[Laszlo-dev] For Review: Change 20090603-hqm-U Summary: fix for text selection in DHTML

[P T Withington]

I have a couple of comments:

o Should we be browser-switching in getSelectedText, rather than  
probing for functions?  If we do probe for functions, are we doing it  
in the right order (which to me would be: 1) DOM2 Standard, 2) IE, 3)  
Firefox, 4) etc.

o Similarly, should we use browser-switching to insert the appropriate  
browser-specific CSS, rather than just shoving them all in there?  I  
can imagine there might be a performance penalty for stray styles, or  
even a confusion if a browser tries to emulate another.

o I'm confused as to why we have both Khtml- and Webkit- specific  
styles.  I thought Webkit was the new Khtml?  Is there still a Khtml  
browser that is not Webkit?

o Can you put a comment where you removed "// FIXME: [20090602 anba]",  
explaining what is being done, so future generations will not be  
mystified?  (e.g., "We have handled the event, so we stop propagation  
to outer divs, but, we still want the browser default action (e.g.,  
select in an input text) to occur, so we _don't_ return false.")  Even  
better, to my mind, would be to use the actual DOM2 interface to the  
event and call `.stopPropagation()`, but not `.preventDefault()`.

On 2009-06-03, at 22:56EDT, Henry Minsky wrote:

> Change 20090603-hqm-U by hqm at badtzmaru.home on 2009-06-03 22:27:28 EDT
>    in /Users/hqm/openlaszlo/trunk5
>    for http://svn.openlaszlo.org/openlaszlo/trunk
>
> Summary:  fix for text selection in DHTML
>
> New Features:
>
> Bugs Fixed: LPP-8200
>
> Technical Reviewer: max
> QA Reviewer: andre
> Doc Reviewer: (pending)
>
> Documentation:
>
> Release Notes:
>
> Details:
>
> +  LzSprite.js: only toggle the focus in focus_on_mouseover quirk  
> when there is some text selected.
>
> + LzKeyboardKernel.js: Instead of cancelling a mouse event completely,
>  just cancel bubbling. This lets the div handle the event, and allows
>  text selection to work, but should disable it from propagating to
>  global handlers.
>
> + LzMouseKernel.js: don't cancel event with keyCode == 0 entirely,  
> just cancel bubbling.
>
> + LzTextSprite.js: use correct CSS properties for toggling  
> selectability, in Safari
>
> + LzInputTextSprite.js: do not bind the global  
> document.onselectstart handler, that prevents
> text selection from working in some browsers
>
> + LzText.lzs: add the 'onselectable' event, not required for this
> patch, but I noticed it was missing when writing a test case
>
> Tests:
>
> + added lpp-8200.lzx test, try selecting a region in each the text
> fields, except for the last (non-selectable) one.
>
> + text selection should work in DHTML on selectable text or input  
> text, all
> browsers
>
> + NOTE: there is a bug in IE7 text selection [maybe related to
> (LPP-8249) "IE7 DHTML text letter spacing looks bad"], where in the
> test case lpp-8200, if you try to drag the mouse to select the text in
> the <text> view which says "This is selectable text", you cannot use
> the mouse to select the last word ('text'). I think that maybe the
> letter spacing setting causes the browser to miscalulate the text
> width?
>
> Files:
> A      test/lfc/lpp-8200.lzx
> M      WEB-INF/lps/lfc/kernel/dhtml/LzKeyboardKernel.js
> M      WEB-INF/lps/lfc/kernel/dhtml/LzSprite.js
> M      WEB-INF/lps/lfc/kernel/dhtml/LzTextSprite.js
> M      WEB-INF/lps/lfc/kernel/dhtml/LzMouseKernel.js
> M      WEB-INF/lps/lfc/kernel/dhtml/LzInputTextSprite.js
> M      WEB-INF/lps/lfc/views/LzText.lzs
>
> Changeset: http://svn.openlaszlo.org/openlaszlo/patches/20090603-hqm-U.tar