/*
* Copyright 2003-2016 JetBrains s.r.o.
*
* 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 jetbrains.mps.openapi.editor.cells.traversal;
import jetbrains.mps.openapi.editor.cells.CellTraversalUtil;
import jetbrains.mps.openapi.editor.cells.EditorCell;
import jetbrains.mps.openapi.editor.cells.EditorCell_Collection;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import java.util.Iterator;
abstract class Direction {
static final Direction FORWARD = new Direction() {
@NotNull
@Override
public Iterator<EditorCell> getChildren(@NotNull EditorCell_Collection collection) {
return collection.iterator();
}
@Nullable
@Override
public EditorCell getLastCell(@NotNull EditorCell_Collection collection) {
return collection.lastCell();
}
@Nullable
@Override
public EditorCell getNextSibling(@NotNull EditorCell cell) {
return CellTraversalUtil.getNextSibling(cell);
}
};
static final Direction BACKWARD = new Direction() {
@NotNull
@Override
public Iterator<EditorCell> getChildren(@NotNull EditorCell_Collection collection) {
return collection.reverseIterator();
}
@Nullable
@Override
public EditorCell getLastCell(@NotNull EditorCell_Collection collection) {
return collection.firstCell();
}
@Nullable
@Override
public EditorCell getNextSibling(@NotNull EditorCell cell) {
return CellTraversalUtil.getPrevSibling(cell);
}
};
private Direction() { }
@NotNull
public abstract Iterator<EditorCell> getChildren(@NotNull EditorCell_Collection collection);
@Nullable
public abstract EditorCell getLastCell(@NotNull EditorCell_Collection collection);
@Nullable
public abstract EditorCell getNextSibling(@NotNull EditorCell cell);
}