Geltrude Geltrude - 2 months ago 28
Android Question

Custom Square LinearLayout. How?

I create my own class for the square layout:

public class SquareLayout extends LinearLayout{

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

public SquareLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}

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


@Override public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = MeasureSpec.getSize(heightMeasureSpec);
int size = width > height ? height : width;
setMeasuredDimension(size, size);
}


Then, in my xml:

...
<com.myApp.SquareLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_gravity="center_horizontal"
android:orientation="horizontal" >

<ImageView
android:id="@+id/cellImageView"
android:adjustViewBounds="true"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="2dp"
android:padding="2dp"
android:scaleType="centerCrop"
android:src="@drawable/image" />
</com.myApp.SquareLayout>
...


Nothing written more in my java code.
But instead if my layout and my Image, I see only a white rectangle...

What am I wrong?

Answer

// you forget to call super.onMeasure(widthMeasureSpec, widthMeasureSpec);

@Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

    super.onMeasure(widthMeasureSpec, widthMeasureSpec);
    int width = MeasureSpec.getSize(widthMeasureSpec);
    int height = MeasureSpec.getSize(heightMeasureSpec);
    int size = width > height ? height : width;
    setMeasuredDimension(size, size);

}

// xml file

<com.example.testapplication.SquareLayout
    android:id="@+id/layout"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:layout_gravity="center_horizontal"
    android:orientation="horizontal" >

    <ImageView
        android:id="@+id/cellImageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="2dp"
        android:adjustViewBounds="true"
        android:padding="2dp"
        android:scaleType="centerCrop"
        android:src="@drawable/ic_launcher" />

  </com.example.testapplication.SquareLayout>