/**
* 1.自定义下划线
* 2.@authorDell
* 3.@date2017/10/11 19:18
*/
public class CustomDecoration extends RecyclerView.ItemDecoration{
public static final int HORIZONTAL_LIST= LinearLayoutManager.HORIZONTAL;
public static final int VERTICAL_LIST= LinearLayoutManager.VERTICAL;
private Drawablem Divider;
private int mOrientation;
/**
* 分割线缩进值
*/
private int inset;
private Paint paint;
/**
*@param context
*@param orientationlayout的方向
*@param drawable引入的drawable的ID
*@param inset分割线缩进值
*/
public CustomDecoration(FragmentA context,int orientation,int drawable,int inset) {
mDivider= context.getResources().getDrawable(drawable);
this.inset= inset;
paint=newPaint();
paint.setColor(context.getResources().getColor(R.color.white));
paint.setStyle(Paint.Style.FILL);
paint.setAntiAlias(true);
setOrientation(orientation);
}
public void setOrientation(int orientation) {
if(orientation !=HORIZONTAL_LIST&& orientation !=VERTICAL_LIST) {
throw newIllegalArgumentException("invalid orientation");
}
mOrientation= orientation;
}
@Override
public void onDraw(Canvas c, RecyclerView parent) {
if(mOrientation==VERTICAL_LIST) {
drawVertical(c, parent);
}else{
drawHorizontal(c, parent);
}
}
private void drawVertical(Canvas c, RecyclerView parent) {
final int left = parent.getPaddingLeft();
final int right = parent.getWidth() - parent.getPaddingRight();
final int childCount = parent.getChildCount();
//最后一个item不画分割线
for(inti =0; i < childCount -1; i++) {
final View child = parent.getChildAt(i);
final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
final int top = child.getBottom() + params.bottomMargin;
final int bottom = top +mDivider.getIntrinsicHeight();
if(inset>0) {
c.drawRect(left, top, right, bottom,paint);
mDivider.setBounds(left +inset, top, right -inset, bottom);
}else{
mDivider.setBounds(left, top, right, bottom);
}
mDivider.draw(c);
}
}
private void drawHorizontal(Canvas c, RecyclerView parent) {
final int top = parent.getPaddingTop();
final int bottom = parent.getHeight() - parent.getPaddingBottom();
final int childCount = parent.getChildCount();
for(inti =0; i < childCount -1; i++) {
final View child = parent.getChildAt(i);
final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
final int left = child.getRight() + params.rightMargin;
final int right = left +mDivider.getIntrinsicHeight();
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
}
}
//由于Divider也有宽高，每一个Item需要向下或者向右偏移
@Override
public void getItemOffsets(Rect outRect,int itemPosition, RecyclerView parent) {
if(mOrientation==VERTICAL_LIST) {
outRect.set(0,0,0,mDivider.getIntrinsicHeight());
}else{
outRect.set(0,0,mDivider.getIntrinsicWidth(),0);
}
}
}
