RecyclerView.itemDecoration onDraw c.drawLine incompatible with pre-installed devices?
I am trying to create my own CustomDivider class that extends to RecyclerView
. ItemDecoration is based on Google swatches that have a separator. Luckily, the code I tried works, but I only tried it in an emulator that works in Lollipop
, and I found it doesn't work on my device Kitkat
.
Here is a screenshot of the emulator and the result.
Here is a screenshot from my Asus Zenfone 4 running Kitkat.
Here is my code:
public class CustomDivider extends RecyclerView.ItemDecoration {
public static final int LINEAR_HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;
public static final int LINEAR_VERTICAL_LIST = LinearLayoutManager.VERTICAL;
public static final int LINE_FLAT = 0;
private Paint paint = new Paint();
private int color;
private int orientation;
private int top, bottom, left, right;
private int lineType; //TODO LineTypes
private View child;
public CustomDivider(Context context, int orientation, int resourceColor) {
color = context.getResources().getColor(resourceColor);
paint.setColor(color);
paint.setStrokeWidth(3);
checkOrientation(orientation);
lineType = LINE_FLAT;
}
private void checkOrientation(int orientation) {
if (orientation != LINEAR_HORIZONTAL_LIST && orientation != LINEAR_VERTICAL_LIST) {
throw new IllegalArgumentException("Invalid Orientation");
} else
this.orientation = orientation;
}
@Override
public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
super.onDraw(c, parent, state);
if (orientation == LINEAR_HORIZONTAL_LIST) {
//drawLinearHorizontalDivider(c, parent);
} else if (orientation == LINEAR_VERTICAL_LIST) {
drawLinearVerticalDivider(c, parent);
}
}
private void drawLinearVerticalDivider(Canvas c, RecyclerView parent) {
left = parent.getLeft();
right = parent.getWidth();
for (int i = 0; i < parent.getChildCount(); i++) {
child = parent.getChildAt(i);
top = child.getTop();
bottom = child.getBottom();
Log.d("Dimensions: ", "Top is: " + top + ", Bottom is " + bottom);
if (i != parent.getChildCount() - 1) {
c.drawLine(left, bottom, right, bottom, paint);
}
}
}
@Override
public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
super.onDrawOver(c, parent, state);
}
}
Can anyone provide more information on whether I am missing something?
+3
source to share
2 answers
Below is a good example, take a look at it:
public class DividerItemDecoration extends RecyclerView.ItemDecoration {
private static final int[] ATTRS = new int[]{
android.R.attr.listDivider
};
public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;
public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;
private Drawable mDivider;
private int mOrientation;
public DividerItemDecoration(Context context, int orientation) {
final TypedArray a = context.obtainStyledAttributes(ATTRS);
mDivider = a.getDrawable(0);
a.recycle();
setOrientation(orientation);
}
public void setOrientation(int orientation) {
if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) {
throw new IllegalArgumentException("invalid orientation");
}
mOrientation = orientation;
}
@Override
public void onDraw(Canvas c, RecyclerView parent) {
if (mOrientation == VERTICAL_LIST) {
drawVertical(c, parent);
} else {
drawHorizontal(c, parent);
}
}
public void drawVertical(Canvas c, RecyclerView parent) {
final int left = parent.getPaddingLeft();
final int right = parent.getWidth() - parent.getPaddingRight();
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.getBottom() + params.bottomMargin;
final int bottom = top + mDivider.getIntrinsicHeight();
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
}
}
public void drawHorizontal(Canvas c, RecyclerView parent) {
final int top = parent.getPaddingTop();
final int bottom = parent.getHeight() - parent.getPaddingBottom();
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 left = child.getRight() + params.rightMargin;
final int right = left + mDivider.getIntrinsicHeight();
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
}
}
@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);
}
}
}
And here is my Snippet, it works well which divisor is clear and subtle:
public static class RecyclerViewFragment extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.fragment_recyclerview, container, false);
RecyclerView recyclerView = (RecyclerView) root.findViewById(R.id.recycler_view);
recyclerView.setHasFixedSize(true);
recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
recyclerView.addItemDecoration(new DividerItemDecoration(getActivity(), DividerItemDecoration.VERTICAL_LIST));
RecyclerViewAdapter adapter = new RecyclerViewAdapter(getActivity(), getResources()
.getStringArray(R.array.countries));
recyclerView.setAdapter(adapter);
return root;
}
}
Hope you get inspired.
+2
source to share
After reading this answer: fooobar.com/questions/2227661 / ...
Which is also indicated for overriding onDrawOver, I edited my code and put my code that was inside onDraw in onDrawOver and found that the divider is now showing in Pre-Lollipop devices.
@Override
public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
super.onDrawOver(c, parent, state);
if (orientation == LINEAR_HORIZONTAL_LIST) {
//drawLinearHorizontalDivider(c, parent);
} else if (orientation == LINEAR_VERTICAL_LIST) {
drawLinearVerticalDivider(c, parent);
}
}
+1
source to share