TextFieldUtil

/*
    CASA Lib for ActionScript 3.0
    Copyright (c) 2011, Aaron Clinger & Contributors of CASA Lib
    All rights reserved.
    
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      may be used to endorse or promote products derived from this software
      without specific prior written permission.
    
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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    ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
    LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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*/
package org.casalib.util {
    import flash.text.TextField;
    import flash.text.TextFormat;
    import org.casalib.util.StringUtil;
    
    /**
        Utilities for working with TextFields.
        
        @author Aaron Clinger
        @author Mike Creighton
        @version 09/06/09
    */
    public class TextFieldUtil {
        
        
        /**
            Determines if textfield has more text than can be displayed at once.
            
            @param field: Textfield to check for text overflow.
            @return Returns true if textfield has text overflow; otherwise false.
        */
        public static function hasOverFlow(field:TextField):Boolean {
            return field.maxScrollV > 1 || field.maxScrollH > 1;
        }
        
        /**
            Applies the supplied TextFormat to all upper case letters then upper cases all lower case characters.
            
            @param field: TextField to convert to small caps.
            @param largeFormat: The format you wish to apply to the upper case letters (usually a larger text size).
            @example
                
                    var small:TextFormat = new TextFormat();
                    var large:TextFormat = new TextFormat();
                    
                    small.size = 15;
                    large.size = 30;
                    
                    var title:TextField = new TextField();
                    title.autoSize      = TextFieldAutoSize.LEFT;
                    title.text          = "This Text is Small Caps.";
                    title.setTextFormat(small);
                    
                    TextFieldUtil.formatSmallCaps(title, large);
                    
                    this.addChild(title);
                
            @see TextFieldUtil#classSmallCaps
        */
        public static function formatSmallCaps(field:TextField, largeFormat:TextFormat):void {
            var copy:String = field.text;
            var l:int       = copy.length;
            var char:String;
            
            field.text = copy.toUpperCase();
            
            while (l--) {
                char = copy.charAt(l);
                
                if (!StringUtil.isPunctuation(char) && !StringUtil.isLowerCase(char) || StringUtil.isNumber(char))
                    field.setTextFormat(largeFormat, l, l + 1);
            }
        }
        
        /**
            Adds the supplied CSS class to all upper case letters then upper cases all lower case characters. The function works by wrapping each upper case letter in a span tag with the defined class name applied.
            
            @param field: TextField to convert to small caps.
            @param largeClass: The CSS class name you wish to apply to the upper case letters.
            @example
                
                    var smallCapsStyle:StyleSheet = new StyleSheet();
                    smallCapsStyle.parseCSS("p {font-size:15px;} .smallCaps {font-size:30px;}");
                    
                    var title:TextField = new TextField();
                    title.autoSize      = TextFieldAutoSize.LEFT;
                    title.styleSheet    = smallCapsStyle;
                    title.htmlText      = "
This Text is Small Caps.
";
                    
                    TextFieldUtil.classSmallCaps(title, "smallCaps");
                    
                    this.addChild(title);
                
            @see TextFieldUtil#formatSmallCaps
        */
        public static function classSmallCaps(field:TextField, largeClass:String):void {
            var copy:String = field.htmlText;
            var l:int       = copy.length;
            var char:String;
            var tag:Boolean;
            
            while (l--) {
                char = copy.charAt(l);
                
                if (char == '>')
                    tag = true;
                
                if (char == '<')
                    tag = false;
                
                if (tag)
                    continue;
                
                if (!StringUtil.isPunctuation(char, false) && !StringUtil.isLowerCase(char) || StringUtil.isNumber(char))
                    copy = StringUtil.replaceAt(copy, l, '' + char + '');
                else
                    copy = StringUtil.replaceAt(copy, l, char.toUpperCase());
            }
            
            field.htmlText = copy.toUpperCase();
        }
        
        /**
            Removes text overflow on a textfield with the option of an ommission indicator.
            
            @param field: Textfield to remove overflow.
            @param omissionIndicator: Text indication that an omission has occured, normally "..."; defaults to no indication.
            @return Returns the omitted text; if there was no text ommitted function returns a empty String ("").
            @usageNote The TextField cannot contain HTML text.
        */
        public static function removeOverFlow(field:TextField, omissionIndicator:String = ""):String {
            if (!TextFieldUtil.hasOverFlow(field))
                return '';
            
            omissionIndicator ||= '';
            
            var originalCopy:String        = field.text;
            var lines:Array                = field.text.split('. ');
            var isStillOverflowing:Boolean = false;
            var words:Array;
            var lastSentence:String;
            var sentences:String;
            var overFlow:String;
            
            while (TextFieldUtil.hasOverFlow(field)) {
                lastSentence = String(lines.pop());
                field.text   = (lines.length == 0) ? '' : lines.join('. ') + '. ';
            }
            
            sentences = (lines.length == 0) ? '' : lines.join('. ') + '. ';
            words     = lastSentence.split(' ');
            field.appendText(lastSentence);
            
            while (TextFieldUtil.hasOverFlow(field)) {
                if (words.length == 0) {
                    isStillOverflowing = true;
                    break;
                } else {
                    words.pop();
                    
                    if (words.length == 0)
                        field.text = sentences.substr(0, -1) + omissionIndicator;
                    else
                        field.text = sentences + words.join(' ') + omissionIndicator;
                }
            }
            
            if (isStillOverflowing) {
                words = field.text.split(' ');
                
                while (TextFieldUtil.hasOverFlow(field)) {
                    words.pop();
                    field.text = words.join(' ') + omissionIndicator;
                }
            }
            
            overFlow = originalCopy.substring(field.text.length);
            
            return (overFlow.charAt(0) == ' ') ? overFlow.substring(1) : overFlow;
        }
    }
}