/*
* Copyright (c) 2012, the Dart project authors.
*
* Licensed under the Eclipse Public License v1.0 (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.eclipse.org/legal/epl-v10.html
*
* 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 com.google.dart.tools.ui.internal.text.functions;
import com.google.dart.tools.core.DartCore;
import com.google.dart.tools.core.formatter.DefaultCodeFormatterConstants;
import com.google.dart.tools.ui.DartToolsPlugin;
import com.google.dart.tools.ui.DartX;
import com.google.dart.tools.ui.internal.util.CodeFormatterUtil;
import com.google.dart.tools.ui.text.editor.tmp.JavaScriptCore;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;
import org.eclipse.ui.texteditor.AbstractDecoratedTextEditorPreferenceConstants;
/**
* Uses the {@link com.google.dart.tools.ui.DartHeuristicScanner} to get the indentation level for a
* certain position in a document.
* <p>
* An instance holds some internal position in the document and is therefore not thread-safe.
*/
public class DartIndenter {
/**
* The Dart Core preferences.
*/
private final class CorePrefs {
final boolean prefUseTabs;
final int prefTabSize;
final int prefIndentationSize;
final boolean prefArrayDimensionsDeepIndent;
final int prefArrayIndent;
final boolean prefArrayDeepIndent;
final boolean prefTernaryDeepAlign;
final int prefTernaryIndent;
final int prefCaseIndent;
final int prefCaseBlockIndent;
final int prefSimpleIndent;
final int prefBracketIndent;
final boolean prefMethodDeclDeepIndent;
final int prefMethodDeclIndent;
final boolean prefMethodCallDeepIndent;
final int prefMethodCallIndent;
final boolean prefParenthesisDeepIndent;
final int prefParenthesisIndent;
final int prefBlockIndent;
final int prefMethodBodyIndent;
final int prefTypeIndent;
final boolean prefIndentBracesForBlocks;
final boolean prefIndentBracesForArrays;
final boolean prefIndentBracesForMethods;
final boolean prefIndentBracesForTypes;
final int prefContinuationIndent;
final boolean prefHasGenerics;
final String prefTabChar;
final int prefDefunIndent;
private final IProject fProject;
CorePrefs(IProject project) {
fProject = project;
if (isStandalone()) {
prefUseTabs = false;
prefTabSize = CodeFormatterUtil.getTabWidth();
prefIndentationSize = CodeFormatterUtil.getTabWidth();
prefArrayDimensionsDeepIndent = true;
prefContinuationIndent = 2;
prefBlockIndent = 1;
prefArrayIndent = prefContinuationIndent;
prefArrayDeepIndent = true;
prefTernaryDeepAlign = false;
prefTernaryIndent = prefContinuationIndent;
prefCaseIndent = 1;
prefCaseBlockIndent = prefBlockIndent;
prefIndentBracesForBlocks = false;
prefSimpleIndent = (prefIndentBracesForBlocks && prefBlockIndent == 0) ? 1
: prefBlockIndent;
prefBracketIndent = prefBlockIndent;
prefMethodDeclDeepIndent = true;
prefMethodDeclIndent = 1;
prefMethodCallDeepIndent = false;
prefMethodCallIndent = 2;
prefParenthesisDeepIndent = false;
prefParenthesisIndent = prefContinuationIndent;
prefMethodBodyIndent = 1;
prefTypeIndent = 1;
prefIndentBracesForArrays = false;
prefIndentBracesForMethods = false;
prefIndentBracesForTypes = false;
prefHasGenerics = true;
prefTabChar = JavaScriptCore.SPACE;
prefDefunIndent = prefContinuationIndent;
} else {
prefUseTabs = prefUseTabs();
prefTabSize = prefTabSize();
prefIndentationSize = prefIndentationSize();
prefArrayDimensionsDeepIndent = prefArrayDimensionsDeepIndent();
prefContinuationIndent = prefContinuationIndent();
prefBlockIndent = prefBlockIndent();
prefArrayIndent = prefArrayIndent();
prefArrayDeepIndent = prefArrayDeepIndent();
prefTernaryDeepAlign = prefTernaryDeepAlign();
prefTernaryIndent = prefTernaryIndent();
prefCaseIndent = prefCaseIndent();
prefCaseBlockIndent = prefCaseBlockIndent();
prefIndentBracesForBlocks = prefIndentBracesForBlocks();
prefSimpleIndent = prefSimpleIndent();
prefBracketIndent = prefBracketIndent();
prefMethodDeclDeepIndent = prefMethodDeclDeepIndent();
prefMethodDeclIndent = prefMethodDeclIndent();
prefMethodCallDeepIndent = prefMethodCallDeepIndent();
prefMethodCallIndent = prefMethodCallIndent();
prefParenthesisDeepIndent = prefParenthesisDeepIndent();
prefParenthesisIndent = prefParenthesisIndent();
prefMethodBodyIndent = prefMethodBodyIndent();
prefTypeIndent = prefTypeIndent();
prefIndentBracesForArrays = prefIndentBracesForArrays();
prefIndentBracesForMethods = prefIndentBracesForMethods();
prefIndentBracesForTypes = prefIndentBracesForTypes();
prefHasGenerics = hasGenerics();
prefTabChar = getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_TAB_CHAR);
prefDefunIndent = prefDefunIndent();
}
}
/**
* Returns the possibly project-specific core preference defined under <code>key</code>.
*
* @param key the key of the preference
* @return the value of the preference
*/
private String getCoreFormatterOption(String key) {
// if (fProject != null) {
// return fProject.getOption(key, true);
// }
return DartCore.getOption(key);
}
private boolean hasGenerics() {
return true;
}
/**
* Returns <code>true</code> if the class is used outside the workbench, <code>false</code> in
* normal mode
*
* @return <code>true</code> if the plug-ins are not available
*/
private boolean isStandalone() {
DartX.todo();
return true;
// return JavaScriptCore.getPlugin() == null;
}
private boolean prefArrayDeepIndent() {
String option = getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_ALIGNMENT_FOR_EXPRESSIONS_IN_ARRAY_INITIALIZER);
try {
return DefaultCodeFormatterConstants.getIndentStyle(option) == DefaultCodeFormatterConstants.INDENT_ON_COLUMN;
} catch (IllegalArgumentException e) {
// ignore and return default
}
return true;
}
private boolean prefArrayDimensionsDeepIndent() {
return true; // sensible default, no formatter setting
}
private int prefArrayIndent() {
String option = getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_ALIGNMENT_FOR_EXPRESSIONS_IN_ARRAY_INITIALIZER);
try {
if (DefaultCodeFormatterConstants.getIndentStyle(option) == DefaultCodeFormatterConstants.INDENT_BY_ONE) {
return 1;
}
} catch (IllegalArgumentException e) {
// ignore and return default
}
return prefContinuationIndent(); // default
}
private int prefBlockIndent() {
String option = getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_INDENT_STATEMENTS_COMPARE_TO_BLOCK);
if (DefaultCodeFormatterConstants.FALSE.equals(option)) {
return 0;
}
return 1; // sensible default
}
private int prefBracketIndent() {
return prefBlockIndent();
}
private int prefCaseBlockIndent() {
if (DefaultCodeFormatterConstants.TRUE.equals(getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_INDENT_SWITCHSTATEMENTS_COMPARE_TO_CASES))) {
return prefBlockIndent();
} else {
return 1;
}
}
private int prefCaseIndent() {
if (DefaultCodeFormatterConstants.TRUE.equals(getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_INDENT_SWITCHSTATEMENTS_COMPARE_TO_SWITCH))) {
return prefBlockIndent();
} else {
return 1;
}
}
private int prefContinuationIndent() {
try {
return Integer.parseInt(getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_CONTINUATION_INDENTATION));
} catch (NumberFormatException e) {
// ignore and return default
}
return 2; // sensible default
}
private int prefDefunIndent() {
return prefContinuationIndent();
}
