Android custom imageview with zoom and scroll -
i trying create image view zoom , scroll. checked many solutions on internet , didn't accurate result. current imageview having scroll property.need add zoom.
public class mapview extends imageview { private gesturedetectorcompat gesturedetector; private overscroller overscroller; private final int screenw; private final int screenh; private int positionx = 0; private int positiony = 0; public mapview(context context) { super(context); // need screen dimensions make sure don't on scroll image displaymetrics dm = getresources().getdisplaymetrics(); screenw = dm.widthpixels; screenh = dm.heightpixels; gesturedetector = new gesturedetectorcompat(context, gesturelistener); overscroller = new overscroller(context); } @override public boolean ontouchevent(motionevent event) { gesturedetector.ontouchevent(event); return true; } @override public void computescroll() { super.computescroll(); // computescrolloffset() returns true when scrolling isn't // finished if (overscroller.computescrolloffset()) { positionx = overscroller.getcurrx(); positiony = overscroller.getcurry(); scrollto(positionx, positiony); } else { // when scrolling over, want "spring back" if // image overscrolled overscroller.springback(positionx, positiony, 0, getmaxhorizontal(), 0, getmaxvertical()); } } private int getmaxhorizontal() { return (math.abs(getdrawable().getbounds().width() - screenw)); } private int getmaxvertical() { return (math.abs(getdrawable().getbounds().height() - screenh)); } private simpleongesturelistener gesturelistener = new simpleongesturelistener() { @override public boolean ondown(motionevent e) { overscroller.forcefinished(true); viewcompat.postinvalidateonanimation(mapview.this); return true; } @override public boolean onfling(motionevent e1, motionevent e2, float velocityx, float velocityy) { overscroller.forcefinished(true); overscroller.fling(positionx, positiony, (int) -velocityx, (int) -velocityy, 0, getmaxhorizontal(), 0, getmaxvertical()); viewcompat.postinvalidateonanimation(mapview.this); return true; } @override public boolean onscroll(motionevent e1, motionevent e2, float distancex, float distancey) { overscroller.forcefinished(true); // normalize scrolling distances not overscroll image int dx = (int) distancex; int dy = (int) distancey; int newpositionx = positionx + dx; int newpositiony = positiony + dy; if (newpositionx < 0) { dx -= newpositionx; } else if (newpositionx > getmaxhorizontal()) { dx -= (newpositionx - getmaxhorizontal()); } if (newpositiony < 0) { dy -= newpositiony; } else if (newpositiony > getmaxvertical()) { dy -= (newpositiony - getmaxvertical()); } overscroller.startscroll(positionx, positiony, dx, dy, 0); viewcompat.postinvalidateonanimation(mapview.this); return true; } }; } can pointers on this?
you might wish check out open source lib: https://github.com/ozeetee/androidimagezoomcrop
it need , way more quite easy trim down need
