I'm new to android app development and i have recently made my first app containing a basic tablayout with two fragments in my MainActivity.
In my second tab, it consists of only one RecyclerView as a rootlayout. What i did was populating the RecyclerView with an arraylist of my own dataModel.
My RecyclerView has 13 items. The view of these items is a expansion layout from https://github.com/florent37/ExpansionPanel I followed exactly the way he did for RecyclerView and it worked perfectly.
HOWEVER, my app's startup time has INCREASED significantly to 1s++. I found that the onBindViewHolder method in my RecyclerViewAdapter is the culprit. I tried commenting out the content of onBindViewHolder method and the startup time has reduced by half to 600ms, which is okay for me.
So my questions is How can I solve this problem? Should I bind my data in a different way?
I dont want to have a slow startup time. I saw some posts about using databinding API, running on a different threads and asyncs, but i dont know how to do it.
Please help ~ Thanks in advance!
Here's my Adapter:
public class MyAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private Context context;
private ArrayList<DataModel> list;
private final ExpansionLayoutCollection expansionsCollection = new ExpansionLayoutCollection();
MyAdapter(ArrayList<DataModel> list, Context context) {
this.list = list;
this.context = context;
expansionsCollection.openOnlyOne(true);
}
@NonNull
@Override
public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View itemView == LayoutInflater.from(parent.getContext()).inflate(R.layout.expansion_panel, parent, false);
return new ViewHolder(itemView);
}
@Override
public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
DataModel currentData = list.get(position);
switch (currentData.getType()) {
case DataModel.NO_FORMULA:
holder.titleText.setText(currentData.getTitle());
holder.contentText.setText(currentData.getContent());
holder.formulaView.removeAllViews();
expansionsCollection.add(holder.expansionLayout);
break;
case DataModel.WITH_FORMULA:
View formulaLayout = ((Activity)context).getLayoutInflater().inflate(currentData.getFormulaLayoutId(),null);
holder.titleText.setText(currentData.getTitle());
holder.contentText.setText(currentData.getContent());
holder.formulaView.removeAllViews();
holder.formulaView.addView(formulaLayout);
expansionsCollection.add(holder.expansionLayout);
break;
}
}
@Override
public int getItemCount() {
return list.size();
}
private static class ViewHolder extends RecyclerView.ViewHolder {
TextView titleText, contentText;
ExpansionLayout expansionLayout;
FrameLayout formulaView;
ViewHolder(View itemView) {
super(itemView);
this.titleText = itemView.findViewById(R.id.title_text);
this.contentText = itemView.findViewById(R.id.content_text);
this.expansionLayout = itemView.findViewById(R.id.expansionLayout);
this.formulaView = itemView.findViewById(R.id.formula_view);
}
}
This is my item layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
tools:ignore="ContentDescription,RtlHardcoded,HardcodedText">
<com.github.florent37.expansionpanel.ExpansionHeader
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#fff"
app:expansion_headerIndicator="@id/headerIndicator"
app:expansion_layout="@id/expansionLayout"
app:expansion_toggleOnClick="true">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?android:attr/selectableItemBackground"
android:minHeight="50dp"
android:paddingLeft="16dp"
android:paddingRight="16dp"
android:theme="@style/RecyclerViewTheme">
<TextView
android:id="@+id/title_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_centerVertical="true"
android:layout_toLeftOf="@id/headerIndicator"
android:textColor="#000" />
<android.support.v7.widget.AppCompatImageView
android:id="@+id/headerIndicator"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:layout_marginLeft="16dp"
android:adjustViewBounds="true"
app:srcCompat="@drawable/ic_expansion_header_indicator_grey_24dp" />
</RelativeLayout>
</com.github.florent37.expansionpanel.ExpansionHeader>
<com.github.florent37.expansionpanel.ExpansionLayout
android:id="@+id/expansionLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:expansion_expanded="false">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:background="#F5F5F5">
<TextView
android:id="@+id/content_text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="16dp"
android:textColor="#000" />
<FrameLayout
android:id="@+id/formula_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</LinearLayout>
</com.github.florent37.expansionpanel.ExpansionLayout>
<View
android:layout_width="match_parent"
android:layout_height="0.7dp"
android:background="?android:attr/listDivider" />
</LinearLayout>
Here's my datamodel:
public class DataModel {
public static final int WITH_FORMULA = 0;
public static final int NO_FORMULA = 1;
private String title, content;
private int type, formulaLayoutId;
DataModel(int type, String title, String content) {
this.type = type;
this.title = title;
this.content = content;
}
DataModel(int type, String title, String content, int formulaLayoutId) {
this.type = type;
this.title = title;
this.content = content;
this.formulaLayoutId = formulaLayoutId;
}
public String getTitle() {
return title;
}
public String getContent() {
return content;
}
public int getFormulaLayoutId() {
return formulaLayoutId;
}
public int getType() {
return type;
}
*I've created 13 DataModel objects with long titles and long paragraphs as contents and put them in an arraylist. When the user click on the expansion panel's header, the expansion layout will expand to show the contents of it.
Only 2 out of the 13 items in the recyclerview is the type of WITH_FORMULA that has to inflate the formulaLayout.