private int prefIndentationSize() {
return CodeFormatterUtil.getIndentWidth(fProject);
}
private boolean prefIndentBracesForArrays() {
return DefaultCodeFormatterConstants.NEXT_LINE_SHIFTED.equals(getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_BRACE_POSITION_FOR_ARRAY_INITIALIZER));
}
private boolean prefIndentBracesForBlocks() {
return DefaultCodeFormatterConstants.NEXT_LINE_SHIFTED.equals(getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_BRACE_POSITION_FOR_BLOCK));
}
private boolean prefIndentBracesForMethods() {
return DefaultCodeFormatterConstants.NEXT_LINE_SHIFTED.equals(getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_BRACE_POSITION_FOR_METHOD_DECLARATION));
}
private boolean prefIndentBracesForTypes() {
return DefaultCodeFormatterConstants.NEXT_LINE_SHIFTED.equals(getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_BRACE_POSITION_FOR_TYPE_DECLARATION));
}
private int prefMethodBodyIndent() {
if (DefaultCodeFormatterConstants.FALSE.equals(getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_INDENT_STATEMENTS_COMPARE_TO_BODY))) {
return 0;
}
return 1; // sensible default
}
private boolean prefMethodCallDeepIndent() {
String option = getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_ALIGNMENT_FOR_ARGUMENTS_IN_METHOD_INVOCATION);
try {
return DefaultCodeFormatterConstants.getIndentStyle(option) == DefaultCodeFormatterConstants.INDENT_ON_COLUMN;
} catch (IllegalArgumentException e) {
// ignore and return default
}
return false; // sensible default
}
private int prefMethodCallIndent() {
String option = getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_ALIGNMENT_FOR_ARGUMENTS_IN_METHOD_INVOCATION);
try {
if (DefaultCodeFormatterConstants.getIndentStyle(option) == DefaultCodeFormatterConstants.INDENT_BY_ONE) {
return 1;
} else {
return prefContinuationIndent();
}
} catch (IllegalArgumentException e) {
// ignore and return default
}
return 1; // sensible default
}
private boolean prefMethodDeclDeepIndent() {
String option = getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_ALIGNMENT_FOR_PARAMETERS_IN_METHOD_DECLARATION);
try {
return DefaultCodeFormatterConstants.getIndentStyle(option) == DefaultCodeFormatterConstants.INDENT_ON_COLUMN;
} catch (IllegalArgumentException e) {
// ignore and return default
}
return true;
}
private int prefMethodDeclIndent() {
String option = getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_ALIGNMENT_FOR_PARAMETERS_IN_METHOD_DECLARATION);
try {
if (DefaultCodeFormatterConstants.getIndentStyle(option) == DefaultCodeFormatterConstants.INDENT_BY_ONE) {
return 1;
} else {
return prefContinuationIndent();
}
} catch (IllegalArgumentException e) {
// ignore and return default
}
return 1;
}
private boolean prefParenthesisDeepIndent() {
String option = getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_CONTINUATION_INDENTATION);
try {
return DefaultCodeFormatterConstants.getIndentStyle(option) == DefaultCodeFormatterConstants.INDENT_ON_COLUMN;
} catch (IllegalArgumentException e) {
// ignore and return default
}
return false; // sensible default
}
private int prefParenthesisIndent() {
return prefContinuationIndent();
}
private int prefSimpleIndent() {
if (prefIndentBracesForBlocks() && prefBlockIndent() == 0) {
return 1;
} else {
return prefBlockIndent();
}
}
private int prefTabSize() {
return CodeFormatterUtil.getTabWidth();
}
private boolean prefTernaryDeepAlign() {
String option = getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_ALIGNMENT_FOR_CONDITIONAL_EXPRESSION);
try {
return DefaultCodeFormatterConstants.getIndentStyle(option) == DefaultCodeFormatterConstants.INDENT_ON_COLUMN;
} catch (IllegalArgumentException e) {
// ignore and return default
}
return false;
}
private int prefTernaryIndent() {
String option = getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_ALIGNMENT_FOR_CONDITIONAL_EXPRESSION);
try {
if (DefaultCodeFormatterConstants.getIndentStyle(option) == DefaultCodeFormatterConstants.INDENT_BY_ONE) {
return 1;
} else {
return prefContinuationIndent();
}
} catch (IllegalArgumentException e) {
// ignore and return default
}
return prefContinuationIndent();
}
private int prefTypeIndent() {
String option = getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_INDENT_BODY_DECLARATIONS_COMPARE_TO_TYPE_HEADER);
if (DefaultCodeFormatterConstants.FALSE.equals(option)) {
return 0;
}
return 1; // sensible default
}
private boolean prefUseTabs() {
return !JavaScriptCore.SPACE.equals(getCoreFormatterOption(DefaultCodeFormatterConstants.FORMATTER_TAB_CHAR));
}
}
/** The document being scanned. */
private final IDocument fDocument;
/** The indentation accumulated by <code>findReferencePosition</code>. */
private int fIndent;
/**
* The absolute (character-counted) indentation offset for special cases (method defs, array
* initializers)
*/
private int fAlign;
/** The stateful scan position for the indentation methods. */
private int fPosition;
/** The previous position. */
private int fPreviousPos;
/** The most recent token. */
private int fToken;
/** The line of <code>fPosition</code>. */
private int fLine;
/**
* The scanner we will use to scan the document. It has to be installed on the same document as
* the one we get.
*/
private final DartHeuristicScanner fScanner;
/**
* The Dart Core preferences.
*/
private final CorePrefs fPrefs;
private int extraIndent = 0;
/**
* Creates a new instance.
*
* @param document the document to scan
* @param scanner the {@link DartHeuristicScanner} to be used for scanning the document. It must
* be installed on the same <code>IDocument</code>.
*/
public DartIndenter(IDocument document, DartHeuristicScanner scanner) {
this(document, scanner, null);
}
/**
* Creates a new instance.
*
* @param document the document to scan
* @param scanner the {@link DartHeuristicScanner}to be used for scanning the document. It must be
* installed on the same <code>IDocument</code>.
* @param project the project to get the formatter preferences from, or <code>null</code> to use
* the workspace settings
*/
public DartIndenter(IDocument document, DartHeuristicScanner scanner, IProject project) {
Assert.isNotNull(document);
Assert.isNotNull(scanner);
fDocument = document;
fScanner = scanner;
fPrefs = new CorePrefs(project);
}
/**
* Computes the indentation at <code>offset</code>.
*
* @param offset the offset in the document
* @return a String which reflects the correct indentation for the line in which offset resides,
* or <code>null</code> if it cannot be determined
*/
public StringBuffer computeIndentation(int offset) {
return computeIndentation(offset, false);
}
/**
* Computes the indentation at <code>offset</code>.
*
* @param offset the offset in the document
* @param assumeOpeningBrace <code>true</code> if an opening brace should be assumed
* @return a String which reflects the correct indentation for the line in which offset resides,
* or <code>null</code> if it cannot be determined
*/
public StringBuffer computeIndentation(int offset, boolean assumeOpeningBrace) {
StringBuffer reference = getReferenceIndentation(offset, assumeOpeningBrace);
// handle special alignment
if (fAlign != DartHeuristicScanner.NOT_FOUND) {
try {
// a special case has been detected.
