BaseActivity is used to reuse code on the different place for the same purpose. you can see it in this tutorial.
Steps to use BaseActivity in your project.
Steps to use BaseActivity in your project.
- Crate a project(BaseActivityDeleteDemo) in android studio.
- Create a Activity Activity1.Java and update it-
package com.pankaj.mmm; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.Toast; public class Activity1 extends BaseActivity { private Button btnGetSelectedTag1; @Override protected void onCreate(Bundle savedInstanceState) { setContentView(R.layout.activity1); super.onCreate(savedInstanceState); //initialization btnGetSelectedTag1 = findViewById(R.id.btnGetSelectedTag1); //Add Listeners btnGetSelectedTag1.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { String message = ""; for (String data : getSelectedTagList()) { if (!data.isEmpty()) message += data + "\n"; } message.trim(); Toast.makeText(Activity1.this, message, Toast.LENGTH_SHORT).show(); } }); } public void openSecondActivity(View view) { Intent intent = new Intent(this, Activity2.class); startActivity(intent); } }
- Create a xml activity1.xml and update it-
<?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.pankaj.mmm.BaseActivity"> <LinearLayout android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <include layout="@layout/tag_layout" /> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content"> <Button android:id="@+id/btnGetSelectedTag1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:imeOptions="actionNone" android:text="Show entered Data" /> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:imeOptions="actionNone" android:onClick="openSecondActivity" android:text="Open Second Screen" /> </LinearLayout> </LinearLayout> </android.support.constraint.ConstraintLayout>
- Create a activity Activity2.Java and update it-
package com.pankaj.mmm; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.Toast; public class Activity2 extends BaseActivity { private Button btnGetSelectedTag2; @Override protected void onCreate(Bundle savedInstanceState) { setContentView(R.layout.activity2); super.onCreate(savedInstanceState); //initialization btnGetSelectedTag2 = findViewById(R.id.btnGetSelectedTag2); //Add Listeners btnGetSelectedTag2.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { String message = ""; for (String data : getSelectedTagList()) { if (!data.isEmpty()) message += data + "\n"; } message.trim(); Toast.makeText(Activity2.this, message, Toast.LENGTH_SHORT).show(); } }); } }
- Create a interface CallBack.Java and update it-
package com.pankaj.mmm; /** * Created by pankaj on 7/12/17. */ public interface CallBacks { //to get event on select item void onSelected(String s); //to get event on delete item void onDeleted(int rowPosition); //to get event on done/enter click void onDone(String s); }
Create a xml activity2.xml and update it-<?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.pankaj.mmm.BaseActivity"> <LinearLayout android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <include layout="@layout/tag_layout" /> <Button android:id="@+id/btnGetSelectedTag2" android:layout_width="match_parent" android:layout_height="wrap_content" android:imeOptions="actionNone" android:text="Show entered Data" /> </LinearLayout> </android.support.constraint.ConstraintLayout>
- Create a activity BaseActivity.Java and update it-
package com.pankaj.mmm; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.LinearLayoutManager; import android.support.v7.widget.RecyclerView; import android.view.View; import android.widget.Toast; import java.util.ArrayList; import java.util.List; public class BaseActivity extends AppCompatActivity implements CallBacks { //create objects private RecyclerView rvTagList; private List<String> dataSelected = new ArrayList<>(); private List<String> dataOptions = new ArrayList<>(); private TagAdapter tagAdapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); initialization(); } public void initialization(){ //Initialize list view rvTagList = findViewById(R.id.rvTagList); //Create layout manager LinearLayoutManager manager = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false); //Set layout manager rvTagList.setLayoutManager(manager); //Add data to show entry point dataSelected.add(""); //Create suggestions for (int i = 0; i < 500; i++) { dataOptions.add("data" + i); } //Initialize adapter tagAdapter = new TagAdapter(BaseActivity.this, dataSelected, dataOptions); //Set callbacks tagAdapter.setCallBacks(this); //Set adapter rvTagList.setAdapter(tagAdapter); } @Override public void onSelected(String selected) { //Check size and put data into selecteddata list if (dataSelected.size() > 1) { dataSelected.add(dataSelected.size() - 1, selected); } else { dataSelected.add(0, selected); } scrollToLastPosition(false); } @Override public void onDeleted(int rowPosition) { //Delete selected item dataSelected.remove(rowPosition); scrollToLastPosition(true); } @Override public void onDone(String selected) { //Check size and put data into selecteddata list if (dataSelected.size() > 1) { dataSelected.add(dataSelected.size() - 1, selected); } else { dataSelected.add(0, selected); } scrollToLastPosition(true); } private void scrollToLastPosition(boolean goToLast) { //notify adapter to refresh data in it tagAdapter.notifyDataSetChanged(); // if (goToLast) rvTagList.scrollToPosition(dataSelected.size() - 1); } //function to show selected data public void selectedData(View view) { String message = ""; for (String data : dataSelected) { if (!data.isEmpty()) message += data + "\n"; } message.trim(); Toast.makeText(this, message, Toast.LENGTH_SHORT).show(); } public List<String> getSelectedTagList() { return dataSelected; } }
