org.pageseeder.diffx.action.ActionsBuffer Maven / Gradle / Ivy
/*
* Copyright (c) 2010-2021 Allette Systems (Australia)
* http://www.allette.com.au
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.pageseeder.diffx.action;
import org.jetbrains.annotations.NotNull;
import org.pageseeder.diffx.api.DiffHandler;
import org.pageseeder.diffx.api.Operator;
import java.util.ArrayList;
import java.util.List;
/**
* Generates a list of actions from the output of the algorithms.
*
* This handler is useful to capture the operations resulting from a diff and generate and edit script.
*
* @author Christophe Lauret
* @version 0.9.0
* @see OperationsBuffer
*/
public class ActionsBuffer implements DiffHandler {
/**
* The list of actions produced by this handler.
*/
private final List> actions = new ArrayList<>();
/**
* The action used in the last operation.
*/
private Action action = null;
@Override
public void handle(@NotNull Operator operator, @NotNull T token) {
setupAction(operator);
this.action.add(token);
}
/**
* @return the list of actions generated by this formatter.
*/
public List> getActions() {
return this.actions;
}
/**
* Count the number of atomic operations of type INS or DEL.
*
* @return The number of edits in the buffer.
*/
public int countEdits() {
int edits = 0;
for (Action action : this.actions) if (action.operator().isEdit()) edits += action.tokens().size();
return edits;
}
/**
* Sets up the action prior to handling the operation.
*
* If the action does not exist or is of a different type, create a new one
* and add to the list of actions.
*
* @param operator The type of action.
*/
private void setupAction(Operator operator) {
if (this.action == null || this.action.operator() != operator) {
this.action = new Action<>(operator);
this.actions.add(this.action);
}
}
/**
* Apply the action captured by this handler to the specified handler.
*
* This method invokes both the start and end methods on the handler.
*
* @param handler receives start, handler and end events.
*/
public void applyTo(DiffHandler handler) {
handler.start();
for (Action action : this.actions) {
for (T token : action.tokens()) {
handler.handle(action.operator(), token);
}
}
handler.end();
}
@Override
public String toString() {
return "ActionsBuffer";
}
}