I know this question already has an answer, But I don't want the answer. I would like to solve it! Every answer says that in order to add dots indicator into your recycler view, you create a class more like this:
public class DotsIndicatorDecoration extends RecyclerView.ItemDecoration {
private int colorActive = 0xDE000000;
private int colorInactive = 0x33000000;
private static final float DP = Resources.getSystem().getDisplayMetrics().density;
/**
* Height of the space the indicator takes up at the bottom of the view.
*/
private final int mIndicatorHeight = (int) (DP * 16);
/**
* Indicator stroke width.
*/
private final float mIndicatorStrokeWidth = DP * 4;
/**
* Indicator width.
*/
private final float mIndicatorItemLength = DP * 4;
/**
* Padding between indicators.
*/
private final float mIndicatorItemPadding = DP * 8;
/**
* Some more natural animation interpolation
*/
private final Interpolator mInterpolator = new AccelerateDecelerateInterpolator();
private final Paint mPaint = new Paint();
public DotsIndicatorDecoration() {
mPaint.setStrokeWidth(mIndicatorStrokeWidth);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setAntiAlias(true);
}
@Override
public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
super.onDrawOver(c, parent, state);
int itemCount = parent.getAdapter().getItemCount();
// center horizontally, calculate width and subtract half from center
float totalLength = mIndicatorItemLength * itemCount;
float paddingBetweenItems = Math.max(0, itemCount - 1) * mIndicatorItemPadding;
float indicatorTotalWidth = totalLength + paddingBetweenItems;
float indicatorStartX = (parent.getWidth() - indicatorTotalWidth) / 2F;
// center vertically in the allotted space
float indicatorPosY = parent.getHeight() - mIndicatorHeight / 2F;
drawInactiveIndicators(c, indicatorStartX, indicatorPosY, itemCount);
// find active page (which should be highlighted)
LinearLayoutManager layoutManager = (LinearLayoutManager) parent.getLayoutManager();
int activePosition = layoutManager.findFirstVisibleItemPosition();
if (activePosition == RecyclerView.NO_POSITION) {
return;
}
// find offset of active page (if the user is scrolling)
final View activeChild = layoutManager.findViewByPosition(activePosition);
int left = activeChild.getLeft();
int width = activeChild.getWidth();
int right = activeChild.getRight();
// on swipe the active item will be positioned from [-width, 0]
// interpolate offset for smooth animation
float progress = mInterpolator.getInterpolation(left * -1 / (float) width);
drawHighlights(c, indicatorStartX, indicatorPosY, activePosition, progress);
}
private void drawInactiveIndicators(Canvas c, float indicatorStartX, float indicatorPosY, int itemCount) {
mPaint.setColor(colorInactive);
// width of item indicator including padding
final float itemWidth = mIndicatorItemLength + mIndicatorItemPadding;
float start = indicatorStartX;
for (int i = 0; i < itemCount; i++) {
c.drawCircle(start, indicatorPosY, mIndicatorItemLength / 2F, mPaint);
start += itemWidth;
}
}
private void drawHighlights(Canvas c, float indicatorStartX, float indicatorPosY,
int highlightPosition, float progress) {
mPaint.setColor(colorActive);
// width of item indicator including padding
final float itemWidth = mIndicatorItemLength + mIndicatorItemPadding;
if (progress == 0F) {
// no swipe, draw a normal indicator
float highlightStart = indicatorStartX + itemWidth * highlightPosition;
c.drawCircle(highlightStart, indicatorPosY, mIndicatorItemLength / 2F, mPaint);
} else {
float highlightStart = indicatorStartX + itemWidth * highlightPosition;
// calculate partial highlight
float partialLength = mIndicatorItemLength * progress + mIndicatorItemPadding*progress;
c.drawCircle(highlightStart + partialLength, indicatorPosY, mIndicatorItemLength / 2F, mPaint);
}
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
super.getItemOffsets(outRect, view, parent, state);
outRect.bottom = mIndicatorHeight;
}
}
But the problem with this code is that the dots don't actually appear on the recyclerview. It appears under it just like this:
Is it possible for me to change it's position on the y axis so it becomes on the recycler view?
try to increase indicatorPosY value, it becomes to vertical position.
you could try changing this line
float indicatorPosY = parent.getHeight() - mIndicatorHeight / 2F;
to
float indicatorPosY = parent.getHeight()/6 - mIndicatorHeight / 0.1F;
Try removing this method
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
super.getItemOffsets(outRect, view, parent, state);
outRect.bottom = mIndicatorHeight;
}
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