setlayoutParams() throws an exception

Question

I'm working on a subClass that extends from RelativeLayout, and have a OnScaleGestureListener. I want that when you scale on the view, the height of this change(it's like scalaing, but resizing the object). But it takes me an exception that I don't know how can I interprete it.

My code is:

public class simpleOnScaleGestureListener extends SimpleOnScaleGestureListener {
    @Override
    public boolean onScale(ScaleGestureDetector detector) {
        tmpScale = detector.getCurrentSpan() / detector.getPreviousSpan();
        Log.d("DEBUG", ".getCurrentSpan() is "+detector.getCurrentSpan());
        Log.d("DEBUG", ".getPreviousSpan() is "+detector.getPreviousSpan());
        Log.d("DEBUG", ".getScaleFactor() is "+detector.getScaleFactor());
        scaling = true;
        RelativeLayout.LayoutParams params = new LayoutParams(kTicketWidth, (int) (getMeasuredHeight()*mScaleFactor));
        setLayoutParams(params);
        //invalidate();
        requestLayout();
    return true;
    }
    @Override
    public void onScaleEnd(ScaleGestureDetector detector) {
        mScaleFactor = detector.getCurrentSpan() / detector.getPreviousSpan();
        adjustTickets();
        //Expand Animation
        /*if (mScaleFactor >= kMinScale){
            ScaleAnimation anim = new ScaleAnimation(1, 1, mScaleFactor, 1);
            startAnimation(anim);
            tmpScale=1;
            adjustTickets();
        } else if (mScaleFactor < kMinScale){
            ScaleAnimation anim = new ScaleAnimation(1, 1, mScaleFactor, 1);
            startAnimation(anim);
            tmpScale = kMinScale;
            adjustTickets();
        }
        scaling = false;*/
        Log.d("SCALE", "Scale have ended");
    }
}

Also the exception that it takes to me is:

05-19 13:10:28.943: E/AndroidRuntime(15701): FATAL EXCEPTION: main
05-19 13:10:28.943: E/AndroidRuntime(15701): java.lang.ClassCastException: android.widget.RelativeLayout$LayoutParams cannot be cast to android.widget.LinearLayout$LayoutParams
05-19 13:10:28.943: E/AndroidRuntime(15701):    at android.widget.LinearLayout.measureVertical(LinearLayout.java:655)
05-19 13:10:28.943: E/AndroidRuntime(15701):    at android.widget.LinearLayout.onMeasure(LinearLayout.java:574)
05-19 13:10:28.943: E/AndroidRuntime(15701):    at android.view.View.measure(View.java:15190)

And another thing that I don't know why it happens is that mScaleFactor changes to 1.0 constantly, when it changes to 0.81464 or 1.28774 then it changes again to 1.0. Does anyone knows why this happens?

score 2 · Accepted Answer · answered May 19 '13 at 11:20

2

exception shows what's the problem

 android.widget.RelativeLayout$LayoutParams cannot be cast to android.widget.LinearLayout$LayoutParams

you are trying to cast a LinearLayout to RelativeLayout , check your XML file

answered May 19 '13 at 11:20

Arash GM

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In my XML file I only added my custom view, that it's the view that have the code that I posted. Inside that class I added three LinearLayouts, but the height that I'm chanching is the height of this custom view. – Gabriel Esteban May 19 '13 at 12:19

setlayoutParams() throws an exception

1 Answers1