Android search by letter

When reading Oplayer, You can see Sliding letters to search for listView content. Therefore, the core function deduction is used as a demo, which is divided into two parts: layout, the other is the code. The specific layout is as follows: [html] <? Xml version = "1.0" encoding = "UTF-8"?> <LinearLayout xmlns: android = "http://schemas.android.com/apk/res/android" android: layout_width = "fill_parent" android: layout_height = "fill_parent" android: layout_weight = "1.0" android: orientation = "horizontal"> <FrameLayout android: layout_width = "0dip" android: layout_height = "fill_parent" android: layout_weight = "1.0" android: orientation = "vertical"> <ListView android: id = "@ + id/list" android: layout_width =" Fill_parent "android: layout_height =" fill_parent "android: cacheColorHint =" @ android: color/transparent "android: divider =" @ drawable/ic_line "android: drawSelectorOnTop =" false "android: fadingEdge = "none" android: listSelector = "@ android: color/transparent" android: scrollbars = "none"/> <TextView android: id = "@ + id/first_letter_overlay" android: layout_width = "wrap_content" android: layout_height = "wrap_content" Droid: layout_gravity = "right" android: layout_marginRight = "501_dip" android: layout_marginTop = "49366dip" android: background = "@ drawable/strong" android: gravity = "center" android: paddingBottom = "5.0dip" android: scaleType = "center" android: textSize = "43.0dip" android: visibility = "gone"/> </FrameLayout> <ImageView android: id = "@ + id/alphabet_scroller" android: layout_width = "wrap_content" android: l Ayout_height = "match_parent" android: layout_gravity = "center" android: paddingRight = "0dip" android: scaleType = "fitXY" android: src = "@ drawable/alphabet_scroller_bg"/> </LinearLayout> <? Xml version = "1.0" encoding = "UTF-8"?> <LinearLayout xmlns: android = "http://schemas.android.com/apk/res/android" android: layout_width = "fill_parent" android: layout_height = "fill_parent" android: layout_weight = "1.0" android: orientation = "horizontal"> <FrameLayout android: layout_width = "0dip" android: layout_height = "fill_parent" android: layout_weight = "1.0" android: orientation = "vertical"> <ListView android: id = "@ + id/list" android: layout_width = "f Ill_parent "android: layout_height =" fill_parent "android: cacheColorHint =" @ android: color/transparent "android: divider =" @ drawable/ic_line "android: drawSelectorOnTop =" false "android: fadingEdge = "none" android: listSelector = "@ android: color/transparent" android: scrollbars = "none"/> <TextView android: id = "@ + id/first_letter_overlay" android: layout_width = "wrap_content" android: layout_height = "wrap_content" and Roid: layout_gravity = "right" android: layout_marginRight = "501_dip" android: layout_marginTop = "491_dip" android: background = "@ drawable/strong" android: gravity = "center" android: paddingBottom = "5.0dip" android: scaleType = "center" android: textSize = "43.0dip" android: visibility = "gone"/> </FrameLayout> <ImageView android: id = "@ + id/alphabet_scroller" android: layout_width = "wrap_content" android: la Yout_height = "match_parent" android: layout_gravity = "center" android: paddingRight = "0dip" android: scaleType = "fitXY" android: src = "@ drawable/alphabet_scroller_bg"/> </LinearLayout> contains an ImageView image [html] <? Xml version = "1.0" encoding = "UTF-8"?> <Selector xmlns: android = "http://schemas.android.com/apk/res/android"> <item android: state_pressed = "true" android: drawable = "@ drawable/contact_list_scroll_pressed"/> <item android: drawable = "@ drawable/contact_list_scroll_normal"/> </selector> <? Xml version = "1.0" encoding = "UTF-8"?> <Selector xmlns: android = "http://schemas.android.com/apk/res/android"> <item android: state_pressed = "true" android: drawable = "@ drawable/contact_list_scroll_pressed"/> <item android: drawable = "@ drawable/contact_list_scroll_normal"/> </selector> the code is as follows: [java] package com. example. test; import java. util. arrayList; import java. util. list; import android. app. activity; import android. OS. bundle; import androi D. util. log; import android. view. motionEvent; import android. view. view; import android. view. viewGroup; import android. view. view. onTouchListener; import android. widget. baseAdapter; import android. widget. imageView; import android. widget. listView; import android. widget. textView; public class Main6 extends Activity {ListView iListView; TextView showChar; ImageView myChar; List <String> iList; MAdapter m Adapter; @ Override protected void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); setContentView (R. layout. main5); iListView = (ListView) findViewById (R. id. list); showChar = (TextView) findViewById (R. id. first_letter_overlay); myChar = (ImageView) findViewById (R. id. alphabet_scroller); iList = initChar (); Log. e ("t", "" + iList. size (); mAdapter = new MAdapter (); iListView. setAda Pter (mAdapter); myChar. setClickable (true); myChar. setOnTouchListener (asOnTouch);}/*** A-Z */private OnTouchListener asOnTouch = new OnTouchListener () {@ Override public boolean onTouch (View v, MotionEvent event) {switch (event. getAction () {case MotionEvent. ACTION_DOWN: // 0 myChar. setPressed (true); showChar. setVisibility (View. VISIBLE); mathScrollerPosition (event. getY (); break; case MotionEv Ent. ACTION_UP: // 1 myChar. setPressed (false); showChar. setVisibility (View. GONE); break; case MotionEvent. ACTION_MOVE: mathScrollerPosition (event. getY (); break;} return false ;};/*** display character ** @ param y */private void mathScrollerPosition (float y) {int height = myChar. getHeight (); float charHeight = height/28366f; char c = 'a'; if (y <0) y = 0; else if (y> height) y = height; int index = (I Nt) (y/charHeight)-1; if (index <0) index = 0; else if (index> 25) index = 25; String key = String. valueOf (char) (c + index); showChar. setText (key); int position = 0; if (index = 0) iListView. setSelection (0); else if (index = 25) iListView. setSelection (mAdapter. getCount ()-1); else {if (mAdapter! = Null) {for (int I = 0; I <iList. size (); I ++) {if (iList. get (I ). startsWith (key) {iListView. setSelection (position); break;} position ++; }}}/*** ListView data * @ return */public List <String> initChar () {List <String> list = new ArrayList <String> (); char c = 'a'; for (int I = 0; I <26; I ++) {list. add (String. valueOf (char) (c + I); list. add (String. valueOf (char) (c + I); list. add (Strin G. valueOf (char) (c + I);} return list;} class MAdapter extends BaseAdapter {@ Override public int getCount () {return iList. size () ;}@ Override public Object getItem (int position) {return iList. get (position) ;}@ Override public long getItemId (int position) {return position ;}@ Override public View getView (int position, View convertView, ViewGroup parent) {TextView text = new TextView (getApp LicationContext (); text. setText (iList. get (position); return text ;}} package com. example. test; import java. util. arrayList; import java. util. list; import android. app. activity; import android. OS. bundle; import android. util. log; import android. view. motionEvent; import android. view. view; import android. view. viewGroup; import android. view. view. onTouchListener; import android. widget. baseAdapter; import android Oid. widget. imageView; import android. widget. listView; import android. widget. textView; public class Main6 extends Activity {ListView iListView; TextView showChar; ImageView myChar; List <String> iList; MAdapter mAdapter; @ Overrideprotected void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); setContentView (R. layout. main5); iListView = (ListView) findViewById (R. id. list); showChar = (Tex TView) findViewById (R. id. first_letter_overlay); myChar = (ImageView) findViewById (R. id. alphabet_scroller); iList = initChar (); Log. e ("t", "" + iList. size (); mAdapter = new MAdapter (); iListView. setAdapter (mAdapter); myChar. setClickable (true); myChar. setOnTouchListener (asOnTouch);}/*** A-Z */private OnTouchListener asOnTouch = new OnTouchListener () {@ Overridepublic boolean onTouch (View v, MotionEvent) {Switch (event. getAction () {case MotionEvent. ACTION_DOWN: // 0myChar. setPressed (true); showChar. setVisibility (View. VISIBLE); mathScrollerPosition (event. getY (); break; case MotionEvent. ACTION_UP: // 1myChar. setPressed (false); showChar. setVisibility (View. GONE); break; case MotionEvent. ACTION_MOVE: mathScrollerPosition (event. getY (); break;} return false ;};/*** display character ** @ param y */private void mathScrollerPos Ition (float y) {int height = myChar. getHeight (); float charHeight = height/28366f; char c = 'a'; if (y <0) y = 0; else if (y> height) y = height; int index = (int) (y/charHeight)-1; if (index <0) index = 0; else if (index> 25) index = 25; String key = String. valueOf (char) (c + index); showChar. setText (key); int position = 0; if (index = 0) iListView. setSelection (0); else if (index = 25) iListView. se TSelection (mAdapter. getCount ()-1); else {if (mAdapter! = Null) {for (int I = 0; I <iList. size (); I ++) {if (iList. get (I ). startsWith (key) {iListView. setSelection (position); break;} position ++; }}}/*** ListView data * @ return */public List <String> initChar () {List <String> list = new ArrayList <String> (); char c = 'a'; for (int I = 0; I <26; I ++) {list. add (String. valueOf (char) (c + I); list. add (String. valueOf (char) (c + I); list. add (String. valueOf (char) (c + I);} return list;} class MAdapter extends BaseAdapter {@ Overridepublic int getCount () {return iList. size () ;}@ Overridepublic Object getItem (int position) {return iList. get (position) ;}@ Overridepublic long getItemId (int position) {return position ;}@ Overridepublic View getView (int position, View convertView, ViewGroup parent) {TextView text = new TextView (getApplicationContext (); text. setText (iList. get (position); return text ;}}}