package com.liaoinstan.dragrecyclerview.common
;
import android.content.Context
;
import android.content.res.TypedArray
;
import android.graphics.Canvas
;
import android.graphics.Rect
;
import android.graphics.drawable.Drawable
;
import android.support.v7.widget.GridLayoutManager
;
import android.support.v7.widget.RecyclerView
;
import android.support.v7.widget.RecyclerView.LayoutManager
;
import android.support.v7.widget.RecyclerView.State
;
import android.support.v7.widget.StaggeredGridLayoutManager
;
import android.view.View
;
/**
* @author zhy
*/
public class DividerGridItemDecoration
extends RecyclerView.ItemDecoration {
private static final int[]
ATTRS =
new int[]{android.R.attr.
listDivider}
;
private Drawable
mDivider;
private int lineWidth =
2;
public DividerGridItemDecoration(Context context) {
final TypedArray a = context.obtainStyledAttributes(
ATTRS)
;
mDivider = a.getDrawable(
0)
;
a.recycle()
;
}
@Override
public void onDraw(Canvas c
, RecyclerView parent
, State state) {
drawHorizontal(c
, parent)
;
drawVertical(c
, parent)
;
}
private int getSpanCount(RecyclerView parent) {
// 列数
int spanCount = -
1;
LayoutManager layoutManager = parent.getLayoutManager()
;
if (layoutManager
instanceof GridLayoutManager) {
spanCount = ((GridLayoutManager) layoutManager).getSpanCount()
;
}
else if (layoutManager
instanceof StaggeredGridLayoutManager) {
spanCount = ((StaggeredGridLayoutManager) layoutManager)
.getSpanCount()
;
}
return spanCount
;
}
public void drawHorizontal(Canvas c
, RecyclerView parent) {
int childCount = parent.getChildCount()
;
for (
int i =
0; i < childCount
; i++) {
final View child = parent.getChildAt(i)
;
final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
.getLayoutParams()
;
final int left = child.getLeft() - params.
leftMargin;
final int right = child.getRight() + params.
rightMargin +
lineWidth;
final int top = child.getBottom() + params.
bottomMargin;
final int bottom = top +
lineWidth;
mDivider.setBounds(left
, top
, right
, bottom)
;
mDivider.draw(c)
;
}
}
public void drawVertical(Canvas c
, RecyclerView parent) {
final int childCount = parent.getChildCount()
;
for (
int i =
0; i < childCount
; i++) {
final View child = parent.getChildAt(i)
;
final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams()
;
final int top = child.getTop() - params.
topMargin;
final int bottom = child.getBottom() + params.
bottomMargin;
final int left = child.getRight() + params.
rightMargin;
final int right = left +
lineWidth;
mDivider.setBounds(left
, top
, right
, bottom)
;
mDivider.draw(c)
;
}
}
private boolean isLastColum(RecyclerView parent
, int pos
, int spanCount
, int childCount) {
LayoutManager layoutManager = parent.getLayoutManager()
;
if (layoutManager
instanceof GridLayoutManager) {
if ((pos +
1) % spanCount ==
0)
// 如果是最后一列，则不需要绘制右边
{
return true;
}
}
else if (layoutManager
instanceof StaggeredGridLayoutManager) {
int orientation = ((StaggeredGridLayoutManager) layoutManager)
.getOrientation()
;
if (orientation == StaggeredGridLayoutManager.
VERTICAL) {
if ((pos +
1) % spanCount ==
0)
// 如果是最后一列，则不需要绘制右边
{
return true;
}
}
else {
childCount = childCount - childCount % spanCount
;
if (pos >= childCount)
// 如果是最后一列，则不需要绘制右边
return true;
}
}
return false;
}
private boolean isLastRaw(RecyclerView parent
, int pos
, int spanCount
, int childCount) {
LayoutManager layoutManager = parent.getLayoutManager()
;
if (layoutManager
instanceof GridLayoutManager) {
childCount = childCount - childCount % spanCount
;
if (pos >= childCount)
// 如果是最后一行，则不需要绘制底部
return true;
}
else if (layoutManager
instanceof StaggeredGridLayoutManager) {
int orientation = ((StaggeredGridLayoutManager) layoutManager)
.getOrientation()
;
// StaggeredGridLayoutManager 且纵向滚动
if (orientation == StaggeredGridLayoutManager.
VERTICAL) {
childCount = childCount - childCount % spanCount
;
// 如果是最后一行，则不需要绘制底部
if (pos >= childCount)
return true;
}
else
// StaggeredGridLayoutManager 且横向滚动
{
// 如果是最后一行，则不需要绘制底部
if ((pos +
1) % spanCount ==
0) {
return true;
}
}
}
return false;
}
@Override
public void getItemOffsets(Rect outRect
, View view
, RecyclerView parent
, State state) {
// Log.e("liao", state.toString());
boolean b = state.willRunPredictiveAnimations()
;
int itemPosition = ((RecyclerView.LayoutParams) view.getLayoutParams()).getViewLayoutPosition()
;
int spanCount = getSpanCount(parent)
;
int childCount = parent.getAdapter().getItemCount()
;
// if (isLastRaw(parent, itemPosition, spanCount, childCount))// 如果是最后一行，则不需要绘制底部
// {
// outRect.set(0, 0, lineWidth, 0);
// }
// else if (isLastColum(parent, itemPosition, spanCount, childCount))// 如果是最后一列，则不需要绘制右边
// {
if (b){
outRect.set(0, 0, lineWidth, lineWidth);
}else {
// outRect.set(0, 0, 0, lineWidth);
}
// }
// else {
outRect.set(
0, 0, lineWidth, lineWidth)
;
// }
}
}
