+1 - Great idea, let's do it. I'll have to think about whether there are
other questions that should be added, but I like the idea and think the
list here is a great start.
-Nick
On Sun, Jan 14, 2018 at 3:37 PM, Mike Jumper <mike.jum...@guac-dev.org>
wrote:
> Hello all,
>
> With the frequency that questions like the forwarded email below are
> asked, I think we should look to adding an up-to-date FAQ on the website
> (not within the manual) which covers these questions/issues.
>
> So far, the following come to mind:
>
> * Something fundamental to Guacamole isn't working for me. Where do I
> report this? (Remember that guac is used by many others without issue, and
> the more fundamental a problem is, the less likely it's a bug -
> troubleshooting steps, check the logs, failing that ask on the mailing
> lists.)
>
> * I have set things up successfully, however if i try [X], instead of [Y]
> happening as documented, [Z] happens. Where should I report this? (JIRA)
>
> * I have found an issue which may have security implications. Where should
> I report this? (private@)
>
> * Why don't you just use the clipboard directly instead of the box in the
> menu? (JavaScript cannot access the clipboard directly for security reasons)
>
> * I see the browser has "copy" and "paste" events. Why don't you handle
> these events so clipboard works? (Doing so is actually varying combinations
> of impossible and unreliable, and ultimately results in confusion.)
>
> * I press [keyboard shortcut] but it's handled by my browser or operating
> system instead of the remote desktop. Can you fix this? (No, guac already
> attempts to handle all keyboard events, and can't control whether your
> browser or operating system reserve some keyboard shortcuts for their own
> use.)
>
> * I need to share files on my computer with the remote desktop. I see
> Guacamole has drive redirection support, but only for files accessible to
> the Guacamole server. How can I share local files? (This is not possible,
> JavaScript cannot access local files directly in this way.)
>
> * I want to print to my local printer. I see Guacamole has printing
> support, but this produces a PDF download. How do I print directly to my
> local printers? (This is not possible, JavaScript cannot access local
> printers. It is possible to cause the PDF to automatically open a print
> dialog, and on some browsers it is also possible to automatically open the
> PDF, but currently this does not actually work reliably across all
> platforms and whether it will work cannot be detected.)
>
> * Can you add support for X11 forwarding to SSH? (No, this wouldn't
> actually work well in practice, but there is an X.Org driver being written)
>
> * I'm trying to connect to my remote desktop by it isn't working. Why?
> (troubleshooting procedures, how to check the logs)
>
> * I am using an application within the remote desktop under Guacamole, but
> the application isn't working correctly. Can you fix Guacamole so it
> doesn't break my application? (it isn't)
>
> * When I connect via RDP, the screen size is set correctly, but it does
> not update if I resize the browser window. Why?
>
> * When I connect via VNC, the screen size is not set correctly. It remains
> the same regardless of the browser window's size. Why?
>
> * I want to do [Y] in order to accomplish [X]. How do I do [Y] with
> Guacamole? (Rather than assume Y is the correct approach, instead look into
> how to do X with Guacamole - see "the xy problem")
>
> Any thoughts/suggestions?
>
> - Mike
>
> On Sun, Jan 14, 2018 at 1:16 AM, Mike Jumper <mike.jum...@guac-dev.org>
> wrote:
>
>> On Fri, Jan 12, 2018 at 6:25 AM, Amarjeet Singh <amarjee...@gmail.com>
>> wrote:
>>
>>> ...
>>>
>>> 1. After more debugging I have noticed that these functions take lot of
>>> time to process if buffer size if large ( copying or pasting large amount
>>> of data ).
>>>
>>>
>>> 1.
>>> *__encode_utf8 *
>>> 2.
>>> *__append_utf8 *
>>> 3.
>>> *array_writer.sendData(__encode_utf8(text)); *
>>> 4. *__decode_utf8*
>>>
>>>
>> Can you elaborate here? What leads you to the conclusion that encoding
>> things to UTF-8 is taking significant processing time?
>>
>> 2. There are many function in Guacamole Javascript which are independent
>>> of user interface elements, such as the DOM and common JS functions like
>>> getElementById where we can use Webworker to improve the performance of
>>> Guacamole.
>>>
>>
>> Again, can you elaborate? What specifically do you believe would be
>> improved through the use of WebWorkers? Have you tried making this change
>> yourself and observed significant improvement?
