कोटलिन में आप बस ConstraintSet
क्लास का विस्तार कर सकते हैं और कोटलिन में डीएसएल का लाभ उठाने के लिए कुछ तरीके जोड़ सकते हैं और अधिक पठनीय कोड का उत्पादन कर सकते हैं। ऐशे ही
class KotlinConstraintSet : ConstraintSet() {
companion object {
inline fun buildConstraintSet(block:KotlinConstraintSet.()->Unit) =
KotlinConstraintSet().apply(block)
}
//add this if you plan on using the margin param in ConstraintSet.connect
var margin: Int? = null
get() {
val result = field
margin = null //reset it to work with other constraints
return result
}
inline infix fun Unit.and(other: Int) = other // just to join two functions
inline infix fun Int.topToBottomOf(bottom: Int) =
margin?.let {
connect(this, TOP, bottom, BOTTOM, it)
} ?: connect(this, TOP, bottom, BOTTOM)
inline fun margin(margin: Int) {
this.margin = margin
}
inline infix fun Int.bottomToBottomOf(bottom: Int) =
margin?.let {
connect(this, BOTTOM, bottom, BOTTOM, it)
} ?: connect(this, BOTTOM, bottom, BOTTOM)
inline infix fun Int.topToTopOf(top: Int) =
margin?.let {
connect(this, TOP, top, TOP, it)
} ?: connect(this, TOP, top, TOP)
inline infix fun Int.startToEndOf(end: Int) =
margin?.let {
connect(this, START, end, END, it)
} ?: connect(this, START, end, END)
...
//TODO generate other functions depending on your needs
infix fun Int.clear(constraint: Constraints) =
when (constraint) {
Constraints.TOP -> clear(this, TOP)
Constraints.BOTTOM -> clear(this, BOTTOM)
Constraints.END -> clear(this, END)
Constraints.START -> clear(this, START)
}
//inline infix fun clearTopCon
inline infix fun appliesTo(constraintLayout: ConstraintLayout) =
applyTo(constraintLayout)
inline infix fun clones(constraintLayout: ConstraintLayout) =
clone(constraintLayout)
inline fun constraint(view: Int, block: Int.() -> Unit) =
view.apply(block)
}
enum class Constraints {
TOP, BOTTOM, START, END //you could add other values to use with the clear fun like LEFT
}
और इसे इस तरह से उपयोग करें
buildConstraintSet {
this clones yourConstraintLayout
constraint(R.id.view1) {
margin(value:Int) and this topToBottomOf R.id.view2
margin(30) and this bottomToBottomOf ConstraintSet.PARENT_ID
}
constraint(R.id.view2) {
this clear Constraints.BOTTOM
margin(0) and this topToTopOf R.id.topGuide
}
constraint(R.id.view4) {
this topToTopOf R.id.view2
this bottomToBottomOf R.id.view3
this startToEndOf R.id.view2
}
//or you could simply do
R.id.view1 startToEndOf R.view2
R.id.view1 toptToBottomOf R.view3
R.id.view3 bottomtToBottomOf R.view2
R.id.view3 clear Constraints.END
// and finally call applyTo()
this appliesTo yourConstraintLayout
}