[FLEX-21494] getCharIndexAtPoint does not work as expected on textAreas and horizontal scroll

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: Adobe Flex SDK 3.4 (Release)
• Component/s: mx: TextArea, mx: TextInput
• Environment: Affected OS(s): All OS Platforms; Affected OS(s): All OS Platforms; Browser: Internet Explorer 6.x; Language Found: English
• Assignee: Unassigned
• Reporter: Adobe JIRA
• Created: 12/Oct/09 23:17
• Updated: 19/Jul/10 00:58

Description

Steps to reproduce:
1. extend a TextArea field and implement the following functions:
public function mouseToCursorPos(x: uint, y: uint): uint {
var p: Point = textField.globalToLocal(localToGlobal(new Point(x + horizontalScrollPosition, y + verticalScrollPosition)));
x = p.x; y = p.y;
var index: int = textField.getCharIndexAtPoint(x, y);
if (index == -1)

{ index = textField.getLineIndexAtPoint(x, y); if (index == -1) index = textField.numLines - 1; index = textField.getLineOffset(index) + textField.getLineLength(index) - 1; }

}

public function set cursorPos(value: uint): void { selectionBeginIndex = value; selectionEndIndex = value; }
2. on mouse move set the cursorPos to the result of mouseToCursorPos(event.localX, event.localY);
3. disable wordwrap on the text area
4. enter enough text to horizontally scroll, then scroll across to the right and move the mouse so the carrot follows it.

Actual Results:
carrot does not follow the cursor if the x position is greater then the width of the textField, getCharIndexAtPoint is returning -1;

Expected Results:
The cursor should be correctly offset by the horizontal scroll position and follow the cursor around.

Workaround (if any):
Update the function with the version below that contains a kludge to widen the textField temporally

public function mouseToCursorPos(x: uint, y: uint): uint {
/* kludge to work around flex SDK bug */
var oldwidth: int;
var oldscroll: int;
oldwidth = textField.width;
oldscroll = horizontalScrollPosition;
textField.width = 10000;

var p: Point = textField.globalToLocal(localToGlobal(new Point(x + horizontalScrollPosition, y + verticalScrollPosition)));
x = p.x; y = p.y;
var index: int = textField.getCharIndexAtPoint(x, y);
if (index == -1) { index = textField.getLineIndexAtPoint(x, y); if (index == -1) index = textField.numLines - 1; index = textField.getLineOffset(index) + textField.getLineLength(index) - 1; }

/* undo the kludge to work around the bug */
textField.width = oldwidth;
horizontalScrollPosition = oldscroll;
return index;
}