Mobile App Dev 2021W: Tutorial 9

This tutorial is still in developoment.

Questions

1. Where in the application is the following behaviour specified?
   1. The size of the red circle
   2. No application title on the screens.
2. The layout of the application change when you switch the device to dark/night mode, beyond different colors. Why?

Code

MainActivity.kt

package carleton.comp1601.intentdemo

import android.os.Bundle
import android.util.Log
import android.view.View
import androidx.appcompat.app.AppCompatActivity
import android.content.Intent
import android.net.Uri
import android.view.MotionEvent

val appName = "IntentDemo"

class MainActivity : AppCompatActivity() {
    private lateinit var circle: View

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        circle = findViewById(R.id.circle)
        circle.setOnTouchListener(trackCircle)

        Log.d(appName, "Main screen created")
    }

    fun openPage(v: View) {
        Log.d(appName, "Opening URL")
        val intent = Intent(Intent.ACTION_VIEW, Uri.parse("https://homeostasis.scs.carleton.ca/wiki"))
        startActivity(intent)
        Log.d(appName, "URL intent sent")
    }

    val trackCircle = object: View.OnTouchListener {
        override fun onTouch(v: View?, event: MotionEvent?): Boolean {
            if (event == null || v == null) {
                return false
            }

            val action = event.getAction()
            val x = event.rawX - 128F
            val y = event.rawY - 128F

            if (action == MotionEvent.ACTION_DOWN) {
                Log.d(appName, "Circle touched at ${x}, ${y}")
            } else if (action == MotionEvent.ACTION_UP) {
                circle.x = x
                circle.y = y
                Log.d(appName, "Circle released at ${x}, ${y}")
            } else if (action == MotionEvent.ACTION_MOVE) {
                circle.x = x
                circle.y = y
                Log.d(appName, "Circle repositioned to ${x}, ${y}")
            }
            return true;
        }
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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="match_parent"
    tools:context=".MainActivity">

    <ImageView
        android:id="@+id/circle"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:src="@drawable/circle"
        android:visibility="visible"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="openPage"
        android:text="Open Page"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.501"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.944" />

</androidx.constraintlayout.widget.ConstraintLayout>

SplashScreen.kt

package carleton.comp1601.intentdemo

import android.content.Intent
import android.os.Bundle
import android.util.Log
import android.view.View
import androidx.appcompat.app.AppCompatActivity

class SplashScreen : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.splashscreen)
        Log.d(appName, "Splash screen created")
    }

    fun startMain(v: View) {
        Log.d(appName, "Starting Main button pressed")
        intent = Intent(this, MainActivity::class.java)
        startActivity(intent)
        Log.d(appName, "Starting Main intent sent")
    }
}

splashscreen.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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="match_parent"
    android:onClick="startMain"
    tools:context=".SplashScreen">

    <TextView
        android:id="@+id/title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Intent &amp; Drag Demo"
        android:textAlignment="center"
        android:textAppearance="@style/TextAppearance.AppCompat.Display3"
        android:textStyle="bold"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="COMP 1601"
        android:textAppearance="@style/TextAppearance.AppCompat.Display2"
        app:layout_constraintBottom_toTopOf="@+id/continueButton"
        app:layout_constraintTop_toBottomOf="@+id/title"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent" />

    <Button
        android:id="@+id/continueButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="16dp"
        android:onClick="startMain"
        android:text="Continue"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="carleton.comp1601.intentdemo">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.IntentDemo">
        <activity android:name=".SplashScreen">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".MainActivity" android:exported="true">
        </activity>
    </application>

</manifest>

circle.xml

<?xml version="1.0" encoding="utf-8"?>
<shape android:shape="oval" xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="#ff0000"/>
</shape>