RecyclerView-comment mettre en évidence l'élément central visible pendant le défilement
j'ai besoin d'un RecyclerView comme ceci:
Il ne doit:
-
afficher les 7 éléments en fonction du temps ( FAIT )
-
centrer la RecyclerView sur l'élément central visible ( fait )
-
quand je fais défiler vers droite/gauche, l'élément central sera "surligné" (le bouton est sélectionné > couleur bleue) ( besoin D'aide )
-
quand je clique sur un bouton, il sera centré avec un scrool lisse ( besoin D'aide )
j'ai utilisé la classe SnapHelper
pour centrer le RecyclerView sur les articles centraux (je récupère l'article central visible obtenir l'enfant le plus proche à l'écran centre)
MON ADAPTATEUR:
public class RvTrendsGraphAdapter extends RecyclerView.Adapter<RvTrendsGraphAdapter.ViewHolder> {
private float deviceWidth;
private float itemWidth;
private List<RvTrendsGraphModel> models;
private Context context;
public RvTrendsGraphAdapter(Context context, List<RvTrendsGraphModel> models) {
this.models = models;
this.context = context;
}
private Context getContext() {
return context;
}
public class ViewHolder extends RecyclerView.ViewHolder {
@BindView(R.id.rv_trends_graph_layout) PercentRelativeLayout rootLayout;
@BindView(R.id.rv_trends_graph_layout_superiore) PercentRelativeLayout layoutSuperiore;
@BindView(R.id.rv_trends_graph_layout_inferiore) RelativeLayout layoutInferiore;
@BindView(R.id.rv_trends_graph_vertical_progressbar) ProgressBar verticalProgressBar;
@BindView(R.id.rv_trends_graph_button) Button timeLapseButton;
public ViewHolder(View itemView) {
super(itemView);
ButterKnife.bind(this, itemView);
}
}
@Override
public RvTrendsGraphAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
Context context = parent.getContext();
LayoutInflater inflater = LayoutInflater.from(context);
View view = inflater.inflate(R.layout.recycler_trends_graph, parent, false);
// Set the width to show 7 elements
DisplayMetrics displayMetrics = new DisplayMetrics();
WindowManager windowmanager = (WindowManager) getContext().getSystemService(Context.WINDOW_SERVICE);
windowmanager.getDefaultDisplay().getMetrics(displayMetrics);
deviceWidth = displayMetrics.widthPixels;
float progressBarWidth = getContext().getResources().getDimension(R.dimen.picker_time_lapse_progressbar_width);
itemWidth = ((deviceWidth + progressBarWidth) / 8f + 1f);
view.getLayoutParams().width = (int) itemWidth;
return new ViewHolder(view);
}
@Override
public void onBindViewHolder(RvTrendsGraphAdapter.ViewHolder viewHolder, int position) {
RvTrendsGraphModel model = models.get(position);
PercentRelativeLayout rootLayout = viewHolder.rootLayout;
ProgressBar verticalProgressBar = viewHolder.verticalProgressBar;
Button timeLapseButton = viewHolder.timeLapseButton;
verticalProgressBar.setProgress(model.getProgress());
setTimeLapseButton(timeLapseButton, model.getTimeLapseValue());
}
@Override
public int getItemCount() {
return models.size();
}
public RvTrendsGraphModel getItem(int position) {
return models.get(position);
}
/* UTILS */
private void setTimeLapseButton(Button button, String text) {
//button.setSelected(false);
button.setText(text);
}
}
SETUP RECYCLER VIEW:
mLayoutManager = new LinearLayoutManager(getActivity(), LinearLayoutManager.HORIZONTAL, false);
mRecyclerView.setLayoutManager(mLayoutManager);
SnapHelper snapHelper = new LinearSnapHelper();
snapHelper.attachToRecyclerView(mRecyclerView);
POPULATE RECYCLER VIEW:
list = new ArrayList<>();
/* Create foo list... */
list.add(new RvTrendsGraphModel(75, String.valueOf(list.size())));
list.add(new RvTrendsGraphModel(33, String.valueOf(list.size())));
// ...