- Create a class TagAdapter.Java and update it-
package com.pankaj.mmm; import android.app.Activity; import android.support.v7.widget.RecyclerView; import android.util.Log; import android.view.KeyEvent; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.AutoCompleteTextView; import android.widget.ImageView; import android.widget.LinearLayout; import android.widget.TextView; import java.util.List; /** * Created by pankaj on 7/12/17. */ public class TagAdapter extends RecyclerView.Adapter<TagAdapter.MyViewHolder> { //Objects private String TAG = "TagAdapter"; private List<String> dataOptions; private List<String> dataSelected; private Activity activity; private CallBacks callBacks; /** * View holder class */ public class MyViewHolder extends RecyclerView.ViewHolder { private TextView tvText; private ImageView ivDelete; private AutoCompleteTextView tvAutocomplete; private LinearLayout llSelected; public MyViewHolder(View view) { super(view); tvAutocomplete = (AutoCompleteTextView) view.findViewById(R.id.tvAutocomplete); tvText = (TextView) view.findViewById(R.id.tvText); ivDelete = (ImageView) view.findViewById(R.id.ivDelete); llSelected = view.findViewById(R.id.llSelected); } } //Constructor public TagAdapter(Activity activity, List<String> dataSelected, List<String> dataOptions) { this.dataSelected = dataSelected; this.dataOptions = dataOptions; this.activity = activity; } @Override public void onBindViewHolder(final MyViewHolder holder, final int rowPosition) { if (rowPosition != dataSelected.size() - 1) { //Set null to listeners holder.tvAutocomplete.setOnItemClickListener(null); holder.tvAutocomplete.setOnEditorActionListener(null); //selected data holder.llSelected.setVisibility(View.VISIBLE); holder.tvAutocomplete.setVisibility(View.GONE); //Set data in cells holder.tvText.setText(dataSelected.get(rowPosition)); //Add listener to delete cells holder.ivDelete.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //send event to delete selected cell callBacks.onDeleted(rowPosition); } }); } else { //options in autocomplete //Hide cells holder.llSelected.setVisibility(View.GONE); holder.tvAutocomplete.setVisibility(View.VISIBLE); //Create adapter to show suggestion final ArrayAdapter<String> adapter = new ArrayAdapter<String>(activity, android.R.layout.simple_dropdown_item_1line, dataOptions); //Add adapter to show suggestion holder.tvAutocomplete.setAdapter(adapter); //reset entry point for new entry holder.tvAutocomplete.setText(""); //Add listener to select item from suggestion holder.tvAutocomplete.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { Log.e(TAG, holder.tvAutocomplete.getText() + " Position : " + position); //send event to add selected suggestion in cells callBacks.onSelected(holder.tvAutocomplete.getText().toString()); } }); //Add listener to create cell of entered data holder.tvAutocomplete.setOnEditorActionListener(new TextView.OnEditorActionListener() { @Override public boolean onEditorAction(TextView v, int actionId, KeyEvent event) { Log.e(TAG, "" + actionId); //check if pressed on Ok/Done button if (actionId == 6) { if (holder.tvAutocomplete.getText().toString().trim().length() > 0) { //send event to add entered text in cells callBacks.onDone(holder.tvAutocomplete.getText().toString().trim()); //reset entry point for new entry holder.tvAutocomplete.setText(""); } } return false; } }); } } @Override public int getItemCount() { return dataSelected.size(); } //Initialize callbacks interface public void setCallBacks(CallBacks callBacks) { this.callBacks = callBacks; } @Override public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { View v = LayoutInflater.from(parent.getContext()) .inflate(R.layout.row, parent, false); return new MyViewHolder(v); } }
- Create a xml row.xml to show individual selected item and update it-
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="wrap_content" android:layout_height="match_parent" android:minHeight="30dp"> <LinearLayout android:id="@+id/llSelected" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="3dp" android:layout_marginLeft="3dp" android:layout_marginTop="3dp" android:background="@drawable/bg_button_with_corner_orange" android:gravity="center_vertical" android:padding="3dp"> <TextView android:id="@+id/tvText" android:layout_width="wrap_content" android:layout_height="wrap_content" android:editable="false" android:singleLine="true" android:text="@string/app_name" /> <ImageView android:id="@+id/ivDelete" android:layout_width="wrap_content" android:layout_height="match_parent" android:src="@android:drawable/ic_delete" /> </LinearLayout> <AutoCompleteTextView android:id="@+id/tvAutocomplete" android:layout_width="200dp" android:layout_height="match_parent" android:imeOptions="actionDone" android:layout_marginLeft="5dp" android:background="@android:color/transparent" android:hint="@string/app_name" android:singleLine="true" android:textSize="12sp" /> </LinearLayout>
- Create a xml tag_layout.Java and update it-
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="wrap_content"> <android.support.v7.widget.RecyclerView android:id="@+id/rvTagList" android:layout_width="match_parent" android:layout_height="wrap_content" /> </LinearLayout>
- All the application development process with Base Activity has completed, Now run the app and look the screen.
- Good bye, Thanks to read this blog.
