Kotlinでの動的レイアウト作成のたった13の方法

val linearLayout = LinearLayout(this)
linearLayout.orientation = LinearLayout.VERTICAL
linearLayout.layoutParams = ViewGroup.LayoutParams(
    ViewGroup.LayoutParams.MATCH_PARENT,
    ViewGroup.LayoutParams.MATCH_PARENT
)

val button = Button(this)
button.text = "動的に追加したボタン"
linearLayout.addView(button)

setContentView(linearLayout)

val relativeLayout = RelativeLayout(this)
relativeLayout.layoutParams = ViewGroup.LayoutParams(
    ViewGroup.LayoutParams.MATCH_PARENT,
    ViewGroup.LayoutParams.MATCH_PARENT
)

val button1 = Button(this)
button1.text = "ボタン1"
button1.id = View.generateViewId()
val params1 = RelativeLayout.LayoutParams(
    RelativeLayout.LayoutParams.WRAP_CONTENT,
    RelativeLayout.LayoutParams.WRAP_CONTENT
)
params1.addRule(RelativeLayout.CENTER_IN_PARENT)
button1.layoutParams = params1

val button2 = Button(this)
button2.text = "ボタン2"
button2.id = View.generateViewId()
val params2 = RelativeLayout.LayoutParams(
    RelativeLayout.LayoutParams.WRAP_CONTENT,
    RelativeLayout.LayoutParams.WRAP_CONTENT
)
params2.addRule(RelativeLayout.BELOW, button1.id)
button2.layoutParams = params2

relativeLayout.addView(button1)
relativeLayout.addView(button2)

setContentView(relativeLayout)

val frameLayout = FrameLayout(this)
frameLayout.layoutParams = ViewGroup.LayoutParams(
    ViewGroup.LayoutParams.MATCH_PARENT,
    ViewGroup.LayoutParams.MATCH_PARENT
)

// 上にくるボタンの設定
val buttonTop = Button(this)
buttonTop.text = "最前面のボタン"
val paramsTop = FrameLayout.LayoutParams(
    FrameLayout.LayoutParams.WRAP_CONTENT,
    FrameLayout.LayoutParams.WRAP_CONTENT,
    Gravity.CENTER
)
buttonTop.layoutParams = paramsTop

// 下にくるボタンの設定
val buttonBottom = Button(this)
buttonBottom.text = "背後のボタン"
val paramsBottom = FrameLayout.LayoutParams(
    FrameLayout.LayoutParams.MATCH_PARENT,
    FrameLayout.LayoutParams.MATCH_PARENT
)
buttonBottom.layoutParams = paramsBottom

frameLayout.addView(buttonBottom)
frameLayout.addView(buttonTop)

setContentView(frameLayout)

val gridLayout = GridLayout(this)
gridLayout.layoutParams = ViewGroup.LayoutParams(
    ViewGroup.LayoutParams.MATCH_PARENT,
    ViewGroup.LayoutParams.MATCH_PARENT
)
gridLayout.rowCount = 2
gridLayout.columnCount = 2

// 4つのボタンを生成してGridLayoutに追加する
for (i in 0..3) {
    val button = Button(this)
    button.text = "ボタン${i + 1}"
    val params = GridLayout.LayoutParams()
    params.rowSpec = GridLayout.spec(i / 2)
    params.columnSpec = GridLayout.spec(i % 2)
    button.layoutParams = params
    gridLayout.addView(button)
}

setContentView(gridLayout)

// ConstraintLayoutの初期設定
val constraintLayout = ConstraintLayout(this)
constraintLayout.layoutParams = ViewGroup.LayoutParams(
    ViewGroup.LayoutParams.MATCH_PARENT,
    ViewGroup.LayoutParams.MATCH_PARENT
)

// ボタンの生成と設定
val button = Button(this)
button.text = "サンプルボタン"
val buttonId = View.generateViewId()
button.id = buttonId

// ConstraintLayoutにボタンを追加
constraintLayout.addView(button)

