Android：觸發MotionEvent.ACTION_CANCEL

要求：確保itemLookup僅在按鈕被保持至少1秒後才執行。當按鈕被保持3秒時停止按鈕事件，因此用於查找的記錄不會包含不必要的數據。Android：觸發MotionEvent.ACTION_CANCEL

問題：MotionEvent.ACTION_CANCEL即使調試確認TableLayoutForIntercept的onInterceptTouchEvent被調用之前MainActivity「稱爲s OnTouchListener事件，預期不會被調用。也許我不明白onInterceptTouchEvent的目的？我已看過有關此事的其他帖子，但所有人都在處理刷卡或拖動事件，而不是取消按鈕按。也許這不可行？

代碼：僅顯示MainActivity的相關部分，以及完整的TableLayoutForIntercept類，當然還有<com.company.myapplication.TableLayoutForIntercept></com.company.myapplication.TableLayoutForIntercept>標記環繞着我的xml佈局。

public class MainActivity extends Activity { 

    //... 

    DateTime recordingStartedTime; 
    DateTime recordingEndedTime; 
    boolean buttonHeldLongEnough = false; 

    PackageManager pm = getPackageManager(); 
    boolean micPresent = pm.hasSystemFeature(PackageManager.FEATURE_MICROPHONE); 

    if (micPresent) { 
     recordBtn.setOnTouchListener(new View.OnTouchListener() { 

      @Override 
      public boolean onTouch(View recordView, MotionEvent recordEvent) { 

       switch (recordEvent.getAction()) { 

        case MotionEvent.ACTION_DOWN: 
         // Try to record audio 
         try { 
          recordingOff.setVisibility(View.INVISIBLE); 
          recordingOn.setVisibility(View.VISIBLE); 

          recordingStartedTime = DateTime.now(); 
          constructPrepareStartRecording(); 
         } 
         catch (Exception ex) { 
          Log.e(MainActivity.class.getSimpleName(), "An unknown error occurred."); 
         } 
         return true; 

        case MotionEvent.ACTION_UP: 
         recordingOff.setVisibility(View.VISIBLE); 
         recordingOn.setVisibility(View.INVISIBLE); 

         recordingEndedTime = DateTime.now(); 
         Seconds seconds = Seconds.secondsBetween(recordingStartedTime, recordingEndedTime); 
         int secondsButtonHeld = seconds.getSeconds(); 

         // Button must have been held at least 1 second before running itemLookup 
         if (secondsButtonHeld > 0) { 
          buttonHeldLongEnough = true; 
         } 
         else { 
          buttonHeldLongEnough = false; 
         } 

         // Need to release resources regardless 
         stopReleaseResetRecording(); 

         if (buttonHeldLongEnough) { 
          itemLookup(); 
         } 
         return true; 

        case MotionEvent.ACTION_CANCEL: 
         // I think this is the event I have to trigger to halt the button press 
         boolean codeHasHitCancel = true; 
         return codeHasHitCancel; 

       } 
       return false; 
      } 
     }); 
    } 
    else { 
     toastTitle = "Unable To Record"; 
     toastMessage = "Device microphone not found."; 
     toast = new GenericCustomToast(); 
     toast.show(toastTitle, toastMessage, MainActivity.this); 
    } 

    //... 
} 

public class TableLayoutForIntercept extends TableLayout { 

    public TableLayoutForIntercept (Context context) { 
     super(context); 
    } 

    public TableLayoutForIntercept (Context context, AttributeSet attrs) { 
     super(context, attrs); 
    } 

    private CancelPressTask cancelPressTask = null; 
    private boolean stopTouchEvent = false; 

    @Override 
    public boolean onInterceptTouchEvent (MotionEvent event) { 

     final int action = event.getAction(); 

     switch (action) { 

      case MotionEvent.ACTION_DOWN: 
       stopTouchEvent = false; 
       cancelPressTask = new CancelPressTask(); 
       break; 

      case MotionEvent.ACTION_CANCEL: 
      case MotionEvent.ACTION_UP: 
       cancelPressTask.resetCancelPressTimer(); 
       cancelPressTask.stopCancelPressTimer(); 
       return stopTouchEvent; 
     } 

     return super.onInterceptTouchEvent(event); 
    } 

    @Override 
    public boolean onTouchEvent (MotionEvent event) { 

     if (!stopTouchEvent) { 
     return super.onTouchEvent(event); 
     } 

     return true; 
    } 

    private class CancelPressTask { 

     public final long CANCEL_PRESS_TIMEOUT = 3000; // 3 seconds 

     private Handler cancelPressHandler = new Handler(){ 
      public void handleMessage(Message msg) { 
      } 
     }; 

     private Runnable cancelPressCallback = new Runnable() { 
      @Override 
      public void run() { 
       stopTouchEvent = true; 
      } 
     }; 

     public void resetCancelPressTimer(){ 
      cancelPressHandler.removeCallbacks(cancelPressCallback); 
      cancelPressHandler.postDelayed(cancelPressCallback, CANCEL_PRESS_TIMEOUT); 
     } 

     public void stopCancelPressTimer(){ 
      cancelPressHandler.removeCallbacks(cancelPressCallback); 
     } 
    } 
}

