Hi VDG,

yesterday I finally integrated touch support into kwin_wayland and that made me aware of a need: global touch gestures like "swipe from left to open present windows" or "swipe window to the top to close".

I would like that you brainstorm which actions we want to be triggered by global gestures (global means applying to the workspace, e.g. pinch to zoom in an application is not a global gesture) and how these gestures should look like. There is no time pressure, it's at least three more months till kwin_wayland becomes somewhat useable

Let's have a look what other platforms do:
For instance on Windows 8, which sucks for Desktops but is pretty intuitive on a touch device, you have the following "Edge swipe" gestures:
- Swipe in from the left side of the screen lets you drag in the recentmost used application. Swiping in and back out yields the application switcher.
- Swipe in from the right side of the screen yields the "Charms menu", a sidebar with five actions (Search, Share, Home, Device, Settings).
- Swipe in from the top lets you drag the current application window to "quick tile" them left or right, or close them when pulling it to the bottom of the screen
- Swipe in from the bottom yields a toolbar with contextual actions, such as Sort, Filter, etc

On an iPad you can do the following global touch gestures:
- A four finger swipe to the left or right allows you to switch between applications
- A four finger pinch brings you to the multitasking overview, or all the way back to the home screen

I think allowing to drag in the tabbox or Activity Manager from the left side of the screen makes a lot of sense. The other actions are quite touch device centric, however. From the right side we could maybe have a notification center, or settings menu. But at the moment we don't have any sidebars on the right side. Switching between applications using gestures is more suitable when all windows are fullscreened but could perhaps be used to switch between Activities or virtual desktops.

Here are my ideas for the possible collection of gestures:

• Edge swipes
  
  • Swipe from top - Search (Krunner or some such)
  • Swipe from left - Show (Alt-Tab) window list
  • Swipe from right - Maybe desktop toolbox (at that location) or similar system-level actions OR Slide/rotate to next desktop
  • Swipe from bottom - ?
• Normal (within screen boundary) single finger swipes - All reserved for applications
• Normal (within screen boundary) multiple finger swipes
  
  • Two finger swipes - Reserved for applications
  • Three finger swipes
    
    • Up - Maximize window
    • Down - Restore window from maximized state, Minimize window from normal state
  • Four finger swipes - Switch desktop
• Tap and hold
  
  • Single finger tap and hold - Probably reserved for applicatons
  • Two finger tap and hold - ?
  • Three finger tap and hold - Window resizing mode
  • Four finger tap and hold - ?
• Pinch
  
  • Two finger pinch - Reserved for applications
  • Three finger pinch - Present Windows
  • Four finger pinch - Desktop Grid

On a Mac double-tap on the mouse is zoom in for content, two finger swipe right or left is changing from virtual desktop. Two fingers swipe up and down is scrolling.

Just a thought,

Is it worth considering laptops (& desktops) that have touchpads too?

As far as i'm aware, if a touch pad acts as a mouse (so it behaves in 'relative' mode rather than like i've got my wacom setup in 'absolute' mode), then you wouldn't be able to swipe in from the screen edges without mousing over to those screen edges in the first place which defeats the ease of control that the gestures give.

We could either:
1 - Just accept that the gestures that involve dragging in from the touch screen edges won't be accessible on a touch pad which seems a shame.
2 - When you're using a touch pad instead of a touch screen the behaviour changes to detect swipes in from the edge of the touchpad not the edge of the screen.
3 - Try and have none of the gestures relying on screen edges - but then we end up having lots of very similar gestures like 'swipe down with 2 fingers to do Search', 'swipe down with 3 fingers to do ??' etc... which isn't great.

I would vote for option 2 if its possible - you'd still get all the convenience of the full range of gestures if you've got a touchpad not a touch screen.

One thing I'm desperately missing is the ability to access the context menu which should be accessible through eg. long-press. However, that's more of an application/Qt issue. Or perhaps longpress could simulate right click but that might break other things again.

kbroulik wrote:One thing I'm desperately missing is the ability to access the context menu which should be accessible through eg. long-press. However, that's more of an application/Qt issue. Or perhaps longpress could simulate right click but that might break other things again.

We can emulate it, though I'm not sure whether we should. Sounds to me like should be something done in the application.

Hey Martin,

Question. Are you thinking that maybe there are some actions on the desktop that are very useful but that do not currently have a gesture for them? I am thinking that not only can we follow other platforms but that we could also invent some good ones.

anditosan wrote:Question. Are you thinking that maybe there are some actions on the desktop that are very useful but that do not currently have a gesture for them? I am thinking that not only can we follow other platforms but that we could also invent some good ones.

Of course we can also invent some. If you have ideas just post them. Personally I don't want to influence the discussion with own ideas.

anditosan wrote:Question. Are you thinking that maybe there are some actions on the desktop that are very useful but that do not currently have a gesture for them? I am thinking that not only can we follow other platforms but that we could also invent some good ones.

Activities.

What about long press on the desktop brings up a menu or window of your choice? Or maybe just KRunner by default.

Waaaaitaminute.

Before we continue brainstorming wildly, we should clarify a few things.

1. There are two kinds of devices with multitouch gesture support: Touchpads and touchscreens. The amount of gestures that equally make sense for both is pretty much zero.
So, which ones are we talking about here?

2. If we're talking about touchpads, I'd say let the ideas fly, the more (useful!) gestures, the better, as long as a gesture is never ever the only way to do something.

3. If we're talking about touchscreen support in Plasma Desktop, we should really limit the touch features. We do not want a Windows 8. For touch-based devices, we have Plasma Active. Yes, many laptops and desktops now have touchscreens as well, but their primary input method is still mouse/touchpad while in "laptop mode" (and we'd switch to Plasma Active in "tablet mode"). Therefore we must make sure that a touch feature is never to the detriment of mouse/keyboad input on Plasma Desktop.

Sooo then...

How exactly is Kwin different between Plasma Desktop and Plasma Active? Except for its existence, I don't know anything about Plasma Active.

@colomar: of course we are talking about touch screens and yes I am especially thinking about hybrid systems. I have seen people using them, so why not use the features you get from the additional device? Why limit people to keyboard and mouse while we could give them better support?

mgraesslin wrote:@colomar: of course we are talking about touch screens and yes I am especially thinking about hybrid systems. I have seen people using them, so why not use the features you get from the additional device? Why limit people to keyboard and mouse while we could give them better support?

I'm not against introducing touch gestures for Plasma Desktop, not at all. I just said that we have to be careful that Plasma Desktop continues to work optimally with mouse + keyboard as primary input - which is where Windows 8 utterly failed.