Add Custom View dinamically

Question

I've got a problem while adding custom view dynamically.

Below are my current codes.

attrs.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="SkillItemView">
        <attr name="skill" format="string" />
        <attr name="proficiency" format="integer" />
    </declare-styleable>
</resources>

skill_item.view.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="@drawable/progress_item_incomplete"
    android:paddingTop="@dimen/list_row_margin_default"
    android:paddingBottom="@dimen/list_row_margin_default"
    android:paddingLeft="@dimen/text_padding"
    android:paddingRight="@dimen/text_padding"
    android:layout_margin="@dimen/list_row_margin_default">

    <TextView
        android:id="@+id/text_skill"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="@color/colorBlack_2"
        android:textStyle="italic"
        android:text="Art Direction" />
</LinearLayout>

SkillItemView.kt

class SkillItemView (context: Context, attrs: AttributeSet): LinearLayout(context, attrs) {

    init {
        inflate(context, R.layout.skill_item_view, this)

        val textSkill: TextView = findViewById(R.id.text_skill)

        val attributes = context.obtainStyledAttributes(attrs, R.styleable.SkillItemView)
        textSkill.text = attributes.getString(R.styleable.SkillItemView_skill)
        attributes.recycle()

    }
}

And I am going to add this view dynamically in adapter

for (skill in profileList[position].getSkills()) {
    var skillView = SkillItemView(context, ???)
    parentView.addView(skillView)
}

The SkillItemView Constructor has 2 parameters. Context and AttributeSet. (See ??? in above codes)

What I have to write for AttributeSet?

Andrei Tanana · Accepted Answer · 2019-10-06T08:25:55.027

You have to declare attrs attribute as nullable AttributeSet?. In that case you can instantiate SkillItemView in the adapter:

class SkillItemView(context: Context, attrs: AttributeSet? = null) : LinearLayout(context, attrs) {
    init {
        inflate(context, R.layout.skill_item_view, this)

        val textSkill: TextView = findViewById(R.id.text_skill)

        if (attrs != null) {
            val attributes = context.obtainStyledAttributes(attrs, R.styleable.SkillItemView)
            textSkill.text = attributes.getString(R.styleable.SkillItemView_skill)
            attributes.recycle()
        }
    }
}

...

for (skill in profileList[position].getSkills()) {
    var skillView = SkillItemView(context)
    parentView.addView(skillView)
}

If you want to pass parameters while creating SkillItemView dynamically, you can create a custom constructor:

class SkillItemView : LinearLayout {
    constructor(context: Context, attrs: AttributeSet? = null) : super(context, attrs) {
        inflate(context, R.layout.skill_item_view, this)
        val textSkill: TextView = findViewById(R.id.text_skill)

        if (attrs != null) {
            val attributes = context.obtainStyledAttributes(attrs, R.styleable.SkillItemView)
            textSkill.text = attributes.getString(R.styleable.SkillItemView_skill)
            attributes.recycle()
        }
    }

    constructor(context: Context, skill:String? = null, proficiency: Int? = null) : super(context) {
        inflate(context, R.layout.skill_item_view, this)
        if (skill != null) {
            val textSkill: TextView = findViewById(R.id.text_skill)
            textSkill.text = skill
        }
    }
}
...
for (skill in profileList[position].getSkills()) {
    var skillView = SkillItemView(context, "test skill")
    parentView.addView(skillView)
}

Add Custom View dinamically

1 Answers1