I am working to achieve a recycler view interface that looks like this:
Presently, am only using a recyclerview with LinearLayoutManager using an adapter with two viewholders, i tried gridLayout manager too but i did not achieve the target interface: I need help achieving this, Do i have to create a custom Layout Manager? or What exactly do i have to do? Please, I am really stuck on this.
This is my adapter code
public class SimpleStringRecyclerViewAdapter : RecyclerView.Adapter
{
private List<Data> mValues;
private Context context;
private const int TYPE_FULL = 0;
private const int TYPE_HALF = 1;
private const int TYPE_QUARTER = 2;
public SimpleStringRecyclerViewAdapter(Context context, List<Data> items)
{
this.context = context;
mValues = items;
}
public override int ItemCount
{
get
{
return mValues.Count();
}
}
public override void OnBindViewHolder(RecyclerView.ViewHolder holder, int position)
{
if (holder is SimpleViewHolder)
try
{
Data item = mValues.ElementAt(position);
var simpleHolder = holder as SimpleViewHolder;
simpleHolder.mTxtView.Text = Android.Text.Html.FromHtml(item.article.Title).ToString();
simpleHolder.mTxtView2.Text = item.article.Description;
using (var imageView = simpleHolder.mImageView)
{
string url = Android.Text.Html.FromHtml(item.article.UrlToImage).ToString();
//Download and display image
UrlImageViewHelper.SetUrlDrawable(imageView,
url, Resource.Drawable.cheese_1
);
}
// simpleHolder.mprogressbar.Visibility = ViewStates.Gone;
}
catch (Exception e)
{
//Toast.MakeText(this.context, e.ToString(), ToastLength.Long).Show();
}
else
{
try
{
Data item = mValues.ElementAt(position);
var simpleHolder = holder as SimpleViewHolder2;
simpleHolder.mTxtView.Text = Android.Text.Html.FromHtml(item.youTubeItem.Title).ToString();
// simpleHolder.mTxtView2.Text = item.DescriptionShort;
using (var imageView = simpleHolder.mImageView)
{
string url = Android.Text.Html.FromHtml(item.youTubeItem.MaxResThumbnailUrl).ToString();
//Download and display image
UrlImageViewHelper.SetUrlDrawable(imageView,
url, Resource.Drawable.cheese_1
);
}
}
catch (Exception e)
{
//Toast.MakeText(this.context, e.ToString(), ToastLength.Long).Show();
}
}
}
public override int GetItemViewType(int position)
{
if (mValues.ElementAt(position).type == 1)
{
return Resource.Layout.ItemsList;
}
else
{
return Resource.Layout.VideoList;
}
}
public override RecyclerView.ViewHolder OnCreateViewHolder(ViewGroup parent, int viewType)
{
if (viewType == Resource.Layout.ItemsList)
{
View view = LayoutInflater.From(parent.Context).Inflate(Resource.Layout.ItemsList, parent, false);
view.SetBackgroundColor(Color.White);
SimpleViewHolder holder = new SimpleViewHolder(view);
// holder.mprogressbar = view.FindViewById<ProgressBar>(Resource.Id.progressBar);
// holder.mprogressbar.Visibility = ViewStates.Visible;
//Showing loading progressbar
return holder;
}
else
{
View view = LayoutInflater.From(parent.Context).Inflate(Resource.Layout.VideoList, parent, false);
view.SetBackgroundColor(Color.White);
SimpleViewHolder2 holder = new SimpleViewHolder2(view);
return holder;
}
}
}
public class SimpleViewHolder : RecyclerView.ViewHolder
{
public string mBoundString;
public readonly View mView;
public readonly ImageView mImageView;
public readonly TextView mTxtView;
public readonly TextView mTxtView2;
// public ProgressBar mprogressbar;
public SimpleViewHolder(View view) : base(view)
{
mView = view;
mImageView = view.FindViewById<ImageView>(Resource.Id.avatar2);
mTxtView = view.FindViewById<TextView>(Resource.Id.Text11);
mTxtView2 = view.FindViewById<TextView>(Resource.Id.Text12);
// mprogressbar = view.FindViewById<ProgressBar>(Resource.Id.progressBar);
