ExtendedEditText.java

public class ExtendedEditText extends AppCompatEditText {

    String TAG = "ExtendedEditText";
    TextPaint textPaint = new TextPaint();
    private String suffix = "";
    private String prefix = "";
    private boolean appendWhiteSpace;
    private int hackPadding; /**Used to fix wrong positioning of EditText cursor, when both prefix and suffix are set*/
    private int leftPadding, prefixXPosition, stringXPosition, suffixXPosition;

    /**
     * This constructor is called when view is created from code, ie,
     * ExtendedEditText exEditText = new ExtendedEditText(this);
     * */
    public ExtendedEditText(Context context) {
        super(context);
    }

    /**
     * This constructor is called usually, when you add View in layout xml file, ie,
     * <your.package.name.ExtendedEditText
     *  android:layout_width = ""
     *  android:layout_height = ""/>
     * */
    public ExtendedEditText(Context context, AttributeSet attrs) {
        super(context, attrs);
        getAttributes(context, attrs, 0);
    }

    /**
     * This constructor is called, when you add View in layout xml file and Specify a style for it, ie,
     * <your.package.name.ExtendedEditText
     *  android:layout_width = ""
     *  android:layout_height = ""
     *  android:style="@style/my_style"/>
     * */
    public ExtendedEditText(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        getAttributes(context, attrs, defStyleAttr);
    }

    /**
     * set color for text
     * */
    @Override
    protected void onFinishInflate() {
        super.onFinishInflate();
        textPaint.setColor(getCurrentTextColor());
        textPaint.setTextSize(getTextSize());
        textPaint.setTextAlign(Paint.Align.LEFT);
        textPaint.setAntiAlias(true);
    }

    /**
     * get the value user entered, as string
     * */
    public String getUserInput(){
        return getText().toString();
    }

    /**
     * get the whole string from the view, including prefix and suffix, if any.
     * */
    public String getCompleteString() {
        return prefix+getText().toString()+suffix;
    }

    /**
     * onDraw draws the view on device screen
     * */
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        suffixXPosition = (int) (textPaint.measureText(getText().toString()) + leftPadding + textPaint.measureText(prefix));
        canvas.drawText(prefix, prefixXPosition, getBaseline(), textPaint);
        canvas.drawText(getText().toString(), stringXPosition, getBaseline(), textPaint);
        canvas.drawText(suffix, suffixXPosition, getBaseline(), textPaint);
    }

    @Override
    public void setSelection(int index) {
        super.setSelection(index);
        Log.d(TAG, "setSelection: called at "+index);
    }

    @Override
    public void setOnFocusChangeListener(OnFocusChangeListener l) {
        super.setOnFocusChangeListener(l);
        setSelection(getText().toString().length());
    }

    /**
     * set suffix string programmatically
     * */
    public void setSuffix(String suffix){
        this.suffix = suffix;
        if(appendWhiteSpace){
            this.suffix = " " + suffix;
        }
        invalidate();
    }

    /**
     * set prefix string programmatically
     * */
    public void setPrefix(String prefix){
        this.prefix = prefix;
        if(appendWhiteSpace){
            this.prefix = prefix + " ";
        }
        invalidate();
    }

    /**
     * called before onDraw, to measure dimensions of view
     * */
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        hackPadding = (int) (leftPadding + textPaint.measureText(prefix));
        prefixXPosition = leftPadding;
        stringXPosition = (int) (leftPadding + textPaint.measureText(prefix));
        setPadding(hackPadding, getPaddingTop(), getPaddingRight(),getPaddingBottom());

    }

    @Override
    protected void onAttachedToWindow() {
        super.onAttachedToWindow();
        setSelection(getText().toString().length());
    }

    /**
     * gets the custom attributes defined in attrs.xml for ExtendedEditText,
     * such as prefix, suffix, etc, before inflating view.
     * */
    private void getAttributes(Context context, AttributeSet attrs, int defStyleAttr) {

        leftPadding = getPaddingLeft();
        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.ExtendedEditText, defStyleAttr, 0);
        if(a != null) {
            suffix = a.getString(R.styleable.ExtendedEditText_suffix);
            prefix = a.getString(R.styleable.ExtendedEditText_prefix);
            appendWhiteSpace = a.getBoolean(R.styleable.ExtendedEditText_appendWhiteSpace, false);

            Log.d(TAG, "getAttributes: prefix : "+prefix+"\n suffix : "+suffix);
            if(suffix == null) {
                suffix = "";
            }else {
                if(appendWhiteSpace) {
                    suffix = " " + suffix;
                }
            }
            if(prefix == null) {
                prefix = "";
            }else {
                if(appendWhiteSpace) {
                    prefix = prefix + " ";
                }
            }
        }else {
            Log.d(TAG, "getAttributes: typed array null");
        }
        a.recycle();
    }

}