Touch and slide to achieve Straight Line Selection

First look:

Source code:

package com.momo.selectvalue;import android.app.Activity;import android.os.Bundle;import android.view.MotionEvent;import android.view.View;import android.view.View.OnTouchListener;import android.widget.ImageView;import android.widget.LinearLayout;import android.widget.TextView;public class MainActivity extends Activity implements OnTouchListener {private ImageView strength_select;private LinearLayout strength_select_bg;private LinearLayout strength_select_tvs;private int typeStrength = 1 ;private int lastX;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);strength_select = (ImageView) findViewById(R.id.strength_select);strength_select.setOnTouchListener(this);strength_select_bg = (LinearLayout)findViewById(R.id.strength_select_bg);strength_select_tvs = (LinearLayout) findViewById(R.id.strength_select_tvs);strength_select_bg.setOnTouchListener(this);}@Overridepublic boolean onTouch(View v, MotionEvent event) {// TODO Auto-generated method stubif(v.getId() == R.id.strength_select_bg){setSlidePointPosition((int) event.getX());return false;}int width = strength_select_bg.getMeasuredWidth();int pointWidth = v.getWidth();switch(event.getAction()){case MotionEvent.ACTION_DOWN:lastX = (int) event.getRawX();strength_select_bg.requestDisallowInterceptTouchEvent(true);break;case MotionEvent.ACTION_MOVE:int detelX = (int) (event.getRawX() - lastX);int left = v.getLeft() + detelX;int right = left + pointWidth;if(right > width || left < 0){return false;}v.layout(left, v.getTop(), right, v.getBottom());lastX = (int) event.getRawX();break;case MotionEvent.ACTION_CANCEL:case MotionEvent.ACTION_UP:int left2 = (int) (v.getLeft() + pointWidth*0.5);setSlidePointPosition(left2);break;}return false;}private void setSlidePointPosition(int leftPosition){((TextView)strength_select_tvs.getChildAt(typeStrength*2-2)).setTextSize(12);int pointWidth = strength_select.getMeasuredWidth();int width = strength_select_bg.getMeasuredWidth();int unitWidth = (width - pointWidth)/6;ImageView v = strength_select;if(leftPosition > unitWidth*5+pointWidth/2){v.layout(width-pointWidth, v.getTop(), width, v.getBottom());((TextView)strength_select_tvs.getChildAt(6)).setTextSize(18);typeStrength = 4;}else if(leftPosition <= unitWidth*5+pointWidth/2 && leftPosition > unitWidth*3+pointWidth/2){v.layout(unitWidth*4, v.getTop(), unitWidth*4+pointWidth, v.getBottom());((TextView)strength_select_tvs.getChildAt(4)).setTextSize(18);typeStrength = 3;}else if(leftPosition > unitWidth+pointWidth/2 && leftPosition <= unitWidth*3+pointWidth/2){v.layout(unitWidth*2, v.getTop(), unitWidth*2+pointWidth, v.getBottom());((TextView)strength_select_tvs.getChildAt(2)).setTextSize(18);typeStrength = 2;}else{v.layout(0, v.getTop(), pointWidth, v.getBottom());((TextView)strength_select_tvs.getChildAt(0)).setTextSize(18);typeStrength = 1;}}}

Touch and slide to achieve Straight Line Selection