toggle Headings

[leotiger]

command.doHeading = function(chunk, postProcessing, useDefaultText){

    //chunk.trimWhitespace();
    // Remove leading/trailing whitespace and reduce internal spaces to single spaces.
    var chunkOrigSel = chunk.selection;
    chunk.selection = chunk.selection.replace(/\s+/g, " ");
    chunk.selection = chunk.selection.replace(/(^\s+|\s+$)/g, "");
    var firstChr = chunk.selection.substring(0, 1);
    // If we clicked the button with no selected text, we just
    // make a level 2 hash header around some default text.
    if(!chunk.selection){
        chunk.findTags(/[^\n]/, /[^\n]/);       
        if(/[^\n]/.test(chunk.startTag))
            chunk.startTag += "\n\n## ";
        else chunk.startTag = "## ";
        chunk.selection = "Heading";
        if(/[^\n]/.test(chunk.startTag))
            chunk.endTag = " ##\n\n" + chunk.endTag;
        else chunk.endTag = " ##";
        return;
    }

    var headerLevel = 0;        // The existing header level of the selected text.

    // Remove any existing hash heading markdown and save the header level.
    chunk.findTags(/#+[ ]*/, /[ ]*#+/);
    if(/#+/.test(chunk.startTag)){
        headerLevel = re.lastMatch.length;
    }
    chunk.startTag = chunk.endTag = "";

    var addNewLine = "";
    if (headerLevel == 0)
    {
        chunk.findTags(/[^\n]/, null);      
        if(/[^\n]/.test(chunk.startTag)){
            addNewLine = chunk.startTag.substring(0,1);
        }
        chunk.startTag = chunk.endTag = "";
    }

    var removeNewLines = false;
    if (headerLevel < 6) headerLevel++;
    else if (headerLevel == 6) 
    {
        headerLevel = 0;
        removeNewLines = true;
    }

    var headerChar = "#";
    var len = headerLevel;
    if (headerLevel > 0)
    {
        if (headerLevel == 1 && addNewLine != "") 
        {
            chunk.startTag = addNewLine.replace(/\s+/g, "") + "\n\n";
        }
        chunk.endTag = " ";
        while(len--){
            chunk.endTag += headerChar;
            chunk.startTag += headerChar;
        }
        chunk.startTag += " ";

        if (headerLevel == 1) 
        {
            chunk.endTag += "\n\n";
            chunk.selection = firstChr + chunk.selection;
        }

    }
    else
    {
        chunk.findTags(/[\n]+/, /[\n]+/);       
        if(/[\n]+/.test(chunk.startTag)){
            chunk.startTag = "";
        }
        if(/[\n]+/.test(chunk.endTag)){
            chunk.endTag = "";
        }
        chunk.selection = chunkOrigSel;     
        chunk.findTags(/[^\n]/, /[^\n]/);       
        if(/[^\n]/.test(chunk.startTag)){
            chunk.startTag = chunk.startTag.substring(0,1) + " ";
            chunk.startTag = chunk.startTag.replace(/\s+/g, " ");
        }
        if(/[^\n]/.test(chunk.endTag)){
            chunk.endTag = " " + chunk.endTag.substring(0,1);
            chunk.endTag = chunk.endTag.replace(/\s+/g, " ");
        }
        chunk.selection = chunkOrigSel;         
    }

};