package irdc.ex04_23;
/* import相關class */
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.view.View;
import android.widget.AbsoluteLayout;
import android.widget.Button;
import android.widget.ImageView;
public class EX04_23 extends Activity
{
/* 相關變量聲明 */
private ImageView mImageView;
private Button mButton01;
private Button mButton02;
private AbsoluteLayout layout1;
private Bitmap bmp;
private int id=0;
private int displayWidth;
private int displayHeight;
private float scaleWidth=1;
private float scaleHeight=1;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
/* 載入main.xml Layout */
setContentView(R.layout.main);
/* 取得屏幕分辨率大小 */
DisplayMetrics dm=new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dm);
displayWidth=dm.widthPixels;
/* 屏幕高度須扣除下方Button高度 */
displayHeight=dm.heightPixels-80;
/* 初始化相關變量 */
bmp=BitmapFactory.decodeResource(getResources(),
R.drawable.ex04_23);
mImageView = (ImageView)findViewById(R.id.myImageView);
layout1 = (AbsoluteLayout)findViewById(R.id.layout1);
mButton01 = (Button)findViewById(R.id.myButton1);
mButton02 = (Button)findViewById(R.id.myButton2);
/* 縮小按鈕onClickListener */
mButton01.setOnClickListener(new Button.OnClickListener()
{
@Override
public void onClick(View v)
{
small();
}
});
/* 放大按鈕onClickListener */
mButton02.setOnClickListener(new Button.OnClickListener()
{
@Override
public void onClick(View v)
{
big();
}
});
}
/* 圖片縮小的method */
private void small()
{
int bmpWidth=bmp.getWidth();
int bmpHeight=bmp.getHeight();
/* 設置圖片縮小的比例 */
double scale=0.8;
/* 計算出這次要縮小的比例 */
scaleWidth=(float) (scaleWidth*scale);
scaleHeight=(float) (scaleHeight*scale);
/* 產生reSize後的Bitmap對象 */
Matrix matrix = new Matrix();
matrix.postScale(scaleWidth, scaleHeight);
Bitmap resizeBmp = Bitmap.createBitmap(bmp,0,0,bmpWidth,
bmpHeight,matrix,true);
if(id==0)
{
/* 如果是第一次按,就刪除原來默認的ImageView */
layout1.removeView(mImageView);
}
else
{
/* 如果不是第一次按,就刪除上次放大縮小所產生的ImageView */
layout1.removeView((ImageView)findViewById(id));
}
/* 產生新的ImageView,放入reSize的Bitmap對象,再放入Layout中 */
id++;
ImageView imageView = new ImageView(EX04_23.this);
imageView.setId(id);
imageView.setImageBitmap(resizeBmp);
layout1.addView(imageView);
setContentView(layout1);
/* 因爲圖片放到最大時放大按鈕會disable,所以在縮小時把他重設爲enable */
mButton02.setEnabled(true);
}
/* 圖片放大的method */
private void big()
{
int bmpWidth=bmp.getWidth();
int bmpHeight=bmp.getHeight();
/* 設置圖片放大的比例 */
double scale=1.25;
/* 計算這次要放大的比例 */
scaleWidth=(float)(scaleWidth*scale);
scaleHeight=(float)(scaleHeight*scale);
/* 產生reSize後的Bitmap對象 */
Matrix matrix = new Matrix();
matrix.postScale(scaleWidth, scaleHeight);
Bitmap resizeBmp = Bitmap.createBitmap(bmp,0,0,bmpWidth,
bmpHeight,matrix,true);
if(id==0)
{
/* 如果是第一次按,就刪除原來設置的ImageView */
layout1.removeView(mImageView);
}
else
{
/* 如果不是第一次按,就刪除上次放大縮小所產生的ImageView */
layout1.removeView((ImageView)findViewById(id));
}
/* 產生新的ImageView,放入reSize的Bitmap對象,再放入Layout中 */
id++;
ImageView imageView = new ImageView(EX04_23.this);
imageView.setId(id);
imageView.setImageBitmap(resizeBmp);
layout1.addView(imageView);
setContentView(layout1);
/* 如果再放大會超過屏幕大小,就把Button disable */
if(scaleWidth*scale*bmpWidth>displayWidth||
scaleHeight*scale*bmpHeight>displayHeight)
{
mButton02.setEnabled(false);
}
}
}