长按,以及何时因手指移动过多而取消。 我们使用initialTouchXinitialTouchY来检查用户是否退出一个 10 像素的正方形区域,每边 5。

这是我使用OnTouchListener ListView Cell中的Click & LongClick 委托Activity完整代码:

    ClickDelegate delegate; 
    boolean goneFlag = false;
    float initialTouchX;
    float initialTouchY;
    final Handler handler = new Handler();
    Runnable mLongPressed = new Runnable() {
        public void run() {
            Log.i("TOUCH_EVENT", "Long press!");
            if (delegate != null) {
                goneFlag = delegate.onItemLongClick(index);
            } else {
                goneFlag = true;
            }
        }
    };

    @OnTouch({R.id.layout})
    public boolean onTouch (View view, MotionEvent motionEvent) {
        switch (motionEvent.getAction()) {
            case MotionEvent.ACTION_DOWN:
                handler.postDelayed(mLongPressed, ViewConfiguration.getLongPressTimeout());
                initialTouchX = motionEvent.getRawX();
                initialTouchY = motionEvent.getRawY();
                return true;
            case MotionEvent.ACTION_MOVE:
            case MotionEvent.ACTION_CANCEL:
                if (Math.abs(motionEvent.getRawX() - initialTouchX) > 5 || Math.abs(motionEvent.getRawY() - initialTouchY) > 5) {
                    handler.removeCallbacks(mLongPressed);
                    return true;
                }
                return false;
            case MotionEvent.ACTION_UP:
                handler.removeCallbacks(mLongPressed);
                if (goneFlag || Math.abs(motionEvent.getRawX() - initialTouchX) > 5 || Math.abs(motionEvent.getRawY() - initialTouchY) > 5) {
                    goneFlag = false;
                    return true;
                }
                break;
        }
        Log.i("TOUCH_EVENT", "Short press!");
        if (delegate != null) {
            if (delegate.onItemClick(index)) {
                return false;
            }
        }
        return false;
    }

ClickDelegate是一个interface用于像Activity一样将点击事件发送到处理程序类

    public interface ClickDelegate {
        boolean onItemClick(int position);
        boolean onItemLongClick(int position);
    }

如果您需要委托行为,您需要做的就是在您的Activity或父View实现它:

public class MyActivity extends Activity implements ClickDelegate {

    //code...
    //in some place of you code like onCreate, 
    //you need to set the delegate like this:
    SomeArrayAdapter.delegate = this;
    //or:
    SomeViewHolder.delegate = this;
    //or:
    SomeCustomView.delegate = this;

    @Override
    public boolean onItemClick(int position) {
        Object obj = list.get(position);
        if (obj) {
            return true; //if you handle click
        } else {
            return false; //if not, it could be another event
        }
    }

    @Override
    public boolean onItemLongClick(int position) {
        Object obj = list.get(position);
        if (obj) {
            return true; //if you handle long click
        } else {
            return false; //if not, it's a click
        }
    }
}
setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {

                int action = MotionEventCompat.getActionMasked(event);


                switch (event.getAction()) {
                    case MotionEvent.ACTION_DOWN:
                        longClick = false;
                        x1 = event.getX();
                        break;

                    case MotionEvent.ACTION_MOVE:
                        if (event.getEventTime() - event.getDownTime() > 500 && Math.abs(event.getX() - x1) < MIN_DISTANCE) {
                            longClick = true;
                        }
                        break;

                    case MotionEvent.ACTION_UP:
                                if (longClick) {
                                    Toast.makeText(activity, "Long preess", Toast.LENGTH_SHORT).show();
                                } 
                }
                return true;
            }
        });

这是一种基于 MSquare 检测按钮长按的好主意的方法,它有一个附加功能:不仅是响应长按而执行的操作,而且该操作会重复执行,直到 MotionEvent.ACTION_UP 消息出现已收到。 在这种情况下,长按和短按操作是相同的,但它们可能不同。

请注意,正如其他人所报告的那样,删除回调以响应 MotionEvent.ACTION_MOVE 消息会阻止回调被执行,因为我的手指无法保持足够的静止。 我通过忽略该消息解决了该问题。

private void setIncrementButton() {
    final Button btn = (Button) findViewById(R.id.btn);
    final Runnable repeater = new Runnable() {
        @Override
        public void run() {
            increment();
            final int milliseconds = 100;
            btn.postDelayed(this, milliseconds);
        }
    };
    btn.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent e) {
            if (e.getAction() == MotionEvent.ACTION_DOWN) {
                increment();
                v.postDelayed(repeater, ViewConfiguration.getLongPressTimeout());
            } else if (e.getAction() == MotionEvent.ACTION_UP) {
                v.removeCallbacks(repeater);
            }
            return true;
        }
    });
}

private void increment() {
    Log.v("Long Press Example", "TODO: implement increment operation");   
}

选项:自定义检测器class

abstract public class
Long_hold
extends View.OnTouchListener
{
  public@Override boolean
  onTouch(View view, MotionEvent touch)
  {
    switch(touch.getAction())
    {
    case ACTION_DOWN: down(touch); return true;
    case ACTION_MOVE: move(touch);
    }
    return true;
  }

  private long
  time_0;
  private float
  x_0, y_0;

  private void
  down(MotionEvent touch)
  {
    time_0= touch.getEventTime();
    x_0= touch.getX();
    y_0= touch.getY();
  }

  private void
  move(MotionEvent touch)
  {
    if(held_too_short(touch) {return;}
    if(moved_too_much(touch)) {return;}

    long_press(touch);
  }
  abstract protected void
  long_hold(MotionEvent touch);
}

采用

private double
moved_too_much(MotionEvent touch)
{
  return Math.hypot(
      x_0 -touch.getX(),
      y_0 -touch.getY()) >TOLERANCE;
}

private double
held_too_short(MotionEvent touch)
{
  return touch.getEventTime()-time_0 <DOWN_PERIOD;
}

在哪里

  • TOLERANCE是最大容许运动

  • DOWN_PERIOD是必须按下的时间

import

static android.view.MotionEvent.ACTION_MOVE;
static android.view.MotionEvent.ACTION_DOWN;

在代码中

setOnTouchListener(new Long_hold()
  {
  protected@Override boolean
  long_hold(MotionEvent touch)
  {
    /*your code on long hold*/
  }
});

我找到了一个解决方案,它不需要定义可运行或其他东西,而且工作正常。

    var lastTouchTime: Long = 0

    // ( ViewConfiguration.#.DEFAULT_LONG_PRESS_TIMEOUT =500)
    val longPressTime = 500

    var lastTouchX = 0f
    var lastTouchY = 0f

    view.setOnTouchListener { v, event ->

        when (event.action) {
            MotionEvent.ACTION_DOWN -> {
                lastTouchTime = SystemClock.elapsedRealtime()
                lastTouchX = event.x
                lastTouchY = event.y
                return@setOnTouchListener true
            }
            MotionEvent.ACTION_UP -> {
                if (SystemClock.elapsedRealtime() - lastTouchTime > longPressTime
                        && Math.abs(event.x - lastTouchX) < 3
                        && Math.abs(event.y - lastTouchY) < 3) {
                    Log.d(TAG, "Long press")
                }
                return@setOnTouchListener true
            }
            else -> {
                return@setOnTouchListener false
            }
        }

    }

暂无
暂无

声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.

 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM