gridview - Pull to refresh in Android without popular library -

i want implement pull-to-refresh in android app, don't want use pull-to-refresh library available on internet because slow gridview using. want implement hand, know how this? or methods should use gridview?

pullrefreshcontainerview.java

import android.content.context; import android.util.attributeset; import android.view.motionevent; import android.view.view; import android.view.viewgroup; import android.widget.linearlayout; import android.widget.listview; import android.widget.textview;  /**  * container listview can pulled refresh.  * create listview , refresh header automatically, can  * customize them using {@link #setlist(listview)} , {@link #setrefreshheader(view, int)}  * <p>  * use, put put listview. since not extend  * listview, must use {@link #getlist()} modify list or provide own.  * <p>  * actions of list, use {@link onchangestatelistener} {@link #setonchangestatelistener(onchangestatelistener)}.  * if want change how refresh header looks, should during these state changes.     */ public class pullrefreshcontainerview extends linearlayout {         /**      * interface listening when refresh container changes state.      */     public interface onchangestatelistener {         /**          * notifies listener when refresh view's state changes.          * @param container container contains header          * @param state state of header. may state_idle, state_ready,          *      or state_refreshing.          */         public void onchangestate(pullrefreshcontainerview container, int state);     }      /**      * state of refresh header when doing nothing or being pulled down slightly.      */     public static final int state_idle = 0;      /**      * state of refresh header when has been pulled down not enough start refreshing, ,      * has not yet been released.      */     public static final int state_pull = 1;      /**      * state of refresh header when has been pulled down enough start refreshing,      * has not yet been released.      */     public static final int state_release = 2;      /**      * state of refresh header when list should refreshing.      */     public static final int state_loading = 3;      private linearlayout mheadercontainer;     private view mheaderview;     private listview mlist;     private int mstate;     private onchangestatelistener monchangestatelistener;      private int refresh_view_height = 60;      /**      * creates new pull refresh container.      *       * @param context application context      */     public pullrefreshcontainerview(context context) {         super(context);         init(context);     }      /**      * creates new pull refresh container.      *       * @param context application context      * @param attrs xml attribute set      */     public pullrefreshcontainerview(context context, attributeset attrs) {         super(context, attrs);         init(context);     }      /**      * creates new pull refresh container.      *       * @param context application context      * @param attrs xml attribute set      * @param defstyle style view      */     public pullrefreshcontainerview(context context, attributeset attrs, int defstyle) {         super(context, attrs);         init(context);     }      private void init(context context) {         mstate = state_idle; // start out idle.          float densityfactor = context.getresources().getdisplaymetrics().density;         refresh_view_height *= densityfactor;          // don't want see fading edge on container.         setverticalfadingedgeenabled(false);         setverticalscrollbarenabled(false);          setorientation(linearlayout.vertical);          // set default list , header.         mheadercontainer = new linearlayout(context);         addview(mheadercontainer);         setrefreshviewheight(1);          textview headerview = new textview(context);         headerview.settext("default refresh header.");         setrefreshheader(headerview);          listview list = new listview(context);         setlist(list);     }      private boolean mscrollinglist = true;     private float mintercepty;     private int mlastmotiony;      @override     public boolean dispatchtouchevent (motionevent ev) {         float oldlasty = mintercepty;         mintercepty = ev.gety();          if (mstate == state_loading) {             return super.dispatchtouchevent(ev);         }          switch (ev.getaction()) {         case motionevent.action_down:             mlastmotiony = (int) ev.gety();             mscrollinglist = true;             return super.dispatchtouchevent(ev);          case motionevent.action_move:             if (mlist.getfirstvisibleposition() == 0                     && (mlist.getchildcount() == 0 || mlist.getchildat(0).gettop() == 0)) {                 if ((mintercepty - oldlasty > 5) || (mstate == state_pull) || (mstate == state_release)) {                     mscrollinglist = false;                     applyheaderheight(ev);                     return true;                 } else {                     mscrollinglist = true;                     return super.dispatchtouchevent(ev);                 }             } else if (mscrollinglist) {                 return super.dispatchtouchevent(ev);             } else {                 return super.dispatchtouchevent(ev);             }          case motionevent.action_up:         case motionevent.action_cancel:             if (mstate == state_release) {                 refresh();             } else {                 changestate(state_idle);             }              if (mscrollinglist) {                 return super.dispatchtouchevent(ev);             } else {                 return true;             }          default:             return super.dispatchtouchevent(ev);         }     }      private void applyheaderheight(motionevent ev) {         final int historysize = ev.gethistorysize();          if (historysize > 0) {             (int h = 0; h < historysize; h++) {                 int historicaly = (int) (ev.gethistoricaly(h));                 updaterefreshview(historicaly - mlastmotiony);             }         } else {             int historicaly = (int) ev.gety();             updaterefreshview(historicaly - mlastmotiony);         }     }      private void updaterefreshview(int height) {         if (height <= 0) {             return;         }          if ((refresh_view_height/4 <= mcurrefreshviewheight) && (mcurrefreshviewheight < refresh_view_height)) {             setrefreshviewheight(height);             changestate(state_pull);         } else if (mcurrefreshviewheight >= refresh_view_height) {             if (height > refresh_view_height) {                 height = (int) (refresh_view_height + (height - refresh_view_height) *  refresh_view_height * 1.0f/height);             }              setrefreshviewheight(height);             changestate(state_release);         } else {             setrefreshviewheight(height);         }     }      private int mcurrefreshviewheight = 60;     private void setrefreshviewheight(int height) {         if (mcurrefreshviewheight == height) {             return;         }          if (height == 1) {             mheadercontainer.setlayoutparams(new layoutparams(1, 1));         } else {             mheadercontainer.setlayoutparams(new layoutparams(layoutparams.match_parent, height));         }         mcurrefreshviewheight = height;     }      private void changestate(int state) {         switch (state) {         case state_idle:             setrefreshviewheight(1);             break;         case state_pull:             break;         case state_release:             break;         case state_loading:             setrefreshviewheight(refresh_view_height);             break;         }          mstate = state;          notifystatechanged();     }      /**      * sets list used in pull refresh container.      * @param list list use      */     public void setlist(listview list) {         if (mlist != null) {             removeview(mlist);         }         mlist = list;         if (mlist.getparent() != null) {             viewgroup parent = (viewgroup) mlist.getparent();             parent.removeview(mlist);         }          mlist.setlayoutparams(new linearlayout.layoutparams(layoutparams.match_parent, layoutparams.match_parent));         addview(mlist);     }      /**      * @return list inside pull refresh container      */     public listview getlist() {         return mlist;     }      /**      * sets view use refresh header.       * <p />      * header view view @ top show while list      * refreshing. usually, simple rectangle says "refreshing" , like.      * <p />      *       * @param headerview view use whole header.      */     public void setrefreshheader(view header) {         if (mheaderview != null) {             mheadercontainer.removeview(mheaderview);         }                 if (header == null) {             throw new runtimeexception("please supply non-null header container.");         }          mheadercontainer.addview(header, 0);         mheaderview = header;     }      public void refresh() {          changestate(state_loading);              }      /**      * notifies pull-to-refresh view refreshing complete.      * hide refreshing header.      */     public void completerefresh() {         changestate(state_idle);     }      /**      * notifies listener state has changed.      */     private void notifystatechanged() {         if (monchangestatelistener != null) {             monchangestatelistener.onchangestate(this, mstate);         }     }      /**      * @param listener listener notified when header state should change      */     public void setonchangestatelistener(onchangestatelistener listener) {         monchangestatelistener = listener;     } } 

