VectorApplier

Kotlin |Java

class VectorApplier : AbstractApplier<VNode>

kotlin.Any
↳	androidx.compose.runtime.AbstractApplier<androidx.compose.ui.graphics.vector.VNode>
	↳	androidx.compose.ui.graphics.vector.VectorApplier

Summary

Public constructors
<init>(root: VNode)

Public methods
Unit	insertBottomUp(index: Int, instance: VNode) Indicates that instance should be inserted as a child of current at index.
Unit	insertTopDown(index: Int, instance: VNode) Indicates that instance should be inserted as a child to current at index.
Unit	move(from: Int, to: Int, count: Int) Indicates that count children of current should be moved from index from to index to.
Unit	remove(index: Int, count: Int) Indicates that the children of current from index to index + count should be removed.

Protected methods
Unit	onClear() Called to perform clearing of the root when clear is called.

Inherited functions
From class AbstractApplier Unit clear() Move to the root and remove all nodes from the root, preparing both this Applier and its root to be used as the target of a new composition in the future. Unit down(node: T) Indicates that the applier is getting traversed "down" the tree. When this gets called, node is expected to be a child of current, and after this operation, node is expected to be the new current. Unit move(from: Int, to: Int, count: Int) Unit remove(index: Int, count: Int) Unit up() Indicates that the applier is getting traversed "up" the tree. After this operation completes, the current should return the "parent" of the current node at the beginning of this operation.
From class Applier Unit insertBottomUp(index: Int, instance: N) Indicates that instance should be inserted as a child of current at index. An applier should insert the node into the tree either in insertTopDown or insertBottomUp, not both. See the description of insertTopDown to which describes when to implement insertTopDown and when to use insertBottomUp. Unit insertTopDown(index: Int, instance: N) Indicates that instance should be inserted as a child to current at index. An applier should insert the node into the tree either in insertTopDown or insertBottomUp, not both. The insertTopDown method is called before the children of instance have been created and inserted into it. insertBottomUp is called after all children have been created and inserted. Some trees are faster to build top-down, in which case the insertTopDown method should be used to insert the instance. Other tress are faster to build bottom-up in which case insertBottomUp should be used. To give example of building a tree top-down vs. bottom-up consider the following tree, R | B / \ A C where the node B is being inserted into the tree at R. Top-down building of the tree first inserts B into R, then inserts A into B followed by inserting C into B`. For example, 1 2 3 R R R | | | B B B / / \ A A C A bottom-up building of the tree starts with inserting A and C into B then inserts B tree into R. 1 2 3 B B R | / \ | A A C B / \ A C To see how building top-down vs. bottom-up can differ significantly in performance consider a tree where whenever a child is added to the tree all parent nodes, up to the root, are notified of the new child entering the tree. If the tree is built top-down, R is notified of B entering. B is notified of A entering, R is notified of A entering. B is notified of C entering, R is notified of C entering. for a total of 5 notifications. The number of notifications grows exponentially with the number of inserts. For bottom-up, the notifications are, B is notified A entering. B is notified C entering. R is notified B entering. The notifications are linear to the number of nodes inserted. If, on the other hand, all children are notified when the parent enters a tree, then the notifications are, for top-down, B is notified it is entering R. A is notified it is entering B. C is notified it is entering B. which is linear to the number of nodes inserted. For bottom-up, the notifications look like, A is notified it is entering B. C is notified it is entering B. B is notified it is entering R, A is notified it is entering R, C is notified it is entering R. which exponential to the number of nodes inserted. Unit move(from: Int, to: Int, count: Int) Indicates that count children of current should be moved from index from to index to. The to index is relative to the position before the change, so, for example, to move an element at position 1 to after the element at position 2, from should be 1 and to should be 3. If the elements were A B C D E, calling move(1, 3, 1) would result in the elements being reordered to A C B D E. Unit onBeginChanges() Called when the Composer is about to begin applying changes using this applier. onEndChanges will be called when changes are complete. Unit onEndChanges() Called when the Composer is finished applying changes using this applier. A call to onBeginChanges will always precede a call to onEndChanges. Unit remove(index: Int, count: Int) Indicates that the children of current from index to index + count should be removed.

Inherited properties
From class AbstractApplier T current The node that operations will be applied on at any given time. It is expected that the value of this property will change as down and up are called. T root

Public constructors

<init>

VectorApplier(root: VNode)

Public methods

insertBottomUp

fun insertBottomUp(
    index: Int, 
    instance: VNode
): Unit

Indicates that instance should be inserted as a child of current at index. An applier should insert the node into the tree either in