adapter = new RvTrendsGraphAdapter(getActivity(), list);
mRecyclerView.setAdapter(adapter);
adapter.notifyDataSetChanged();
mRecyclerView.smoothScrollToPosition(list.size() - 1);
SCROLL MANAGEMENT:
mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
// Get adapter position of the central item
PercentRelativeLayout root = (PercentRelativeLayout) mRecyclerView.findChildViewUnder(centralX, 0);
pos = mRecyclerView.getChildAdapterPosition(root);
// first try (very bad)
if (lastPos != pos) {
pos = lastPos;
adapter.notifyDataSetChanged();
}
// second try (I cannot call notifyitemchanged during the scroll
if () {
final int pos = mRecyclerView.getChildAdapterPosition(root);
adapter.getItem(pos).setCentered(true);
adapter.notifyItemChanged(pos);
}
}
});
EN PAGE DE L'ÉLÉMENT:
<?xml version="1.0" encoding="utf-8"?>
<android.support.percent.PercentRelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/rv_trends_graph_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:ignore="MissingPrefix">
<android.support.percent.PercentRelativeLayout
android:id="@+id/rv_trends_graph_layout_superiore"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_heightPercent="75%">
<ProgressBar
android:id="@+id/rv_trends_graph_vertical_progressbar"
style="@style/Widget.ProgressBar.Vertical"
android:layout_width="@dimen/picker_time_lapse_progressbar_width"
android:layout_height="match_parent"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:progress="50"
/>
</android.support.percent.PercentRelativeLayout>
<RelativeLayout
android:id="@+id/rv_trends_graph_layout_inferiore"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_below="@+id/rv_trends_graph_layout_superiore"
app:layout_heightPercent="25%">
<Button
android:id="@+id/rv_trends_graph_button"
fontPath="fonts/Roboto-Light.ttf"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:background="@drawable/picker_time_lapse_selector"
android:minHeight="0dp"
android:minWidth="0dp"
android:textAllCaps="true"
android:textColor="@color/picker_time_lapse_text_color_selector"
android:textSize="@dimen/text_size_medium"
tools:ignore="ContentDescription"
tools:text="16"/>
</RelativeLayout>
</android.support.percent.PercentRelativeLayout>
1 réponses
Espérons que cette aide -
notez qu'il s'agit d'une solution hacky, en particulier la mise en évidence sur le rouleau.
En outre, je n'ai pas profilé de performance. Vous devriez probablement vérifier.
J'ai aussi changé timeLapseButton
en TextView
car changer le fond sur Button
va faire s'effondrer d'autres propriétés de layout.
si vous n'aimez pas la solution hacky, vous pouvez consulter quelques bibliothèques de cartes.
ex:) https://github.com/PhilJay/MPAndroidChart
Classe Adaptateur
public interface TimeLapseButtonClickListener {
void onClick(int position);
}
private TimeLapseButtonClickListener timeLapseButtonListener;
public void setTimeLapseButtonClickListener(TimeLapseButtonClickListener listener) {
this.timeLapseButtonListener = listener;
}
private void setTimeLapseButton(Button button, String text, final int position) {
button.setText(text);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
this.timeLapseButtonListener.onClick(position);
}
});
}
activité ou Fragment où vous avez recyclerView & adaptateur
...
private int prevCenterPos; // Keep track the previous pos to dehighlight
...
// Click and smooth scroll to get clicked item in the middle
adapter.setListener(new RvTrendsGraphAdapter.TimeLapseButtonClickListener() {
@Override
public void onClick(int position) {
View view = mRecyclerView.getLayoutManager().findViewByPosition(position);
int middle = mRecyclerView.getWidth() / 2;
mRecyclerView.smoothScrollBy(view.getLeft() - middle, 0, new AccelerateDecelerateInterpolator());
}
});
// Highlight view in the middle on scroll
mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
int center = mRecyclerView.getWidth() / 2;
View centerView = mRecyclerView.findChildViewUnder(center, mRecyclerView.getTop());
int centerPos = mRecyclerView.getChildAdapterPosition(centerView);
if (prevCenterPos != centerPos) {
// dehighlight the previously highlighted view
View prevView = mRecyclerView.getLayoutManager().findViewByPosition(prevCenterPos);
if (prevView != null) {
View button = prevView.findViewById(R.id.rv_trends_graph_button);
int white = ContextCompat.getColor(context, R.color.white);
button.setBackgroundColor(white);
}
// highlight view in the middle
if (centerView != null) {
View button = centerView.findViewById(R.id.rv_trends_graph_button);
int highlightColor = ContextCompat.getColor(context, R.color.colorAccent);
button.setBackgroundColor(highlightColor);
}
prevCenterPos = centerPos;
}
}
});