Android：将任意变换应用于视图

最后,我基于AbsoluteLayout创建了自己的布局,在我的LayoutParams中添加了@L_192_4@matrix,利用了getChildStaticTransformation,并覆盖了dispatchTouchEvent,以便我的孩子在旋转时响应正确的边界.比我预想的要困难得多.

public class UIViewLayout extends ViewGroup {

@Override
protected Boolean getChildStaticTransformation(View child,Transformation t) {
    if(child instanceof UIViewLayout) {
        t.getMatrix().reset();
        UIViewLayout.LayoutParams params = (UIViewLayout.LayoutParams)child.getLayoutParams();
        t.setTransformationType(Transformation.TYPE_MATRIX);
        t.getMatrix().set(params.matriX);
    }
    return true;
}

public UIViewLayout(android.content.Context context) {
    super(context);
    this.setClipChildren(false);
    this.setCliPTOPadding(false);
    this.setChildrenDrawingOrderEnabled(true);
    this.setStaticTransformationsEnabled(true);
}

public UIViewLayout(Context context,AttributeSet attrs) {
    super(context,attrs);
}

public UIViewLayout(Context context,AttributeSet attrs,int defStylE) {
    super(context,attrs,defStylE);
}

@Override
protected void onMeasure(int widthMeasureSpec,int heightMeasureSpeC) {
    int count = getChildCount();

    int maxHeight = 0;
    int maxWidth = 0;

    // Find out how big everyone wants to be
    measureChildren(widthMeasureSpec,heightMeasureSpec);

    // Find rightmost and bottom-most child
    for (int i = 0; i < count; i++) {
        View child = getChildAt(i);
        if (child.getVisibility() != GONE) {
            int childRight;
            int childBottom;

            UIViewLayout.LayoutParams lp
                    = (UIViewLayout.LayoutParams) child.getLayoutParams();

            childRight = lp.x + child.getMeasuredWidth();
            childBottom = lp.y + child.getMeasuredHeight();

            maxWidth = Math.max(maxWidth,childRight);
            maxHeight = Math.max(maxHeight,childBottom);
        }
    }

    // Account for padding too
    //maxWidth += mPaddingLeft + mPaddingRight;
    //maxHeight += mPaddingTop + mPaddingBottom;

    // check against minimum height and width
    maxHeight = Math.max(maxHeight,getSuggestedMinimumHeight());
    maxWidth = Math.max(maxWidth,getSuggestedMinimumWidth());

    setMeasuredDimension(resolveSizeAndState(maxWidth,widthMeasureSpec,0),resolveSizeAndState(maxHeight,heightMeasureSpec,0));
}

@Override
protected ViewGroup.LayoutParams generateDefaultLayoutParams() {
    return new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT,0);
}

@Override
protected void onLayout(Boolean changed,int l,int t,int r,int b) {
    int count = getChildCount();

    for (int i = 0; i < count; i++) {
        View child = getChildAt(i);
        if (child.getVisibility() != GONE) {

            UIViewLayout.LayoutParams lp =
                    (UIViewLayout.LayoutParams) child.getLayoutParams();

            int childLeft = lp.x;
            int childTop = lp.y;
            child.layout(childLeft,childTop,childLeft + child.getMeasuredWidth(),childTop + child.getMeasuredHeight());

        }
    }
}

@Override
public ViewGroup.LayoutParams generateLayoutParams(AttributeSet attrs) {
    return new UIViewLayout.LayoutParams(getContext(),attrs);
}

// Override to allow type-checking of LayoutParams.
@Override
protected Boolean checkLayoutParams(ViewGroup.LayoutParams p) {
    return p instanceof UIViewLayout.LayoutParams;
}

@Override
protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
    return new LayoutParams(p);
}

@Override
public Boolean shouldDelayChildPressedState() {
    return false;
}

@Override
public Boolean dispatchTouchEvent(MotionEvent ev) {
    for(int i = 0; i < this.getChildCount(); i++) {
        View child = getChildAt(i);
        if(child instanceof UIViewLayout) {
            UIViewLayout.LayoutParams params = (UIViewLayout.LayoutParams)child.getLayoutParams();
            if(!params.matrix.isIdentity()) {
                MotionEvent ev2 = MotionEvent.obtain(ev);

                ev2.setLOCATIOn(ev2.getX() - params.x,ev2.getY() - params.y);

                Matrix m = new Matrix();
                params.matrix.invert(m);
                ev2.transform(m);
                if(child.dispatchTouchEvent(ev2)) {
                    return true;
                }
                ev2.recycle();
            }
        }
    }
    return super.dispatchTouchEvent(ev);
}

public static class LayoutParams extends ViewGroup.LayoutParams {
    public int x;
    public int y;
    public Matrix matrix;

    public LayoutParams(int width,int height,int x,int y) {
        super(width,height);
        this.x = x;
        this.y = y;
        this.matrix = new Matrix();
    }

    public LayoutParams(Context c,AttributeSet attrs) {
        super(c,attrs);
    }

    public LayoutParams(ViewGroup.LayoutParams sourcE) {
        super(sourcE);
    }
}

}