在onLayout期间隐藏孩子

Question

我试图在onLayout期间隐藏视图中的孩子。问题是postInvalidate在我隐藏孩子

后没有调用onLayout

    public class EllipseFlowLayout extends ViewGroup {
    private int paddingHorizontal;
    private int paddingVertical;
    private int mMaxLines = -1;
    private EllipseView mEllipse;
    private View ellipseView;
    private int numHidden;
    private boolean mEllipseRemoved = true;

    public EllipseFlowLayout(Context context) {
        super(context);
        init();
    }

    public void setMaxLines(int max) {
        mMaxLines = max;
    }

    public EllipseFlowLayout(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public EllipseFlowLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }

    private void init() {
        paddingHorizontal = getResources().getDimensionPixelSize(R.dimen.flowlayout_horizontal_padding);
        paddingVertical = getResources().getDimensionPixelSize(R.dimen.flowlayout_vertical_padding);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        int childLeft = getPaddingLeft();
        int childTop = getPaddingTop();
        int lineHeight = 0;
        int numLines = 1;
        // 100 is a dummy number, widthMeasureSpec should always be EXACTLY for FlowLayout
        int myWidth = resolveSize(MeasureSpec.EXACTLY, widthMeasureSpec);
        int wantedHeight = 0;
        for (int i = 0; i < getChildCount(); i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() == View.GONE || child.getTag() == GONE) {
                continue;
            }
            // let the child measure itself
            child.measure(
                    getChildMeasureSpec(widthMeasureSpec, 0, child.getLayoutParams().width),
                    getChildMeasureSpec(heightMeasureSpec, 0, child.getLayoutParams().height));
            int childWidth = child.getMeasuredWidth();
            int childHeight = child.getMeasuredHeight();



            // lineheight is the height of current line, should be the height of the heightest view
            lineHeight = Math.max(childHeight, lineHeight);
            if (childWidth + childLeft + getPaddingRight() > myWidth) {
                // wrap this line
                childLeft = getPaddingLeft();
                childTop += paddingVertical + lineHeight;
                lineHeight = childHeight;
                numLines++;
                Log.d("TEST", "measure" + numLines);
            }
            childLeft += childWidth + paddingHorizontal;
        }



        wantedHeight += childTop + lineHeight + getPaddingBottom();
        setMeasuredDimension(myWidth, resolveSize(wantedHeight, heightMeasureSpec));
    }

    @Override
    public void addView(View child) {
        //super.addView(child);
        if (mEllipseRemoved) {
            addEllipseView();
        }
        super.addView(child, getChildCount() - 1);
    }

    public void setEllipseView(EllipseView ellipse) {
        mEllipse = ellipse;
        ellipseView = mEllipse.getView();
    }

    @Override
    public void removeAllViews() {
        mEllipseRemoved = true;
        super.removeAllViews();
    }

    private void addEllipseView() {
        mEllipseRemoved = false;
        if (ellipseView.getParent() != null) {
            ((ViewGroup) ellipseView.getParent()).removeView(ellipseView);
        }
        ellipseView.setVisibility(View.GONE);
        addView(ellipseView);
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        int childLeft = getPaddingLeft();
        int childTop = getPaddingTop();
        int lineHeight = 0;
        int myWidth = right - left;
        int lineNum = 1;
        for (int i = 0; i < getChildCount(); i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() == View.GONE) {
                continue;
            }
            int childWidth = child.getMeasuredWidth();
            int childHeight = child.getMeasuredHeight();
            lineHeight = Math.max(childHeight, lineHeight);
            if (childWidth + childLeft + getPaddingRight() > myWidth) {
                childLeft = getPaddingLeft();
                childTop += paddingVertical + lineHeight;
                lineHeight = childHeight;
                lineNum++;
                Log.d("TEST", "layout" + lineNum);
            }


            child.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight);
            childLeft += childWidth + paddingHorizontal;

        }
        if (lineNum > mMaxLines) {
//            if (ellipseView.getVisibility() == View.GONE) {
//                ellipseView.setVisibility(VISIBLE);
//            }
            //Skip the last view which is the hidden one
            int at = numHidden;
            if (at < getChildCount() && getChildAt(at) != null) {
                View child = getChildAt(at);
                numHidden++;
                if (child.getVisibility() == View.VISIBLE) {
                    child.setVisibility(View.GONE);
                    child.setTag(GONE);
                    requestLayout();
                }

            }
            if (mEllipse.getCount() != numHidden) {
                mEllipse.setEllipseSize(numHidden);
            }
        }
    }

    /**
     * Was removed so semi untested but leaving for possible use later
     *
     * @param max max children
     */
    public void setMaxChildren(int max) {
    }
}

Answer 1

隐藏onDraw中的视图记得调用this.setWillNotDraw（false）;