kotlindeclare-styleable

Add Custom View dinamically


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?


Solution

  • 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)
    }