android 用代码实现文本选择器，改变字体颜色，背景色，渐变

一下代码可以一定程度上代替我们编写xml来设置背景。
有报错自己修改一下就好。

public static MyDrawable instance ( ) {
        return new MyDrawable ( );
    }

    private MyDrawable ( ) {
        foreStyle = new ForeStyle ( );
        backStyle = new BackStyle ( );
    }

    /**
     * 前景
     */
    private final ForeStyle foreStyle;
    /**
     * 背景
     */
    private final BackStyle backStyle;

    //============================前景===============================

    public MyDrawable fore ( int color ) {
        foreStyle.setColor ( color );
        return this;
    }

    public MyDrawable fore ( String color ) {
        foreStyle.setColor ( color );
        return this;
    }

    public MyDrawable foreRes ( int resId ) {
        foreStyle.setColorRes ( resId );
        return this;
    }

    public MyDrawable fore ( int color, int colorSel ) {
        foreStyle.setColor ( color, colorSel );
        return this;
    }

    public MyDrawable fore ( String color, String colorSel ) {
        foreStyle.setColor ( color, colorSel );
        return this;
    }

    public MyDrawable foreRes ( int resId, int resIdSel ) {
        foreStyle.setColorRes ( resId, resIdSel );
        return this;
    }

    public MyDrawable fore ( int... colors ) {
        foreStyle.setColors ( colors );
        return this;
    }

    //============================背景===============================
    public MyDrawable backRadius ( int radius ) {
        backStyle.setRadius ( radius );
        return this;
    }

    public MyDrawable backRadius ( int topLeft, int topRight, int bottomLeft,
                                   int bottomRight ) {
        backStyle.setRadius ( topLeft, topRight, bottomLeft, bottomRight );
        return this;
    }

    public MyDrawable back ( int color ) {
        backStyle.setColor ( color );
        return this;
    }

    public MyDrawable back ( String color ) {
        backStyle.setColor ( color );
        return this;
    }

    public MyDrawable backRes ( int resId ) {
        backStyle.setColorRes ( resId );
        return this;
    }

    public MyDrawable backRes ( int resId, int colorResSel ) {
        backStyle.setColorRes ( resId, colorResSel );
        return this;
    }

    public MyDrawable back ( int color, int colorSel ) {
        backStyle.setColor ( color, colorSel );
        return this;
    }

    public MyDrawable back ( int... colors ) {
        backStyle.setColors ( colors );
        return this;
    }

    public MyDrawable backBorder ( int color, int width ) {
        backStyle.setBorderColor ( color, width );
        return this;
    }

    public MyDrawable backBorderRes ( int resId, int width ) {
        backStyle.setBorderColorRes ( resId, width );
        return this;
    }

    public MyDrawable backBorderRes ( String color, int width ) {
        backStyle.setBorderColor ( color, width );
        return this;
    }
    //============================提取===============================

    /**
     * 提取
     *
     * @param target 目标控件
     */
    public void into ( View target ) {
        //前景色
        if ( target instanceof TextView ) {
            target.setClickable ( true );
            if ( foreStyle.colors != null && foreStyle.colors.length == 2 ) {
                LinearGradient mLinearGradient = new LinearGradient ( 0, 0, 0,
                        ( ( TextView ) target ).getPaint ( ).getTextSize ( ),
                        foreStyle.colors[ 0 ], foreStyle.colors[ 1 ],
                        Shader.TileMode.CLAMP );
                ( ( TextView ) target ).getPaint ( ).setShader ( mLinearGradient );
                target.invalidate ( );
            } else {
                if ( foreStyle.normalColor == Integer.MAX_VALUE ) {
                    foreStyle.setColor ( ( ( TextView ) target ).getCurrentTextColor ( ) );
                }
                if ( foreStyle.selectColor == Integer.MAX_VALUE ) {
                    ( ( TextView ) target ).setTextColor ( foreStyle.normalColor );
                } else {
                    ColorStateList colorStateList = new ColorStateList ( new int[][] {
                            { - android.R.attr.state_pressed },
                            { android.R.attr.state_pressed }
                    }, new int[] { foreStyle.normalColor, foreStyle.selectColor } );
                    ( ( TextView ) target ).setTextColor ( colorStateList );
                }
            }
        }

