Question

I have defined my custom view with the only onMeasure() overridden:

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    setMeasuredDimension((int)(iwidth * cellWidth), (int)(iheight * cellHeight));
}

used variables are class members which are set by one single setter named setStep().

I change it with button:

button.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {

            float step = hidingPanel.getStep();

            step += stepstep;

            hidingPanel.setStep(step);
            hidingPanel.invalidate();

            setTextButton();
        }

    });

The layout is following

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>

<com.inthemoon.incubation.HidingPanel
    android:id="@+id/hidingPanel"
    android:background="@android:color/darker_gray"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:layout_alignParentTop="true"
    android:layout_alignParentLeft="true"
    android:layout_marginTop="0dp"
    android:layout_marginLeft="0dp"
    />

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
    android:layout_alignParentBottom="true"
    android:background="@android:color/black" 
    >
    <Button
        android:id="@+id/button"
        android:layout_width="200dp"
        android:layout_height="100dp" 
        />    
</LinearLayout>



</RelativeLayout>

where HidingPanel is my custom view.

I was expecting that my view will grow on button press but it doesn’t. I found that onMeasure() is called only few times at the beginning, when dimensions are zero. How to promote measuring later, on button click?

Answer 1

You need to call requestLayout(); on the parent of the View.