來源

2014-08-27 esme_louise

我想出了另一種方式來進行此事。而不是試圖觸發一個事件，我決定偷它而不是！下面的代碼將停止記錄，然後在3秒鐘後查找項目，無論用戶嘗試按下按鈕的時間長短。唯一的缺點是對於記錄太短（小於1秒）的記錄，它仍然需要全部3秒鐘通過吐司消息來通知用戶。但我願意接受這一點。

public class Main Activity extends Activity { 

     DateTime recordingStartedTime; 
     DateTime recordingEndedTime = null; 
     boolean buttonHeldLongEnough = false; 
     LimitRecordingTask limitRecordingTask; 

     PackageManager pm = getPackageManager(); 
     boolean micPresent = pm.hasSystemFeature(PackageManager.FEATURE_MICROPHONE); 

     if (micPresent) { 
      recordBtn.setOnTouchListener(new View.OnTouchListener() { 
       @Override 
       public boolean onTouch(View recordView, MotionEvent recordEvent) { 

        limitRecordingTask = new LimitRecordingTask(); 
        switch (recordEvent.getAction()) { 

         case MotionEvent.ACTION_DOWN: 
          // Try to record audio 
          try { 
           recordBtn.setBackgroundColor(Color.DKGRAY); 
           recordingOff.setVisibility(View.INVISIBLE); 
           recordingOn.setVisibility(View.VISIBLE); 

           recordingStartedTime = DateTime.now(); 
           constructPrepareStartRecording(); 
           limitRecordingTask.resetRecordingTimer(); 
          } 
          catch (Exception ex) { 
           Log.e(MainActivity.class.getSimpleName(), "An unknown error occurred."); 
           limitRecordingTask.stopRecordingTimer(); 
          } 
          return true; 

         case MotionEvent.ACTION_UP: 
          // After 3 seconds limitRecordingTask will 'steal' this event 
          recordBtn.setBackgroundResource(R.drawable.custom_button); 
          recordingOff.setVisibility(View.VISIBLE); 
          recordingOn.setVisibility(View.INVISIBLE); 

          recordingEndedTime = DateTime.now(); 
          Seconds seconds = Seconds.secondsBetween(recordingStartedTime, recordingEndedTime); 
          int secondsButtonHeld = Math.abs(seconds.getSeconds()); 

          if (secondsButtonHeld > 0) { 
           buttonHeldLongEnough = true; 
          } 
          else { 
           buttonHeldLongEnough = false; 
          } 
          return true; 
        } 
        return false; 
       } 
      }); 
     } 
     else { 
      toastTitle = "Unable To Record"; 
      toastMessage = "Device microphone not found."; 
      toast = new GenericCustomToast(); 
      toast.show(toastTitle, toastMessage, MainActivity.this); 
     } 

     private class LimitRecordingTask { 

      public final long RECORDING_TIMEOUT = 3000; // 3 seconds 

      private Handler limitRecordingHandler = new Handler(){ 
       public void handleMessage(Message msg) { 
       } 
      }; 

      private Runnable limitRecordingCallback = new Runnable() { 
       @Override 
       public void run() { 
        // 'Stolen' MotionEvent.ACTION_UP 
        recordBtn.setBackgroundResource(R.drawable.custom_button); 
        recordingOff.setVisibility(View.VISIBLE); 
        recordingOn.setVisibility(View.INVISIBLE); 

        if (recordingEndedTime == null) { 
         recordingEndedTime = DateTime.now(); 
        } 
        Seconds seconds = Seconds.secondsBetween(recordingStartedTime, recordingEndedTime); 
        int secondsButtonHeld = Math.abs(seconds.getSeconds()); 

        if (secondsButtonHeld > 0) { 
         buttonHeldLongEnough = true; 
        } 
        else { 
         buttonHeldLongEnough = false; 
        } 

        limitRecordingTask.stopRecordingTimer(); 

        stopReleaseResetRecording(); 
        itemLookup(); 
       } 
      }; 

      public void resetRecordingTimer(){ 
       limitRecordingHandler.removeCallbacks(limitRecordingCallback); 
       limitRecordingHandler.postDelayed(limitRecordingCallback, RECORDING_TIMEOUT); 
      } 

      public void stopRecordingTimer(){ 
       limitRecordingHandler.removeCallbacks(limitRecordingCallback); 
      } 
     } 
    }

來源

2014-08-28 18:52:28

Android：觸發MotionEvent.ACTION_CANCEL

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