Android gridview drag item

Public class draggridview extends gridview
{
Private string tag = "draggridview ";

Private int dragposition; // The position to start dragging.

Private int dropposition; // The Position of the end drag

Private int dragpointx; // The X coordinate relative to the item

Private int dragpointy; // y coordinate relative to item

Private int dragoffsetx;

Private int dragoffsety;

Private imageview dragimageview; // drag the preview of the item

Private windowmanager;

Private windowmanager. layoutparams windowparams;

Public draggridview (context)
{
Super (context );
}

Public draggridview (context, attributeset attrs)
{
Super (context, attrs );
}

@ Override
Public Boolean onintercepttouchevent (motionevent eV)
{
Log. D (TAG, "onintercepttouchevent" + super. onintercepttouchevent (EV ));
If (EV. getaction () = motionevent. action_down)
{
Int x = (INT) eV. getx ();
Int y = (INT) eV. Gety ();
Log. D (TAG, "x =" + x + "getrawx =" + eV. getrawx ());
Log. D (TAG, "Y =" + Y + "getrawy =" + eV. getrawy ());
Dragposition = dropposition = pointtoposition (x, y );
Log. I ("tag", "dragposition =" + dragposition );
If (dragposition = adapterview. invalid_position)
{
Return super. onintercepttouchevent (EV );
}
Log. D (TAG, "getfirstposition" + getfirstvisibleposition ());
View itemview = (View) getchildat (dragposition-getfirstvisibleposition ());
// Obtain the offset of the current point in the item, that is, the coordinate relative to the upper left corner of the item.
Log. D (TAG, "itemview. getleft =" + itemview. getleft () + ", itemview. gettop =" + itemview. gettop ());

Dragpointx = x-itemview. getleft (); // obtain the coordinates of the point to the left of the item.
Dragpointy = Y-itemview. gettop ();

// Coordinates in the upper left corner of the item. (x, y)
Dragoffsetx = (INT) (EV. getrawx ()-x );
Dragoffsety = (INT) (EV. getrawy ()-y );

Log. D (TAG, "dragpointx =" + dragpointx + ", dragpointy =" + dragpointy + ", dragoffsetx =" + dragoffsetx
+ ", Dragoffsety =" + dragoffsety );

// Solve problem 3
// Destroy the cache once each time and regenerate a bitmap
Itemview. destroydrawingcache ();
Itemview. setdrawingcacheenabled (true );
Bitmap Bm = bitmap. createbitmap (itemview. getdrawingcache ());

// Create a thumbnail of the item
Startdrag (BM, x, y );
Return false;
}
Return super. onintercepttouchevent (EV );
}

Private void startdrag (Bitmap BM, int X, int y)
{
Stopdrag ();
Windowparams = new windowmanager. layoutparams ();
Log. I ("xqqlog", "X:" + x + "dragpointx:" + dragpointx + "dragoffsetx:" + dragoffsetx );
Windowparams. Gravity = gravity. Top | gravity. Left; // This parameter must be added.
// Obtain the coordinates of the upper left corner of the preview relative to the screen.
Windowparams. x = x-dragpointx + dragoffsetx;
Windowparams. Y = Y-dragpointy + dragoffsety;
// Set the width and height
Windowparams. Height = windowmanager. layoutparams. wrap_content;
Windowparams. width = windowmanager. layoutparams. wrap_content;
Windowparams. Flags =
Windowmanager. layoutparams. flag_not_focusable | windowmanager. layoutparams. flag_not_touchable
| Windowmanager. layoutparams. flag_keep_screen_on | windowmanager. layoutparams. flag_layout_in_screen;

Windowparams. format = pixelformat. translucent;
Windowparams. windowanimations = 0;

Imageview IV = new imageview (getcontext ());
Iv. setimagebitmap (BM );
Windowmanager = (windowmanager) getcontext (). getsystemservice (context. window_service); // "window"

Windowmanager. addview (IV, windowparams );
Dragimageview = IV;

}

@ Override
Public Boolean ontouchevent (motionevent eV)
{
If (dragimageview! = NULL & dragposition! = Adapterview. invalid_position)
{

Switch (EV. getaction ())
{
Case motionevent. action_up:
Int UPX = (INT) eV. getx ();
Int upy = (INT) eV. Gety ();
Stopdrag ();
Ondrop (UPX, upy );
Break;

Case motionevent. action_move:
Int movex = (INT) eV. getx ();
Int Movey = (INT) eV. Gety ();
Log. D ("action_move", "action_move X" + movex + "Ev. getrawx =" + eV. getrawx ());
Ondrag (movex, Movey );
Break;

}
}
Return super. ontouchevent (EV );
}

Private void ondrag (int x, int y)
{
If (dragimageview! = NULL)
{
Windowparams. Alpha = 0.6f;

// X indicates the layout coordinate of the view relative to the edge.
// Dragpointx indicates the position on the left of the item
// Dragoffsetx indicates the position of the layout relative to the screen (0, 0)

// X-dragpointx = getleft ();
// Y-dragponity = gettop ();
Windowparams. x = x-dragpointx + dragoffsetx;
Windowparams. Y = Y-dragpointy + dragoffsety;
Windowmanager. updateviewlayout (dragimageview, windowparams );
}
}

Private void ondrop (int x, int y)
{
Int tempposition = pointtoposition (x, y );
If (tempposition! = Adapterview. invalid_position)
{
Dropposition = tempposition;
}
If (dropposition! = Dragposition)
{
System. Out. println ("dragposition:" + dragposition + "dropposition:" + dropposition );
Imageadapter adapter = (imageadapter) This. getadapter ();
Adapter. Exchange (dragposition, dropposition );

// Solve problem 3
/*
* Viewgroup itemview1 = (viewgroup) getchildat (dragposition-
* Getfirstvisibleposition (); viewgroup itemview2 =
* (Viewgroup) getchildat (dropposition-getfirstvisibleposition ());
* Itemview1.destroydrawingcache (); itemview2.destroydrawingcache ();
*/
}
}

Private void stopdrag ()
{
If (dragimageview! = NULL)
{
Windowmanager. removeview (dragimageview );
Dragimageview = NULL;
}

}

}