1. activity_main.xml
<AbsoluteLayout 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"
tools:context=".MainActivity" >
<com.example.app3.GalleryDemo
android:id="@+id/gallery1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_x="10dp"
android:layout_y="10dp"
android:spacing="25dp"/>
<com.example.app3.TouchImageView
android:id="@+id/imageView1"
android:layout_width="340dp"
android:layout_height="350dp"
android:layout_x="7dp"
android:layout_y="180dp"
android:src="@drawable/a" />
</AbsoluteLayout>
2. TouchImageView.java
import android.content.Context;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;
import android.widget.ImageView;
public class TouchImageView extends ImageView {
Matrix matrix;
// We can be in one of these 3 states
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;
// Remember some things for zooming
PointF last = new PointF();
PointF start = new PointF();
float minScale = 1f;
float maxScale = 3f;
float[] m;
int viewWidth, viewHeight;
static final int CLICK = 3;
float saveScale = 1f;
protected float origWidth, origHeight;
int oldMeasuredWidth, oldMeasuredHeight;
ScaleGestureDetector mScaleDetector;
Context context;
public TouchImageView(Context context) {
super(context);
sharedConstructing(context);
}
public TouchImageView(Context context, AttributeSet attrs) {
super(context, attrs);
sharedConstructing(context);
}
private void sharedConstructing(Context context) {
super.setClickable(false);
this.context = context;
mScaleDetector = new ScaleGestureDetector(this.context,
new ScaleListener());
matrix = new Matrix();
m = new float[9];
setImageMatrix(matrix);
setScaleType(ScaleType.MATRIX);
setOnTouchListener(new OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
mScaleDetector.onTouchEvent(event);
PointF curr = new PointF(event.getX(), event.getY());
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
last.set(curr);
start.set(last);
mode = DRAG;
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) {
float deltaX = curr.x - last.x;
float deltaY = curr.y - last.y;
float fixTransX = getFixDragTrans(deltaX, viewWidth,
origWidth * saveScale);
float fixTransY = getFixDragTrans(deltaY, viewHeight,
origHeight * saveScale);
matrix.postTranslate(fixTransX, fixTransY);
fixTrans();
last.set(curr.x, curr.y);
}
break;
case MotionEvent.ACTION_UP:
mode = NONE;
int xDiff = (int) Math.abs(curr.x - start.x);
int yDiff = (int) Math.abs(curr.y - start.y);
if (xDiff < CLICK && yDiff < CLICK)
performClick();
break;
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
break;
}
setImageMatrix(matrix);
invalidate();
return true; // indicate event was handled
}
});
}
public void setMaxZoom(float x) {
maxScale = x;
}
private class ScaleListener extends
ScaleGestureDetector.SimpleOnScaleGestureListener {
@Override
public boolean onScaleBegin(ScaleGestureDetector detector) {
mode = ZOOM;
return true;
}
@Override
public boolean onScale(ScaleGestureDetector detector) {
float mScaleFactor = detector.getScaleFactor();
float origScale = saveScale;
saveScale *= mScaleFactor;
if (saveScale > maxScale) {
saveScale = maxScale;
mScaleFactor = maxScale / origScale;
} else if (saveScale < minScale) {
saveScale = minScale;
mScaleFactor = minScale / origScale;
}
if (origWidth * saveScale <= viewWidth
|| origHeight * saveScale <= viewHeight)
matrix.postScale(mScaleFactor, mScaleFactor, viewWidth / 2,
viewHeight / 2);
else
matrix.postScale(mScaleFactor, mScaleFactor,
detector.getFocusX(), detector.getFocusY());
fixTrans();
return true;
}
}
void fixTrans() {
matrix.getValues(m);
float transX = m[Matrix.MTRANS_X];
float transY = m[Matrix.MTRANS_Y];
float fixTransX = getFixTrans(transX, viewWidth, origWidth * saveScale);
float fixTransY = getFixTrans(transY, viewHeight, origHeight
* saveScale);
if (fixTransX != 0 || fixTransY != 0)
matrix.postTranslate(fixTransX, fixTransY);
}
float getFixTrans(float trans, float viewSize, float contentSize) {
float minTrans, maxTrans;
if (contentSize <= viewSize) {
minTrans = 0;
maxTrans = viewSize - contentSize;
} else {
minTrans = viewSize - contentSize;
maxTrans = 0;
}
if (trans < minTrans)
return -trans + minTrans;
if (trans > maxTrans)
