/**
* Copyright (c) 2013 Puppet Labs, Inc. and other contributors, as listed below.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Puppet Labs
*/
package com.puppetlabs.geppetto.pp.dsl.formatting;
import java.util.List;
import com.puppetlabs.geppetto.common.stats.IntegerCluster;
import com.puppetlabs.geppetto.pp.SelectorExpression;
import com.puppetlabs.geppetto.pp.dsl.services.PPGrammarAccess;
import com.puppetlabs.xtext.dommodel.IDomNode;
import com.puppetlabs.xtext.dommodel.formatter.DelegatingLayoutContext;
import com.puppetlabs.xtext.dommodel.formatter.DomNodeLayoutFeeder;
import com.puppetlabs.xtext.dommodel.formatter.ILayoutManager.ILayoutContext;
import com.puppetlabs.xtext.dommodel.formatter.css.Alignment;
import com.puppetlabs.xtext.dommodel.formatter.css.IStyleFactory;
import com.puppetlabs.xtext.dommodel.formatter.css.StyleSet;
import com.puppetlabs.xtext.textflow.ITextFlow;
import com.puppetlabs.xtext.textflow.MeasuredTextFlow;
import com.puppetlabs.xtext.textflow.TextFlow;
import org.eclipse.xtext.ParserRule;
import org.eclipse.xtext.RuleCall;
import com.google.common.base.Predicate;
import com.google.common.collect.Lists;
import com.google.inject.Inject;
/**
* A sub layout handler for SelectorExpression and SelctorEntry
*
*/
public class SelectorLayout {
@Inject
private IStyleFactory styles;
private PPGrammarAccess grammarAccess;
@Inject
private DomNodeLayoutFeeder feeder;
protected final Predicate<IDomNode> caseFatCommaPredicate = new Predicate<IDomNode>() {
@Override
public boolean apply(IDomNode input) {
return input.getGrammarElement() == grammarAccess.getSelectorEntryAccess().getEqualsSignGreaterThanSignKeyword_1_1();
}
};
/** used to find the case nodes */
private final ParserRule selectorEntryRule;
private static final int SELECTOR_EXPRESSION_CLUSTER_SIZE = 20;
@Inject
public SelectorLayout(PPGrammarAccess grammarAccess) {
this.grammarAccess = grammarAccess;
selectorEntryRule = grammarAccess.getSelectorEntryRule();
}
protected boolean _format(SelectorExpression o, StyleSet styleSet, IDomNode node, ITextFlow flow,
ILayoutContext context) {
// unify the width of selector entry expressions
// Step 1, must format up to the first selector entry expression to know the correct indentation of the selector entry
// expression. (At point of entry to this method, the whitespace between a preceding statement and the selector
// expression has not yet been processed, and thus, no WS, break, indent etc. has taken place.
//
DelegatingLayoutContext dlc = new DelegatingLayoutContext(context);
MeasuredTextFlow continuedFlow = new MeasuredTextFlow((MeasuredTextFlow) flow);
int currentMaxWidth = flow.getPreferredMaxWidth();
int availableWidth = 0; // set when first case is seen
// IBreakAndAlignAdvice advice = adviceProvider.get(); // TODO: Advice? this formatting ?
final boolean doAlignment = true; // advice.isAlignCases();
// used to collect the widths of each case's width of its values
List<Integer> widths = Lists.newArrayList();
// int maxLastLine = 0;
boolean firstSelectoEntrySeen = false;
List<IDomNode> fatCommaNodes = Lists.newArrayList();
IntegerCluster clusters = new IntegerCluster(SELECTOR_EXPRESSION_CLUSTER_SIZE);
for(IDomNode n : node.getChildren()) {
if(n.getGrammarElement() instanceof RuleCall &&
((RuleCall) n.getGrammarElement()).getRule() == selectorEntryRule) {
if(!firstSelectoEntrySeen) {
// finish measurement of the position the selectorEntry will appear at
//
continuedFlow.appendBreak();
continuedFlow.getIndentation();
availableWidth = currentMaxWidth - (continuedFlow.getIndentation() + 1) *
continuedFlow.getIndentSize();
}
// used to measure output of formatted selector entry values
// adjust its width to available width (and do not mark items consumed in the given context)
DelegatingLayoutContext innerContext = new DelegatingLayoutContext(context, availableWidth);
TextFlow measuredFlow = new TextFlow(innerContext);
// visit all nodes in case until the colon is hit, and format the output to the measured flow
IDomNode fatCommaNode = feeder.sequence(n, measuredFlow, innerContext, caseFatCommaPredicate);
fatCommaNodes.add(fatCommaNode);
// collect the width of the last selector entry's values
int lastLineWidth = measuredFlow.getWidthOfLastLine();
if(!firstSelectoEntrySeen) {
// the space before the first entry triggers selector expression indentation of 1, this must be adjusted
lastLineWidth -= measuredFlow.getIndentSize();
}
clusters.add(lastLineWidth);
widths.add(lastLineWidth);
firstSelectoEntrySeen = true;
}
else if(!firstSelectoEntrySeen) {
// continue to feed everything (until first case seen). Exceptional case, there are no entries - then this is just wasted
feeder.sequence(n, continuedFlow, dlc);
}
}
markupWidths(fatCommaNodes, widths, availableWidth, clusters, /* doCompaction, */doAlignment);
return false;
}
/**
* assign widths and alignment to the fat comma nodes
* compute available width for remainder if all cases are compactable
*
* @param fatCommaNodes
* @param widths
* @param availableWidth
* @param clusters
* @param doCompaction
* @return
*/
private void markupWidths(List<IDomNode> fatCommaNodes, List<Integer> widths, int availableWidth,
IntegerCluster clusters, boolean doAlignment) {
// assign widths and alignment to the fat comma nodes
for(int i = 0; i < fatCommaNodes.size(); i++) {
IDomNode c = fatCommaNodes.get(i);
int w = widths.get(i);
int mw = doAlignment
? clusters.clusterMax(w)
: w;
if(doAlignment)
c.getStyles().add(StyleSet.withStyles(styles.align(Alignment.right), //
styles.width(2 + mw - w)));
}
}
}