/**
* Copyright 2010 Google Inc.
*
* 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.waveprotocol.wave.client.paging;
import com.google.common.base.Preconditions;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
/**
* Simple block tree for testing.
*
*/
public final class FakeBlock extends AbstractTreeNode<FakeBlock> implements Block {
interface Factory {
FakeBlock create(String name, Dimensions size);
}
static class Dimensions {
/** Maximum margin size. */
private final static int MAX_MARGIN = 40;
/** Maximum padding size. */
private final static int MAX_PADDING = 40;
/** Probability that a block will be an offset parent. */
private final static double PARENT_PROBABILITY = 0.3;
/** Randomizer for wobbling. */
private final Random random;
/** External space before and after this block. */
int margin;
/** Internal space at each end of this block. */
int padding;
/** True iff this block acts as a new origin for descendant positions. */
boolean isOffsetParent;
private Dimensions(Random random) {
this.random = random;
}
/** @return a specification for an empty block. */
static Dimensions zero() {
return new Dimensions(null);
}
/** @return a specification for block of random size. */
static Dimensions create(Random random) {
Dimensions dimensions = new Dimensions(random);
dimensions.wobble();
return dimensions;
}
/**
* Randomly adjusts this size specification.
*/
void wobble() {
if (random != null) {
margin = random.nextInt(MAX_MARGIN);
padding = random.nextInt(MAX_PADDING);
isOffsetParent = random.nextDouble() < PARENT_PROBABILITY;
}
}
}
private final String name;
private final Dimensions layout;
private boolean pagedIn;
private static final Factory ROOT = new Factory() {
@Override
public FakeBlock create(String name, Dimensions size) {
return new FakeBlock(name, size);
}
};
private FakeBlock(String name, Dimensions size) {
this.name = name;
this.layout = size;
}
@Override
protected FakeBlock self() {
return this;
}
public static FakeBlock.Factory root() {
return ROOT;
}
private boolean hasParent() {
return getParent() != null;
}
//
// Covariant mutation.
//
public FakeBlock.Factory prepend() {
return new FakeBlock.Factory() {
@Override
public FakeBlock create(String name, Dimensions size) {
return prepend(new FakeBlock(name, size));
}
};
}
public FakeBlock.Factory append() {
return new FakeBlock.Factory() {
@Override
public FakeBlock create(String name, Dimensions size) {
return append(new FakeBlock(name, size));
}
};
}
public FakeBlock.Factory insertBefore(final FakeBlock reference) {
return new FakeBlock.Factory() {
@Override
public FakeBlock create(String name, Dimensions size) {
return insertBefore(reference, new FakeBlock(name, size));
}
};
}
public FakeBlock.Factory insertAfter(final FakeBlock reference) {
return new FakeBlock.Factory() {
@Override
public FakeBlock create(String name, Dimensions size) {
return insertAfter(reference, new FakeBlock(name, size));
}
};
}
public void removeFomParent() {
Preconditions.checkState(hasParent());
remove();
}
//
// Paging state.
//
@Override
public void pageIn() {
Preconditions.checkState(!pagedIn);
Preconditions.checkState(!hasParent() || getParent().isPagedIn());
pagedIn = true;
layout.wobble();
}
@Override
public void pageOut() {
Preconditions.checkState(pagedIn);
Preconditions.checkState(hasParent() || getParent().isPagedIn());
pagedIn = false;
layout.wobble();
}
public boolean isPagedIn() {
return pagedIn;
}
//
// Dimensions.
//
/** @return the start of this block's margin box. */
private double getOuterStart() {
if (getPreviousSibling() != null) {
return getPreviousSibling().getOuterEnd();
} else if (getParent() != null) {
return getParent().getInnerStart() - getParent().getChildrenOrigin();
} else {
return 0;
}
}
/** @return the end of this block's margin box. */
private double getOuterEnd() {
return getEnd() + layout.margin;
}
private double getInnerStart() {
return getStart() + layout.padding;
}
private double getInnerEnd() {
if (getLastChild() != null) {
return getLastChild().getOuterEnd() + getChildrenOrigin();
} else {
return getInnerStart();
}
}
@Override
public double getStart() {
return getOuterStart() + layout.margin;
}
@Override
public double getEnd() {
return getInnerEnd() + layout.padding;
}
@Override
public double getChildrenOrigin() {
return layout.isOffsetParent ? getInnerStart() : 0;
}
//
// Naming.
//
public String getName() {
return name;
}
//
// Random.
//
public List<FakeBlock> collect() {
List<FakeBlock> all = new ArrayList<FakeBlock>();
collectInto(all);
return all;
}
private void collectInto(List<FakeBlock> all) {
all.add(this);
for (FakeBlock child = getFirstChild(); child != null; child = child.getNextSibling()) {
child.collectInto(all);
}
}
public String render() {
return render(new StringBuffer()).toString();
}
public String renderWithNames() {
return renderWithNames(new StringBuffer()).toString();
}
private StringBuffer render(StringBuffer sb) {
sb.append(pagedIn ? "[" : "(");
for (FakeBlock child = getFirstChild(); child != null; child = child.getNextSibling()) {
child.render(sb);
}
sb.append(pagedIn ? "]" : ")");
return sb;
}
private StringBuffer renderWithNames(StringBuffer sb) {
sb.append(pagedIn ? "[ " : "( ");
sb.append(name);
for (FakeBlock child = getFirstChild(); child != null; child = child.getNextSibling()) {
sb.append(" ");
child.renderWithNames(sb);
}
sb.append(pagedIn ? " ]" : " )");
return sb;
}
@Override
public String toString() {
return render();
}
}