Android UI development Part 6-sliding tab like QQ

Public class mainactivity extends activitygroup {private relativelayout layout; private inclulayout1; private relativelayout layout2; private relativelayout layout3; private inclubodylayout; private imageview tab1; private imageview tab2; private imageview tab3; private imageview first; private int current = 1; // the first one is selected by default. This parameter value can be dynamically changed: Public void oncreate (bundle savedinstancestate) {super. Oncreate (savedinstancestate); setcontentview (R. layout. main); initui ();} private void initui () {layout = (relativelayout) findviewbyid (R. id. root); layout1 = (relativelayout) findviewbyid (R. id. layout1); layout2 = (relativelayout) findviewbyid (R. id. layout2); layout3 = (relativelayout) findviewbyid (R. id. layout3); bodylayout = (relativelayout) findviewbyid (R. id. bodylayout); tab1 = (imageview) findviewbyid (R. ID. Tab1); tab1.setonclicklistener (onclicklistener); tab2 = (imageview) findviewbyid (R. id. tab2); tab2.setonclicklistener (onclicklistener); tab3 = (imageview) findviewbyid (R. id. tab3); tab3.setonclicklistener (onclicklistener); relativelayout. layoutparams RL = new relativelayout. layoutparams (layoutparams. wrap_content, layoutparams. wrap_content); RL. addrule (relativelayout. center_in_parent, relativelayout. true ); First = new imageview (this); first. settag ("first"); first. setimageresource (R. drawable. topbar_select); // switch (current) {Case 1: layout1.addview (first, rl); current = R. id. tab1; break; Case 2: layout2.addview (first, rl); current = R. id. tab2; break; Case 3: layout3.addview (first, rl); current = R. id. tab3; break; default: break;} view = getlocalactivitymanager (). startactivity ("Index", new intent (mainactiv Ity. this, tab1.class )). getdecorview (); bodylayout. addview (View);} private Boolean isadd = false; // whether top_selectprivate int select_width has been added; // top_select_widthprivate int select_height; // top_select_heightprivate int firstleft; // The left margin after the first addition *** private int startleft; // The left margin of the Start *** // Add a view and remove a viewprivate void Replace () {Switch (current) {case R. id. tab1: changetop (layout1); break; case R. id. tab2: Chang Etop (layout2); break; case R. id. tab3: changetop (layout3); break; default: break;} private void changetop (relativelayout) {imageview old = (imageview) relativelayout. findviewwithtag ("first"); select_width = old. getwidth (); select_height = old. getheight (); relativelayout. layoutparams RL = new relativelayout. layoutparams (select_width, select_height); RL. leftmargin = old. getleft () + (relativelay Out) Old. getparent ()). getleft (); RL. topmargin = old. gettop () + (relativelayout) Old. getparent ()). gettop (); // get the starting position firstleft = old. getleft () + (relativelayout) Old. getparent ()). getleft (); imageview IV = new imageview (this); IV. settag ("move"); IV. setimageresource (R. drawable. topbar_select); layout. addview (IV, rl); relativelayout. removeview (old);} private onclicklistener = new onclicklistene R () {public void onclick (view v) {If (! Isadd) {Replace (); // for the first time, use remove old to add a new top_select as isadd = true;} imageview top_select = (imageview) layout. findviewwithtag ("move"); int tableft; int endleft = 0; Boolean run = false; Switch (v. GETID () {case R. id. tab1: If (current! = R. id. tab1) {// The central location tableft = (relativelayout) tab1.getparent ()). getleft () + tab1.getleft () + tab1.getwidth ()/2; // The final position endleft = tableft-select_width/2; current = R. id. tab1; run = true; bodylayout. removeallviews (); view = getlocalactivitymanager (). startactivity ("Index", new intent (mainactivity. this, tab1.class )). getdecorview (); bodylayout. addview (View);} break; case R. id. tab2: If (current! = R. id. tab2) {tableft = (relativelayout) tab2.getparent ()). getleft () + tab2.getleft () + tab2.getwidth ()/2; endleft = tableft-select_width/2; current = R. id. tab2; run = true; bodylayout. removeallviews (); view = getlocalactivitymanager (). startactivity ("Index", new intent (mainactivity. this, tab2.class )). getdecorview (); bodylayout. addview (View);} break; case R. id. tab3: If (current! = R. id. tab3) {tableft = (relativelayout) tab3.getparent ()). getleft () + tab3.getleft () + tab3.getwidth ()/2; endleft = tableft-select_width/2; current = R. id. tab3; run = true; bodylayout. removeallviews (); view = getlocalactivitymanager (). startactivity ("Index", new intent (mainactivity. this, tab3.class )). getdecorview (); bodylayout. addview (View);} break; default: break;} If (run) {translateanimation animation = new translateanimation (startleft, endleft-firstleft, 0, 0 ); startleft = endleft-firstleft; // reset the starting position of animation. setduration (400); animation. setfillafter (true); top_select.bringtofront (); top_select.startanimation (animation );}}};}

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"android:id="@+id/root" android:layout_width="fill_parent"android:layout_height="fill_parent"><LinearLayout android:orientation="vertical"android:layout_width="fill_parent" android:layout_height="fill_parent"android:background="@drawable/default_bg"><LinearLayout android:orientation="horizontal"android:layout_width="fill_parent" android:layout_height="fill_parent"android:layout_weight="6.0"><RelativeLayout android:id="@+id/layout1"android:layout_width="fill_parent" android:layout_height="wrap_content"android:layout_weight="1.0" android:layout_gravity="center_vertical"><ImageView android:id="@+id/tab1" android:layout_width="wrap_content"android:layout_height="wrap_content" android:src="@drawable/tab1"android:layout_centerInParent="true" /></RelativeLayout><RelativeLayout android:id="@+id/layout2"android:layout_width="fill_parent" android:layout_height="wrap_content"android:layout_weight="1.0" android:layout_gravity="center_vertical"><ImageView android:id="@+id/tab2" android:layout_width="wrap_content"android:layout_height="wrap_content" android:src="@drawable/tab2"android:layout_centerInParent="true" /></RelativeLayout><RelativeLayout android:id="@+id/layout3"android:layout_width="fill_parent" android:layout_height="wrap_content"android:layout_weight="1.0" android:layout_gravity="center_vertical"><ImageView android:id="@+id/tab3" android:layout_width="wrap_content"android:layout_height="wrap_content" android:src="@drawable/tab3"android:layout_centerInParent="true" /></RelativeLayout></LinearLayout><RelativeLayout android:orientation="horizontal"android:layout_width="fill_parent" android:layout_height="fill_parent"android:layout_weight="1.0" android:background="#ffffff"android:gravity="center" android:id="@+id/bodylayout"></RelativeLayout></LinearLayout></RelativeLayout>