IRegion line = fDocument.getLineInformationOfOffset(fAlign);
int lineOffset = line.getOffset();
return createIndent(lineOffset, fAlign, false);
} catch (BadLocationException e) {
return null;
}
}
if (reference == null) {
return null;
}
// add additional indent
return createReusingIndent(reference, fIndent);
}
/**
* Returns the reference position regarding to indentation for <code>offset</code>, or
* <code>NOT_FOUND</code>. This method calls {@link #findReferencePosition(int, int)
* findReferencePosition(offset, nextChar)} where <code>nextChar</code> is the next character
* after <code>offset</code>.
*
* @param offset the offset for which the reference is computed
* @return the reference statement relative to which <code>offset</code> should be indented, or
* {@link DartHeuristicScanner#NOT_FOUND}
*/
public int findReferencePosition(int offset) {
return findReferencePosition(offset, peekChar(offset));
}
/**
* Returns the reference position regarding to indentation for <code>position</code>, or
* <code>NOT_FOUND</code>.<code>fIndent</code> will contain the relative indentation (in
* indentation units, not characters) after the call. If there is a special alignment (e.g. for a
* method declaration where parameters should be aligned), <code>fAlign</code> will contain the
* absolute position of the alignment reference in <code>fDocument</code>, otherwise
* <code>fAlign</code> is set to <code>DartHeuristicScanner.NOT_FOUND</code>.
*
* @param offset the offset for which the reference is computed
* @param danglingElse whether a dangling else should be assumed at <code>position</code>
* @param matchBrace whether the position of the matching brace should be returned instead of
* doing code analysis
* @param matchParen whether the position of the matching parenthesis should be returned instead
* of doing code analysis
* @param matchCase whether the position of a switch statement reference should be returned
* (either an earlier case statement or the switch block brace)
* @return the reference statement relative to which <code>position</code> should be indented, or
* {@link DartHeuristicScanner#NOT_FOUND}
*/
public int findReferencePosition(int offset, boolean danglingElse, boolean matchBrace,
boolean matchParen, boolean matchCase) {
extraIndent = 0;
fIndent = 0; // the indentation modification
fAlign = DartHeuristicScanner.NOT_FOUND;
fPosition = offset;
// forward cases
// an unindentation happens sometimes if the next token is special, namely
// on braces, parens and case labels
// align braces, but handle the case where we align with the method
// declaration start instead of the opening brace.
if (matchBrace) {
if (skipScope(Symbols.TokenLBRACE, Symbols.TokenRBRACE)) {
try {
// align with the opening brace that is on a line by its own
int lineOffset = fDocument.getLineOffset(fLine);
if (lineOffset <= fPosition
&& fDocument.get(lineOffset, fPosition - lineOffset).trim().length() == 0) {
return fPosition;
}
} catch (BadLocationException e) {
// concurrent modification - walk default path
}
// if the opening brace is not on the start of the line, skip to the start
int pos = skipToStatementStart(true, true);
fIndent = 0; // indent is aligned with reference position
return pos;
} else {
// if we can't find the matching brace, the heuristic is to unindent
// by one against the normal position
int pos = findReferencePosition(offset, danglingElse, false, matchParen, matchCase);
fIndent--;
return pos;
}
}
// align parenthesis
if (matchParen) {
if (skipScope(Symbols.TokenLPAREN, Symbols.TokenRPAREN)) {
// fIndent = fPrefs.prefContinuationIndent; // uncomment to indent initial ')' to continuation
return fPosition;
} else {
// if we can't find the matching paren, the heuristic is to unindent
// by one against the normal position
int pos = findReferencePosition(offset, danglingElse, matchBrace, false, matchCase);
fIndent--;
return pos;
}
}
// the only reliable way to get case labels aligned (due to many different
// styles of using braces in a block)
// is to go for another case statement, or the scope opening brace
if (matchCase) {
return matchCaseAlignment();
}
nextToken();
switch (fToken) {
case Symbols.TokenGREATERTHAN:
case Symbols.TokenRBRACKET: // see below for alternative
case Symbols.TokenRBRACE:
// skip the block
// if we can't complete the scope, reset the scan position
int pos = fPosition;
if (!skipScope()) {
fPosition = pos;
}
return skipToStatementStart(danglingElse, false);
case Symbols.TokenSEMICOLON:
// this is the 90% case: after a statement block
// the end of the previous statement / block previous.end
// search to the end of the statement / block before the previous; the
// token just after that is previous.start
pos = fPosition;
if (isForStatement()) {
fIndent = fPrefs.prefContinuationIndent;
return fPosition;
} else {
fPosition = pos;
return skipToStatementStart(danglingElse, false);
}
// scope introduction
case Symbols.TokenLPAREN:
case Symbols.TokenLBRACE:
case Symbols.TokenLBRACKET:
return handleScopeIntroduction(offset + 1);
case Symbols.TokenEOF:
// trap when hitting start of document
return DartHeuristicScanner.NOT_FOUND;
case Symbols.TokenEQUAL:
// indent assignments
return handleEqual();
case Symbols.TokenDEFUN:
// indent short-form functions
fIndent = fPrefs.prefDefunIndent;
return fPosition;
case Symbols.TokenCOLON:
// TODO handle ternary deep indentation
// TODO handle initializers in constructor decl
DartX.todo();
fIndent = fPrefs.prefCaseBlockIndent;
return fPosition;
case Symbols.TokenQUESTIONMARK:
if (fPrefs.prefTernaryDeepAlign) {
setFirstElementAlignment(fPosition, offset + 1);
return fPosition;
} else {
fIndent = fPrefs.prefTernaryIndent;
return fPosition;
}
// indentation for block-less introducers:
case Symbols.TokenDO:
case Symbols.TokenWHILE:
case Symbols.TokenELSE:
fIndent = fPrefs.prefSimpleIndent;
return fPosition;
case Symbols.TokenTRY:
return skipToStatementStart(danglingElse, false);
// case Symbols.TokenRBRACKET: // use this case to make initial ']' indent at continuation level
// fIndent = fPrefs.prefContinuationIndent;
// return fPosition;
case Symbols.TokenRPAREN:
int line = fLine;
if (skipScope(Symbols.TokenLPAREN, Symbols.TokenRPAREN)) {
int scope = fPosition;
nextToken();
if (fToken == Symbols.TokenIF || fToken == Symbols.TokenWHILE
|| fToken == Symbols.TokenFOR) {
fIndent = fPrefs.prefSimpleIndent;
return fPosition;
}
fPosition = scope;
if (looksLikeMethodDecl()) {
return skipToStatementStart(danglingElse, false);
}
if (fToken == Symbols.TokenCATCH) {
return skipToStatementStart(danglingElse, false);
}
fPosition = scope;
if (looksLikeAnonymousTypeDecl()) {
return skipToStatementStart(danglingElse, false);
}
}
// restore
fPosition = offset;
fLine = line;
return skipToPreviousListItemOrListStart();
case Symbols.TokenRETURN:
fIndent = fPrefs.prefContinuationIndent;
return fPosition;
case Symbols.TokenCOMMA:
// inside a list of some type
// easy if there is already a list item before with its own indentation
// - we just align
// if not: take the start of the list ( LPAREN, LBRACE, LBRACKET ) and
// either align or
// indent by list-indent
default:
// inside whatever we don't know about: similar to the list case:
// if we are inside a continued expression, then either align with a
// previous line that has indentation
// or indent from the expression start line (either a scope introducer
// or the start of the expr).
return skipToPreviousListItemOrListStart();
}
}
/**
* Returns the reference position regarding to indentation for <code>position</code>, or
* <code>NOT_FOUND</code>.
