io.apicurio.datamodels.models.visitors.TraversalContextImpl Maven / Gradle / Ivy

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package io.apicurio.datamodels.models.visitors;

import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Stack;

/**
 * Context used during traversal of a model. This gives insight into where in
 * the traversal of a model a visitor/traverser might be. The traverser
 * maintains this context and optionally makes it available to the visitor (only
 * if the visitor implements the TraversingVisitor interface.
 *
 * @author [email protected]
 */
public class TraversalContextImpl implements TraversalContext {

	private final Stack stack = new Stack<>();

	public void pushProperty(String propertyName) {
		this.stack.push(TraversalStep.fromNodeProperty(propertyName));
	}
	public void pushListIndex(int index) {
		this.stack.push(TraversalStep.fromListIndex(index));
	}
	public void pushMapIndex(String key) {
		this.stack.push(TraversalStep.fromMapIndex(key));
	}

	public void pop() {
		this.stack.pop();
	}

	public TraversalStep peek() {
		return this.stack.peek();
	}

	@Override
	public TraversalStep getMostRecentStep() {
		return this.stack.peek();
	}

	@Override
	public List getAllSteps() {
		TraversalStep[] steps = this.stack.toArray(new TraversalStep[this.stack.size()]);
		return Collections.unmodifiableList(Arrays.asList(steps));
	}

	@Override
	public String getMostRecentPropertyStep() {
		for (int idx = stack.size() - 1; idx >= 0; idx--) {
			TraversalStep step = stack.get(idx);
			if (step.getType() == TraversalStepType.property) {
				return (String) step.getValue();
			}
		}
		return null;
	}

	@Override
	public boolean containsStep(TraversalStepType type, Object value) {
		for (TraversalStep step : stack) {
			if (step.getType() == type && value.equals(step.getValue())) {
				return true;
			}
		}
		return false;
	}

}