source: other-projects/rsyntax-textarea/src/java/org/fife/ui/rsyntaxtextarea/templates/StaticCodeTemplate.java@ 25584

/*
 * 02/21/2005
 *
 * CodeTemplate.java - A "template" (macro) for commonly-typed code.
 * 
 * This library is distributed under a modified BSD license.  See the included
 * RSyntaxTextArea.License.txt file for details.
 */
package org.fife.ui.rsyntaxtextarea.templates;

import java.io.IOException;
import java.io.ObjectInputStream;
import javax.swing.text.BadLocationException;
import javax.swing.text.Caret;
import javax.swing.text.Element;

import org.fife.ui.rsyntaxtextarea.RSyntaxDocument;
import org.fife.ui.rsyntaxtextarea.RSyntaxTextArea;
import org.fife.ui.rsyntaxtextarea.RSyntaxUtilities;


/**
 * A code template that inserts static text before and after the caret.<p>
 *
 * For example, you can associate the identifier <code>forb</code>
 * (short for "for-block") with the following code:<p>
 *
 * <pre>
 *   for (&lt;caret&gt;) {
 *
 *   }
 * </pre>
 *
 * Then, whenever you type <code>forb</code> followed by a trigger
 * (e.g., a space) into a text area with this <code>CodeTemplate</code>,
 * the code snippet is added in place of <code>forb</code>.  Further,
 * the caret is placed at the position denoted by <code>&lt;caret&gt;</code>.
 *
 * @author Robert Futrell
 * @version 0.1
 * @see CodeTemplate
 */
public class StaticCodeTemplate extends AbstractCodeTemplate {

    private static final long serialVersionUID = 1;

    /**
     * The code inserted before the caret position.
     */
    private String beforeCaret;

    /**
     * The code inserted after the caret position.
     */
    private String afterCaret;

    /**
     * Cached value representing whether <code>beforeCaret</code> contains
     * one or more newlines.
     */
    private transient int firstBeforeNewline;

    /**
     * Cached value representing whether <code>afterCaret</code> contains
     * one or more newlines.
     */
    private transient int firstAfterNewline;

    private static final String EMPTY_STRING        = "";


    /**
     * Constructor.  This constructor only exists to support persistance
     * through serialization.
     */
    public StaticCodeTemplate() {
    }


    /**
     * Constructor.
     *
     * @param id The ID of this code template.
     * @param beforeCaret The text to place before the caret.
     * @param afterCaret The text to place after the caret.
     */
    public StaticCodeTemplate(String id, String beforeCaret, String afterCaret){
        super(id);
        setBeforeCaretText(beforeCaret);
        setAfterCaretText(afterCaret);
    }


    /**
     * Returns the text that will be placed after the caret.
     *
     * @return The text.
     * @see #setAfterCaretText
     */
    public String getAfterCaretText() {
        return afterCaret;
    }


    /**
     * Returns the text that will be placed before the caret.
     *
     * @return The text.
     * @see #setBeforeCaretText
     */
    public String getBeforeCaretText() {
        return beforeCaret;
    }


    /**
     * Returns the "after caret" text, with each new line indented by
     * the specified amount.
     *
     * @param indent The amount to indent.
     * @return The "after caret" text.
     */
    private String getAfterTextIndented(String indent) {
        return getTextIndented(getAfterCaretText(), firstAfterNewline, indent);
    }


    /**
     * Returns the "before caret" text, with each new line indented by
     * the specified amount.
     *
     * @param indent The amount to indent.
     * @return The "before caret" text.
     */
    private String getBeforeTextIndented(String indent) {
        return getTextIndented(getBeforeCaretText(),firstBeforeNewline,indent);
    }


    /**
     * Returns text with newlines indented by the specifed amount.
     *
     * @param text The original text.
     * @param firstNewline The index of the first '\n' character.
     * @param indent The amount to indent.
     * @return The indented text.
     */
    private String getTextIndented(String text,int firstNewline,String indent) {
        if (firstNewline==-1) {
            return text;
        }
        int pos = 0;
        int old = firstNewline+1;
        StringBuffer sb = new StringBuffer(text.substring(0, old));
        sb.append(indent);
        while ((pos=text.indexOf('\n', old))>-1) {
            sb.append(text.substring(old, pos+1));
            sb.append(indent);
            old = pos+1;
        }
        if (old<text.length()) {
            sb.append(text.substring(old));
        }
        return sb.toString();
    }


    /**
     * Invokes this code template.  The changes are made to the given text
     * area.
     *
     * @param textArea The text area to operate on.
     * @throws BadLocationException If something bad happens.
     */
    public void invoke(RSyntaxTextArea textArea) throws BadLocationException {

        Caret c = textArea.getCaret();
        int dot = c.getDot();
        int mark = c.getMark();
        int p0 = Math.min(dot, mark);
        int p1 = Math.max(dot, mark);
        RSyntaxDocument doc = (RSyntaxDocument)textArea.getDocument();
        Element map = doc.getDefaultRootElement();

        int lineNum = map.getElementIndex(dot);
        Element line = map.getElement(lineNum);
        int start = line.getStartOffset();
        int end = line.getEndOffset()-1; // Why always "-1"?
        String s = textArea.getText(start,end-start);
        int len = s.length();

        // endWS is the end of the leading whitespace
        // of the current line.
        int endWS = 0;
        while (endWS<len && RSyntaxUtilities.isWhitespace(s.charAt(endWS))) {
            endWS++;
        }
        s = s.substring(0, endWS);
        p0 -= getID().length();
        String beforeText = getBeforeTextIndented(s);
        String afterText = getAfterTextIndented(s);
        doc.replace(p0,p1-p0, beforeText+afterText, null);
        textArea.setCaretPosition(p0+beforeText.length());

    }


    /**
     * Called when reading a serialized version of this document.  This is
     * overridden to initialize the transient members of this class.
     *
     * @param in The input stream to read from.
     * @throws ClassNotFoundException Never.
     * @throws IOException If an IO error occurs.
     */
    private void readObject(ObjectInputStream in) throws ClassNotFoundException,
                                            IOException  {
        in.defaultReadObject();
        // "Resetting" before and after text to the same values will replace
        // nulls with empty srings, and set transient "first*Newline" values.
        setBeforeCaretText(this.beforeCaret);
        setAfterCaretText(this.afterCaret);
    }


    /**
     * Sets the text to place after the caret.
     *
     * @param afterCaret The text.
     * @see #getAfterCaretText()
     */
    public void setAfterCaretText(String afterCaret) {
        this.afterCaret = afterCaret==null ? EMPTY_STRING : afterCaret;
        firstAfterNewline = this.afterCaret.indexOf('\n');
    }


    /**
     * Sets the text to place before the caret.
     *
     * @param beforeCaret The text.
     * @see #getBeforeCaretText()
     */
    public void setBeforeCaretText(String beforeCaret) {
        this.beforeCaret = beforeCaret==null ? EMPTY_STRING : beforeCaret;
        firstBeforeNewline = this.beforeCaret.indexOf('\n');
    }


    /**
     * Returns a string representation of this template for debugging
     * purposes.
     *
     * @return A string representation of this template.
     */
    public String toString() {
        return "[StaticCodeTemplate: id=" + getID() +
            ", text=" + getBeforeCaretText() + "|" + getAfterCaretText() + "]";
    }


}