I want to use the ternary operator to change the color of a custom view in terms of a Boolean. Here is my custom view
class AddButton(context: Context, attrs: AttributeSet): RelativeLayout(context, attrs) {
private var imageView: AppCompatImageView
private var textView: TextView
init {
inflate(context, R.layout.add_button, this)
imageView = findViewById(R.id.add_button_icon)
textView = findViewById(R.id.add_button_text)
val attributes = context.obtainStyledAttributes(attrs, R.styleable.AddButton)
val iconTint = attributes.getResourceId(R.styleable.AddButton_iconColor, 0)
imageView.setImageDrawable(attributes.getDrawable(R.styleable.AddButton_icon))
textView.text = attributes.getString(R.styleable.AddButton_text)
setIconTint(iconTint)
attributes.recycle()
}
fun setIconTint(colorId: Int) {
imageView.setColorFilter(ContextCompat.getColor(context, colorId), android.graphics.PorterDuff.Mode.SRC_IN);
}
fun setText(text: String) {
textView.text = text
}
}
values/attr.xml :
<declare-styleable name="AddButton">
<attr name="icon" format="reference"/>
<attr name="iconColor" format="color"/>
<attr name="text" format="string"/>
</declare-styleable>
In the layout :
<com.my.package.ui.customview.AddButton
app:icon="@drawable/ic_add"
app:iconColor="@{selected ? @color/colorRed : @color/colorBlack}"
app:text="@{selected ? @string/selected : @string/not_selected}"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
It is working as expected for the app:text but when i want to do it for the iconColor i have this error :
Cannot find a setter for <com.my.package.ui.customview.AddButton app:iconColor> that accepts parameter type 'int'
For now to solve the problem, i have to change the color in the code behind by listening when the selected boolean changes and then call the setIconTint of my AddButton view.
Is there a way to change the color directly in the layout file using the ternary operator ?
You are looking for a custom data binding adapter for your custom view. First, check out this for the complete document.
So, in short, you need to define a method named: setIconColor that accepts iconId and sets the icon color by the provided resource id.
But if you want to use your current method named setIconTint, you just need to annotate your class with:
@BindingMethods(value = [
BindingMethod(
type = AddButton::class,
attribute = "iconColor",
method = "setIconTint")])
After all, I again suggest you check other variants of binding adapters in the official document.