return -trans + maxTrans;
return 0;
}
float getFixDragTrans(float delta, float viewSize, float contentSize) {
if (contentSize <= viewSize) {
return 0;
}
return delta;
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
viewWidth = MeasureSpec.getSize(widthMeasureSpec);
viewHeight = MeasureSpec.getSize(heightMeasureSpec);
if (oldMeasuredHeight == viewWidth && oldMeasuredHeight == viewHeight
|| viewWidth == 0 || viewHeight == 0)
return;
oldMeasuredHeight = viewHeight;
oldMeasuredWidth = viewWidth;
if (saveScale == 1) {
float scale;
Drawable drawable = getDrawable();
if (drawable == null || drawable.getIntrinsicWidth() == 0
|| drawable.getIntrinsicHeight() == 0)
return;
int bmWidth = drawable.getIntrinsicWidth();
int bmHeight = drawable.getIntrinsicHeight();
Log.d("bmSize", "bmWidth: " + bmWidth + " bmHeight : " + bmHeight);
float scaleX = (float) viewWidth / (float) bmWidth;
float scaleY = (float) viewHeight / (float) bmHeight;
scale = Math.min(scaleX, scaleY);
matrix.setScale(scale, scale);
float redundantYSpace = (float) viewHeight
- (scale * (float) bmHeight);
float redundantXSpace = (float) viewWidth
- (scale * (float) bmWidth);
redundantYSpace /= (float) 2;
redundantXSpace /= (float) 2;
matrix.postTranslate(redundantXSpace, redundantYSpace);
origWidth = viewWidth - 2 * redundantXSpace;
origHeight = viewHeight - 2 * redundantYSpace;
setImageMatrix(matrix);
}
fixTrans();
}
}
3. GalleryDemo.java
import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.Gallery;
public class GalleryDemo extends Gallery {
public GalleryDemo(Context context, AttributeSet attrs) {
super(context, attrs);
}
public GalleryDemo(Context context) {
super(context);
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
// TODO Auto-generated method stub
return super.onFling(e1, e2, velocityX / 4, velocityY);
}
}
4. ImageAdapter.java
import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
public class ImageAdapter extends BaseAdapter {
private Context mContext;
private Integer width;
private Integer height;
private Integer[] mImageIds;
public ImageAdapter(Context c) {
mContext = c;
}
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView = new ImageView(mContext);
// 設定圖片來源
imageView.setImageResource(mImageIds[position]);
// 設定圖片的寬、高
imageView.setLayoutParams(new GalleryDemo.LayoutParams(width, height));
return imageView;
}
public Integer getHeight() {
return height;
}
public void setHeight(Integer height) {
this.height = height;
}
public Integer[] getmImageIds() {
return mImageIds;
}
public void setmImageIds(Integer[] mImageIds) {
this.mImageIds = mImageIds;
}
public Integer getWidth() {
return width;
}
public void setWidth(Integer width) {
this.width = width;
}
public int getCount() {
return mImageIds.length;
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
}
5. MainActivity.java
import android.app.Activity;
import android.os.Bundle;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Toast;
import android.view.Gravity;
import android.view.View;
public class MainActivity extends Activity {
private TouchImageView imageView;
private Integer[] mImageIds = { R.drawable.a, R.drawable.b, R.drawable.c,
R.drawable.d, R.drawable.e, R.drawable.f, R.drawable.g,
R.drawable.h, R.drawable.i };
private ImageAdapter imageAdapter;
private GalleryDemo gallery;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
imageView = (TouchImageView) this.findViewById(R.id.imageView1);
gallery = (GalleryDemo) findViewById(R.id.gallery1);
imageView.setMaxZoom(50f);
imageAdapter = new ImageAdapter(this);
imageAdapter.setmImageIds(mImageIds);
imageAdapter.setWidth(300);
imageAdapter.setHeight(350);
gallery.setAdapter(imageAdapter);
gallery.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView parent, View v, int position,
long id) {
imageView.setImageResource(mImageIds[position]);
Toast toast = Toast.makeText(getApplicationContext(),
"You have selected " + (+position + 1) + " picture",
Toast.LENGTH_LONG);
toast.setGravity(Gravity.CENTER_HORIZONTAL | Gravity.BOTTOM, 0,
-100);
toast.show();
}
});
}
}
註備 : 以上使用圖片解析度為1024x1024,本實作沒提供圖片,請自備圖片
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