Fwd: future development idea: presentation mode

Marek Sterzik marek.sterzik at gmail.com
Tue Apr 28 23:40:38 UTC 2015


I have an idea what could be implemented in Ubuntu to have a much more
better experience in presenting things with a computer.

The current situation is quite horrible I think. Not only in Ubuntu, but in
all (known to me) operating systems. There is a quite sophisticated support
for dual screen mode these times, when one is *working* on both screens. I
will call this dual screen mode as "working mode".

But in fact, very few (in terms of percentage) people are using two screens
in "working mode". Maybe developers use the "working mode" a bit more than
ordinary users, but not much. Much more people are using the second screen
for presenting. By presenting I meen everything when one wants to share
something with a group of other people. It means beamer presentations,
movie watching or anything else. When one is using the second screen for
presentations, I will call it as "presentation mode".

The biggest mistake in the current operating systems behavior is the
assumption that dualscreen working mode is equal to presentation mode. I
think, that for a good presenting experience, it is completely necessary to
distinguish between these two modes in the OS. There are some crucial

* Typically, the presenter cannot look simultaneously on both screens. The
"working screen" is more accessible for the presenter. Therefore it gives
no sense to have any controls on the "presenting screen". It gives even no
sense to have normal windows on the presenting screen. For example, I
really *don't like* the situation, when I plug the display cable into my
laptop and compiz will move one half of the opened windows to the
presenting screen. I have to chase them on a screen which I almost don't
see and move them back. Arggghhhh!:-) Yes, maybe it is configurable
somewhere, but I think nobody wants his windows to move from a working
screen to a presentation screen. Therefore it should be automatic. (but of
course, if my second screen would be a working one, than I would like
moving half of the windows to the second screen)
* The presenter wants to have a full control what should be visible on the
presentation screen. In the "working mode", it is absolutely not possible.
When I want to present the content of some window, I have to drag it, move
on the presentation screen and then fullscreen the window. When I am
watching a presentation, I can say, that such a moving of the windows is
really ugly.
* There is no geometric relation between the presentation screen and the
primary working screen. It is not above, it is not below, it is not left of
and it is not right of the primary screen. This typicaly confuses the
presenter when trying to do something with the mouse pointer.

Therefore, I am looking for some implementation of the "presentation mode".
I also think, that I am not alone. Presentation mode would be much more
frequently used than working mode. I have also an idea, how the
presentation mode should work:

* There should be a possibility to setup if the secondary screen should be
a presentation screen or working screen. When I plug a screen into my
computer, it will become a presentation or working screen depending on this
setting. Laptop default would be presentation screen, desktop default would
be working screen.
* When a screen becomes a working screen, it will have the same behavior as
in the current dualscreen implementation.
* When a screen becomes a presentation screen, it will have a completely
different behavior: Nothing will appear on the screen, no controls, no
icons, just black. Alternatively, somebody could set the background of the
screen. But I think, there should be no relation between the background of
the working screen and the background of the presentation screen.
* Crossing one and only one edge of the working screen with the mouse
pointer to reach the presentation screen is not a good idea. As I already
wrote, there is no geometrical relation between the working (main) screen
and the presenting screen.
* All windows are appearing only on the working screen, the presentation
screen is still completely empty.
* But every window gets a new power. It may be switched in a presentation
mode. Only one window at a time may be in presentation mode. Therefore,
switching window B to presentation mode should disable the presentatnion
mode of window A. I was thinking about to add a fourth button in the window
to the three: close, maximize, minimize. But there are even other
* There could be even a possibility to switch the whole desktop in the
presenting mode. Then it could act like the mirroring mode.
* When an window is in presentation mode, it should *not* disappear from
the working screen. It should be replicated pixel by pixel to the
presentation screen instead. On the presentation screen it should appear
just centered and without decoration.
* There should be also a possiblility how an application could tell the OS,
that the content displayed on the presentation screen is different from
that one displayed on the working screen.
* An application has then these two possibilities: 1. it supports
presentation mode - then it is able to render anything in the presentation
window 2. it does not support presentation mode - then the OS will
replicate the content of the window pixel by pixel.
* The support for presenting mode should be also available when only one
screen is available (for example PC connected to a data projector). Then it
should act a bit differently, but consistent with the previous dualscreen

I know, that developing such a functionality would not be easy at all, but
could be really interesting. What do you think about such an idea?

Best regards

Marek Sterzik
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