Question

I am having some spacing trouble when building part of my UI programmatically in Android 4.0. I am trying to add stylized buttons to a stylized LinearLayout. To space the buttons equally, each one is wrapped in a LinearLayout with a weight of 1. I started with a layout defined in XML (somewhat of a proof of concept,) which renders like I expect:

<LinearLayout android:id="@+id/dialog_footer" 
        android:layout_width="500dp"
        android:layout_height="wrap_content"
        android:background="@drawable/dialog_footer">

    <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:orientation="horizontal"
            android:gravity="center">
        <Button android:id="@+id/cancel"
            style="@style/Button"
            android:layout_width="130dp"
            android:layout_height="38dp"
            android:text="Cancel" />
    </LinearLayout>

    <!-- Another LinearLayout with a nested Button like the one above -->

</LinearLayout>

To add buttons programmatically, I removed the inner LinearLayouts and put them in their own layout file that I can inflate and add to the outer LinearLayout in Java. It is nearly identical.

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:orientation="horizontal"
        android:gravity="center" >
    <Button android:id="@+id/button"
            style="@style/Button"
            android:layout_width="130dp"
            android:layout_height="38dp" />
</LinearLayout>

And this is roughly how I’m adding buttons in code:

LinearLayout dialogFooter = (LinearLayout)dialogView.findViewById(R.id.dialog_footer);
LinearLayout wrappedButton = (LinearLayout)getLayoutInflater().inflate(R.layout.dialog_button_wrapped, null);

Button button = (Button)wrappedButton.findViewById(R.id.button);
button.setText(R.string.button_one_text);

// button.setOnClickListener(...);

dialogFooter.addView(wrappedButton);

The buttons appear but now they are grouped together and shifted to the left. Is there something Android does when it parses a Layout that I would need to do myself if I’m adding to the dialog_footer? Since weights come into play here, I thought that calling setWeightSum() on the container I’m adding to (dialog_footer) might be necessary but that didn’t help. Does anyone have any ideas what might be causing the difference between the XML and Java approaches?

Answer 1

I believe this is your problem:

LinearLayout wrappedButton = (LinearLayout)getLayoutInflater().inflate(R.layout.dialog_button_wrapped, null);

The null should be replaced with the parent view , so that it will get the layoutParams you want to set for it .

Another thing is about the weight you set – you should set the width/height to 0px so that the weight won’t cause the layout process work in a weird/inefficient way .

BTW , you can remove the inner layout (that has the button) and use a single button instead. just set the layout_gravity there to center_horizontal .