android - How to create an endeless / moveable Layout? "endless paper"-Metapher -

how create endless / movable layout, endless/movable in directions? want develop app create diagrams, , if diagram gets big want movable in directions.

i hope understandable.

with regards

@override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_draw);            _root = (viewgroup) findviewbyid(r.id.draw);         _view = new imageview(this);         _view.setimageresource(r.drawable.greenbutton);         bitmapdrawable bd=(bitmapdrawable) this.getresources().getdrawable(r.drawable.greenbutton);         int height=bd.getbitmap().getheight();         int width=bd.getbitmap().getwidth();          /*myscrollview myv = new myscrollview(this);         myv.setlayoutparams(_root.getlayoutparams());*/          relativelayout.layoutparams layoutparams=new relativelayout.layoutparams(height,width);         _view.setlayoutparams(layoutparams);          _view.setontouchlistener(new view.ontouchlistener() {             @override             public boolean ontouch(view v, motionevent event) {                 final int x = (int) event.getrawx();                 final int y = (int) event.getrawy();                 switch (event.getaction() & motionevent.action_mask) {                     case motionevent.action_down:                         relativelayout.layoutparams lparams = (relativelayout.layoutparams) v.getlayoutparams();                         _xdelta = x - lparams.leftmargin;                         _ydelta = y - lparams.topmargin;                         break;                     case motionevent.action_up:                         break;                     case motionevent.action_pointer_down:                         break;                     case motionevent.action_pointer_up:                         break;                     case motionevent.action_move:                         relativelayout.layoutparams layoutparams = (relativelayout.layoutparams) v.getlayoutparams();                         layoutparams.leftmargin = x - _xdelta;                         layoutparams.topmargin = y - _ydelta;                         layoutparams.rightmargin = -250;                         layoutparams.bottommargin = -250;                         v.setlayoutparams(layoutparams);                         break;                 }                 _root.invalidate();                 return true;             }         });         //myv.addview(_view);         _root.addview(_view); 

<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:orientation="horizontal"     tools:context=".draw">       <relativelayout         android:id="@+id/draw"         android:layout_width="match_parent"         android:layout_height="match_parent"         android:layout_weight="1"         android:background="@drawable/layout_grid">      </relativelayout>       <linearlayout         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_weight="5"         android:orientation="vertical">          <gridview             android:id="@+id/mostusedbar"             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:numcolumns="2"             android:layout_weight="1">         </gridview>         <gridview             android:id="@+id/elementbar"             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:numcolumns="2"             android:layout_weight="1"></gridview>         <gridview             android:id="@+id/relbar"             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:numcolumns="2"             android:layout_weight="1"></gridview>        </linearlayout>   </linearlayout> 

create custom view scrolls (do manually) , keep in 2 variables let's scrollx , scrolly (assume point @ top left point of screen). draw on top offset of scrollx , scrolly.

here code:

public class myscrollview extends view {     private int scrollx, scrolly;     private int pinpointx, pinpointy;      public myscrollview(context context)     {         super(context);          //initialize scroll @ top left edge of "paper"         scrollx = 0;         scrolly = 0;     }      public void ontouchevent(motionevent e)     {         switch (e.getaction())         {             case motionevent.action_down:                 //mark touch point                 pinpointx = (int) e.getx();                 pinpointy = (int) e.gety();                 break;             case motionevent.action_move:                 //scroll view                 scrollx += (int) e.getx() -pinpointx;                 scrolly += (int) e.gety() -pinpointy;                  //mark new point                 pinpointx = (int) e.getx();                 pinpointy = (int) e.gety();                 break;         }     }      @override     public void ondraw(canvas canvas)     {         super.ondraw(canvas);          //draw here offset of scrollx, scrolly     } } 

sorry may have made mistakes (mainly android's class names) wrote code on go, if u see minor mistake make sure correct it.

note code allow scroll "infinitely" @ least long scrollx , scrolly remain on int limits (from -2,147,483,648 2,147,483,647) can keep since nobody scroll far, i'd recommend applying limits make app more "perfect".

also i'm not sure think code may have issue if scroll negative side (leftwards , upwards - when scrollx and/or scrolly negative) may wrong.

if want include more views (like layout ask) make viewgroup don't have experience using that. showed logic follow it's attach code like.