Android Question [B4X] CLVSwipe Error

yiankos1

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Licensed User
Longtime User
I use Erel's [B4X] CLVSwipe and especially pull to refresh. If you try lib's example and don't add any item at listview and try left or right gesture at blank CLV, reproduces this error.
B4X:
Error occurred on line: 211 (CLVSwipe)
java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.Object java.lang.reflect.Method.invoke(java.lang.Object, java.lang.Object[])' on a null object reference
    at anywheresoftware.b4a.shell.Shell.runGoodChain(Shell.java:479)
    at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:293)
    at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:255)
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:144)
    at anywheresoftware.b4a.BA.raiseEvent(BA.java:176)
    at anywheresoftware.b4a.objects.TouchPanelCreator$TouchView.onInterceptTouchEvent(TouchPanelCreator.java:32)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2402)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2865)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2550)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2865)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2550)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2865)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2550)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2865)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2550)
    at com.android.internal.policy.DecorView.superDispatchTouchEvent(DecorView.java:559)
    at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1870)
    at android.app.Activity.dispatchTouchEvent(Activity.java:3236)
    at com.android.internal.policy.DecorView.dispatchTouchEvent(DecorView.java:521)
    at android.view.View.dispatchPointerEvent(View.java:10946)

211 line at clvSwipe is this:
B4X:
Private Sub TouchPanel_OnInterceptTouchEvent (Action As Int, X As Float, Y As Float, MotionEvent As Object) As Boolean
    If HandlingSwipe Or WaitingForRefreshToComplete Then Return True
    Select Action
        Case Base.TOUCH_ACTION_DOWN
            TouchXStart = X
            TouchYStart = Y
            HandlingSwipe = False
        Case Base.TOUCH_ACTION_MOVE
            Dim dx As Float = Abs(x - TouchXStart)
            Dim dy As Float = Abs(y - TouchYStart)
            If mPullToRefreshPanel.IsInitialized And mCLV.sv.ScrollViewOffsetY = 0 And y - TouchYStart > 3dip Then
                HandlingSwipe = True
                PullToRefreshSwipe = True
                mPullToRefreshPanel.Visible = True
                CloseLastSwiped
            Else If dy < 20dip And dx > 10dip Then
                If HandlingSwipe = False Then
                    Dim NewSwipeItem As Int = mCLV.FindIndexFromOffset(TouchYStart + mCLV.sv.ScrollViewOffsetY)  <-----------
                    If NewSwipeItem <> LastSwipedItem Then CloseLastSwiped
                    LastSwipedItem = NewSwipeItem
                End If
                HandlingSwipe = True
                PullToRefreshSwipe = False
            End If
    End Select
    Return HandlingSwipe
End Sub
 
Last edited:

yiankos1

Well-Known Member
Licensed User
Longtime User
Upvote 0

yiankos1

Well-Known Member
Licensed User
Longtime User
Can you upload the project?
I use Lib's example. I commented out line about inserting rows at clv. After that, if swipe left or right at blank clv, causes this bug.
 
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