* <p>
* If <code>peekNextChar</code> is <code>true</code>, the next token after <code>offset</code> is
* read and taken into account when computing the indentation. Currently, if the next token is the
* first token on the line (i.e. only preceded by whitespace), the following tokens are specially
* handled:
* <ul>
* <li><code>switch</code> labels are indented relative to the switch block</li>
* <li>opening curly braces are aligned correctly with the introducing code</li>
* <li>closing curly braces are aligned properly with the introducing code of the matching opening
* brace</li>
* <li>closing parenthesis' are aligned with their opening peer</li>
* <li>the <code>else</code> keyword is aligned with its <code>if</code>, anything else is aligned
* normally (i.e. with the base of any introducing statements).</li>
* <li>if there is no token on the same line after <code>offset</code>, the indentation is the
* same as for an <code>else</code> keyword</li>
* </ul>
*
* @param offset the offset for which the reference is computed
* @param nextToken the next token to assume in the document
* @return the reference statement relative to which <code>offset</code> should be indented, or
* {@link DartHeuristicScanner#NOT_FOUND}
*/
public int findReferencePosition(int offset, int nextToken) {
extraIndent = 0;
int cascadeIndent = 0;
boolean danglingElse = false;
boolean unindent = false;
boolean indent = false;
boolean matchBrace = false;
boolean matchParen = false;
boolean matchCase = false;
// account for un-indentation characters already typed in, but after position
// if they are on a line by themselves, the indentation gets adjusted accordingly
//
// also account for a dangling else
if (offset < fDocument.getLength()) {
try {
boolean matchCascade = false;
if (fScanner.isCurrentTokenCascade()) {
matchCascade = true;
cascadeIndent = 2;
fAlign = -1;
}
IRegion line = fDocument.getLineInformationOfOffset(offset);
int lineOffset = line.getOffset();
int prevPos = Math.max(offset - 1, 0);
boolean isFirstTokenOnLine = fDocument.get(lineOffset, prevPos + 1 - lineOffset).trim().length() == 0;
int prevToken = fScanner.previousToken(prevPos, DartHeuristicScanner.UNBOUND);
boolean bracelessBlockStart = fScanner.isBracelessBlockStart(
prevPos,
DartHeuristicScanner.UNBOUND);
if (fScanner.isCurrentTokenCascade() && matchCascade) {
return fScanner.getPosition();
}
switch (nextToken) {
case Symbols.TokenELSE:
danglingElse = true;
break;
case Symbols.TokenCASE:
case Symbols.TokenDEFAULT:
if (isFirstTokenOnLine) {
matchCase = true;
}
break;
case Symbols.TokenLBRACE: // for opening-brace-on-new-line style
if (bracelessBlockStart && !fPrefs.prefIndentBracesForBlocks) {
unindent = true;
} else if ((prevToken == Symbols.TokenCOLON || prevToken == Symbols.TokenEQUAL || prevToken == Symbols.TokenRBRACKET)
&& !fPrefs.prefIndentBracesForArrays) {
unindent = true;
} else if (!bracelessBlockStart && fPrefs.prefIndentBracesForMethods) {
indent = true;
}
break;
case Symbols.TokenRBRACE: // closing braces get unindented
if (isFirstTokenOnLine) {
matchBrace = true;
}
break;
case Symbols.TokenRPAREN:
if (isFirstTokenOnLine) {
matchParen = true;
}
break;
case Symbols.TokenOTHER:
// if (fScanner.isCurrentTokenCascade()) {
// cascadeIndent = 1;
// }
break;
}
} catch (BadLocationException e) {
}
} else {
// don't assume an else could come if we are at the end of file
danglingElse = false;
}
int ref = findReferencePosition(offset, danglingElse, matchBrace, matchParen, matchCase);
if (unindent) {
fIndent--;
}
if (indent) {
fIndent++;
}
extraIndent = cascadeIndent;
return ref;
}
public String getBlockIndent() {
extraIndent = 1;
try {
return createIndent(0, 0, false).toString();
} finally {
extraIndent = 0;
}
}
public String getCascadeIndent() {
extraIndent = 2;
try {
return createIndent(0, 0, false).toString();
} finally {
extraIndent = 0;
}
}
/**
* Computes the indentation at the reference point of <code>position</code>.
*
* @param offset the offset in the document
* @return a String which reflects the indentation at the line in which the reference position to
* <code>offset</code> resides, or <code>null</code> if it cannot be determined
*/
public StringBuffer getReferenceIndentation(int offset) {
return getReferenceIndentation(offset, false);
}
/**
* Computes the indentation at the reference point of <code>position</code>.
*
* @param offset the offset in the document
* @param assumeOpeningBrace <code>true</code> if an opening brace should be assumed
* @return a String which reflects the indentation at the line in which the reference position to
* <code>offset</code> resides, or <code>null</code> if it cannot be determined
*/
public StringBuffer getReferenceIndentation(int offset, boolean assumeOpeningBrace) {
int unit;
if (assumeOpeningBrace) {
unit = findReferencePosition(offset, Symbols.TokenLBRACE);
} else {
unit = findReferencePosition(offset, peekChar(offset));
}
// if we were unable to find anything, return null
if (unit == DartHeuristicScanner.NOT_FOUND) {
return null;
}
return getLeadingWhitespace(unit);
}
// public boolean isAfterClassPrologue(int offset) {
// fPosition = offset;
// nextToken();
// if (fToken == Symbols.TokenLBRACE) {
// while (true) {
// nextToken();
// if (fToken == Symbols.TokenEOF) {
// return false;
// }
// if (fToken == Symbols.TokenIDENT) {
// nextToken();
// if (fToken == Symbols.TokenCLASS) {
// return true;
// }
// if (fToken == Symbols.TokenEXTENDS || fToken == Symbols.TokenIMPLEMENTS
// || fToken == Symbols.TokenCOMMA) {
// continue;
// }
// return false;
// }
// }
// }
// return false;
// }
/**
* Computes the length of a <code>CharacterSequence</code>, counting a tab character as the size
* until the next tab stop and every other character as one.
*
* @param indent the string to measure
* @return the visual length in characters
*/
private int computeVisualLength(CharSequence indent) {
final int tabSize = fPrefs.prefTabSize;
int length = 0;
for (int i = 0; i < indent.length(); i++) {
char ch = indent.charAt(i);
switch (ch) {
case '\t':
if (tabSize > 0) {
int reminder = length % tabSize;
length += tabSize - reminder;
}
break;
case ' ':
length++;
break;
}
}
return length;
}
/**
* Creates an indentation string of the length indent - start, consisting of the content in
* <code>fDocument</code> in the range [start, indent), with every character replaced by a space
* except for tabs, which are kept as such.
* <p>
* If <code>convertSpaceRunsToTabs</code> is <code>true</code>, every run of the number of spaces
* that make up a tab are replaced by a tab character. If it is not set, no conversion takes
* place, but tabs in the original range are still copied verbatim.
* </p>
*
* @param start the start of the document region to copy the indent from
* @param indent the exclusive end of the document region to copy the indent from
* @param convertSpaceRunsToTabs whether to convert consecutive runs of spaces to tabs
* @return the indentation corresponding to the document content specified by <code>start</code>
* and <code>indent</code>
*/
private StringBuffer createIndent(int start, final int indent,
final boolean convertSpaceRunsToTabs) {
final boolean convertTabs = fPrefs.prefUseTabs && convertSpaceRunsToTabs;
final int tabLen = fPrefs.prefTabSize;
final StringBuffer ret = new StringBuffer();
try {
int spaces = extraIndent * tabLen;
while (start < indent) {
char ch = fDocument.getChar(start);
if (ch == '\t') {
ret.append('\t');
spaces = 0;
} else if (convertTabs) {
spaces++;
if (spaces == tabLen) {
ret.append('\t');
spaces = 0;
}
} else {
ret.append(' ');
}
start++;
}
// remainder
while (spaces-- > 0) {
ret.append(' ');
}
} catch (BadLocationException e) {
}
return ret;
}
/**
* Creates a string with a visual length of the given <code>indentationSize</code>.