how use usagedemoactivity.java

import java.util.arraylist; import java.util.timer; import java.util.timertask;  import com.dmobile.pulltorefresh.pullrefreshcontainerview.onchangestatelistener; import com.dmobile.pulltorefresh.r;  import android.app.activity; import android.os.bundle; import android.view.gravity; import android.view.viewgroup.layoutparams; import android.widget.arrayadapter; import android.widget.listview; import android.widget.textview;  public class usagedemoactivity extends activity {      private pullrefreshcontainerview mcontainerview;     private textview mrefreshheader;     private listview mlist;      private arraylist<string> mstrings = new arraylist<string>();     private arrayadapter<string> madapter;      /** called when activity first created. */     @override     public void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.main);          mrefreshheader = new textview(this);         mrefreshheader.setlayoutparams(new layoutparams(layoutparams.match_parent, layoutparams.match_parent));         mrefreshheader.setgravity(gravity.center);         mrefreshheader.settext("pull refresh...");          mcontainerview = (pullrefreshcontainerview) findviewbyid(r.id.container);         mcontainerview.setrefreshheader(mrefreshheader);          mcontainerview.setonchangestatelistener(new onchangestatelistener() {             @override             public void onchangestate(pullrefreshcontainerview container, int state) {                 switch (state) {                 case pullrefreshcontainerview.state_idle:                 case pullrefreshcontainerview.state_pull:                     mrefreshheader.settext("pull refresh...");                     break;                 case pullrefreshcontainerview.state_release:                     mrefreshheader.settext("release refresh...");                     break;                 case pullrefreshcontainerview.state_loading:                     mrefreshheader.settext("loading...");                      final timer t = new timer();                     t.schedule(new timertask() {                          @override                         public void run() {                             usagedemoactivity.this.runonuithread(new runnable() {                                 @override                                 public void run() {                                      addstrings(1);                                     mcontainerview.completerefresh();                                     t.cancel();                                 }                             });                         }                     }, 5000, 5000);                      break;                 }             }         });          mlist = mcontainerview.getlist();         madapter = new arrayadapter<string>(this, android.r.layout.simple_list_item_1, mstrings);         mlist.setadapter(madapter);          addstrings(3);     }      private void addstrings(int count) {         int cursize = mstrings.size();         (int = 0; < count; ++i) {             mstrings.add("string " + (cursize + i));         }          madapter.notifydatasetchanged();     } } 

main.xml

<?xml version="1.0" encoding="utf-8"?> <linearlayout xmlns:android="http://schemas.android.com/apk/res/android"     android:orientation="vertical"     android:layout_width="fill_parent"     android:layout_height="fill_parent"     >      <com.dmobile.pulltorefresh.pullrefreshcontainerview         android:id="@+id/container"         android:layout_width="fill_parent"         android:layout_height="fill_parent"/>  </linearlayout> 

update work gridview pullrefreshcontainerview.java

private void init(context context) {         mstate = state_idle; // start out idle.      float densityfactor = context.getresources().getdisplaymetrics().density;     refresh_view_height *= densityfactor;      // don't want see fading edge on container.     setverticalfadingedgeenabled(false);     setverticalscrollbarenabled(false);      setorientation(linearlayout.vertical);      // set default list , header.     mheadercontainer = new linearlayout(context);     addview(mheadercontainer);     setrefreshviewheight(1);      textview headerview = new textview(context);     headerview.settext("default refresh header.");     setrefreshheader(headerview);      gridview grid = new gridview(context);     setlist(grid); } 

and make related change in setlistmethod();