Layout的放大和缩小效果例子(ScaleAnimation)

一个Layout从中心放大和缩小的例子,直接上代码:
1.ScaleDialog.java文件

package cn.com;

import android.app.Activity;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;

public class ScaleDialog extends Activity implements OnClickListener {

	RelativeLayout layout_parent;
	
	Button scale_btn;

	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.first);

		scale_btn = (Button) findViewById(R.id.scale_btn);
		scale_btn.setOnClickListener(this);

		layout_parent = (RelativeLayout) findViewById(R.id.layout_parent);
	}

	@Override
	public void onClick(View v) {
		// TODO Auto-generated method stub
		switch (v.getId()) {
		case R.id.scale_btn:
			displayPage();
			v.setEnabled(false);
			break;
		case R.id.dismiss_btn:
			dismissPage();
			break;
		}

	}

	View layout;
	ImageView jobShadow;

	public void displayPage() {
		LayoutInflater inflater = (LayoutInflater) getSystemService(LAYOUT_INFLATER_SERVICE);
		layout = inflater.inflate(R.layout.second, null);
		layout.setId(Constant.KEY_LAYOUT_ID);
		jobShadow = (ImageView) layout.findViewById(R.id.jobShadow);

		Drawable ico = getResources().getDrawable(R.drawable.dbg);
		jobShadow.setBackgroundDrawable(ico);
		ico.mutate().setAlpha(200);

		LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
				LinearLayout.LayoutParams.FILL_PARENT,
				LinearLayout.LayoutParams.FILL_PARENT);
		layout_parent.addView(layout, layoutParams);

		findDialogView();

		// 显示layout进行缩放动画效果
		ScaleAnimationHelper scaleHelper = new ScaleAnimationHelper(this,
				Constant.KEY_FIRSTPAGE);
		scaleHelper.ScaleOutAnimation(layout);
	}

	public void removeLayout() {

		layout_parent.removeView(layout_parent
				.findViewById(Constant.KEY_LAYOUT_ID));
	}

	Button dismiss_btn;

	public void findDialogView() {
		dismiss_btn = (Button) findViewById(R.id.dismiss_btn);
		dismiss_btn.setOnClickListener(this);
	}

	public void dismissPage() {
		ScaleAnimationHelper scaleHelper = new ScaleAnimationHelper(this,
				Constant.KEY_SECONDPAGE);
		scaleHelper.ScaleInAnimation(layout);
		scale_btn.setEnabled(true);
	}
}

2. ScaleAnimationHelper.java的辅助类

package cn.com;

import android.content.Context;
import android.view.View;
import android.view.animation.AccelerateInterpolator;
import android.view.animation.Animation;
import android.view.animation.AnimationSet;
import android.view.animation.ScaleAnimation;

public class ScaleAnimationHelper {
	Context con;
	int order;

	public ScaleAnimationHelper(Context con, int order) {
		this.con = con;
		this.order = order;
	}

	DisplayNextView listener;
	ScaleAnimation myAnimation_Scale;
        //放大的类,不需要设置监听器
	public void ScaleOutAnimation(View view) {
		myAnimation_Scale = new ScaleAnimation(0.1f, 1.0f, 0.1f, 1f,
				Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF,
				0.5f);
		myAnimation_Scale.setInterpolator(new AccelerateInterpolator());
		AnimationSet aa = new AnimationSet(true);
		aa.addAnimation(myAnimation_Scale);
		aa.setDuration(500);

		view.startAnimation(aa);
	}

	public void ScaleInAnimation(View view) {
		listener = new DisplayNextView((ScaleDialog) con, order);
		myAnimation_Scale = new ScaleAnimation(1.0f, 0.0f, 1.0f, 0.0f,
				Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF,
				0.5f);
		myAnimation_Scale.setInterpolator(new AccelerateInterpolator());
               //缩小Layout的类,在动画结束需要从父View移除它
		myAnimation_Scale.setAnimationListener(listener);
		AnimationSet aa = new AnimationSet(true);
		aa.addAnimation(myAnimation_Scale);
		aa.setDuration(500);

		view.startAnimation(aa);
	}
}

3. DisplayNextView.java动画结束的监听类

package cn.com;

import android.app.Activity;
import android.view.animation.Animation;

public class DisplayNextView implements Animation.AnimationListener {

	Object obj;

	// 动画监听器的构造函数
	Activity ac;
	int order;

	public DisplayNextView(Activity ac, int order) {
		this.ac = ac;
		this.order = order;
	}

	public void onAnimationStart(Animation animation) {
	}

	public void onAnimationEnd(Animation animation) {
		doSomethingOnEnd(order);
	}

	public void onAnimationRepeat(Animation animation) {
	}

	private final class SwapViews implements Runnable {
		public void run() {
			switch (order) {
			case Constant.KEY_SECONDPAGE:
				((ScaleDialog) ac).removeLayout();
				break;
			}
		}
	}

	public void doSomethingOnEnd(int _order) {
		switch (_order) {
		
		case Constant.KEY_SECONDPAGE:
			((ScaleDialog) ac).layout_parent.post(new SwapViews());
			break;
		}
	}
}

4. Constant.java标识ID常量的类

package cn.com;

public class Constant {

	public final static int KEY_FIRSTPAGE = 1;
	
	public final static int KEY_SECONDPAGE = 2;
	
	public final static int KEY_LAYOUT_ID = 3;
}

5.first.xml文件

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:orientation="vertical" android:layout_width="fill_parent"
	android:layout_height="fill_parent" android:id="@+id/layout_parent">
	<Button android:text="Scale" android:id="@+id/scale_btn"
		android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
</RelativeLayout>

6.second.xml文件

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:layout_width="fill_parent" android:layout_height="fill_parent"
	android:id="@+id/jobContent">
	<ImageView android:layout_width="fill_parent"
		android:layout_height="fill_parent" android:id="@+id/jobShadow" />
	<Button android:layout_width="fill_parent" android:text="Dismiss"
		android:layout_marginTop="20dp" android:layout_height="wrap_content"
		android:src="@drawable/jobbg" android:layout_alignParentBottom="true"
		android:id="@+id/dismiss_btn" />
</RelativeLayout>