Migrate from Java to Kotlin (#24)

Author: Meakk

f3d/src/main/java/app/f3d/F3D/android/Line.java

@@ -0,0 +1,16 @@
+package app.f3d.F3D.android
+
+/**
+ * Provides a simple implementation of a line with two points.
+ */
+class Line(firstPoint: Point = Point(), secondPoint: Point = Point()) {
+    var p1: Point = firstPoint
+    var p2: Point = secondPoint
+
+    val center: Point
+        /**
+         * Calculates the center point of the line.
+         * @return A point representing the center of the line.
+         */
+        get() = Point((this.p1.x + this.p2.x) / 2, (this.p1.y + this.p2.y) / 2)
+}

f3d/src/main/java/app/f3d/F3D/android/Line.kt

@@ -0,0 +1,65 @@
+package app.f3d.F3D.android
+
+import android.net.Uri
+import android.os.Bundle
+import android.view.View
+import androidx.activity.result.ActivityResultCallback
+import androidx.activity.result.ActivityResultLauncher
+import androidx.appcompat.app.ActionBar
+import androidx.appcompat.app.AppCompatActivity
+import androidx.constraintlayout.widget.ConstraintLayout
+import app.f3d.F3D.android.Utils.FileInteractionContract
+import com.google.android.material.floatingactionbutton.FloatingActionButton
+import java.util.Objects
+
+class MainActivity : AppCompatActivity() {
+    private var mView: MainView? = null
+    private var fileInteractionLauncher: ActivityResultLauncher<Void?>? = null
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_main)
+
+        val mainLayout = findViewById<ConstraintLayout>(R.id.mainLayout)
+
+        val addButton = findViewById<FloatingActionButton>(R.id.addButton)
+
+        supportActionBar!!.hide()
+
+        mView = MainView(this)
+
+        handleSelectedFileAppNotOpen()
+
+        fileInteractionLauncher = registerForActivityResult<Void?, Uri?>(
+            FileInteractionContract(),
+            ActivityResultCallback { uri: Uri? -> this.handleSelectedFile(uri) })
+
+        addButton.setOnClickListener(View.OnClickListener { view: View? ->
+            fileInteractionLauncher!!.launch(null)
+        })
+
+        mainLayout.addView(mView)
+    }
+
+    private fun handleSelectedFile(uri: Uri?) {
+        mView!!.updateActiveUri(uri)
+    }
+
+    private fun handleSelectedFileAppNotOpen() {
+        val intent = getIntent()
+        if (intent != null && intent.data != null) {
+            val uri = intent.data
+            handleSelectedFile(uri)
+        }
+    }
+
+    override fun onPause() {
+        super.onPause()
+        mView!!.onPause()
+    }
+
+    override fun onResume() {
+        super.onResume()
+        mView!!.onResume()
+    }
+}