de.jcup.egradle.codeassist.SourceCodeInsertionSupport.java Source code

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Here is the source code for de.jcup.egradle.codeassist.SourceCodeInsertionSupport.java

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/*
 * Copyright 2016 Albert Tregnaghi
 *
 * 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 de.jcup.egradle.codeassist;

import java.util.regex.Pattern;

import org.apache.commons.lang3.StringUtils;

public class SourceCodeInsertionSupport {

    public static final String CURSOR_VARIABLE = "$cursor";

    private static Pattern REPLACE_CURSOR_POS = Pattern.compile("\\" + CURSOR_VARIABLE);

    /**
     * Calculates insertion data
     * 
     * @param oiriginInsertion
     *            - what shall be inserted (the "template")
     * @param textBeforeColumn
     *            - what is before?
     * @return insertion data
     */
    public InsertionData prepareInsertionString(String oiriginInsertion, String textBeforeColumn) {
        return prepareInsertionString(oiriginInsertion, textBeforeColumn, true);
    }

    private InsertionData prepareInsertionString(String originInsertion, String textBeforeColumn,
            boolean ignoreIndentOnFirstLine) {
        InsertionData result = new InsertionData();
        if (StringUtils.isEmpty(originInsertion)) {
            return result;
        }
        String insertion = originInsertion;
        /* first do indent if necessary */
        if (StringUtils.isNotEmpty(textBeforeColumn)) {
            /* build indent */
            String indention = transformTextBeforeToIndentString(textBeforeColumn);

            /* for each line append indent before... */
            boolean endsWithNewLine = insertion.endsWith("\n");
            StringBuilder sb = new StringBuilder();
            String[] splitted = StringUtils.splitByWholeSeparator(insertion, "\n");
            for (int i = 0; i < splitted.length; i++) {
                boolean lastLineEmpty = endsWithNewLine;
                lastLineEmpty = lastLineEmpty && i == splitted.length - 1;
                lastLineEmpty = lastLineEmpty && StringUtils.isEmpty(splitted[i]);

                boolean appendLine = !lastLineEmpty;
                if (!appendLine) {
                    continue;
                }
                if (i > 0 || !ignoreIndentOnFirstLine) {
                    sb.append(indention);
                }
                sb.append(splitted[i]);
                sb.append("\n");

            }
            insertion = sb.toString();

        }
        result.cursorOffset = insertion.indexOf("$cursor");
        if (result.cursorOffset != -1) {
            result.sourceCode = REPLACE_CURSOR_POS.matcher(insertion).replaceAll("");
        } else {
            result.sourceCode = insertion;
        }
        return result;

    }

    /**
     * Transform text before column to indent string. Purpose for this method is
     * to have exact same column as on code completion before. Because text
     * before can also contain parts of the code proposal itself the text before
     * last whitespace will not be used for indention.<br>
     * <br>
     * 
     * An example:
     * 
     * <pre>
     *    "123 cod" will be transformed to "    "
     *  "  3 cod" will be transformed to "    "
     *  "  3 co " will be transformed to "       "
     * 
     * </pre>
     * 
     * @param textBeforeColumn
     * @return transformed string never <code>null</code>
     */
    String transformTextBeforeToIndentString(String textBeforeColumn) {
        if (textBeforeColumn == null) {
            return "";
        }
        StringBuilder indentSb = new StringBuilder();
        int lastOriginWhitespacePos = -1;
        for (int i = 0; i < textBeforeColumn.length(); i++) {
            char c = textBeforeColumn.charAt(i);
            if (Character.isWhitespace(c)) {
                indentSb.append(c);
                lastOriginWhitespacePos = i + 1;
            } else {
                indentSb.append(" ");
            }
        }
        if (lastOriginWhitespacePos == -1) {
            return ""; // there were no origin whitespaces so do not indent
        }
        String indent = indentSb.substring(0, lastOriginWhitespacePos);
        return indent;
    }

    public class InsertionData {
        String sourceCode = "";
        int cursorOffset = -1;

        public String getSourceCode() {
            return sourceCode;
        }

        public int getCursorOffset() {
            return cursorOffset;
        }
    }

}