Android Developers Maximum: Dynamic View

Showing posts with label Dynamic View. Show all posts

Get child view at run-time, using getChildCount() and getChildAt().

This exercise show how to retrieve child view at run time, using getChildCount() and getChildAt().

Last exercise show how to "Get text from dynamically added view" using button with OnClickListener to include text directly while creating and adding the view. In this exercise, we add a button, named "Show All", to retrieve all dynamic added view indirectly from their parent LinearLayout, container.

Get child view at run-time, using getChildCount() and getChildAt().

package com.example.androiddynamicview;

import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;
import android.animation.LayoutTransition;
import android.app.Activity;
import android.content.Context;

public class MainActivity extends Activity {
 
 EditText textIn;
 Button buttonAdd;
 LinearLayout container;
 Button buttonShowAll;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  textIn = (EditText)findViewById(R.id.textin);
  buttonAdd = (Button)findViewById(R.id.add);
  container = (LinearLayout)findViewById(R.id.container);
  
  buttonAdd.setOnClickListener(new OnClickListener(){

   @Override
   public void onClick(View arg0) {
    LayoutInflater layoutInflater = 
      (LayoutInflater) getBaseContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    final View addView = layoutInflater.inflate(R.layout.row, null);
    final TextView textOut = (TextView)addView.findViewById(R.id.textout);
    textOut.setText(textIn.getText().toString());
    Button buttonRemove = (Button)addView.findViewById(R.id.remove);
    buttonRemove.setOnClickListener(new OnClickListener(){

     @Override
     public void onClick(View v) {
      ((LinearLayout)addView.getParent()).removeView(addView);
     }});
    
    Button buttonInsert = (Button)addView.findViewById(R.id.insert);
    buttonInsert.setOnClickListener(new OnClickListener(){

     @Override
     public void onClick(View v) {
      String text = textOut.getText().toString();
      String newText = textIn.getText().toString() + text;
      textIn.setText(newText);
     }});
    
    container.addView(addView, 0);
   }});
  
  LayoutTransition transition = new LayoutTransition();
  container.setLayoutTransition(transition);
  
  buttonShowAll = (Button)findViewById(R.id.showall);
  buttonShowAll.setOnClickListener(new OnClickListener(){

   @Override
   public void onClick(View arg0) {
    
    String showallPrompt = "";

    int childCount = container.getChildCount();
    showallPrompt += "childCount: " + childCount + "\n\n";

    for(int c=0; c<childCount; c++){
     View childView = container.getChildAt(c);
     TextView childTextView = (TextView)(childView.findViewById(R.id.textout));
     String childTextViewText = (String)(childTextView.getText());
     
     showallPrompt += c + ": " + childTextViewText + "\n";
    }
    
    Toast.makeText(MainActivity.this, 
      showallPrompt, 
      Toast.LENGTH_LONG).show();
   }});
 }
}

<LinearLayout 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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:autoLink="web"
        android:text="http://arteluzevida.blogspot.com/"
        android:textStyle="bold" />
    
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <Button
            android:id="@+id/add"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentRight="true"
            android:text="Add"/>
        <EditText
            android:id="@+id/textin"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_toLeftOf="@id/add"/>
    </RelativeLayout>
    <Button
        android:id="@+id/showall"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Show All" />
    <LinearLayout 
        android:id="@+id/container"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">
    </LinearLayout>

</LinearLayout>

The layout of the dynamic view, /res/layout/row.xml, refer last exercise.

download files

Download the files.

Get text from dynamically added view

In the post "Add and Remove view dynamically", views are added dynamically ar run-time, with add and remove function. It's modified to have a "insert" button on each row, the associated text will be inserted in EditView if the button clicked.