}
public override string ToString()
{
return base.ToString() + " '" + mTxtView.Text;
}
}
public class SimpleViewHolder2 : RecyclerView.ViewHolder
{
public string mBoundString;
public readonly View mView;
public readonly ImageView mImageView;
public readonly TextView mTxtView;
public readonly TextView mTxtView2;
public SimpleViewHolder2(View view) : base(view)
{
mView = view;
mImageView = view.FindViewById<ImageView>(Resource.Id.videoavatar);
mTxtView = view.FindViewById<TextView>(Resource.Id.videoText1);
// mprogressbar = view.FindViewById<ProgressBar>(Resource.Id.progressBar);
}
}
SetUpRecyclerView Method:
dataUse = OfflineDeserializer.OfflineData(content, json2);
recyclerView.SetLayoutManager(new LinearLayoutManager(recyclerView.Context));
recyclerView.SetAdapter(new SimpleStringRecyclerViewAdapter(recyclerView.Context, dataUse));
if (vp.IsShown)
{
vp.Visibility = ViewStates.Invisible;
}
This is what I have presently:
you can use recycler view with multiple view type
here is the link you can refer
Recyclerview with multiple view types
Here is a sample code you can modify it according to your need
public class MyFeedsAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
final int
VIDEO = 1,
IMAGE = 2,
AUDIO = 3;
public MyFeedsAdapter(HomeActivity homeActivity, ArrayList<MyFeedsModel> list, MyFeedsFragment myFeedsFragment) {
this.activity = homeActivity;
this.list = list;
this.myFeedsFragment = myFeedsFragment;
metrics = new DisplayMetrics();
activity.getWindowManager().getDefaultDisplay().getMetrics(metrics);
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view;
switch (viewType) {
case VIDEO:
view = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_myfeeds, parent, false);
return new ViewForVideo(view);
case IMAGE:
view = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_myfeeds, parent, false);
return new ViewForImage(view);
case AUDIO:
view = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_myfeeds, parent, false);
return new ViewForAudio(view);
default:
return null;
}
}
#Override
public void onBindViewHolder(final RecyclerView.ViewHolder holder, final int position) {
if (list.get(position).getFile_type().equals(IntentString.VIDEO)) {
setViewForVideo((ViewForVideo) holder, position);
} else if (list.get(position).getFile_type().equals(IntentString.IMAGE)) {
setViewForImage((ViewForImage) holder, position);
} else if (list.get(position).getFile_type().equals(IntentString.AUDIO)) {
setViewForAudio((ViewForAudio) holder, position);
}
}
#Override
public int getItemCount() {
return list.size();
}
#Override
public int getItemViewType(int position) {
if (list.get(position).getFile_type().equals(IntentString.VIDEO)) {
return VIDEO;
} else if (list.get(position).getFile_type().equals(IntentString.IMAGE)) {
return IMAGE;
} else if (list.get(position).getFile_type().equals(IntentString.AUDIO)) {
return AUDIO;
} else {
return 0;
}
}
public void setViewForVideo(final ViewForVideo holder, final int position) {
}
public void setViewForImage(final ViewForImage holder, final int position) {
}
public void setViewForAudio(final ViewForAudio holder, int position) {
}
public class ViewForVideo extends RecyclerView.ViewHolder {
public ViewForVideo(View itemView) {
super(itemView);
}
}
public class ViewForImage extends RecyclerView.ViewHolder {
public ViewForImage(View itemView) {
super(itemView);
ButterKnife.bind(this, itemView);
}
}
public class ViewForAudio extends RecyclerView.ViewHolder {
public ViewForAudio(View itemView) {
super(itemView);
ButterKnife.bind(this, itemView);
}
}
}
I want to hide/show FloatingActionButton on scroll of RecyclerView.
