The wanted scenario: My app has started and is visible. I press button A and want to display the width of button bMap. In short my not working method:
// Is called by button bQuestions' onClick
public void QuestionsButton(View v) {
Context context = getApplicationContext();
// getting button bMap
Button bMap = (Button)findViewById(R.id.bMap);
// getting the width of button bMap
int width = bMap.getMeasuredWidth(); // getWidht() also returns 0
CharSequence text = String.valueOf(width);
int duration = Toast.LENGTH_SHORT;
Toast.makeText(context, text, duration).show();
}
I know this question has been asked at least a million times, but in all those scenario's the getWidth() is called too soon. In my case it isn't as I have to press another existing button to call this method. Why does bMap still have a width of 0, long after it already exists?
What i did find out was that if i first press bMap en save the view as a variable, that it does work. But of course it's not an option to first let a button be pressed before the function of another button works.
Edit Complete implementation: MainscreenActivity.java:
package com.jswebcom.jeroensak.zuydopendag;
import android.content.Context;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.os.Build;
import android.widget.Button;
import android.widget.Toast;
public class MainscreenActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_mainscreen);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.commit();
}
}
public void ActivityButton(View v) {
Context context = getApplicationContext();
CharSequence text = "Activiteiten";
int duration = Toast.LENGTH_SHORT;
Toast.makeText(context, text, duration).show();
}
public void MapButton(View v) {
Context context = getApplicationContext();
CharSequence text = "Plattegrond";
int duration = Toast.LENGTH_SHORT;
Toast.makeText(context, text, duration).show();
}
public void InfoButton(View v) {
Context context = getApplicationContext();
CharSequence text = "Info";
int duration = Toast.LENGTH_SHORT;
Toast.makeText(context, text, duration).show();
}
public void QuizButton(View v) {
Context context = getApplicationContext();
CharSequence text = "Quizvraag";
int duration = Toast.LENGTH_SHORT;
Toast.makeText(context, text, duration).show();
}
public void QuestionsButton(View v) {
Context context = getApplicationContext();
Button bMap = (Button)findViewById(R.id.bMap);
int width = bMap.getMeasuredWidth();
CharSequence text = String.valueOf(width);
int duration = Toast.LENGTH_SHORT;
Toast.makeText(context, text, duration).show();
bMap.animate().translationX(v.getWidth());
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_mainscreen, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.activity_mainscreen, container, false);
return rootView;
}
}
}
activity_mainscreen.xml:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context=".MainscreenActivity$PlaceholderFragment"
android:weightSum="2"
android:padding="0dp"
android:id="@+id/container">
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1">
<Button
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_weight="1"
android:backgroundTint="#ff005baa"
android:background="#ff005baa"
android:text="@string/activiteiten"
android:textColor="#ffffff"
android:textSize="25sp"
android:id="@+id/bActivity"
android:onClick="ActivityButton" />
<Button
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_weight="1"
android:background="#ff66beff"
android:backgroundTint="#ff66beff"
android:text="@string/info"
android:textColor="#ffffff"
android:textSize="25sp"
android:onClick="InfoButton"
android:id="@+id/bInfo" />
<Button
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_weight="1"
android:backgroundTint="#ff0077c0"
android:background="#ff0077c0"
android:text="@string/vragen"
android:textColor="#ffffff"
android:textSize="25sp"
android:onClick="QuestionsButton"
android:id="@+id/bQuestions" />
</LinearLayout>
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1">
<Button
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_weight="1"
android:background="#ff66beff"
android:backgroundTint="#ff66beff"
android:text="@string/plattegrond"
android:textColor="#ffffff"
android:textSize="25sp"
android:onClick="MapButton"
android:id="@+id/bMap" />
<Button
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_weight="1"
android:background="#ff0077c0"
android:backgroundTint="#ff0077c0"
android:text="@string/quizvraag"
android:textColor="#ffffff"
android:textSize="25sp"
android:onClick="QuizButton"
android:id="@+id/bQuiz" />
<Button
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_weight="1"
android:background="#ffffffff"
android:id="@+id/bLogo" />
</LinearLayout>