MainActivity.java

package com.example.androiddynamicview;

import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.animation.LayoutTransition;
import android.app.Activity;
import android.content.Context;

public class MainActivity extends Activity {
 
 EditText textIn;
 Button buttonAdd;
 LinearLayout container;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  textIn = (EditText)findViewById(R.id.textin);
  buttonAdd = (Button)findViewById(R.id.add);
  container = (LinearLayout)findViewById(R.id.container);
  
  buttonAdd.setOnClickListener(new OnClickListener(){

   @Override
   public void onClick(View arg0) {
    LayoutInflater layoutInflater = 
      (LayoutInflater) getBaseContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    final View addView = layoutInflater.inflate(R.layout.row, null);
    final TextView textOut = (TextView)addView.findViewById(R.id.textout);
    textOut.setText(textIn.getText().toString());
    Button buttonRemove = (Button)addView.findViewById(R.id.remove);
    buttonRemove.setOnClickListener(new OnClickListener(){

     @Override
     public void onClick(View v) {
      ((LinearLayout)addView.getParent()).removeView(addView);
     }});
    
    Button buttonInsert = (Button)addView.findViewById(R.id.insert);
    buttonInsert.setOnClickListener(new OnClickListener(){

     @Override
     public void onClick(View v) {
      String text = textOut.getText().toString();
      String newText = textIn.getText().toString() + text;
      textIn.setText(newText);
     }});
    
    container.addView(addView, 0);
   }});
  
  LayoutTransition transition = new LayoutTransition();
  container.setLayoutTransition(transition);
 }
}

/res/layout/activity_main.xml

<LinearLayout 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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:autoLink="web"
        android:text="http://arteluzevida.blogspot.com/"
        android:textStyle="bold" />
    
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <Button
            android:id="@+id/add"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentRight="true"
            android:text="Add"/>
        <EditText
            android:id="@+id/textin"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_toLeftOf="@id/add"/>
    </RelativeLayout>
    <LinearLayout 
        android:id="@+id/container"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">
    </LinearLayout>

</LinearLayout>

/res/layout/row.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
    <Button
        android:id="@+id/remove"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:text="Remove"/>
    <Button
        android:id="@+id/insert"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_toLeftOf="@id/remove"
        android:text="Insert"/>
    <TextView
        android:id="@+id/textout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_toLeftOf="@id/remove"/>
</RelativeLayout>

Download the files.

Next: Get child view at run-time, using getChildCount() and getChildAt().

Add and Remove view dynamically

This exercise demonstrate how to add and remove view dynamically at run-time. When user click on the Add button, new view will be added. When user click on Remove button, the corresponding view will be removed.

MainActivity.java

package com.example.androiddynamicview;

import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.app.Activity;
import android.content.Context;

public class MainActivity extends Activity {
 
 EditText textIn;
 Button buttonAdd;
 LinearLayout container;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  textIn = (EditText)findViewById(R.id.textin);
  buttonAdd = (Button)findViewById(R.id.add);
  container = (LinearLayout)findViewById(R.id.container);
  
  buttonAdd.setOnClickListener(new OnClickListener(){

   @Override
   public void onClick(View arg0) {
    LayoutInflater layoutInflater = 
      (LayoutInflater) getBaseContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    final View addView = layoutInflater.inflate(R.layout.row, null);
    TextView textOut = (TextView)addView.findViewById(R.id.textout);
    textOut.setText(textIn.getText().toString());
    Button buttonRemove = (Button)addView.findViewById(R.id.remove);
    buttonRemove.setOnClickListener(new OnClickListener(){

     @Override
     public void onClick(View v) {
      ((LinearLayout)addView.getParent()).removeView(addView);
     }});
    
    container.addView(addView);
   }});
  
 }

}

activity_main.xml

<LinearLayout 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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <Button
            android:id="@+id/add"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentRight="true"
            android:text="Add"/>
        <EditText
            android:id="@+id/textin"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_toLeftOf="@id/add"/>
    </RelativeLayout>
    <LinearLayout 
        android:id="@+id/container"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">
    </LinearLayout>

</LinearLayout>

row.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
    <Button
        android:id="@+id/remove"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:text="Remove"/>
    <TextView
        android:id="@+id/textout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_toLeftOf="@id/remove"/>
</RelativeLayout>

Download the files.

Related:
- Apply animations on layout changes using LayoutTransition
- Get text from dynamically added view