getHeight returns 0 for all Android UI objects
I'm building a UI, and it's all static defined in the XML. All of it has weights all over the place, and while it looks right, I wanted to see that things actually have the right height and all. The problem is that no matter where I call .getHeight() for my format layout I got 0. I tried in both onCreate() and onStart(). Same thing. Happens for all UI objects too. Any idea?
package com.app.conekta;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.Window;
import android.widget.Button;
import android.widget.FrameLayout;
import android.widget.Toast;
public class Conekta extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
requestWindowFeature(Window.FEATURE_NO_TITLE);
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
@Override
public void onStart() {
super.onStart();
}
@Override
public void onResume() {
super.onResume();
FrameLayout fl1 = (FrameLayout) findViewById(R.id.headerFrameLayout);
FrameLayout fl2 = (FrameLayout) findViewById(R.id.footerFrameLayout);
Button b=(Button) findViewById(R.id.searchButton);
Log.d("CONEKTA", String.valueOf(b.getHeight()));
}
}
XML:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<FrameLayout
android:id="@+id/headerFrameLayout"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="0.05"
android:background="#597eAA" >
<ImageView
android:id="@+id/logoImage"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#7ba1d1"
android:src="@drawable/logo_conekta" />
</FrameLayout>
<LinearLayout
android:id="@+id/bodyLinearLayout"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="0.7"
android:background="#f3f3f3"
android:orientation="horizontal" >
<FrameLayout
android:id="@+id/leftBlankFrameLayout"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_weight="0.15"
android:background="#f3f3f3" >
</FrameLayout>
<LinearLayout
android:id="@+id/centerVerticalLayout"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_weight="0.7"
android:orientation="vertical" >
<FrameLayout
android:id="@+id/topCenterFrameLayout"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="0.35" >
</FrameLayout>
<TextView
android:id="@+id/venueLabel"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="0.025"
android:text="What are you looking for?"
android:textAppearance="?android:attr/textAppearanceMedium"
android:textColor="#000000" />
<EditText
android:id="@+id/venueTextField"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="0.025" >
<requestFocus />
</EditText>
<FrameLayout
android:id="@+id/middleCenterFrameLayout"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="0.05" >
</FrameLayout>
<TextView
android:id="@+id/locationLabel"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="0.025"
android:text="Where?"
android:textAppearance="?android:attr/textAppearanceMedium"
android:textColor="#000000" />
<AutoCompleteTextView
android:id="@+id/locationTextField"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="0.025"
android:text="" />
<LinearLayout
android:id="@+id/buttonLinearLayout"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="0.05"
android:background="#f3f3f3"
android:orientation="horizontal" >
<FrameLayout
android:id="@+id/leftButtonLinearLayout"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_weight="0.1" >
</FrameLayout>
<Button
android:id="@+id/searchButton"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_weight="0.8"
android:background="#6fa8dc"
android:text="Search" />
<FrameLayout
android:id="@+id/rightButtonLinearLayout"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_weight="0.1" >
</FrameLayout>
</LinearLayout>
<FrameLayout
android:id="@+id/bottomCenterFrameLayout"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="0.35" >
</FrameLayout>
</LinearLayout>
<FrameLayout
android:id="@+id/rightBlankFrameLayout"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_weight="0.15"
android:background="#f3f3f3" >
</FrameLayout>
</LinearLayout>
<FrameLayout
android:id="@+id/footerFrameLayout"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="0.15"
android:background="#7ba1d1" >
</FrameLayout>
</LinearLayout>
Answer
It's 0 because in both onCreate and onStart, the view hasn't actually been drawn yet. You can get around this by listening for when the view is actually drawn:
final TextView tv = (TextView)findViewById(R.id.venueLabel);
final ViewTreeObserver observer= tv.getViewTreeObserver();
observer.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
tv.getHeight()
observer.removeGlobalOnLayoutListener(this);
}
});
The call to remove the listener is there to prevent repeated invocations of your custom handler on layout changes... if you want to get those, you can omit it.