SelectableTextView

SelectableTextView.java

package com.damon.view;

import android.content.Context;
import android.graphics.Color;
import android.support.v4.view.GestureDetectorCompat;
import android.text.Spanned;
import android.text.style.BackgroundColorSpan;
import android.util.AttributeSet;
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.widget.EditText;

/**
 * Created by damon on 15/5/14.
 */
public class SelectableTextView extends EditText {

    private static final String TAG = "SelectableTextView";

    public SelectableTextView(Context context) {
        super(context);
        init();
    }

    public SelectableTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public SelectableTextView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }

    private GestureDetectorCompat detector;

    private void init(){
        detector = new GestureDetectorCompat(getContext(),new GestureDetector.SimpleOnGestureListener(){

            @Override
            public boolean onDoubleTap(MotionEvent e) {
                onDoubleClick(e);
                return true;
            }
        });

        setOnTouchListener(new OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                return detector.onTouchEvent(event);
            }
        });
    }

    private void onDoubleClick(MotionEvent e){
        Log.d(TAG, "onDoubleClick:" + e.toString());
        int line = getLayout().getLineForVertical(getScrollY()+(int)(e.getY() - getTextSize()/2));
        int currentOffset = getLayout().getOffsetForHorizontal(line, (int) (e.getX()- getTextSize()/2));
        Log.d(TAG, "click offset:" + currentOffset);

        char[] tempCharArray = getText().toString().toCharArray();
        while(!isWordCharacter(tempCharArray[currentOffset])){
            currentOffset++;
        }

        int endCursor = currentOffset;
        while(endCursor<tempCharArray.length){
            if(!isWordCharacter(tempCharArray[endCursor])){
                break;
            }
            endCursor++;
        }
        int startCursor = currentOffset;
        while(startCursor<tempCharArray.length){
            if(!isWordCharacter(tempCharArray[startCursor])){
                break;
            }
            startCursor--;
        }
        startCursor++;

        Log.d(TAG, "click word:[" + getText().toString().substring(startCursor, endCursor)+"]");

        getText().setSpan(new BackgroundColorSpan(Color.GREEN), startCursor, endCursor, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
    }

    private boolean isWordCharacter(char c){
        return (c>='a' && c<='z')
                || (c>='A' && c<='Z')
                || c=='-'
                || c=='\'';
    }

}