From: HJ van Rantwijk <[EMAIL PROTECTED]>
> Ok, and what was the problem?
Well, there was more than one. Your question as to whether the function was
returning false lighted a spark in my head. To summarize the problem again: I
wanted to implement custom behavior for certain keypresses (arrow keys and
numbers) in a dialog. For every other keypress (e.g., ESC, alt-F4 (which on
Windows closes the dialog), etc.), I wanted the default listener to be used.
One of the problems was that I was implicitly returning false/null from some
branches because the function wasn't always explicitly returning a value. So
now I'm always explicitly returning a value, and I've added stopPropagation()
and preventDefault() in the appropriate places, even though I don't think both
function calls are necessary.
The other problem was that event.charCode is always 0 when the arrow keys are
pressed (and perhaps for any non-displayable character). When event.charCode is
0, we should look to event.keyCode for the pressed key. The event.which
property/attribute isn't populated for arrow keys, contrary to the
documentation which IIRC states that event.which should ALWAYS be populated
with either event.charCode or event.keyCode.
The final handler is this, with onkeypress="onKeyPress(event)" as an attribute
on the <dialog/>:
function onKeyPress(evt) {
if (!isNaN(evt.charCode)) { // if it's a number, process it. Probably should
conditionally check evt.keyCode since we use it below!
if (evt.charCode) {
// select specific row in tree corresponding to the pressed number
var row = parseInt(evt.charCode-KeyboardEvent.DOM_VK_0)-1;
row > -1 && row <= accountsTree.view.rowCount-1 &&
accountsTree.view.selection.select(row);
}
else if (evt.keyCode) {
var handled;
switch(evt.keyCode) {
case KeyboardEvent.DOM_VK_UP:
case KeyboardEvent.DOM_VK_LEFT:
// move tree selection up one row
accountsTree.currentIndex>0 &&
accountsTree.view.selection.select(accountsTree.currentIndex-1);
handled = true;
break;
case KeyboardEvent.DOM_VK_DOWN:
case KeyboardEvent.DOM_VK_RIGHT:
// move tree selection down one row
accountsTree.currentIndex<accountsTree.view.rowCount-1 &&
accountsTree.view.selection.select(accountsTree.currentIndex+1);
handled = true;
}
}
if (handled) {
evt.stopPropagation();
evt.preventDefault();
return false;
}
}
return true;
}
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