My XML layout :
<android.support.design.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="match_parent" >
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerview_eventlist"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab_createevent"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="#dimen/fab_margin"
app:layout_anchor="#id/recyclerview_eventlist"
app:layout_anchorGravity="bottom|right|end"
app:layout_behavior="com.eventizon.behavior.ScrollAwareFABBehavior"
android:src="#drawable/ic_edit"
app:backgroundTint="#color/custom_color_1"
app:borderWidth="0dp" />
</android.support.design.widget.CoordinatorLayout>
DrawerLayout is the parent layout of this layout.
public class ScrollAwareFABBehavior extends FloatingActionButton.Behavior {
private static final String TAG = "ScrollAwareFABBehavior";
public ScrollAwareFABBehavior(Context context, AttributeSet attrs) {
super();
Log.e(TAG,"ScrollAwareFABBehavior");
}
#Override
public void onNestedScroll(CoordinatorLayout coordinatorLayout,
FloatingActionButton child, View target, int dxConsumed,
int dyConsumed, int dxUnconsumed, int dyUnconsumed) {
// TODO Auto-generated method stub
super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed,
dxUnconsumed, dyUnconsumed);
Log.e(TAG,"onNestedScroll called");
if (dyConsumed > 0 && child.getVisibility() == View.VISIBLE) {
Log.e(TAG,"child.hide()");
child.hide();
} else if (dyConsumed < 0 && child.getVisibility() != View.VISIBLE) {
Log.e(TAG,"child.show()");
child.show();
}
}
}
Used this layout behaviour for FloatingActionButton.
When I see logcat only constructor is getting called. onNestedScroll() doesn't get called when I scroll the list.
Easiest solution:
recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener()
{
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy)
{
if (dy > 0 ||dy<0 && fab.isShown())
{
fab.hide();
}
}
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState)
{
if (newState == RecyclerView.SCROLL_STATE_IDLE)
{
fab.show();
}
super.onScrollStateChanged(recyclerView, newState);
}
});
This should work for you:
recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrolled(RecyclerView recyclerView, int dx,int dy){
super.onScrolled(recyclerView, dx, dy);
if (dy >0) {
// Scroll Down
if (fab.isShown()) {
fab.hide();
}
}
else if (dy <0) {
// Scroll Up
if (!fab.isShown()) {
fab.show();
}
}
}
});
Ok, here is what you need:
First, since your FAB depends on the RecyclerView, add the following to your behavior class:
#Override
public boolean layoutDependsOn(CoordinatorLayout parent, FloatingActionButton child, View dependency) {
if(dependency instanceof RecyclerView)
return true;
return false;
}
Next, in order to receive onNestedScroll() calls, you need to override this:
public boolean onStartNestedScroll(CoordinatorLayout parent, FloatingActionButton child, View directTargetChild, View target, int nestedScrollAxes) {
//predict whether you will need to react to the RecyclerView's scroll;
//if yes, return true, otherwise return false to avoid future calls
//of onNestedScroll()
return true;
}
Good luck!