*
* @param buffer the original indent to reuse if possible
* @param additional the additional indentation units to add or subtract to reference
* @return the modified <code>buffer</code> reflecting the indentation adapted to
* <code>additional</code>
*/
private StringBuffer createReusingIndent(StringBuffer buffer, int additional) {
int refLength = computeVisualLength(buffer);
int addLength = fPrefs.prefIndentationSize * additional; // may be < 0
int totalLength = Math.max(0, refLength + addLength);
// copy the reference indentation for the indent up to the last tab
// stop within the maxCopy area
int minLength = Math.min(totalLength, refLength);
int tabSize = fPrefs.prefTabSize;
int maxCopyLength = tabSize > 0 ? minLength - minLength % tabSize : minLength; // maximum indent to copy
stripExceedingChars(buffer, maxCopyLength);
// add additional indent
int missing = totalLength - maxCopyLength;
final int tabs, spaces;
if (!DartToolsPlugin.getDefault().getPreferenceStore().getBoolean(
AbstractDecoratedTextEditorPreferenceConstants.EDITOR_SPACES_FOR_TABS)) {
tabs = tabSize > 0 ? missing / tabSize : 0;
spaces = tabSize > 0 ? missing % tabSize : missing;
} else if (JavaScriptCore.SPACE.equals(fPrefs.prefTabChar)) {
tabs = 0;
spaces = missing;
} else if (JavaScriptCore.TAB.equals(fPrefs.prefTabChar)) {
tabs = tabSize > 0 ? missing / tabSize : 0;
spaces = tabSize > 0 ? missing % tabSize : missing;
} else if (DefaultCodeFormatterConstants.MIXED.equals(fPrefs.prefTabChar)) {
tabs = tabSize > 0 ? missing / tabSize : 0;
spaces = tabSize > 0 ? missing % tabSize : missing;
} else {
Assert.isTrue(false);
return null;
}
for (int i = 0; i < tabs; i++) {
buffer.append('\t');
}
for (int i = 0; i < spaces; i++) {
buffer.append(' ');
}
return buffer;
}
private int getBlockIndent(boolean isMethodBody, boolean isTypeBody) {
if (isTypeBody) {
return fPrefs.prefTypeIndent + (fPrefs.prefIndentBracesForTypes ? 1 : 0);
} else if (isMethodBody) {
return fPrefs.prefMethodBodyIndent + (fPrefs.prefIndentBracesForMethods ? 1 : 0);
} else {
return fIndent;
}
}
/**
* Returns the indentation of the line at <code>offset</code> as a <code>StringBuffer</code>. If
* the offset is not valid, the empty string is returned.
*
* @param offset the offset in the document
* @return the indentation (leading whitespace) of the line in which <code>offset</code> is
* located
*/
private StringBuffer getLeadingWhitespace(int offset) {
StringBuffer indent = new StringBuffer();
try {
IRegion line = fDocument.getLineInformationOfOffset(offset);
int lineOffset = line.getOffset();
int nonWS = fScanner.findNonWhitespaceForwardInAnyPartition(
lineOffset,
lineOffset + line.getLength());
indent.append(fDocument.get(lineOffset, nonWS - lineOffset));
return indent;
} catch (BadLocationException e) {
return indent;
}
}
/**
* Returns the contents of the current token.
*
* @return the contents of the current token
*/
private CharSequence getTokenContent() {
return new DocumentCharacterIterator(fDocument, fPosition, fPreviousPos);
}
/**
* Checks if the statement at position is itself a continuation of the previous, else sets the
* indentation to Continuation Indent.
*
* @return the position of the token
*/
private int handleEqual() {
try {
// If this line is itself continuation of the previous then do nothing
IRegion line = fDocument.getLineInformationOfOffset(fPosition);
int nonWS = fScanner.findNonWhitespaceBackward(line.getOffset(), DartHeuristicScanner.UNBOUND);
if (nonWS != Symbols.TokenEOF) {
int tokenAtPreviousLine = fScanner.nextToken(nonWS, nonWS + 1);
if (tokenAtPreviousLine != Symbols.TokenSEMICOLON
&& tokenAtPreviousLine != Symbols.TokenRBRACE
&& tokenAtPreviousLine != Symbols.TokenLBRACE
&& tokenAtPreviousLine != Symbols.TokenEOF) {
return fPosition;
}
}
} catch (BadLocationException e) {
return fPosition;
}
fIndent = fPrefs.prefContinuationIndent;
return fPosition;
}
/**
* Handles the introduction of a new scope. The current token must be one out of
* <code>Symbols.TokenLPAREN</code>, <code>Symbols.TokenLBRACE</code>, and
* <code>Symbols.TokenLBRACKET</code>. Returns as the reference position either the token
* introducing the scope or - if available - the first token after that.
* <p>
* Depending on the type of scope introduction, the indentation will align (deep indenting) with
* the reference position (<code>fAlign</code> will be set to the reference position) or
* <code>fIndent</code> will be set to the number of indentation units.
* </p>
*
* @param bound the bound for the search for the first token after the scope introduction.
* @return the indent
*/
private int handleScopeIntroduction(int bound) {
switch (fToken) {
// scope introduction
case Symbols.TokenLPAREN:
int pos = fPosition; // store
// special: method declaration deep indentation
if (looksLikeMethodDecl() || looksLikeConstructorDecl()) {
if (fPrefs.prefMethodDeclDeepIndent) {
return setFirstElementAlignment(pos, bound);
} else {
fIndent = fPrefs.prefMethodDeclIndent;
return pos;
}
} else {
fPosition = pos;
if (looksLikeMethodCall()) {
if (fPrefs.prefMethodCallDeepIndent) {
return setFirstElementAlignment(pos, bound);
} else {
fIndent = fPrefs.prefMethodCallIndent;
return pos;
}
} else if (fPrefs.prefParenthesisDeepIndent) {
return setFirstElementAlignment(pos, bound);
}
}
// normal: return the parenthesis as reference
fIndent = fPrefs.prefParenthesisIndent;
return pos;
case Symbols.TokenLBRACE:
pos = fPosition; // store
// special: map literal {} in list literal or argument list
{
nextToken();
if (fToken == Symbols.TokenCOMMA) {
fIndent = fPrefs.prefBlockIndent;
return pos;
}
fPosition = pos;
}
// special: array initializer
if (looksLikeArrayInitializerIntro()) {
fPosition = pos;
fIndent = fPrefs.prefBlockIndent;
} else {
fIndent = fPrefs.prefBlockIndent;
}
// normal: skip to the statement start before the scope introducer
// opening braces are often on differently ending indents than e.g. a
// method definition
if (looksLikeArrayInitializerIntro() && !fPrefs.prefIndentBracesForArrays
|| !fPrefs.prefIndentBracesForBlocks) {
fPosition = pos; // restore
return skipToStatementStart(true, true); // set to true to match the
// first if
} else {
return pos;
}
case Symbols.TokenLBRACKET:
pos = fPosition; // store
fIndent = fPrefs.prefBlockIndent;
return pos; // restore
default:
Assert.isTrue(false);
return -1; // dummy
}
}
/**
* while(condition); is ambiguous when parsed backwardly, as it is a valid statement by its own,
* so we have to check whether there is a matching do. A <code>do</code> can either be separated
* from the while by a block, or by a single statement, which limits our search distance.
*
* @return <code>true</code> if the <code>while</code> currently in <code>fToken</code> has a
* matching <code>do</code>.
