Home › Uncategorized

Error of getLocationInWindow() and getLocationOnScreen()

The View class provide the methods to computes the coordinates:

getLocationInWindow (int[] location): Computes the coordinates of the view in its window.
getLocationOnScreen (int[] location): Computes the coordinates of the view on the screen.

In my experience, the returned x location is correct, but the y location is always error with a fixed offset. The offset various depends on devices and configuration.

To correct it, we can get the offset using the code, after view displayed:
DisplayMetrics displayMetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
int offsetY = displayMetrics.heightPixels - mainScreen.getMeasuredHeight();

offset of getLocationInWindow() and getLocationOnScreen()

package com.example.androidoffsetgetlocation; import android.os.Bundle; import android.app.Activity; import android.util.DisplayMetrics; import android.widget.ImageView; import android.widget.LinearLayout; import android.widget.TextView; public class MainActivity extends Activity { LinearLayout mainScreen; ImageView object; TextView textOnCreate, textOnWindowFocusChanged; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mainScreen = (LinearLayout)findViewById(R.id.mainscreen); object = (ImageView)findViewById(R.id.object); textOnCreate = (TextView)findViewById(R.id.textview1); textOnWindowFocusChanged = (TextView)findViewById(R.id.textview2); readLocation(textOnCreate, "onCreate()"); } @Override public void onWindowFocusChanged(boolean hasFocus) { // TODO Auto-generated method stub super.onWindowFocusChanged(hasFocus); readLocation(textOnWindowFocusChanged, "onWindowFocusChanged()"); } private void readLocation(TextView tv, String status){ DisplayMetrics displayMetrics = new DisplayMetrics(); getWindowManager().getDefaultDisplay().getMetrics(displayMetrics); int offsetX = displayMetrics.widthPixels - mainScreen.getMeasuredWidth(); int offsetY = displayMetrics.heightPixels - mainScreen.getMeasuredHeight(); int[] locationInWindow = new int[2]; object.getLocationInWindow(locationInWindow); int[] locationOnScreen = new int[2]; object.getLocationOnScreen(locationOnScreen); tv.setText( "\n" + status +"\n" + "getLocationInWindow() - " + locationInWindow[0] + " : " + locationInWindow[1] + "\n" + "getLocationOnScreen() - " + locationOnScreen[0] + " : " + locationOnScreen[1] + "\n" + "Offset x: y - " + offsetX + " : " + offsetY); } }

<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:orientation="vertical" android:id="@+id/mainscreen"> <ImageView android:id="@+id/object" android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/ic_launcher"/> <TextView android:id="@+id/textview1" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <TextView android:id="@+id/textview2" android:layout_width="wrap_content" android:layout_height="wrap_content"/> </LinearLayout>

_{-- Delivered by Feed43 service}

There is no other posts in this category.

Android Free for you

Error of getLocationInWindow() and getLocationOnScreen()

Related Posts

Post a Comment

Post a Comment

Popular