Proposal: Canvas Interaction Enhancements

[Arjen Hiemstra]

On Monday 14 May 2012 17:41:14 Przemyslaw Golab wrote:
> Great job! I agree with your statements, but I have something to add.
> 
> My notes:
> 1. Some interactions with canvas, especially rotation needs reset option.
>     I would see this in Modifier + Mouse way, maybe Shift + Right Mouse?

I would personally keep this to keyboard shortcuts and - in the case of 
rotation at least - maybe in the popup that can show up. For rotation, having 
it snap to certain angles is probably also something that would not be too 
hard to implement.

> 2. Zooming. I like a idea of using mouse + modifiers for zooming,
>     it's less distracting that moving my hand to some buttons.
>     The problem with zooming with digital painting is that user not always
>     need fine tune zooming. Constant steps for zooming are sometimes much
>     more useful because it helps eliminate zooming artefacts for
> antialiasting.
>     Also, working with fixed sizes of canvas like 100%, 50%, 25%, 13%
>     may be more comfortable for some Artists.
>     So there should be a way to use fine tune zooming or step zooming
>     with m+mouse, maybe as an option in preferences?

I have been thinking about this in context of the paint tools that draw shapes 
as well. My current line of thinking is that once you start an action all 
subsequent modifier key changes should be sent on to the tool currently 
performing the action. This would enable the shape tools to use shift for 
straight lines and other functions. It could also be used for zooming. Normal 
ctrl + drag does a smooth zoom, ctrl + drag and then add shift does a stepped 
zoom.

However, the danger of this is that the function of the modifier keys changes 
whether you are currently holding down another button or not. I am not sure if 
that is a good idea, hence I have left it out of the proposal for the moment.

> 3. What about Clone Brush?

It is covered by the three tool related actions: Tool Invocation paints, 
Alternate invocation sets the position of the duplicate spot and change 
primary setting changes the brush size.

> 4. Now, next important topic.
>     Should we consider Assistants as part of Canvas operations, interaction?
> It's a bit like a bunch of rulers and piece of paper. What I do with canvas
>     affects the painting process, the same rulers. Currently using
> Assistants
>     as Tools is not encouraging for users. I think making them part of the
>     Canvas interaction, like a Mode, will be more useful for users.
> 

Ah, good point. I entirely missed the assistants. Personally, I think these - 
as well as the mirror axis setup - will need some additional thought. The 
current work flow for them is not ideal, but I do not think that lumping 
everything under this universal actions proposal is a good idea. Especially 
since the default settings for at least KDE mean that you essentially lose two 
of four modifier keys. Alt + Click is generally unusable since it is the 
default combination for dragging a window. Meta is also fairly unusable since 
it has a very strong association with global shortcuts. Therefore we need to 
restrict our default shortcuts to only use Ctrl and Shift.

I think it is best to keep assistants working the same way for now and look at 
what is a good way to interact with them later. Adding universal actions 
should be fairly straightforward once this system is in place so I think it 
better to keep the scope of this part very limited.

- Arjen