*/
private boolean hasMatchingDo() {
Assert.isTrue(fToken == Symbols.TokenWHILE);
nextToken();
switch (fToken) {
case Symbols.TokenRBRACE:
skipScope(); // and fall thru
//$FALL-THROUGH$
case Symbols.TokenSEMICOLON:
skipToStatementStart(false, false);
return fToken == Symbols.TokenDO;
}
return false;
}
private boolean isCascadeLine(int offset) {
try {
IRegion line = fDocument.getLineInformationOfOffset(offset);
String lineStr = fDocument.get(line.getOffset(), line.getLength());
lineStr = lineStr.trim();
return lineStr.startsWith("..");
} catch (BadLocationException e) {
return false;
}
}
/**
* Returns true if the colon at the current position is part of a conditional (ternary)
* expression, false otherwise.
*
* @return true if the colon at the current position is part of a conditional
*/
private boolean isConditional() {
while (true) {
nextToken();
switch (fToken) {
// search for case labels, which consist of (possibly qualified)
// identifiers or numbers
case Symbols.TokenIDENT:
case Symbols.TokenOTHER: // dots for qualified constants
continue;
case Symbols.TokenCASE:
case Symbols.TokenDEFAULT:
return false;
default:
return true;
}
}
}
/**
* Checks if the semicolon at the current position is part of a for statement.
*
* @return returns <code>true</code> if current position is part of for statement
*/
private boolean isForStatement() {
int semiColonCount = 1;
while (true) {
nextToken();
switch (fToken) {
case Symbols.TokenFOR:
return true;
case Symbols.TokenIN:
return false;
case Symbols.TokenLBRACE:
return false;
case Symbols.TokenSEMICOLON:
semiColonCount++;
if (semiColonCount > 2) {
return false;
}
break;
case Symbols.TokenEOF:
return false;
}
}
}
/**
* Returns <code>true</code> if the current tokens look like an anonymous type declaration header
* (i.e. a type name (potentially qualified) and a new keyword). The heuristic calls
* <code>nextToken</code> and expects a possibly qualified identifier (type name) and a new
* keyword
*
* @return <code>true</code> if the current position looks like a anonymous type declaration
* header.
*/
private boolean looksLikeAnonymousTypeDecl() {
nextToken();
if (fToken == Symbols.TokenIDENT) { // type name
nextToken();
while (fToken == Symbols.TokenOTHER) { // dot of qualification
nextToken();
if (fToken != Symbols.TokenIDENT) {
return false;
}
nextToken();
}
return fToken == Symbols.TokenNEW;
}
return false;
}
private boolean looksLikeArgumentListOpen() {
int fPosition_ = fPosition;
int fPreviousPos_ = fPreviousPos;
try {
if (fToken == Symbols.TokenLPAREN) {
nextToken();
if (fToken == Symbols.TokenIDENT) {
// OK, probably closure arguments
fPosition_ = fPosition;
fPreviousPos_ = fPreviousPos;
return true;
}
}
return false;
} finally {
fPosition = fPosition_;
fPreviousPos = fPreviousPos_;
}
}
/**
* Returns <code>true</code> if the next token received after calling <code>nextToken</code> is
* either an equal sign or an array designator ('[]').
*
* @return <code>true</code> if the next elements look like the start of an array definition
*/
private boolean looksLikeArrayInitializerIntro() {
nextToken();
if (fToken == Symbols.TokenEQUAL || skipBrackets()) {
return true;
}
return false;
}
private boolean looksLikeConstructorDecl() {
int p = fPreviousPos;
nextToken();
if (fToken != Symbols.TokenIDENT) {
return false;
}
// check for dot and ident to make named constructor
int pos = fPreviousPos;
nextToken();
if (fToken == Symbols.TokenOTHER) { // dot
pos = fPreviousPos;
nextToken();
if (fToken == Symbols.TokenIDENT) {
pos = fPreviousPos;
nextToken();
} else {
fPosition = p;
return false;
}
}
// check for possible modifiers
if (fToken == Symbols.TokenCONST || fToken == Symbols.TokenFACTORY) {
pos = fPreviousPos;
nextToken();
if (fToken == Symbols.TokenCONST || fToken == Symbols.TokenFACTORY) {
pos = fPreviousPos;
nextToken();
}
}
fPosition = fPreviousPos; // backup one token
fPreviousPos = pos;
try {
fLine = fDocument.getLineOfOffset(fPosition);
} catch (BadLocationException e) {
fLine = -1;
}
pos = fPosition;
int prevPos = fPreviousPos;
int line = fLine;
// scan forward from p to verify formal param list; p is just to the right of the open paren
int end = fScanner.findClosingPeer(p, '(', ')');
if (end == DartHeuristicScanner.NOT_FOUND) {
return false;
}
try {
fPosition = end + 1;
fPreviousPos = end;
boolean looksLikeParams = looksLikeFormalParamList();
return looksLikeParams;
} finally {
fPosition = pos;
fPreviousPos = prevPos;
fLine = line;
}
}
private boolean looksLikeFormalParamList() {
// ignores embedded comments
// this may be too restrictive; might need to relax to skipToPreviousListItemOrListStart()
nextToken();
if (fToken != Symbols.TokenRPAREN) {
return false;
}
int angleBracketCount = 0, parenCount = 1, braceCount = 0, bracketCount = 0;
while (true) {
if (angleBracketCount < 0 || braceCount < 0 || bracketCount < 0) {
return false; // mismatched bracket
}
nextToken();
switch (fToken) {
// right-side (opening) group symbols
case Symbols.TokenRBRACE:
braceCount++;
continue;
case Symbols.TokenRBRACKET:
bracketCount++;
continue;
case Symbols.TokenGREATERTHAN:
angleBracketCount++;
continue;
case Symbols.TokenRPAREN:
parenCount++;
continue;
case Symbols.TokenIDENT:
case Symbols.TokenVAR: // illegal but common
case Symbols.TokenVOID: // illegal but not uncommon
case Symbols.TokenOTHER: // period
case Symbols.TokenCOMMA: // param separator
case Symbols.TokenEQUAL: // optional params
case Symbols.TokenCOLON: // named params
case Symbols.TokenTHIS:
case Symbols.TokenTRUE:
case Symbols.TokenFALSE:
case Symbols.TokenNULL:
case Symbols.TokenAT: // not handling complex metadata args
continue;
// left-side (closing) group symbols
case Symbols.TokenLBRACE:
braceCount--;
continue;
case Symbols.TokenLBRACKET:
bracketCount--;
continue;
case Symbols.TokenLESSTHAN:
angleBracketCount--;
continue;
case Symbols.TokenLPAREN:
parenCount--;
if (parenCount == 0) {
return true; // exit on initial paren
} else {
continue;
}
// return false for anything not permitted in a formal parameter list
default:
return false;
}
}
}
/**
* Returns <code>true</code> if the current tokens look like a method call header (i.e. an
* identifier as opposed to a keyword taking parenthesized parameters such as <code>if</code>).
* <p>
* The heuristic calls <code>nextToken</code> and expects an identifier (method name).
*
* @return <code>true</code> if the current position looks like a method call header.
*/
private boolean looksLikeMethodCall() {
// TODO add awareness for constructor calls with generic types: new List<String>()
// TODO recognize function calls
DartX.todo();
nextToken();
return fToken == Symbols.TokenIDENT; // method name
}
/**
* Returns <code>true</code> if the current tokens look like a method declaration header (i.e.
* only the return type and method name). The heuristic calls <code>nextToken</code> and expects
* an identifier (method name) and a type declaration (an identifier with optional brackets) which
* also covers the visibility modifier of constructors.
*
* @return <code>true</code> if the current position looks like a method declaration header.
*/
private boolean looksLikeMethodDecl() {
/*
* Note: This heuristic relies on indentation to recognize untyped method decls (including
* constructors). Untyped methods defined at deep indentation levels will not be recognized.
