CODEWITHSUNDEEP
androidandroid-recyclerview
Harshit
Harshit

Reputation: 633

Percentage of a layout inside RecyclerView visible on Screen

Is there a way from which I can know what percentage of my layout inside a recyclerView is visible on the Screen.

The layout inflated inside RecyclerView has params of

android:layout_width="match_parent" android:layout_height="match_parent"

Edit added layout file

Layout file - custom_card.xml

    <?xml version="1.0" encoding="utf-8"?
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/card"
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">


    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignBottom="@id/imageView"
        android:layout_alignTop="@id/imageView"
        android:scaleType="fitCenter"
        android:src="@drawable/image_view_screen" />

</RelativeLayout>

Activity Layout File. 

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView
    android:id="@+id/recyclerView"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />
    <ProgressBar
        android:visibility="gone"
        android:layout_width="56dp"
        android:layout_height="56dp"
        android:id="@+id/progress_bar"
        android:layout_centerInParent="true"/>
</RelativeLayout>

I am using a Vertical LinearLayoutManager

Upvotes: 4

Views: 1945

Answers (2)

drojokef
drojokef

Reputation: 425

use this; in your adapter;

    private final Rect mCurrentViewRect = new Rect();
... your inits...

in your onBindViewHolder;

 View firstItemView = linearLayoutManager.findViewByPosition(position);
                                int pos= getVisibilityPercents(position);

use these metods;

  public int getVisibilityPercents(View currentView) {


    int percents = 100;

    currentView.getLocalVisibleRect(mCurrentViewRect);

    int height = currentView.getHeight();

    if (viewIsPartiallyHiddenTop()) { 
        percents = (height - mCurrentViewRect.top) * 100 / height;
    } else if (viewIsPartiallyHiddenBottom(height)) {  
        percents = mCurrentViewRect.bottom * 100 / height;
    }

    return percents;
}

private boolean viewIsPartiallyHiddenBottom(int height) {
    return mCurrentViewRect.bottom > 0 && mCurrentViewRect.bottom < height;
}

private boolean viewIsPartiallyHiddenTop() {
    return mCurrentViewRect.top > 0;
}

btw, dont remember get your recyclerView and linearLayoutManager to your adapter in constructor.

For more => https://github.com/danylovolokh/VideoPlayerManager

Upvotes: -1

Harshit
Harshit

Reputation: 633

After much Try I figured it out. If it helps anyone.

Since my layout height was match_parent it was easier for me. But this method will work for everyone with some calculations.

int firstItemPos=mLayoutManager.findFirstVisibleItemPosition();
View firstItemView=mLayoutManager.findViewByPosition(firstItemPos);
int lastItemPos=mLayoutManager.findLastVisibleItemPosition();
View lastItemView=mLayoutManager.findViewByPosition(lastItemPos);

Now all items between firstItemPos and lastItemPos is visible 100%.

For firstItemView- 

Math.abs(firstItemView.getY()) / firstItemView.getHeight()

Similarly for lastItemView- 

Math.abs(lastItemView.getY()) / lastItemView.getHeight()

Upvotes: 2

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