Android自定义流式标签控件

最近总感觉写博客的激情不高，不知道为啥。放上效果图，demo在最下面

图上那个切换按钮的作用呢，就是模拟改变标签的个数动态变化整个控件的高度。

其实这个控件也算很简单的控件了。关键点只有两个

• 如何控制标签自动换行
• 切换数据源时动态改变控件的高度

再简单的控件也需要一点一点的码出来，咱就从最基础的属性设置开始。

    public FlowTagView textColor(int defaultColor, int selectedColor){
        this.textColorDefault = defaultColor;
        this.textColorSelected = selectedColor;
        return this;
    }

    public FlowTagView textSize(int textSize){
        this.textSize = textSize;
        return this;
    }

    public FlowTagView backgroundColor(int defaultColor, int selectedColor){
        this.backgroundColorDefault = defaultColor;
        this.backgroundColorSelected = selectedColor;
        return this;
    }

    public FlowTagView padding(int horizontalPadding, int verticalPadding, int textHorizontalPadding){
        this.horizontalPadding = horizontalPadding;
        this.verticalPadding = verticalPadding;
        this.textHorizontalPadding = textHorizontalPadding;
        return this;
    }

    public FlowTagView itemHeight(int height){
        this.itemHeight = height;
        return this;
    }

    public FlowTagView datas(String[] datas){
        this.datas = datas;
        return this;
    }

    public FlowTagView listener(OnTagSelectedListener listener){
        this.listener = listener;
        return this;
    }

上面设置了字体颜色啊，背景颜色啊，标签Item的高度啊，内补白和外部白的一些值，还有一个监听器。有的朋友就说了，我比较懒，就想快点看到效果，不想设置怎么办？怎么办？给默认值呗。

    //常亮默认值，这些参数若不调用方法传递，则直接使用默认值
    public static final int ROUND_RADIUS = 30;
    public static final int TEXT_COLOR_DEFAULT = Color.BLACK;
    public static final int TEXT_COLOR_SELECTED = Color.WHITE;
    public static final int TEXT_SIZE = 30;
    public static final int BACKGROUND_COLOR_DEFAULT = Color.GRAY;
    public static final int BACKGROUND_COLOR_SELECTED = Color.GREEN;
    public static final int HORIZONTAL_PADDING = 30;
    public static final int VERTICAL_PADDING = 30;
    public static final int TEXT_HORIZONTAL_PADDING = 30;
    public static final int ITEM_HEIGHT = 60;

    private Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
    private int textColorDefault = TEXT_COLOR_DEFAULT;
    private int textColorSelected = TEXT_COLOR_SELECTED;
    private int textSize = TEXT_SIZE;
    private int backgroundColorDefault = BACKGROUND_COLOR_DEFAULT;
    private int backgroundColorSelected = BACKGROUND_COLOR_SELECTED;
    //Tag之间的横向和纵向的间隔
    private int horizontalPadding = HORIZONTAL_PADDING;
    private int verticalPadding = VERTICAL_PADDING;
    //每个Tag内部的横向间隔
    private int textHorizontalPadding = TEXT_HORIZONTAL_PADDING;
    //每个Tag的高度
    private int itemHeight = ITEM_HEIGHT;

好了，基本的属性设置的代码完成了，那么就用软件的高内聚低耦合的思想封装一个标签类吧。

    public class Tag{
        //文本属性
        public String text;
        public int textColorDefault;
        public int textColorSelected;
        public int backgroundColorDefault;
        public int backgroundColorSelected;
        public boolean isSelected;
        public Paint paint;
        //文本的绘制起点
        public int drawX;
        public int drawY;
        //整个Tag占用的坐标范围
        public RectF rect = new RectF();

        public Tag(String text, int textSize, int textColorDefault, int textColorSelected, 

                   int backgroundColorDefault, int backgroundColorSelected,
                   Paint paint, int height, int horizontalPadding, int startX, int startY){
            this.text = text;
            this.textColorDefault = textColorDefault;
            this.textColorSelected = textColorSelected;
            this.backgroundColorDefault = backgroundColorDefault;
            this.backgroundColorSelected = backgroundColorSelected;
            this.paint = paint;
            //求出整个Tag的宽度
            paint.setTextSize(textSize);
            int textWidth = (int)paint.measureText(text);
            int width = textWidth + 2 * horizontalPadding;
            //计算坐标范围，startX，staryY是指左上角的起点
            rect.left = startX;
            rect.top = startY;
            rect.right = startX + width;
            rect.bottom = startY + height;
            //计算居中绘制时的绘制起点
            drawX = startX + horizontalPadding;
            Paint.FontMetrics metrics =  paint.getFontMetrics();
            drawY = (int)(startY + height / 2 + (metrics.b