        float tl = toFloat ( 1.6, backStyle.topLeft );
        float tr = toFloat ( 1.6, backStyle.topRight );
        float bl = toFloat ( 1.6, backStyle.bottomLeft );
        float br = toFloat ( 1.6, backStyle.bottomRight );
        float[] radius = new float[] { tl, tl, tr, tr, br, br, bl, bl };
        if ( backStyle.colors != null && backStyle.colors.length > 0 ) {
            //处理渐变
            GradientDrawable drawable = new GradientDrawable (
                    GradientDrawable.Orientation.TOP_BOTTOM, backStyle.colors );
            drawable.setCornerRadii ( radius );
            target.setBackground ( drawable );
        } else {
            //处理普通样式
            if ( backStyle.normalColor != Integer.MAX_VALUE ) {
                GradientDrawable normal = new GradientDrawable ( );
                normal.setColor ( backStyle.normalColor );
                normal.setCornerRadii ( radius );
                normal.setStroke ( backStyle.borderWidth, backStyle.borderColor );
                if ( backStyle.selectColor == Integer.MAX_VALUE ) {
                    target.setBackground ( normal );
                } else {
                    target.setClickable ( true );
                    GradientDrawable select = new GradientDrawable ( );
                    select.setColor ( backStyle.selectColor );
                    select.setCornerRadii ( radius );
                    select.setStroke ( backStyle.borderWidth, backStyle.borderColor );
                    StateListDrawable drawable = new StateListDrawable ( );
                    drawable.addState ( new int[] { android.R.attr.state_selected }, select );
                    drawable.addState ( new int[] { android.R.attr.state_pressed }, select );
                    drawable.addState ( new int[] { android.R.attr.state_enabled }, normal );
                    drawable.addState ( new int[] { }, normal );
                    target.setBackground ( drawable );
                }
            }
        }
    }

    public StateListDrawable get ( ) {
        float tl = toFloat ( 1.6, backStyle.topLeft );
        float tr = toFloat ( 1.6, backStyle.topRight );
        float bl = toFloat ( 1.6, backStyle.bottomLeft );
        float br = toFloat ( 1.6, backStyle.bottomRight );
        float[] radius = new float[] { tl, tl, tr, tr, br, br, bl, bl };
        if ( backStyle.colors != null && backStyle.colors.length > 0 ) {
            //处理渐变
            GradientDrawable normal = new GradientDrawable (
                    GradientDrawable.Orientation.TOP_BOTTOM, backStyle.colors );
            normal.setCornerRadii ( radius );
            StateListDrawable drawable = new StateListDrawable ( );
            drawable.addState ( new int[] { android.R.attr.state_selected }, normal );
            drawable.addState ( new int[] { android.R.attr.state_pressed }, normal );
            drawable.addState ( new int[] { android.R.attr.state_enabled }, normal );
            drawable.addState ( new int[] { }, normal );
            return drawable;
        } else {
            //处理普通样式
            if ( backStyle.normalColor != Integer.MAX_VALUE ) {
                GradientDrawable normal = new GradientDrawable ( );
                normal.setColor ( backStyle.normalColor );
                normal.setCornerRadii ( radius );
                normal.setStroke ( backStyle.borderWidth, backStyle.borderColor );
                if ( backStyle.selectColor == Integer.MAX_VALUE ) {
                    StateListDrawable drawable = new StateListDrawable ( );
                    drawable.addState ( new int[] { android.R.attr.state_selected }, normal );
                    drawable.addState ( new int[] { android.R.attr.state_pressed }, normal );
                    drawable.addState ( new int[] { android.R.attr.state_enabled }, normal );
                    drawable.addState ( new int[] { }, normal );
                    return drawable;
                } else {
                    GradientDrawable select = new GradientDrawable ( );
                    select.setColor ( backStyle.selectColor );
                    select.setCornerRadii ( radius );
                    select.setStroke ( backStyle.borderWidth, backStyle.borderColor );
                    StateListDrawable drawable = new StateListDrawable ( );
                    drawable.addState ( new int[] { android.R.attr.state_selected }, select );
                    drawable.addState ( new int[] { android.R.attr.state_pressed }, select );
                    drawable.addState ( new int[] { android.R.attr.state_enabled }, normal );
                    drawable.addState ( new int[] { }, normal );
                    return drawable;
                }
            }
        }
        return null;
    }