*/
nextToken();
if (fToken == Symbols.TokenIDENT) { // method name
int pos = fPosition;
do {
nextToken();
} while (skipBrackets()); // optional brackets for array valued return types
switch (fToken) {
case Symbols.TokenIDENT:
case Symbols.TokenGET:
case Symbols.TokenSET:
case Symbols.TokenOPERATOR:
case Symbols.TokenVOID:
case Symbols.TokenVAR: // common mistake
case Symbols.TokenEOF:
return true;
case Symbols.TokenRBRACE:
// assume that whatever follows a close brace at 0 or 1 indent levels is a method decl
StringBuffer buf = getLeadingWhitespace(pos);
if (buf.length() == 0 || buf.length() == fPrefs.prefTabSize) {
return true;
}
}
}
return false;
}
/**
* Returns as a reference any previous <code>switch</code> labels ( <code>case</code> or
* <code>default</code>) or the offset of the brace that scopes the switch statement. Sets
* <code>fIndent</code> to <code>prefCaseIndent</code> upon a match.
*
* @return the reference offset for a <code>switch</code> label
*/
private int matchCaseAlignment() {
while (true) {
nextToken();
switch (fToken) {
// invalid cases: another case label or an LBRACE must come before a case
// -> bail out with the current position
case Symbols.TokenLPAREN:
case Symbols.TokenLBRACKET:
case Symbols.TokenEOF:
return fPosition;
case Symbols.TokenLBRACE:
// opening brace of switch statement
fIndent = fPrefs.prefCaseIndent;
return fPosition;
case Symbols.TokenCASE:
case Symbols.TokenDEFAULT:
// align with previous label
fIndent = 0;
return fPosition;
// scopes: skip them
case Symbols.TokenRPAREN:
case Symbols.TokenRBRACKET:
case Symbols.TokenRBRACE:
case Symbols.TokenGREATERTHAN:
skipScope();
break;
default:
// keep searching
continue;
}
}
}
/**
* Reads the next token in backward direction from the heuristic scanner and sets the fields
* <code>fToken, fPreviousPosition</code> and <code>fPosition</code> accordingly.
*/
private void nextToken() {
nextToken(fPosition);
}
/**
* Reads the next token in backward direction of <code>start</code> from the heuristic scanner and
* sets the fields <code>fToken, fPreviousPosition</code> and <code>fPosition</code> accordingly.
*
* @param start the start offset from which to scan backwards
*/
private void nextToken(int start) {
fToken = fScanner.previousToken(start - 1, DartHeuristicScanner.UNBOUND);
fPreviousPos = start;
fPosition = fScanner.getPosition() + 1;
try {
fLine = fDocument.getLineOfOffset(fPosition);
} catch (BadLocationException e) {
fLine = -1;
}
}
/**
* Peeks the next char in the document that comes after <code>offset</code> on the same line as
* <code>offset</code>.
*
* @param offset the offset into document
* @return the token symbol of the next element, or TokenEOF if there is none
*/
private int peekChar(int offset) {
if (offset < fDocument.getLength()) {
try {
IRegion line = fDocument.getLineInformationOfOffset(offset);
int lineOffset = line.getOffset();
int next = fScanner.nextToken(offset, lineOffset + line.getLength());
return next;
} catch (BadLocationException e) {
}
}
return Symbols.TokenEOF;
}
/**
* Sets the deep indent offset (<code>fAlign</code>) to either the offset right after
* <code>scopeIntroducerOffset</code> or - if available - the first token after
* <code>scopeIntroducerOffset</code>, but before <code>bound</code>.
*
* @param scopeIntroducerOffset the offset of the scope introducer
* @param bound the bound for the search for another element
* @return the reference position
*/
private int setFirstElementAlignment(int scopeIntroducerOffset, int bound) {
int firstPossible = scopeIntroducerOffset + 1; // align with the first position after the scope intro
fAlign = fScanner.findNonWhitespaceForwardInAnyPartition(firstPossible, bound);
if (fAlign == DartHeuristicScanner.NOT_FOUND) {
fAlign = firstPossible;
}
return fAlign;
}
/**
* Skips brackets if the current token is a RBRACKET. There can be nothing but whitespace in
* between, this is only to be used for <code>[]</code> elements.
*
* @return <code>true</code> if a <code>[]</code> could be scanned, the current token is left at
* the LBRACKET.
*/
private boolean skipBrackets() {
if (fToken == Symbols.TokenRBRACKET) {
nextToken();
if (fToken == Symbols.TokenLBRACKET) {
return true;
}
}
return false;
}
/**
* Skips over the next <code>if</code> keyword. The current token when calling this method must be
* an <code>else</code> keyword. Returns <code>true</code> if a matching <code>if</code> could be
* found, <code>false</code> otherwise. The cursor (<code>fPosition</code>) is set to the offset
* of the <code>if</code> token.
*
* @return <code>true</code> if a matching <code>if</code> token was found, <code>false</code>
* otherwise
*/
private boolean skipNextIF() {
Assert.isTrue(fToken == Symbols.TokenELSE);
while (true) {
nextToken();
switch (fToken) {
// scopes: skip them
case Symbols.TokenRPAREN:
case Symbols.TokenRBRACKET:
case Symbols.TokenRBRACE:
case Symbols.TokenGREATERTHAN:
skipScope();
break;
case Symbols.TokenIF:
// found it, return
return true;
case Symbols.TokenELSE:
// recursively skip else-if blocks
skipNextIF();
break;
// shortcut scope starts
case Symbols.TokenLPAREN:
case Symbols.TokenLBRACE:
case Symbols.TokenLBRACKET:
case Symbols.TokenEOF:
return false;
}
}
}
/**
* Skips a scope and positions the cursor (<code>fPosition</code>) on the token that opens the
* scope. Returns <code>true</code> if a matching peer could be found, <code>false</code>
* otherwise. The current token when calling must be one out of <code>Symbols.TokenRPAREN</code>,
* <code>Symbols.TokenRBRACE</code>, and <code>Symbols.TokenRBRACKET</code>.
*
* @return <code>true</code> if a matching peer was found, <code>false</code> otherwise
*/
private boolean skipScope() {
switch (fToken) {
case Symbols.TokenRPAREN:
return skipScope(Symbols.TokenLPAREN, Symbols.TokenRPAREN);
case Symbols.TokenRBRACKET:
return skipScope(Symbols.TokenLBRACKET, Symbols.TokenRBRACKET);
case Symbols.TokenRBRACE:
return skipScope(Symbols.TokenLBRACE, Symbols.TokenRBRACE);
case Symbols.TokenGREATERTHAN:
if (!fPrefs.prefHasGenerics) {
return false;
}
int storedPosition = fPosition;
int storedToken = fToken;
nextToken();
switch (fToken) {
case Symbols.TokenIDENT:
if (!DartHeuristicScanner.isGenericStarter(getTokenContent())) {
break;
}
//$FALL-THROUGH$
case Symbols.TokenQUESTIONMARK:
case Symbols.TokenGREATERTHAN:
if (skipScope(Symbols.TokenLESSTHAN, Symbols.TokenGREATERTHAN)) {
return true;
}
}
// <> are harder to detect - restore the position if we fail
fPosition = storedPosition;
fToken = storedToken;
return false;
default:
Assert.isTrue(false);
return false;
}
}
/**
* Scans tokens for the matching opening peer. The internal cursor ( <code>fPosition</code>) is
* set to the offset of the opening peer if found.
