子view可以自动换行的父容器

import android.content.Context;import android.content.res.TypedArray;import android.util.AttributeSet;import android.view.View;import android.view.ViewGroup;import java.util.ArrayList;import java.util.List;public class FlowLayout extends ViewGroup {    private static final String TAG = "FlowLayout";    protected List<List<View>> mAllViews = new ArrayList<List<View>>();    protected List<Integer> mLineHeight = new ArrayList<Integer>();    private String mGravity;    public FlowLayout(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);        TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.TagFlowLayout);        mGravity = ta.getString(R.styleable.TagFlowLayout_gravity);        if (mGravity == null)            mGravity = getResources().getString(R.string.gravity_left);        ta.recycle();    }    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);        // wrap_content        int width = 0;        int height = 0;        int lineWidth = 0;        int lineHeight = 0;        int cCount = getChildCount();        for (int i = 0; i < cCount; i++) {            View child = getChildAt(i);            if (child.getVisibility() == View.GONE) {                if (i == cCount - 1) {                    width = Math.max(lineWidth, width);                    height += lineHeight;                }                continue;            }            measureChild(child, widthMeasureSpec, heightMeasureSpec);            MarginLayoutParams lp = (MarginLayoutParams) child                    .getLayoutParams();            int childWidth = child.getMeasuredWidth() + lp.leftMargin                    + lp.rightMargin;            int childHeight = child.getMeasuredHeight() + lp.topMargin                    + lp.bottomMargin;            if (lineWidth + childWidth > sizeWidth - getPaddingLeft() - getPaddingRight()) {                width = Math.max(width, lineWidth);                lineWidth = childWidth;                height += lineHeight;                lineHeight = childHeight;            } else {                lineWidth += childWidth;                lineHeight = Math.max(lineHeight, childHeight);            }            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()//        );    }    @Override    protected void onLayout(boolean changed, int l, int t, int r, int b) {        mAllViews.clear();        mLineHeight.clear();        int width = getWidth();        int lineWidth = 0;        int lineHeight = 0;        List<View> lineViews = new ArrayList<View>();        int cCount = getChildCount();        for (int i = 0; i < cCount; i++) {            View child = getChildAt(i);            if (child.getVisibility() == View.GONE) continue;            MarginLayoutParams lp = (MarginLayoutParams) child                    .getLayoutParams();            int childWidth = child.getMeasuredWidth();            int childHeight = child.getMeasuredHeight();            if (childWidth + lineWidth + lp.leftMargin + lp.rightMargin > width - getPaddingLeft() - getPaddingRight()) {                mLineHeight.add(lineHeight);                mAllViews.add(lineViews);                lineWidth = 0;                lineHeight = childHeight + lp.topMargin + lp.bottomMargin;                lineViews = new ArrayList<View>();            }            lineWidth += childWidth + lp.leftMargin + lp.rightMargin;            lineHeight = Math.max(lineHeight, childHeight + lp.topMargin                    + lp.bottomMargin);            lineViews.add(child);        }        mLineHeight.add(lineHeight);        mAllViews.add(lineViews);        int left = getPaddingLeft();        int top = getPaddingTop();        int lineNum = mAllViews.size();        for (int i = 0; i < lineNum; i++) {            lineViews = mAllViews.get(i);            lineHeight = mLineHeight.get(i);            left = getStartLeft(lineViews);            for (int j = 0; j < lineViews.size(); j++) {                View child = lineViews.get(j);                if (child.getVisibility() == View.GONE) {                    continue;                }                MarginLayoutParams lp = (MarginLayoutParams) child                        .getLayoutParams();                int lc = left + lp.leftMargin;                int tc = top + lp.topMargin;                int rc = lc + child.getMeasuredWidth();                int bc = tc + child.getMeasuredHeight();                child.layout(lc, tc, rc, bc);                left += child.getMeasuredWidth() + lp.leftMargin                        + lp.rightMargin;            }            top += lineHeight;        }    }    private int getStartLeft(List<View> lineViews) {        int left = getPaddingLeft();        int needWidth = 0;        for (int j = 0; j < lineViews.size(); j++) {            View child = lineViews.get(j);            if (child.getVisibility() == View.GONE) {                continue;            }            MarginLayoutParams lp = (MarginLayoutParams) child                    .getLayoutParams();            needWidth += child.getMeasuredWidth() + lp.leftMargin                    + lp.rightMargin;        }        needWidth += getPaddingLeft() + getPaddingRight();        if (mGravity.equals(getResources().getString(R.string.gravity_center))) {            if (getMeasuredWidth() > needWidth) {                left += (getMeasuredWidth() - needWidth) / 2;            }        } else if (mGravity.equals(getResources().getString(R.string.gravity_right))) {            if (getMeasuredWidth() > needWidth) {                left += getMeasuredWidth() - needWidth;            }        }        return left;    }    @Override    public LayoutParams generateLayoutParams(AttributeSet attrs) {        return new MarginLayoutParams(getContext(), attrs);    }    @Override    protected LayoutParams generateDefaultLayoutParams() {        return new MarginLayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);    }    @Override    protected LayoutParams generateLayoutParams(LayoutParams p) {        return new MarginLayoutParams(p);    }}