ScrollView with damping effect, imitation QQ space

Fixes a bug that was known in the last version and works better

Package Com.okdai;

Import Android.content.Context;
Import Android.graphics.Rect;
Import Android.util.AttributeSet;
Import android.view.MotionEvent;
Import Android.widget.ImageView;
Import Android.widget.ScrollView;
Import Android.widget.Scroller;


/**
* ScrollView of damping effect
*/


public class Dampview extends ScrollView {
private static final int LEN = 0XC8;
private static final int DURATION = 500;
private static final int max_dy = 200;
Private Scroller Mscroller;
Touchtool tool;
int left, top;
Float StartX, Starty, CurrentX, currenty;
int IMAGEVIEWH;
int ROOTW, Rooth;
ImageView ImageView;
Boolean scrollertype;


Public Dampview (context context, AttributeSet attrs, int defstyle) {
Super (context, attrs, Defstyle);


}


Public Dampview (context context, AttributeSet Attrs) {
Super (context, attrs);
Mscroller = new Scroller (context);
}


Public Dampview (Context context) {
Super (context);


}


public void Setimageview (ImageView ImageView) {
This.imageview = ImageView;
}


@Override
protected int Computescrolldeltatogetchildrectonscreen (rect rect) {


return 0;
}


Private int[] Li = new int[2];
Private int[] Li2 = new int[2];
private float lastly;
Private Boolean startistop = true;


@Override
public boolean dispatchtouchevent (Motionevent event) {
Super.dispatchtouchevent (event);
int action = Event.getaction ();
if (!mscroller.isfinished ()) {
Return Super.ontouchevent (event);
}
CurrentX = Event.getx ();
CurrentY = Event.gety ();
Imageview.getlocationinwindow (LI);
Getlocationonscreen (LI2);
Imageview.gettop ();
Switch (action) {
Case Motionevent.action_down:
if (li[1]! = li2[1]) {//To determine when the touch is started, the ImageView is aligned with the top of the window
Startistop = false;
}
left = Imageview.getleft ();
top = Imageview.getbottom ();
ROOTW = GetWidth ();
Rooth = GetHeight ();
IMAGEVIEWH = Imageview.getheight ();
StartX = CurrentX;
Starty = CurrentY;
Tool = new Touchtool (Imageview.getleft (), Imageview.getbottom (), Imageview.getleft (),
Imageview.getbottom () + LEN);
Break
Case Motionevent.action_move:
if (!startistop && li[1] = = Li2[1]) {
Starty = CurrentY;
Startistop = true;
}
if (Imageview.isshown () && imageview.gettop () >= 0) {
if (tool! = NULL) {
int t = tool.getscrolly (currenty-starty);
if (!scrollertype && currenty < Lastly && imageview.getheight () > Imageviewh) {
ScrollTo (0, 0);
Imageview.getlocationinwindow (LI);
Getlocationonscreen (LI2);
Android.view.ViewGroup.LayoutParams params = Imageview.getlayoutparams ();
Params.height = t;
Imageview.setlayoutparams (params);
if (imageview.getheight () = = Imageviewh && li[1] = = Li2[1]) {
Scrollertype = true;
}
if (startistop && li[1]! = Li2[1]) {
Startistop = false;
}
}
if (t >= top && T <= imageview.getbottom () + LEN && li[1] = = li2[1] && currenty > Lastly) {
Android.view.ViewGroup.LayoutParams params = Imageview.getlayoutparams ();
Params.height = t;
Imageview.setlayoutparams (params);
}
}
Scrollertype = false;
}


lastly = CurrentY;
Break
Case MOTIONEVENT.ACTION_UP:
if (li[1] = = Li2[1]) {
Scrollertype = true;
Mscroller.startscroll (Imageview.getleft (), Imageview.getbottom (), 0-imageview.getleft (),
Imageviewh-imageview.getbottom (), DURATION);
Invalidate ();
}
Startistop = true;
Break
}


return true;
}


@Override
public void Computescroll () {
Super.computescroll ();
if (Mscroller.computescrolloffset ()) {
int x = Mscroller.getcurrx ();
int y = Mscroller.getcurry ();
Imageview.layout (0, 0, x + imageview.getwidth (), y);
Invalidate ();
if (!mscroller.isfinished () && scrollertype && y > Max_dy) {
Android.view.ViewGroup.LayoutParams params = Imageview.getlayoutparams ();
Params.height = y;
Imageview.setlayoutparams (params);
}
}
}


public class Touchtool {


private int StartX, starty;


Public Touchtool (int startX, int starty, int endx, int endY) {
Super ();
This.startx = StartX;
This.starty = Starty;
}


public int getscrollx (float dx) {
int xx = (int) (StartX + dx/2.5f);
return xx;
}


public int getscrolly (float dy) {
int yy = (int) (starty + dy/2.5f);
return yy;
}
}
}