Update
Here is what your ScrollAwareFABBehavior should look like:
public class ScrollAwareFABBehavior extends FloatingActionButton.Behavior {
private static final String TAG = "ScrollAwareFABBehavior";
public ScrollAwareFABBehavior(Context context, AttributeSet attrs) {
super();
}
public boolean onStartNestedScroll(CoordinatorLayout parent, FloatingActionButton child, View directTargetChild, View target, int nestedScrollAxes) {
return true;
}
#Override
public boolean layoutDependsOn(CoordinatorLayout parent, FloatingActionButton child, View dependency) {
if(dependency instanceof RecyclerView)
return true;
return false;
}
#Override
public void onNestedScroll(CoordinatorLayout coordinatorLayout,
FloatingActionButton child, View target, int dxConsumed,
int dyConsumed, int dxUnconsumed, int dyUnconsumed) {
// TODO Auto-generated method stub
super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed,
dxUnconsumed, dyUnconsumed);
if (dyConsumed > 0 && child.getVisibility() == View.VISIBLE) {
child.hide();
} else if (dyConsumed < 0 && child.getVisibility() != View.VISIBLE) {
child.show();
}
}
}
Also, it was tested using com.android.support:design:23.0.1
Short and Simple Solution:
mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
if (dy > 0 && mFloatingActionButton.getVisibility() == View.VISIBLE) {
mFloatingActionButton.hide();
} else if (dy < 0 && mFloatingActionButton.getVisibility() !=View.VISIBLE) {
mFloatingActionButton.show();
}
}
});
If you are using Material Components for Android and your FAB is inside a CoordinatorLayout then you can use the layout_behavior com.google.android.material.behavior.HideBottomViewOnScrollBehavior
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="#+id/filter_fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
...
app:layout_behavior="#string/hide_bottom_view_on_scroll_behavior"
... />
If you are not using coordinator layout and want to hide and show FAB smoothly. And you want to implement your own logic to hide fab on scroll down, and show it on scrolling up.
Then here is the solution in kotlin,
Declare a variable,
var scrollingDown = false
After that create a listener,
recycler_view_id.addOnScrollListener(object : RecyclerView.OnScrollListener() {
override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
super.onScrolled(recyclerView, dx, dy)
if (scrollingDown && dy >= 0) {
scrollingDown = !scrollingDown
id_show_media_fab.startAnimation(
AnimationUtils.loadAnimation(
getApplicationContext(),
R.anim.fab_close
)
)
} else if (!scrollingDown && dy < 0) {
scrollingDown = !scrollingDown
id_show_media_fab.startAnimation(
AnimationUtils.loadAnimation(
getApplicationContext(),
R.anim.fab_open
)
)
}
}
})
create anim resource file
fab_open.xml
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:fillAfter="true">
<scale
android:duration="300"
android:fromXScale="0.0"
android:fromYScale="0.0"
android:interpolator="#android:anim/linear_interpolator"
android:pivotX="50%"
android:pivotY="100%"
android:toXScale="0.9"
android:toYScale="0.9" />
<alpha
android:duration="300"
android:fromAlpha="0.0"
android:interpolator="#android:anim/accelerate_interpolator"
android:toAlpha="1.0" />
</set>
fab_close.xml
just change
android:fromXScale="0.8"
android:fromYScale="0.8"
This is how I did. It works for me! If you don't know how to implement, You can see detail in this link https://guides.codepath.com/android/floating-action-buttons
public class ScrollAwareFABBehavior extends FloatingActionButton.Behavior {
public ScrollAwareFABBehavior(Context context, AttributeSet attributeSet){
super();
}
#Override
public void onNestedScroll(CoordinatorLayout coordinatorLayout, FloatingActionButton child, View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed) {
super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed);
if (dyConsumed > 0 && child.getVisibility() == View.VISIBLE) {
child.hide();
} else if (dyConsumed < 0 && child.getVisibility() == View.GONE) {
child.show();
}
}
#Override
public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout, FloatingActionButton child, View directTargetChild, View target, int nestedScrollAxes) {
return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL;
}
}
I have created a custom RecyclerView which has OnUpDownScrollListener, OnLeftRightScrollListener ready:
Code:
MBRecyclerView.java
public class MBRecyclerView extends RecyclerView {
private OnScrollListener wrappedUpDownScrollListener;
private OnScrollListener wrappedLeftRightScrollListener;
public MBRecyclerView(Context context) {
super(context);
init();
}
public MBRecyclerView(Context context, #Nullable AttributeSet attrs) {
super(context, attrs);
init();
}
public MBRecyclerView(Context context, #Nullable AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
}
private void init() {
}
// region Scrolling Listener for Up, Down, Left and Right
public void setOnUpDownScrollListener(final OnUpDownScrollListener onUpDownScrollListener) {
if (wrappedUpDownScrollListener == null) {
wrappedUpDownScrollListener = getWrappedUpDownScrollListener(onUpDownScrollListener);
addOnScrollListener(wrappedUpDownScrollListener);
}
}
public void removeOnUpDownScrollListener() {
if (wrappedUpDownScrollListener != null) {
removeOnScrollListener(wrappedUpDownScrollListener);
wrappedUpDownScrollListener = null;
}
}
public void setLeftOnRightScrollListener(final OnLeftRightScrollListener onLeftRightScrollListener) {
if (wrappedLeftRightScrollListener == null) {
wrappedLeftRightScrollListener = getWrappedLeftRightScrollListener(onLeftRightScrollListener);
addOnScrollListener(wrappedLeftRightScrollListener);
}
}
public void removeOnLeftRightScrollListener() {
if (wrappedLeftRightScrollListener != null) {
removeOnScrollListener(wrappedLeftRightScrollListener);
wrappedLeftRightScrollListener = null;
}
}
private OnScrollListener getWrappedUpDownScrollListener(final OnUpDownScrollListener onUpDownScrollListener) {
return new OnScrollListener() {
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
if (onUpDownScrollListener != null) {
// Negative to check scrolling up, positive to check scrolling down
if (!recyclerView.canScrollVertically(-1)) {
onUpDownScrollListener.onScrolledToTop();
} else if (!recyclerView.canScrollVertically(1)) {
onUpDownScrollListener.onScrolledToBottom();
}
if (dy > 0) {
onUpDownScrollListener.onScrollDown(dy);
} else if (dy < 0) {
onUpDownScrollListener.onScrollUp(dy);
}
}
}
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
if (newState == RecyclerView.SCROLL_STATE_IDLE) {
if (onUpDownScrollListener != null) {
onUpDownScrollListener.onScrollStopped();
}
}
}
};
}
private OnScrollListener getWrappedLeftRightScrollListener(final OnLeftRightScrollListener onLeftRightScrollListener) {
return new OnScrollListener() {
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
if (onLeftRightScrollListener != null) {
// Negative to check scrolling left, positive to check scrolling right
if (!recyclerView.canScrollHorizontally(-1)) {
onLeftRightScrollListener.onScrolledToMostLeft();
} else if (!recyclerView.canScrollVertically(1)) {
onLeftRightScrollListener.onScrolledToMostRight();
}
if (dy > 0) {
onLeftRightScrollListener.onScrollRight(dx);
} else if (dy < 0) {
onLeftRightScrollListener.onScrollLeft(dx);
}
}
}
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
if (newState == RecyclerView.SCROLL_STATE_IDLE) {
if (onLeftRightScrollListener != null) {
onLeftRightScrollListener.onScrollStopped();
}
}
}
};
}
public abstract class OnUpDownScrollListener {
public void onScrollUp(int dy) {}
public void onScrollDown(int dy) {}
public void onScrolledToTop() {}
public void onScrolledToBottom() {}
public void onScrollStopped() {}
}
public abstract class OnLeftRightScrollListener {
public void onScrollLeft(int dx) {}
public void onScrollRight(int dx) {}
public void onScrolledToMostRight() {}
public void onScrolledToMostLeft() {}
public void onScrollStopped() {}
}
// endregion
}
Usage (UpDownScrollListener):
mbRecyclerView.setOnUpDownScrollListener(new MBRecyclerView.OnUpDownScrollListener() {
#Override
public void onScrollUp(int dy) {
// show
}
#Override
public void onScrollDown(int dy) {
// hide
}
// aditional functions:
public void onScrolledToTop() {}
public void onScrolledToBottom() {}
public void onScrollStopped() {}
});
similarely you can handle the LeftRight scrolling by setting
setOnLeftRightScrollListener
I hope it can help somebody :)
The solution is in: F.A.B Hides but Doesn't Show
The problem is Android 25.0.x+ sets the view to GONE and thats why the listener is not reporting changes.