*
* @param openToken the opening peer token
* @param closeToken the closing peer token
* @return <code>true</code> if a matching token was found, <code>false</code> otherwise
*/
private boolean skipScope(int openToken, int closeToken) {
int depth = 1;
while (true) {
nextToken();
if (fToken == closeToken) {
depth++;
} else if (fToken == openToken) {
depth--;
if (depth == 0) {
return true;
}
} else if (fToken == Symbols.TokenEOF) {
return false;
}
}
}
/**
* Returns the reference position for a list element. The algorithm tries to match any previous
* indentation on the same list. If there is none, the reference position returned is determined
* depending on the type of list: The indentation will either match the list scope introducer
* (e.g. for method declarations), so called deep indents, or simply increase the indentation by a
* number of standard indents. See also {@link #handleScopeIntroduction(int)}.
*
* @return the reference position for a list item: either a previous list item that has its own
* indentation, or the list introduction start.
*/
private int skipToPreviousListItemOrListStart() {
int startLine = fLine;
int startPosition = fPosition;
while (true) {
nextToken();
// if any line item comes with its own indentation, adapt to it
if (fLine < startLine) {
try {
int lineOffset = fDocument.getLineOffset(startLine);
int bound = Math.min(fDocument.getLength(), startPosition + 1);
fAlign = fScanner.findNonWhitespaceForwardInAnyPartition(lineOffset, bound);
} catch (BadLocationException e) {
// ignore and return just the position
}
return startPosition;
}
switch (fToken) {
// scopes: skip them
case Symbols.TokenRPAREN:
case Symbols.TokenRBRACKET:
case Symbols.TokenRBRACE:
case Symbols.TokenGREATERTHAN:
skipScope();
break;
// scope introduction
case Symbols.TokenLPAREN:
case Symbols.TokenLBRACE:
case Symbols.TokenLBRACKET:
return handleScopeIntroduction(startPosition + 1);
case Symbols.TokenSEMICOLON:
int savedPosition = fPosition;
if (isForStatement()) {
fIndent = fPrefs.prefContinuationIndent;
} else {
fPosition = savedPosition;
}
return fPosition;
case Symbols.TokenQUESTIONMARK:
if (fPrefs.prefTernaryDeepAlign) {
setFirstElementAlignment(fPosition - 1, fPosition + 1);
return fPosition;
} else {
fIndent = fPrefs.prefTernaryIndent;
return fPosition;
}
case Symbols.TokenRETURN:
fIndent = fPrefs.prefContinuationIndent;
return fPosition;
case Symbols.TokenEQUAL:
return handleEqual();
case Symbols.TokenEOF:
return 0;
}
}
}
/**
* Skips to the start of a statement that ends at the current position.
*
* @param danglingElse whether to indent aligned with the last <code>if</code>
* @param isInBlock whether the current position is inside a block, which limits the search scope
* to the next scope introducer
* @return the reference offset of the start of the statement
*/
private int skipToStatementStart(boolean danglingElse, boolean isInBlock) {
final int NOTHING = 0;
final int READ_PARENS = 1;
final int READ_IDENT = 2;
int mayBeMethodBody = NOTHING;
boolean isTypeBody = false;
int prevToken = -1;
while (true) {
nextToken();
if (isInBlock) {
switch (fToken) {
// exit on all block introducers
case Symbols.TokenIF:
case Symbols.TokenELSE:
case Symbols.TokenCATCH:
case Symbols.TokenDO:
case Symbols.TokenWHILE:
case Symbols.TokenFINALLY:
case Symbols.TokenFOR:
case Symbols.TokenTRY:
return fPosition;
case Symbols.TokenCOLON: // recognize constructor; else return pos
int pos = fPosition;
if (!looksLikeFormalParamList()) {
return pos;
}
if (!looksLikeConstructorDecl()) {
return pos;
}
return fPosition;
case Symbols.TokenSTATIC:
mayBeMethodBody = READ_IDENT; // treat static blocks like methods
break;
case Symbols.TokenCLASS:
isTypeBody = true;
break;
case Symbols.TokenSWITCH:
fIndent = fPrefs.prefCaseIndent;
return fPosition;
}
}
switch (fToken) {
// scope introduction through: LPAREN, LBRACE, LBRACKET
// search stop on SEMICOLON, RBRACE, COLON, EOF
// -> the next token is the start of the statement (i.e. previousPos when backward scanning)
case Symbols.TokenLPAREN:
case Symbols.TokenLBRACE:
case Symbols.TokenLBRACKET:
case Symbols.TokenSEMICOLON:
case Symbols.TokenEOF:
if (isInBlock) {
fIndent = getBlockIndent(mayBeMethodBody == READ_IDENT, isTypeBody);
}
if (looksLikeArgumentListOpen()) {
break;
}
// else: fIndent set by previous calls
return fPreviousPos;
case Symbols.TokenCOLON:
int prevPos = fPreviousPos;
int pos = fPosition;
if (!isConditional()) {
return prevPos;
}
// conditionals and constructors are hard to tell apart so look harder for constructor
fPosition = pos;
fPreviousPos = prevPos;
if (looksLikeFormalParamList()) {
if (looksLikeConstructorDecl()) {
return fPosition;
}
}
fPosition = pos;
fPreviousPos = prevPos;
break;
case Symbols.TokenRBRACE:
// RBRACE is a little tricky: it can be the end of a map definition, but
// usually it is the end of a previous block
pos = fPreviousPos; // store state
if (skipScope() && looksLikeArrayInitializerIntro()) {
continue; // it's a map
} else {
if (isInBlock) {
fIndent = getBlockIndent(mayBeMethodBody == READ_IDENT, isTypeBody);
}
return pos; // it's not - do as with all the above
}
// scopes: skip them
case Symbols.TokenRPAREN:
if (isInBlock) {
mayBeMethodBody = READ_PARENS;
}
//$FALL-THROUGH$
case Symbols.TokenRBRACKET:
case Symbols.TokenGREATERTHAN:
if (prevToken == Symbols.TokenEQUAL && fToken == Symbols.TokenGREATERTHAN) {
break;
}
pos = fPreviousPos;
if (skipScope()) {
break;
} else {
return pos;
}
// IF / ELSE: align the position after the conditional block with the if
// so we are ready for an else, except if danglingElse is false
// in order for this to work, we must skip an else to its if
case Symbols.TokenIF:
if (danglingElse) {
return fPosition;
} else {
break;
}
case Symbols.TokenELSE:
// skip behind the next if, as we have that one covered
pos = fPosition;
if (skipNextIF()) {
break;
} else {
return pos;
}
case Symbols.TokenDO:
// align the WHILE position with its do
return fPosition;
case Symbols.TokenWHILE:
// this one is tricky: while can be the start of a while loop
// or the end of a do - while
pos = fPosition;
if (hasMatchingDo()) {
// continue searching from the DO on
break;
} else {
// continue searching from the WHILE on
fPosition = pos;
break;
}
case Symbols.TokenIDENT:
if (mayBeMethodBody == READ_PARENS) {
mayBeMethodBody = READ_IDENT;
}
break;
default:
// keep searching
}
prevToken = fToken;
}
}
/**
* Strips any characters off the end of <code>reference</code> that exceed
* <code>indentLength</code>.
*
* @param reference the string to measure
* @param indentLength the maximum visual indentation length
* @return the stripped <code>reference</code>
*/
private StringBuffer stripExceedingChars(StringBuffer reference, int indentLength) {
final int tabSize = fPrefs.prefTabSize;
int measured = 0;
int chars = reference.length();
int i = 0;
for (; measured < indentLength && i < chars; i++) {
char ch = reference.charAt(i);
switch (ch) {
case '\t':
if (tabSize > 0) {
int reminder = measured % tabSize;
measured += tabSize - reminder;
}
break;
case ' ':
measured++;
break;
}
}
int deleteFrom = measured > indentLength ? i - 1 : i;
return reference.delete(deleteFrom, chars);
}
}