>>
>> 3. On Paste event we can get the data from the Local Clipboard and send
>>> it to the Remote Server so that Remote server also synced with the Local
>>> Server == And then send the Ctrl + V keys to paste the CLipboard data.
>>>
>>
>> The browser will only fire the "paste" event under very strict
>> circumstances. What you describe can work, but you will run into
>> difficulties with:
>>
>> * Differences among platforms between the keys pressed locally vs.
>> remotely for pasting clipboard data (not all platforms use Ctrl+V, and even
>> on platforms which typically use Ctrl+V, not all applications will do so)
>> * The need to allow some key events through to the browser so that
>> keyboard events blossom into actual clipboard events, yet still somehow
>> take control of those events to the extent that they can be sent to the
>> remote desktop unmodified if they do not actually deal with clipboard after
>> all.
>>
>> This was actually tried in the past, years ago, in much older releases of
>> Guacamole. The changes were ultimately removed because they proved too
>> unreliable and confusing for users. Users were confounded when Cmd+V on Mac
>> didn't work for paste connecting to Windows, or when pasting via Ctrl+V did
>> nothing when a remotely-running terminal emulator actually required
>> Ctrl+Shift+V for paste, or when attempting to paste through clicking with
>> the mouse did nothing.
>>
>> 4. On Copy event We are getting the data from the remote Clipboard and
>>> same we can send it the Local Clipboard using the Copy event to make both
>>> the local and remote clipboard synced.
>>>
>>
>> Similar to paste, this does not work well in practice. Besides the issues
>> with keyboard events described above, there are timing issues with
>> retrieval of clipboard data. There is no guarantee that the remote
>> clipboard data will be received locally within a reasonable time frame of
>> Ctrl+C being pressed. Because the clipboard can only be modified during the
>> "copy" event itself, something must block the main JavaScript thread while
>> clipboard data is being received. We did exactly this in older releases of
>> Guacamole, through using synchronous XMLHttpRequest to force the thread to
>> block while the server awaits clipboard data, but again ran into issues:
>>
>> * As with paste, the copy event will not occur during remote mouse
>> interaction.
>> * As with paste, platform and application differences in keyboard
>> shortcuts cannot be reliably handled or predicted.
>> * Synchronous XMLHttpRequest is deprecated and can no longer be relied
>> upon.
>>
>> 5. Main task is to sync the Local and remote Clipboard before copying and
>>> pasting data.
>>>
>>> *My Queries are as follows :- *
>>>
>>>
>>> 3. Can't we send plain data so that we don't have to decode or encode
>>> the data in Clipboard scenario as it can increase the performance ?
>>>
>>>
>>>
>> No. There is no such thing as "plain data". For communication between two
>> systems to make sense (between Guacamole client and server), there must be
>> an agreed upon encoding for data sent and received. Guacamole uses UTF-8
>> for transmitted text, and the processing required to transform JavaScript's
>> own Unicode strings into UTF-8 is very minimal.
>>
>> 4. Can't we make a ajax request to get the plain data which is sent by
>>> remote server { on copy event }. We can save the data in guacamole server
>>> when we receive data from remote server and on copy event fire an ajax
>>> request ).
>>>
>>
>> No (see above-described issues with copy). Being able to modify local
>> clipboard data within the copy event would require blocking the main
>> thread, which cannot be done reliably.
>>
>>
>>> I had already done few change in the JavaScript code to make it work. It
>>> is *working in Chrome* only. Microsoft Edge hangs and IE ( issues while
>>> updating the local clipboard ).
>>>
>>
>> I do not recommend making these changes. It is not possible to do what
>> you describe reliably.
>>
>> If anyone has any suggestions, Please share in this thread.
>>>
>>
>> From my perspective, the best path forward is to use the clipboard APIs
>> which are on the track for standardization and have already been adopted by
>> the mainstream browsers:
>>
>> https://www.w3.org/TR/clipboard-apis/
>>
>> Guacamole already does this. As implementation of these APIs improves,
>> behavior of the clipboard within Guacamole will also improve. Currently,
>> IE10 and IE11 will prompt the user to grant clipboard access when these
>> APIs are used. If other browsers follow suit, displaying permissions
>> prompts for clipboard access similar to the prompts already displayed for
>> audio/video input, etc., then there will be no need to attempt these
>> workarounds.
>>
>> Again, please beware that *we have tried all these clipboard-related
>> workarounds before*. Though they may seem inviting, they do not work well
>> in practice, and actually make the user experience more confusing.
>>
>> - Mike
>>
>>
>