All the answers which goes on the Behavior path and onNestedScroll (instead of recyclerview listener) don't comment about the fact that onNestedScroll will be called many times while scrolling. This means that child.show() and child.hide() will be called many times as well. Although show() and hide() are designed to handle that scenario, they still run a lot of code and create some objects which multiplied by the times onNestedScroll is called, result in a lot of objects created unnecessarily.
Considering that and because I wanted to run a different animation instead of the default show() and hide(), I came up with the following Behavior implementation:
public class ScrollAwareFABBehavior extends CoordinatorLayout.Behavior<FloatingActionButton> {
private static final String TAG = "ScrollAwareFABBehavior";
private boolean fabAnimationStarted = false;
private boolean flingHappened = false;
public ScrollAwareFABBehavior(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
public boolean onStartNestedScroll(#NonNull CoordinatorLayout coordinatorLayout, #NonNull FloatingActionButton child, #NonNull View directTargetChild, #NonNull View target, int axes, int type) {
if (target instanceof RecyclerView) {
return true;
}
return false;
}
#Override
public void onStopNestedScroll(#NonNull CoordinatorLayout coordinatorLayout, #NonNull final FloatingActionButton child, #NonNull View target, int type) {
super.onStopNestedScroll(coordinatorLayout, child, target, type);
// If animation didn't start, we don't need to care about running the restore animation.
// i.e.: when the user swipes to another tab in a viewpager. The onNestedPreScroll is never called.
if (!fabAnimationStarted) {
return;
}
// Animate back when the fling ended (TYPE_NON_TOUCH)
// or if the user made the touch up (TYPE_TOUCH) but the fling didn't happen.
if (type == ViewCompat.TYPE_NON_TOUCH || (type == ViewCompat.TYPE_TOUCH && !flingHappened)) {
ViewCompat.animate(child).translationY(0).start();
fabAnimationStarted = false;
}
}
#Override
public boolean onNestedFling(#NonNull CoordinatorLayout coordinatorLayout, #NonNull FloatingActionButton child, #NonNull View target, float velocityX, float velocityY, boolean consumed) {
// We got a fling. Flag it.
flingHappened = true;
return false;
}
#Override
public void onNestedPreScroll(#NonNull CoordinatorLayout coordinatorLayout, #NonNull FloatingActionButton child, #NonNull View target, int dx, int dy, #NonNull int[] consumed, int type) {
if (!fabAnimationStarted) {
Log.d(TAG, "onStartNestedScroll: animation is starting");
fabAnimationStarted = true;
flingHappened = false;
CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams) child.getLayoutParams();
ViewCompat.animate(child).translationY(child.getHeight() + lp.bottomMargin).start();
}
}
}
The floating action button will hide when there's scrolling and show when the scrolling stops.
recylerview.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrollStateChanged(#NonNull RecyclerView recyclerView, int newState) {
switch (newState) {
case RecyclerView.SCROLL_STATE_IDLE:
addExpenseBtn.show();
break;
default:
addExpenseBtn.hide();
break;
}
super.onScrollStateChanged(recyclerView, newState);
}
});
//lv = ListView
lv.setOnScrollListener(new AbsListView.OnScrollListener() {
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
#Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
fab.setVisibility(view.getFirstVisiblePosition() == 0 ? View.VISIBLE : View.INVISIBLE);
}
});
I used this in a RecyclerView.Adapter's onBindViewHolder method to set the bottom margin of the last item in the list to 72dp so that it will scroll up above the floating action button.
This does not require a dummy entry in the list.
