[Summary view] [Print] [Text view]

   1  /**
   2   * Text selection related functions.
   3   */
   4  
   5  /**
   6   * selection prototype
   7   *
   8   * Object that capsulates the selection in a textarea. Returned by DWgetSelection.
   9   *
  10   * @author Andreas Gohr <andi@splitbrain.org>
  11   */
  12  function selection_class(){
  13      this.start     = 0;
  14      this.end       = 0;
  15      this.obj       = null;
  16      this.scroll    = 0;
  17      this.fix       = 0;
  18  
  19      this.getLength = function(){
  20          return this.end - this.start;
  21      };
  22  
  23      this.getText = function(){
  24          return (!this.obj) ? '' : this.obj.value.substring(this.start,this.end);
  25      };
  26  }
  27  
  28  /**
  29   * Get current selection/cursor position in a given textArea
  30   *
  31   * @link   http://groups.drupal.org/node/1210
  32   * @author Andreas Gohr <andi@splitbrain.org>
  33   * @link   http://linebyline.blogspot.com/2006/11/textarea-cursor-position-in-internet.html
  34   * @returns object - a selection object
  35   */
  36  function DWgetSelection(textArea) {
  37      var sel = new selection_class();
  38  
  39      textArea.focus();
  40      sel.obj   = textArea;
  41      sel.start  = textArea.selectionStart;
  42      sel.end    = textArea.selectionEnd;
  43      sel.scroll = textArea.scrollTop;
  44      return sel;
  45  }
  46  
  47  /**
  48   * Set the selection
  49   *
  50   * You need to get a selection object via DWgetSelection() first, then modify the
  51   * start and end properties and pass it back to this function.
  52   *
  53   * @link http://groups.drupal.org/node/1210
  54   * @author Andreas Gohr <andi@splitbrain.org>
  55   * @param {selection_class} selection  a selection object as returned by DWgetSelection()
  56   */
  57  function DWsetSelection(selection){
  58      selection.obj.setSelectionRange(selection.start, selection.end);
  59      if(selection.scroll) selection.obj.scrollTop = selection.scroll;
  60  }
  61  
  62  /**
  63   * Inserts the given text at the current cursor position or replaces the current
  64   * selection
  65   *
  66   * @author Andreas Gohr <andi@splitbrain.org>
  67   * @param {string}  text           the new text to be pasted
  68   * @param {selection_class}  selection     selection object returned by DWgetSelection
  69   * @param {int}     opts.startofs  number of charcters at the start to skip from new selection
  70   * @param {int}     opts.endofs    number of characters at the end to skip from new selection
  71   * @param {boolean} opts.nosel     set true if new text should not be selected
  72   */
  73  function pasteText(selection,text,opts){
  74      if(!opts) opts = {};
  75      // replace the content
  76  
  77      selection.obj.value =
  78          selection.obj.value.substring(0, selection.start) + text +
  79          selection.obj.value.substring(selection.end, selection.obj.value.length);
  80  
  81      // set new selection
  82      if (is_opera) {
  83          // Opera replaces \n by \r\n when inserting text.
  84          selection.end = selection.start + text.replace(/\r?\n/g, '\r\n').length;
  85      } else {
  86          selection.end = selection.start + text.length;
  87      }
  88  
  89  
  90      // modify the new selection if wanted
  91      if(opts.startofs) selection.start += opts.startofs;
  92      if(opts.endofs)   selection.end   -= opts.endofs;
  93  
  94      // no selection wanted? set cursor to end position
  95      if(opts.nosel) selection.start = selection.end;
  96  
  97      DWsetSelection(selection);
  98  }
  99  
 100  
 101  /**
 102   * Format selection
 103   *
 104   * Apply tagOpen/tagClose to selection in textarea, use sampleText instead
 105   * of selection if there is none.
 106   *
 107   * @author Andreas Gohr <andi@splitbrain.org>
 108   */
 109  function insertTags(textAreaID, tagOpen, tagClose, sampleText){
 110      var txtarea = jQuery('#' + textAreaID)[0];
 111  
 112      var selection = DWgetSelection(txtarea);
 113      var text = selection.getText();
 114      var opts;
 115  
 116      // don't include trailing space in selection
 117      if(text.charAt(text.length - 1) == ' '){
 118          selection.end--;
 119          text = selection.getText();
 120      }
 121  
 122      if(!text){
 123          // nothing selected, use the sample text and select it
 124          text = sampleText;
 125          opts = {
 126              startofs: tagOpen.length,
 127              endofs: tagClose.length
 128          };
 129      }else{
 130          // place cursor at the end
 131          opts = {
 132              nosel: true
 133          };
 134      }
 135  
 136      // surround with tags
 137      text = tagOpen + text + tagClose;
 138  
 139      // do it
 140      pasteText(selection,text,opts);
 141  }
 142  
 143  /**
 144   * Wraps around pasteText() for backward compatibility
 145   *
 146   * @author Andreas Gohr <andi@splitbrain.org>
 147   */
 148  function insertAtCarret(textAreaID, text){
 149      var txtarea = jQuery('#' + textAreaID)[0];
 150      var selection = DWgetSelection(txtarea);
 151      pasteText(selection,text,{nosel: true});
 152  }