流式布局（二）最后一个标签在右下角

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public class FlowLayout extends ViewGroup {    public FlowLayout(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);    }    public FlowLayout(Context context, AttributeSet attrs) {        this(context, attrs, 0);    }    public FlowLayout(Context context) {        this(context, null);    }    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        int sizeWidth = MeasureSpec.getSize(widthMeasureSpec);        int modeWidth = MeasureSpec.getMode(widthMeasureSpec);        int sizeHeight = MeasureSpec.getSize(heightMeasureSpec);        int modeHeight = MeasureSpec.getMode(heightMeasureSpec);        // 如果是warp_content情况下，记录宽和高        int width = 0;        int height = 0;        // 记录每一行的宽度与高度        int lineWidth = 0;        int lineHeight = 0;        // 得到内部元素的个数        int cCount = getChildCount();        for (int i = 0; i < cCount; i++) {            // 通过索引拿到每一个子view            View child = getChildAt(i);            // 测量子View的宽和高,系统提供的measureChild            measureChild(child, widthMeasureSpec, heightMeasureSpec);            // 得到LayoutParams            MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();            // 子View占据的宽度            int childWidth = child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin;            // 子View占据的高度            int childHeight = child.getMeasuredHeight() + lp.topMargin + lp.bottomMargin;            // 换行 判断 当前的宽度大于 开辟新行            if (lineWidth + childWidth > sizeWidth - getPaddingLeft() - getPaddingRight()) {                // 对比得到最大的宽度                width = Math.max(width, lineWidth);                // 重置lineWidth                lineWidth = childWidth;                // 记录行高                height += lineHeight;                lineHeight = childHeight;            } else { // 未换行                // 叠加行宽                lineWidth += childWidth;                // 得到当前行最大的高度                lineHeight = Math.max(lineHeight, childHeight);            }            // 特殊情况,最后一个控件            if (i == cCount - 1) {                width = Math.max(lineWidth, width);                height += lineHeight;            }        }        setMeasuredDimension(                modeWidth == MeasureSpec.EXACTLY ? sizeWidth : width + getPaddingLeft() + getPaddingRight(),                modeHeight == MeasureSpec.EXACTLY ? sizeHeight : height + getPaddingTop() + getPaddingBottom()//        );    }    /**     * 存储所有的View     */    private List<List<View>> mAllViews = new ArrayList<List<View>>();    /**     * 每一行的高度     */    private List<Integer> mLineHeight = new ArrayList<Integer>();    @Override    protected void onLayout(boolean changed, int l, int t, int r, int b) {        mAllViews.clear();        mLineHeight.clear();        // 当前ViewGroup的宽度        int width = getWidth();        int lineWidth = 0;        int lineHeight = 0;        // 存放每一行的子view        List<View> lineViews = new ArrayList<>();        int cCount = getChildCount();        for (int i = 0; i < cCount; i++) {            View child = getChildAt(i);            MarginLayoutParams lp = (MarginLayoutParams) child                    .getLayoutParams();            int childWidth = child.getMeasuredWidth();            int childHeight = child.getMeasuredHeight();            // 如果需要换行            if (childWidth + lineWidth + lp.leftMargin + lp.rightMargin > width - getPaddingLeft() - getPaddingRight()) {                // 记录LineHeight                mLineHeight.add(lineHeight);                // 记录当前行的Views                mAllViews.add(lineViews);                // 重置我们的行宽和行高                lineWidth = 0;                lineHeight = childHeight + lp.topMargin + lp.bottomMargin;                // 重置我们的View集合                lineViews = new ArrayList<View>();            }            lineWidth += childWidth + lp.leftMargin + lp.rightMargin;            lineHeight = Math.max(lineHeight, childHeight + lp.topMargin                    + lp.bottomMargin);            lineViews.add(child);        }// for end        // 处理最后一行        mLineHeight.add(lineHeight);        mAllViews.add(lineViews);        // 设置子View的位置        int left = getPaddingLeft();        int right = getPaddingRight();        int top = getPaddingTop();        // 行数        int lineNum = mAllViews.size();        for (int i = 0; i < lineNum; i++) {            // 当前行的所有的View            lineViews = mAllViews.get(i);            lineHeight = mLineHeight.get(i);            for (int j = 0; j < lineViews.size(); j++) {                View child = lineViews.get(j);                // 判断child的状态                if (child.getVisibility() == View.GONE) {                    continue;                }                MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();                int lc = 0;                int tc = 0;                int rc = 0;                int bc = 0;                WindowManager manager = (WindowManager) getContext().getSystemService(Context.WINDOW_SERVICE);                int wdWidth = manager.getDefaultDisplay().getWidth();                if (j == lineViews.size() - 1 && i == mAllViews.size() - 1) {                    //屏幕宽度减去控件宽度减去左右margin减去padding                    lc = wdWidth - right - child.getMeasuredWidth() - lp.leftMargin - lp.rightMargin;                    tc = top + lp.topMargin;                    rc = lc + child.getMeasuredWidth();                    bc = tc + child.getMeasuredHeight();                } else {                    lc = left + lp.leftMargin;                    tc = top + lp.topMargin;                    rc = lc + child.getMeasuredWidth();                    bc = tc + child.getMeasuredHeight();                }                // 为子View进行布局                child.layout(lc, tc, rc, bc);                left += child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin;            }            left = getPaddingLeft();            top += lineHeight;        }    }    /**     * 与当前ViewGroup对应的LayoutParams     */    @Override    public LayoutParams generateLayoutParams(AttributeSet attrs) {        return new MarginLayoutParams(getContext(), attrs);    }}
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