Some text selection workarounds for MSIE

Ignore-this: b4a14bbf96712ec9ce9011e172f2af81

This patch solves some problems with reading the cursor positions
and text selection on MSIE.

note: development was part of the ICKE 2.0 project see
        http://www.icke-projekt.de for info

darcs-hash:20090804150501-6e07b-5e3cf60261f5f51906df2d4cf15509e9075757e0.gz

2 files changed, 73 insertions, 20 deletions

diff --git a/lib/scripts/edit.js b/lib/scripts/edit.js
index 51a8e3f8e..fe9057898 100644
--- a/lib/scripts/edit.js
+++ b/lib/scripts/edit.js
@@ -210,7 +210,7 @@ function keyHandler(e){
 
     if(e.keyCode == 13){ // Enter //FIXME IE
         // keep current indention for lists and code
-        var match = search.match(/(\n  +([*-] ?)?)/);
+        var match = search.match(/(\n  +([\*-] ?)?)/);
         if(match){
             insertAtCarret(field.id,match[1]);
             e.preventDefault(); // prevent enter key
diff --git a/lib/scripts/textselection.js b/lib/scripts/textselection.js
index 3ebab35e4..8b7632831 100644
--- a/lib/scripts/textselection.js
+++ b/lib/scripts/textselection.js
@@ -15,6 +15,7 @@ function selection_class(){
     this.obj       = null;
     this.rangeCopy = null;
     this.scroll    = 0;
+    this.fix       = 0;
 
     this.getLength = function(){
         return this.end - this.start;
@@ -29,8 +30,9 @@ function selection_class(){
 /**
  * Get current selection/cursor position in a given textArea
  *
- * @link http://groups.drupal.org/node/1210
+ * @link   http://groups.drupal.org/node/1210
  * @author Andreas Gohr <andi@splitbrain.org>
+ * @link   http://linebyline.blogspot.com/2006/11/textarea-cursor-position-in-internet.html
  * @returns object - a selection object
  */
 function getSelection(textArea) {
@@ -46,16 +48,74 @@ function getSelection(textArea) {
         sel.end    = textArea.selectionEnd;
         sel.scroll = textArea.scrollTop;
     } else if(document.selection) {      // MSIE
+        /*
+         * This huge lump of code is neccessary to work around two MSIE bugs:
+         *
+         * 1. Selections trim newlines at the end of the code
+         * 2. Selections count newlines as two characters
+         *
+         * FIXME see what code is not needed here and can be removed
+         */
+
         // The current selection
-        var range = document.selection.createRange();
-        sel.rangeCopy = range.duplicate();
-        // Select all text
-        sel.rangeCopy.moveToElementText(textArea);
-        // Now move 'dummy' end point to end point of original range
-        sel.rangeCopy.setEndPoint( 'EndToEnd', range );
-        // Now we can calculate start and end points
-        sel.start = sel.rangeCopy.text.length - range.text.length;
-        sel.end = sel.start + range.text.length;
+        sel.rangeCopy = document.selection.createRange().duplicate();
+
+        var before_range = document.body.createTextRange();
+        before_range.moveToElementText(textArea);                    // Selects all the text
+        before_range.setEndPoint("EndToStart", sel.rangeCopy);     // Moves the end where we need it
+
+        var before_finished = false, selection_finished = false;
+        var before_text, untrimmed_before_text, selection_text, untrimmed_selection_text;
+
+        // Load the text values we need to compare
+        before_text = untrimmed_before_text = before_range.text;
+        selection_text = untrimmed_selection_text = sel.rangeCopy.text;
+
+        // Check each range for trimmed newlines by shrinking the range by 1 character and seeing
+        // if the text property has changed.  If it has not changed then we know that IE has trimmed
+        // a \r\n from the end.
+        do {
+            if (!before_finished) {
+                if (before_range.compareEndPoints("StartToEnd", before_range) == 0) {
+                    before_finished = true;
+                } else {
+                    before_range.moveEnd("character", -1)
+                        if (before_range.text == before_text) {
+                            untrimmed_before_text += "\n";
+                        } else {
+                            before_finished = true;
+                        }
+                }
+            }
+            if (!selection_finished) {
+                if (sel.rangeCopy.compareEndPoints("StartToEnd", sel.rangeCopy) == 0) {
+                    selection_finished = true;
+                } else {
+                    sel.rangeCopy.moveEnd("character", -1)
+                        if (sel.rangeCopy.text == selection_text) {
+                            untrimmed_selection_text += "\n";
+                        } else {
+                            selection_finished = true;
+                        }
+                }
+            }
+        } while ((!before_finished || !selection_finished));
+
+        var startPoint = untrimmed_before_text.length;
+        var endPoint = startPoint + untrimmed_selection_text.length;
+
+        sel.start = startPoint;
+        sel.end   = endPoint;
+
+
+        // count number of newlines in str to work around stupid IE selection bug
+        var countNL = function(str) {
+            var m = str.split("\r\n");
+            if (!m || !m.length) return 0;
+            return m.length-1;
+        };
+        sel.fix = countNL(sel.obj.value.substring(0,sel.start));
+
     }
     return sel;
 }
@@ -76,16 +136,8 @@ function setSelection(selection){
         selection.obj.setSelectionRange(selection.start,selection.end);
         if(selection.scroll) selection.obj.scrollTop = selection.scroll;
     } else if(document.selection) { // IE
-        // count number of newlines in str to work around stupid IE selection bug
-        var countNL = function(str) {
-            var m = str.split("\n");
-            if (!m || !m.length) return 0;
-            return m.length-1;
-        };
-        var fix = countNL(selection.obj.value.substring(0,selection.start));
-
         selection.rangeCopy.collapse(true);
-        selection.rangeCopy.moveStart('character',selection.start - fix);
+        selection.rangeCopy.moveStart('character',selection.start - selection.fix);
         selection.rangeCopy.moveEnd('character',selection.end - selection.start);
         selection.rangeCopy.select();
     }
@@ -105,6 +157,7 @@ function setSelection(selection){
 function pasteText(selection,text,opts){
     if(!opts) opts = {};
     // replace the content
+
     selection.obj.value =
         selection.obj.value.substring(0, selection.start) + text +
         selection.obj.value.substring(selection.end, selection.obj.value.length);