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
// other binding code goes here.
if (position + 1 == getItemCount()) {
// set bottom margin to 72dp.
setBottomMargin(holder.itemView, (int) (72 * Resources.getSystem().getDisplayMetrics().density));
} else {
// reset bottom margin back to zero. (your value may be different)
setBottomMargin(holder.itemView, 0);
}
}
public static void setBottomMargin(View view, int bottomMargin) {
if (view.getLayoutParams() instanceof ViewGroup.MarginLayoutParams) {
ViewGroup.MarginLayoutParams params = (ViewGroup.MarginLayoutParams) view.getLayoutParams();
params.setMargins(params.leftMargin, params.topMargin, params.rightMargin, bottomMargin);
view.requestLayout();
}
}
A little late, but it works for me.
//This only works on Android M and above
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M)
recyclerView.setOnScrollChangeListener(new View.OnScrollChangeListener() {
#Override
public void onScrollChange(View v, int scrollX, int scrollY, int oldScrollX, int oldScrollY) {
if (scrollY > oldScrollY && fab.isShown()) {
fab.hide();
} else if (scrollY < oldScrollY && !fab.isShown()) {
fab.show();
}
}
});
When scrollY is greater than oldScrollY, that means user has scroll down so, we just need to check FAB is showing. If it is, we hide it.
scrollY is less than oldScrollY means a scroll up. We check if FAB is still hidden to show it.
Try this
recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
//Customize your if statement
if (recyclerView.computeVerticalScrollOffset() > recyclerView.getHeight() * 2) {
if (!fab.isShown()) {
fab.show();
}
} else {
fab.hide();
}
}
});
enjoy.
I've looked over the stackoverflow and the internet and I couldn't find a clear answer that helped me.
I have an assignment and it includes the following class, which is a GUI. I have Junit tested the other classes but for this I didn't know how.
import java.awt.*;
public class CruiseDisplay extends Canvas {
private int recorded = 0; //recorded speed
private boolean cruiseOn = false; //cruise control state
private final static int botY = 200;
private Font small = new Font("Helvetica",Font.BOLD,14);
private Font big = new Font("Helvetica",Font.BOLD,18);
public CruiseDisplay() {
super();
setSize(150,260);
}
Image offscreen;
Dimension offscreensize;
Graphics offgraphics;
public void backdrop() {
Dimension d = getSize();
if ((offscreen == null) || (d.width != offscreensize.width)
|| (d.height != offscreensize.height)) {
offscreen = createImage(d.width, d.height);
offscreensize = d;
offgraphics = offscreen.getGraphics();
offgraphics.setFont(small);
}
offgraphics.setColor(Color.black);
offgraphics.fillRect(0, 0, getSize().width, getSize().height);
offgraphics.setColor(Color.white);
offgraphics.drawRect(5,10,getSize().width-15,getSize().height-40);
offgraphics.setColor(Color.blue);
offgraphics.fillRect(6,11,getSize().width-17,getSize().height-42);
}
public void paint(Graphics g) {
update(g);
}
public void update(Graphics g) {
backdrop();
// display recorded speed
offgraphics.setColor(Color.white);
offgraphics.setFont(big);
offgraphics.drawString("Cruise Control",10,35);
offgraphics.setFont(small);
drawRecorded(offgraphics,20,80,recorded);
if (cruiseOn)
offgraphics.drawString("Enabled",20,botY+15);
else
offgraphics.drawString("Disabled",20,botY+15);
if (cruiseOn)
offgraphics.setColor(Color.green);
else
offgraphics.setColor(Color.red);
offgraphics.fillArc(90,botY,20,20,0,360);
g.drawImage(offscreen, 0, 0, null);
}
public void drawRecorded(Graphics g, int x, int y, int speed) {
g.drawString("Cruise Speed",x,y+10);
g.drawRect(x+20,y+20,50,20);
g.setFont(big);
g.drawString(String.valueOf(speed+20),x+30,y+37);
g.setFont(small);
}
public void enabled() {
cruiseOn = true;
repaint();
}
public void disabled() {
cruiseOn = false;
repaint();
}
public void record(int speed) {
recorded=speed;
repaint();
}
}
Can somebody help me please?