import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.os.Bundle;
import android.util.Log;
import android.view.Display;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.view.WindowManager;
import android.view.GestureDetector.OnGestureListener;
import android.view.ViewGroup.LayoutParams;
public class Timeline extends Activity {
ScrollableImageView scrollImageView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
WindowManager w = getWindowManager();
Display d = w.getDefaultDisplay();
scrollImageView = new ScrollableImageView(this,
BitmapFactory.decodeResource(getResources(), R.drawable.rocks),
d.getWidth(), d.getHeight(),
null);
setContentView(scrollImageView);
}
public boolean onTouchEvent(MotionEvent event) {
return scrollImageView.getGestureScanner().onTouchEvent(event);
}
class ScrollableImageView extends View {
int scrollRate = 40;
int scrollX = 0;
int scrollY = 0;
boolean scrollHorizontalEnabled = true;
boolean scrollVerticalEnabled = true;
Bitmap image;
Bitmap bufferImage;
int maxWidth;
int maxHeight;
int pictureWidth;
int pictureHeight;
Paint paint;
GestureDetector gestureScanner;
public ScrollableImageView(Context context, Bitmap image, int width,
int height, Paint paint) {
super(context);
this.image = image;
this.paint = paint;
bufferImage = Bitmap.createBitmap(image);
calculateSize(width, height);
createGestureListener();
}
public ScrollableImageView(Context context, Bitmap image,
int width, int height, Paint paint,
boolean scrollHorizontal, boolean scrollVertical) {
super(context);
this.image = image;
this.paint = paint;
this.scrollHorizontalEnabled = scrollHorizontal;
this.scrollVerticalEnabled = scrollVertical;
bufferImage = Bitmap.createBitmap(image);
calculateSize(width, height);
createGestureListener();
}
protected void calculateSize(int width, int height) {
//picture size
pictureWidth = image.getWidth();
pictureHeight = image.getHeight();
//window size
maxWidth = Math.min(pictureWidth, width);
maxHeight = Math.min(pictureHeight, height);
//layout size
setLayoutParams(new LayoutParams(pictureWidth, pictureHeight));
}
protected void createGestureListener(){
setGestureScanner(new GestureDetector(new OnGestureListener() {
public boolean onScroll(MotionEvent event1, MotionEvent event2,
float distanceX, float distanceY) {
handleScroll(distanceX, distanceY);
return true;
}
public boolean onDown(MotionEvent event) {
return true;
}
public boolean onFling(MotionEvent event1, MotionEvent event2,
float velocityX, float velocityY) {
return true;
}
public void onLongPress(MotionEvent event) {
//do nothing
}
public void onShowPress(MotionEvent event) {
//do nothing
}
public boolean onSingleTapUp(MotionEvent event) {
return true;
}
}));
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawBitmap(bufferImage, 0, 0, paint);
}
protected void handleScroll(float distX, float distY) {
int maxScrollX = Math.max(pictureWidth - maxWidth, 0);
int maxScrollY = Math.max(pictureHeight - maxHeight, 0);
//X-Axis
if(scrollHorizontalEnabled){
if (distX > 6.0) {
if (scrollX < maxScrollX - scrollRate) {
scrollX += scrollRate;
}
else {
scrollX = maxScrollX;
}
} else if (distX < -6.0) {
if (scrollX >= scrollRate) {
scrollX -= scrollRate;
}
else {
scrollX = 0;
}
}
}
//Y-AXIS
if(scrollVerticalEnabled){
if (distY > 6.0) {
if (scrollY < maxScrollY - scrollRate) {
scrollY += scrollRate;
}
else {
}
} else if (distY < -6.0) {
if (scrollY >= scrollRate) {
scrollY -= scrollRate;
}
else {
scrollY = 0;
}
}
}
//Swap image
if ((scrollX <= maxWidth) && (scrollY <= maxHeight)) {
swapImage();
invalidate();
}
}
protected void swapImage() {
bufferImage = Bitmap.createBitmap(image, scrollX, scrollY,
maxWidth, maxHeight);
}
/**
* @return the gestureScanner
*/
public GestureDetector getGestureScanner() {
return gestureScanner;
}
/**
* @param gestureScanner the gestureScanner to set
*/
public void setGestureScanner(GestureDetector gestureScanner) {
this.gestureScanner = gestureScanner;
}
}
}
http://www.anddev.org/scrolling_a_picture_horizontally_and_vertically-t3245.html