// ボタンの位置を中央に指定
val set = ConstraintSet()
set.clone(constraintLayout)
set.connect(buttonId, ConstraintSet.TOP, ConstraintSet.PARENT_ID, ConstraintSet.TOP)
set.connect(buttonId, ConstraintSet.BOTTOM, ConstraintSet.PARENT_ID, ConstraintSet.BOTTOM)
set.connect(buttonId, ConstraintSet.LEFT, ConstraintSet.PARENT_ID, ConstraintSet.LEFT)
set.connect(buttonId, ConstraintSet.RIGHT, ConstraintSet.PARENT_ID, ConstraintSet.RIGHT)
set.applyTo(constraintLayout)

setContentView(constraintLayout)

val linearLayout = LinearLayout(this)
linearLayout.orientation = LinearLayout.VERTICAL

val addButton = Button(this)
addButton.text = "テキスト追加"
linearLayout.addView(addButton)

addButton.setOnClickListener {
    val textView = TextView(this)
    textView.text = "新しく追加されたテキスト"
    linearLayout.addView(textView)
}

setContentView(linearLayout)

val linearLayout = LinearLayout(this)
linearLayout.orientation = LinearLayout.VERTICAL

val deleteButton = Button(this)
deleteButton.text = "テキスト削除"
linearLayout.addView(deleteButton)

val textView = TextView(this)
textView.text = "削除されるテキスト"
linearLayout.addView(textView)

deleteButton.setOnClickListener {
    linearLayout.removeView(textView)
}

setContentView(linearLayout)

val linearLayout = LinearLayout(this)
linearLayout.orientation = LinearLayout.VERTICAL

val updateButton = Button(this)
updateButton.text = "テキスト更新"
linearLayout.addView(updateButton)

val textView = TextView(this)
textView.text = "更新前のテキスト"
linearLayout.addView(textView)

updateButton.setOnClickListener {
    textView.text = "更新後のテキスト"
}

setContentView(linearLayout)

val linearLayout = LinearLayout(this)
linearLayout.orientation = LinearLayout.VERTICAL

val touchView = TextView(this)
touchView.text = "ここをタップしてください"
linearLayout.addView(touchView)

touchView.setOnTouchListener { _, event ->
    when (event?.action) {
        MotionEvent.ACTION_DOWN -> {
            touchView.text = "タッチを検知しました！"
            true
        }
        else -> false
    }
}

setContentView(linearLayout)

val switchButton = Button(this)
switchButton.text = "レイアウト切り替え"

val layout1 = LinearLayout(this)
layout1.orientation = LinearLayout.VERTICAL

val layout2 = RelativeLayout(this)

switchButton.setOnClickListener {
    if (contentView == layout1) {
        setContentView(layout2)
    } else {
        setContentView(layout1)
    }
}

setContentView(layout1)

val layout = LinearLayout(this)
val animButton = Button(this)
animButton.text = "アニメーション開始"
layout.addView(animButton)

animButton.setOnClickListener {
    val anim = ObjectAnimator.ofFloat(layout, "scaleX", 1.0f, 1.5f, 1.0f)
    anim.duration = 1000
    anim.start()
}

setContentView(layout)

val layout = LinearLayout(this)
val editText = EditText(this)
layout.addView(editText)

editText.addTextChangedListener(object : TextWatcher {
    override fun afterTextChanged(s: Editable?) {
        val length = s?.length ?: 0
        if (length > 10) {
            layout.setBackgroundColor(Color.RED)
        } else {
            layout.setBackgroundColor(Color.WHITE)
        }
    }

    override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {}
    override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {}
})

setContentView(layout)

val layout = LinearLayout(this)
val dataText = TextView(this)
layout.addView(dataText)

// 仮のデータモデル
val dataModel = object {
    var data: String = "初期データ"
        set(value) {
            field = value
            dataText.text = value
        }
}

// ある操作でデータが更新された場合のシミュレーション
val updateButton = Button(this)
updateButton.text = "データ更新"
updateButton.setOnClickListener {
    dataModel.data = "更新後のデータ"
}
layout.addView(updateButton)

setContentView(layout)

val layout = LinearLayout(this)
for (i in 0 until 100) {
    val textView = TextView(this)
    textView.text = "テキスト$i"
    layout.addView(textView)
}
setContentView(layout)

class MainActivity : AppCompatActivity() {
    private val listener = View.OnClickListener {
        // 何らかの処理
    }

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

        val button = findViewById<Button>(R.id.myButton)
        button.setOnClickListener(listener)
    }

    override fun onDestroy() {
        super.onDestroy()
        val button = findViewById<Button>(R.id.myButton)
        button.setOnClickListener(null)  // リスナーを解除
    }
}

val button = Button(this)
button.text = "クリック"

// ボタンの背景色を動的に変更
button.setBackgroundColor(Color.RED)

// ボタンのテキストカラーを動的に変更
button.setTextColor(Color.WHITE)

val layout = LinearLayout(this)

if (resources.configuration.screenWidthDp > 600) {
    // タブレットなどの大きな画面の場合
    layout.orientation = LinearLayout.HORIZONTAL
} else {
    // スマートフォンなどの小さな画面の場合
    layout.orientation = LinearLayout.VERTICAL
}