QuoteHandler.java

package org.elixir_lang;

import com.google.common.collect.ImmutableMap;
import com.intellij.codeInsight.editorActions.MultiCharQuoteHandler;
import com.intellij.openapi.editor.Document;
import com.intellij.openapi.editor.Editor;
import com.intellij.openapi.editor.highlighter.HighlighterIterator;
import com.intellij.openapi.util.TextRange;
import com.intellij.psi.tree.IElementType;
import com.intellij.psi.tree.TokenSet;
import org.elixir_lang.lexer.StackFrame;
import org.elixir_lang.psi.ElixirTypes;
import org.jetbrains.annotations.Nullable;

import java.util.Map;

public class QuoteHandler implements MultiCharQuoteHandler {
    /*
     * CONSTANTS
     */

    private final static Map<IElementType, IElementType> CLOSING_QUOTE_BY_OPENING_QUOTE = ImmutableMap
            .<IElementType, IElementType>builder()
            .put(ElixirTypes.CHAR_LIST_HEREDOC_PROMOTER, ElixirTypes.CHAR_LIST_HEREDOC_TERMINATOR)
            .put(ElixirTypes.CHAR_LIST_SIGIL_HEREDOC_PROMOTER, ElixirTypes.CHAR_LIST_SIGIL_HEREDOC_TERMINATOR)
            .put(ElixirTypes.CHAR_LIST_SIGIL_PROMOTER, ElixirTypes.CHAR_LIST_SIGIL_TERMINATOR)
            .put(ElixirTypes.CHAR_LIST_PROMOTER, ElixirTypes.CHAR_LIST_PROMOTER)
            .put(ElixirTypes.REGEX_HEREDOC_PROMOTER, ElixirTypes.REGEX_HEREDOC_TERMINATOR)
            .put(ElixirTypes.REGEX_PROMOTER, ElixirTypes.REGEX_TERMINATOR)
            .put(ElixirTypes.SIGIL_HEREDOC_PROMOTER, ElixirTypes.SIGIL_HEREDOC_TERMINATOR)
            .put(ElixirTypes.SIGIL_PROMOTER, ElixirTypes.SIGIL_TERMINATOR)
            .put(ElixirTypes.STRING_HEREDOC_PROMOTER, ElixirTypes.STRING_HEREDOC_TERMINATOR)
            .put(ElixirTypes.STRING_SIGIL_HEREDOC_PROMOTER, ElixirTypes.STRING_SIGIL_HEREDOC_TERMINATOR)
            .put(ElixirTypes.STRING_SIGIL_PROMOTER, ElixirTypes.STRING_SIGIL_TERMINATOR)
            .put(ElixirTypes.STRING_PROMOTER, ElixirTypes.STRING_TERMINATOR)
            .put(ElixirTypes.WORDS_HEREDOC_PROMOTER, ElixirTypes.WORDS_HEREDOC_TERMINATOR)
            .put(ElixirTypes.WORDS_PROMOTER, ElixirTypes.WORDS_TERMINATOR)
            .build();

    private final static TokenSet CLOSING_QUOTES = TokenSet.create(
            CLOSING_QUOTE_BY_OPENING_QUOTE
                    .values()
                    .toArray(new IElementType[0])
    );

    private final static TokenSet LITERALS = TokenSet.create(
            ElixirTypes.ATOM_FRAGMENT,
            ElixirTypes.CHAR_LIST_FRAGMENT,
            ElixirTypes.REGEX_FRAGMENT,
            ElixirTypes.SIGIL_FRAGMENT,
            ElixirTypes.STRING_FRAGMENT,
            ElixirTypes.WORDS_FRAGMENT
    );

    private final static TokenSet OPENING_QUOTES = TokenSet.create(
            CLOSING_QUOTE_BY_OPENING_QUOTE
                    .keySet()
                    .toArray(new IElementType[0])
    );

    /*
     * Instance Methods
     */

    @Nullable
    @Override
    public CharSequence getClosingQuote(HighlighterIterator highlighterIterator, int offset) {
        Document document = highlighterIterator.getDocument();
        CharSequence closingQuote = null;

        if (document != null) {
            if (offset >= 3) {
                String openingQuote = document.getText(new TextRange(offset - 3, offset));

                closingQuote = StackFrame.TERMINATOR_BY_PROMOTER.get(openingQuote);

                if (closingQuote != null) {
                    closingQuote = "\n" + closingQuote;
                }
            }

            if (closingQuote == null && offset >= 1) {
                String openingQuote = document.getText(new TextRange(offset - 1, offset));

                closingQuote = StackFrame.TERMINATOR_BY_PROMOTER.get(openingQuote);
            }
        }

        return closingQuote;
    }

    /**
     *
     * @param editor
     * @param highlighterIterator
     * @param offset the offset of the element with {@link HighlighterIterator#getTokenType()}
     * @return {@code true} to automatically insert a closing quote
     *   (from {@link #getClosingQuote(HighlighterIterator, int)}
     * @see <a href="https://github.com/JetBrains/intellij-community/blob/eeefa20d7c43856143c825ca65de6d5089241b35/platform/lang-impl/src/com/intellij/codeInsight/editorActions/TypedHandler.java#L472-L478">TypeHandler#handleQuote</a>
     * @see <a href="https://github.com/JetBrains/intellij-community/blob/eeefa20d7c43856143c825ca65de6d5089241b35/platform/lang-impl/src/com/intellij/codeInsight/editorActions/TypedHandler.java#L529">TypeHandler#hasNonClosedLiterals</a>
     */
    @Override
    public boolean hasNonClosedLiteral(Editor editor, HighlighterIterator highlighterIterator, int offset) {
        /* it is safe to always return true based on XMLQuoteHandler
           @see https://github.com/JetBrains/intellij-community/blob/eeefa20d7c43856143c825ca65de6d5089241b35/xml/impl/src/com/intellij/codeInsight/editorActions/XmlQuoteHandler.java#L38 */
        return true;
    }

    /**
     *
     * @param highlighterIterator
     * @param offset the current offset in the file of the {@code highlighterIterator}
     * @return {@code true} if {@link HighlighterIterator#getTokenType()} is one of {@link #CLOSING_QUOTES} and
     *   {@code offset} is {@link HighlighterIterator#getStart()}
     */
    @Override
    public boolean isClosingQuote(HighlighterIterator highlighterIterator, int offset) {
        boolean isClosingQuote = false;

        if (CLOSING_QUOTES.contains(highlighterIterator.getTokenType())) {
            int start = highlighterIterator.getStart();
            int end = highlighterIterator.getEnd();
            isClosingQuote = end - start >= 1 && offset == end - 1;
        }

        return isClosingQuote;
    }

    @Override
    public boolean isInsideLiteral(HighlighterIterator highlighterIterator) {
        return LITERALS.contains(highlighterIterator.getTokenType());
    }

    @Override
    public boolean isOpeningQuote(HighlighterIterator highlighterIterator, int offset) {
        boolean isOpeningQuote = false;

        if (OPENING_QUOTES.contains(highlighterIterator.getTokenType())){
            int start = highlighterIterator.getStart();
            isOpeningQuote = offset == start;
        }

        return isOpeningQuote;
    }
}