Question

Extend the Hello Goodbye application from the class to include the following using android studio:

1. Add a Text Color button underneath the existing Exclamation button, using the same text color and background image. When this button is clicked, toggle the display color for the Hello or Goodbye text between the original color and the color Red.

2. Add a Reset button underneath the new text color button, using the same text color and background image. When this button is clicked, return the text display to “Hello” in the original color.

activity main 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="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity"
    android:background="@drawable/background">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:text="@string/hello"
        android:id="@+id/textView"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:textColor="@color/dusty_rose"
        android:textSize="60sp" />

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/imageView"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true"
        android:src="@drawable/greetimage"
        android:contentDescription="@string/exclaim_img" />

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/exclaim_btn"
        android:layout_below="@+id/imageView"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="32dp"
        android:background="@drawable/exclamationbtn" />

    <Button
        android:id="@+id/button2"
        android:layout_width="100dp"
        android:layout_height="wrap_content"
        android:layout_below="@+id/imageView"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="102dp"
        android:background="@drawable/exclamationbtn"
        android:text="text color" />
</RelativeLayout>

Main activity.java

package com.cornez.hellogoodbye;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {
    //DECLARE  OBJECTS TO INTERFACE WITH LAYOUT COMPONENTS
    Button exclaimBtn;
    Button textcolBtn;
    private TextView greetingTextView;

    //INDICATES HELLO IS CURRENTLY DISPLAYED
    private boolean isHello;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        //TASK 1: INFLATE THE MAIN SCREEN LAYOUT USED BY THE APP
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //TASK 2: ESTABLISH REFERENCES TO THE TEXTVIEW AND BUTTON
        Button exclaimBtn = (Button) findViewById(R.id.button1);
        Button textcolBtn = (Button) findViewById(R.id.button2);
        greetingTextView = (TextView) findViewById(R.id.textView);
        //TASK 3: INITIALIZE GREETINGS
        initializeGreeting();

        //TASK 4: REGISTER THE LISTENER EVENT FOR THE BUTTON
        exclaimBtn.setOnClickListener(toggleGreeting);
    }

    private final View.OnClickListener toggleGreeting =
            new View.OnClickListener() {

                public void onClick(View btn) {
                    //TASK: CONSTRUCT THE TOGGLE GREETING
                    if (isHello) {
                        isHello = false;
                        greetingTextView.setText(R.string.goodbye);
                    } else {
                        isHello = true;
                        greetingTextView.setText(R.string.hello);

                    }
                }
            };
    int conditionColor;

    private void initializeGreeting() {
        isHello = true;
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu;
        // this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

Answer 1