Android How to - Block draw measure layout thread

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The following code shows how to block draw measure layout thread.

Example

<?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" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:text="hello" />

    <com.java2s.SlowMeasureView
        android:id="@+id/slow_measure"
        android:layout_width="fill_parent"
        android:layout_height="30dp"
        android:background="#00ff00"
        android:text="slow measure" />

    <com.java2s.SlowLayoutView
        android:id="@+id/slow_layout"
        android:layout_width="fill_parent"
        android:layout_height="30dp"
        android:background="#0000ff"
        android:text="slow layout" />

    <com.java2s.SlowDrawView
        android:id="@+id/slow_draw"
        android:layout_width="fill_parent"
        android:layout_height="30dp"
        android:background="#ff0000"
        android:text="slow draw" />

</LinearLayout>

Java code

/*******************************************************************************
 * Copyright (c) 2012 Manning/*from w  w  w. jav a 2 s  .co m*/
 * See the file license.txt for copying permission.
 ******************************************************************************/

import android.content.Context;
import android.util.AttributeSet;
import android.widget.TextView;
import android.content.Context;
import android.util.AttributeSet;
import android.widget.TextView;

import android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.widget.TextView;
import android.app.Activity;
import android.os.Bundle;

public class MainActivity extends Activity {

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
  }
}
class ThreadUtils {

  private static final long DEFAULT_SLEEP_DURATION = 2500L;

  private ThreadUtils() {
  }

  public static void sleep() {
    sleep(DEFAULT_SLEEP_DURATION);
  }

  public static void sleep(long duration) {
    try {
      Thread.sleep(duration);
    } catch (InterruptedException e) {
      e.printStackTrace();
    }
  }

}


class SlowDrawView extends TextView {

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

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

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

  @Override
  protected void onDraw(Canvas canvas) {
    /*
     * Please remember this is just a hack for the purpose of the demonstration.
     * Do not block the main thread in production code as it may fire an
     * "Application Not Responding" dialog.
     */
    ThreadUtils.sleep();
    super.onDraw(canvas);
  }
}


class SlowLayoutView extends TextView {

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

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

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

  @Override
  protected void onLayout(boolean changed, int left, int top,
      int right, int bottom) {
    /*
     * Please remember this is just a hack for the purpose of the demonstration.
     * Do not block the main thread in production code as it may fire an
     * "Application Not Responding" dialog.
     */
    ThreadUtils.sleep();
    super.onLayout(changed, left, top, right, bottom);
  }
}



class SlowMeasureView extends TextView {

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

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

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

  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    /*
     * Please remember this is just a hack for the purpose of the demonstration.
     * Do not block the main thread in production code as it may fire an
     * "Application Not Responding" dialog.
     */
    ThreadUtils.sleep();
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
  }
}
/*******************************************************************************
 * Copyright (c) 2012 Manning
 * See the file license.txt for copying permission.
 ******************************************************************************/

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