Drag an image

Package com. test. time; import android. content. context; import android. graphics. bitmap; import android. graphics. bitmapFactory; import android. graphics. canvas; import android. graphics. paint; import android. util. attributeSet; import android. util. log; import android. view. motionEvent; import android. view. view; public class MyMapView extends View {Paint paint; float initx = 0; // the initial point of the image painting: float inity = 0; float lastx = 0; // The coordinate float lasty = 0 when the record is pressed; float movex = 0; // float movey = 0; float photoWidth; float photoHeight; float X; // float Y; float screenWidth; float screenHeigth; float drawx; // float drawy; WindowManager wm; Bitmap bt; public MyMapView (Context context, AttributeSet attrs) {super (context, attrs); init (context, attrs);} public MyMapView (Context context) {super (co Ntext); init (context, null);} private void init (Context context, AttributeSet attrs) {paint = new Paint (); wm = (Activity) context ). getWindowManager (); File file = new File ("/sdcard/test.jpg"); FileInputStream FCM; ByteArrayOutputStream output = null; byte [] result; try {FCM = new FileInputStream (file); output = new ByteArrayOutputStream (); byte [] buffer = new byte [1024*100]; int n = 0; while (-1! = (N = FCM. read (buffer) {output. write (buffer, 0, n);} result = output. toByteArray (); bt = BitmapFactory. decodeByteArray (result, 0, result. length);} catch (FileNotFoundException e) {// TODO Auto-generated catch blocke. printStackTrace ();} catch (IOException e) {// TODO Auto-generated catch blocke. printStackTrace ();} finally {} Display display = wm. getdefadisplay display (); screenWidth = display. getWidth (); screenHeigth = display. getHeight (); photoWidth = bt. getWidth (); photoHeight = bt. getHeight (); setClickable (true); setFocusableInTouchMode (true); X = screenWidth-photoWidth; Y = screenHeigth-photoHeight; initx = (screenWidth-photoWidth)/2; inity = (screenHeigth-photoHeight)/2;} @ Overridepublic boolean onTouchEvent (MotionEvent event) {// TODO Auto-generated method stubfloat dx; float dy; switch (event. getAction () {case MotionEvent. ACTION_DOWN: lastx = event. getX (); lasty = event. getY (); break; case MotionEvent. ACTION_MOVE: dx = event. getX ()-lastx; dy = event. getY ()-lasty; movex = dx; movey = dy; invalidate (); break; case MotionEvent. ACTION_UP: if (X <= 0) {initx + = movex; if (initx> 0) initx = 0; if (initx <X) {initx = X ;}} if (Y <= 0) {inity + = movey; if (inity> 0) inity = 0; if (inity <Y) {inity = Y ;}} movex = 0; movey = 0; invalidate (); break;} return super. onTouchEvent (event) ;}@ Overrideprotected void onDraw (Canvas canvas) {super. onDraw (canvas); if (X <= 0 & initx + movex> = 0) {// when X> 0, the screen width is sufficient to show the entire image, do not drag drawx = 0; // slide to the right} else if (X <= 0 & initx + movex <= X) {drawx = X ;} else if (X <= 0) {// slide the drawx = initx + movex;} else {drawx = initx ;} if (Y <= 0 & inity + movey> = 0) {drawy = 0;} else if (Y <= 0 & inity + movey <= Y) {drawy = Y;} else if (Y <= 0) {drawy = inity + movey;} else {drawy = inity;} canvas. drawBitmap (bt, drawx, drawy, paint );}

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}