    public static class ForeStyle {

        protected ForeStyle ( ) {
        }

        protected int normalColor = Integer.MAX_VALUE;
        protected int selectColor = Integer.MAX_VALUE;
        protected int[] colors;

        public ForeStyle setColor ( int normalColor, int selectColor ) {
            this.normalColor = normalColor;
            this.selectColor = selectColor;
            return this;
        }

        public ForeStyle setColor ( String normalColor, String selectColor ) {
            this.normalColor = colorParse ( normalColor );
            this.selectColor = colorParse ( selectColor );
            return this;
        }

        public ForeStyle setColorRes ( int normalColor, int selectColor ) {
            this.normalColor = colorByRes ( normalColor );
            this.selectColor = colorByRes ( selectColor );
            return this;
        }

        //==========================================================
        public ForeStyle setColor ( int normalColor ) {
            this.normalColor = normalColor;
            return this;
        }

        public ForeStyle setColor ( String normalColor ) {
            this.normalColor = colorParse ( normalColor );
            return this;
        }

        public ForeStyle setColorRes ( int normalColor ) {
            this.normalColor = colorByRes ( normalColor );
            return this;
        }

        //=====================================================
        public ForeStyle setColors ( int... colors ) {
            this.colors = colors;
            return this;
        }
    }

    public static class BackStyle {
        protected int topLeft, topRight, bottomLeft, bottomRight;
        protected int borderColor = Integer.MAX_VALUE;
        protected int borderWidth;

        protected BackStyle ( ) {
        }

        protected int normalColor = Integer.MAX_VALUE;
        protected int selectColor = Integer.MAX_VALUE;
        protected int[] colors;

        public BackStyle setColor ( int normalColor, int selectColor ) {
            this.normalColor = normalColor;
            this.selectColor = selectColor;
            return this;
        }

        public BackStyle setColor ( String normalColor, String selectColor ) {
            this.normalColor = colorParse ( normalColor );
            this.selectColor = colorParse ( selectColor );
            return this;
        }

        public BackStyle setColorRes ( int normalColor, int selectColor ) {
            this.normalColor = colorByRes ( normalColor );
            this.selectColor = colorByRes ( selectColor );
            return this;
        }

        //==========================================================
        public BackStyle setColor ( int normalColor ) {
            this.normalColor = normalColor;
            return this;
        }

        public BackStyle setColor ( String normalColor ) {
            this.normalColor = colorParse ( normalColor );
            return this;
        }

        public BackStyle setColorRes ( int normalColor ) {
            this.normalColor = colorByRes ( normalColor );
            return this;
        }

        //=====================================================
        public BackStyle setColors ( int... colors ) {
            this.colors = colors;
            return this;
        }


        public BackStyle setRadius ( int radius ) {
            this.topLeft = radius;
            this.topRight = radius;
            this.bottomLeft = radius;
            this.bottomRight = radius;
            return this;
        }

        public BackStyle setRadius ( int topLeft, int topRight, int bottomLeft, int bottomRight ) {
            this.topLeft = topLeft;
            this.topRight = topRight;
            this.bottomLeft = bottomLeft;
            this.bottomRight = bottomRight;
            return this;
        }

        public BackStyle setBorderColor ( int borderColor, int borderWidth ) {
            this.borderColor = borderColor;
            this.borderWidth = borderWidth;
            return this;
        }

        public BackStyle setBorderColorRes ( int borderColor, int borderWidth ) {
            this.borderColor = colorByRes ( borderColor );
            this.borderWidth = borderWidth;
            return this;
        }

        public BackStyle setBorderColor ( String borderColor, int borderWidth ) {
            this.borderColor = colorParse ( borderColor );
            this.borderWidth = borderWidth;
            return this;
        }
    }

    private static Float toFloat ( double value, double per ) {
        return Double.valueOf ( value * per ).floatValue ( );
    }

    private static int colorParse ( String str ) {
        try {
            return Color.parseColor ( str );
        } catch ( Exception e ) {
            return Color.LTGRAY;
        }
    }

    private static int colorByRes ( int resId ) {
        try {
            return ContextCompat.getColor ( BaseApp.getContext ( ), resId );
        } catch ( Exception e ) {
            return Color.LTGRAY;
        }
    }