Mobile App Dev 2021W: Tutorial 9

This tutorial is still in developoment.

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>