2 fingers tap & move: distinguish between zoom and scrolling

[Hubert21]

Hello,
That would be great if there would be a way to distinguish, for the 2 finger tap, between a gesture where two fingers are spread apart (like for zooming) and a gesture where two fingers are moved together without changing the distance between them (like for scrolling the screen)
Thanks,

• I have checked that a similar feature request does not already exist.

Is your feature request related to a problem? Please describe.
Some software like Krita requieres zoom and scrolling, and to distinguish them (otherwise it randomly do both of them)

Describe the solution you'd like
a set of keys (like ctrl, ctrl+alt, or a letter if necessary) to distinguish them

Describe alternatives you've considered
N/A

[rom1v]

Scrcpy injects finger touch events to the device, how it reacts is handled by Android.

[Hubert21]

thanks for you answer ; maybe if there was a way to inject positions of the the fingers movement so that the distance between them does not change ;
if it might help, this project seams to handle multi-touch https://github.com/openstf/minitouch

[rom1v]

Btw, did you read https://github.com/Genymobile/scrcpy/blob/master/doc/control.md#pinch-to-zoom-rotate-and-tilt-simulation ?

[Hubert21]

Thanks for the link. Indeed I do use the ctrl+click feature. Actually as with ctrl we do have the zoom/rotate, I think what is missing for me is the 2 fingers swipe

[rom1v]

I think what is missing for me is the 2 fingers swipe

Vertically or horizontally?

Vertically, you can use Shift+click.

[Hubert21]

Thanks for pointing that out, I did not really understand that "tilt" was équivalent to a vertical 2 fingers swipe ; However on my device (samsung s10 and scrcpy 1.12.1+ds-1 on ubuntu) Shift+click does not seam to do anything.
As a side note, even if I have the version 1.12.1+ds-1 installed, scrcpy -v tells me it's version 1.24 (which introduced the tilt feature)

sudo apt install --only-upgrade scrcpy
=> scrcpy is already the newest version (1.12.1+ds-1).

scrcpy -v
=> scrcpy 1.24 https://github.com/Genymobile/scrcpy

Dependencies (compiled / linked):

• SDL: 2.0.10 / 2.0.10
• libavcodec: 58.54.100 / 58.54.100
• libavformat: 58.29.100 / 58.29.100
• libavutil: 56.31.100 / 56.31.100
• libavdevice: 58.8.100 / 58.8.100
• libusb: - / 1.0.23

[rom1v]

You probably installed several versions in different ways.

Don't use the package from your Debian/Ubuntu distribution, they are completely obsolete/outdated.

Uninstall it and install the latest version (currently 2.7):
https://github.com/Genymobile/scrcpy/blob/master/doc/linux.md#latest-version

[Hubert21]

Thanks! shift+click now works.
My request is now limited to adding a horizontal tilt/scroll in addition to the vertical one with the Shift key.
I succeeded doing so with the ctrl+alt combination (alt alone + click is used by ubuntu to move the window):
bool alt_pressed = keymod & KMOD_ALT;
...
im->vfinger_invert_x = ( ctrl_pressed && !alt_pressed ) || shift_pressed;
im->vfinger_invert_y = ctrl_pressed || alt_pressed;

I also tried several other methods that didn't work:

1. with the meta key
   bool gui_pressed = keymod & KMOD_GUI;
   ...
   im->vfinger_invert_x = ctrl_pressed || shift_pressed;
   im->vfinger_invert_y = ctrl_pressed || gui_pressed;

2. with ctrl+shift
   im->vfinger_invert_x = (ctrl_pressed && !shift_pressed) || ( !ctrl_pressed && shift_pressed );
   im->vfinger_invert_y = ctrl_pressed;

[rom1v]

My request is now limited to adding a horizontal tilt/scroll in addition to the vertical one with the Shift key.

#4529 (comment)

[Hubert21]

Thanks to your help and my hack, this is done!
If ctrl+alt+click is not planned to be used anywhere else, maybe my changes could be commited

[rom1v]

What is your concrete use case for horizontal "sliding"?

[Hubert21]

I am using a drawing app on my phone (Krita or Simple Draw), for making schemas, take notes, grow ideas.
For all apps the phone is easier to use with scrcpy especially when using the computer for other things at the same time. It's easier for these drawing apps also.

[rom1v]

To add Ctrl+Shift for horizontal tilt, I think this is sufficient:

diff --git a/app/src/input_manager.c b/app/src/input_manager.c
index 3c7022b0f..879a9df3a 100644
--- a/app/src/input_manager.c
+++ b/app/src/input_manager.c
@@ -794,7 +794,7 @@ sc_input_manager_process_mouse_button(struct sc_input_manager *im,
     }
 
     bool change_vfinger = event->button == SDL_BUTTON_LEFT &&
-            ((down && !im->vfinger_down && (ctrl_pressed ^ shift_pressed)) ||
+            ((down && !im->vfinger_down && (ctrl_pressed || shift_pressed)) ||
              (!down && im->vfinger_down));
     bool use_finger = im->vfinger_down || change_vfinger;
 
@@ -835,7 +835,7 @@ sc_input_manager_process_mouse_button(struct sc_input_manager *im,
             sc_screen_convert_window_to_frame_coords(im->screen, event->x,
                                                                  event->y);
         if (down) {
-            im->vfinger_invert_x = ctrl_pressed || shift_pressed;
+            im->vfinger_invert_x = ctrl_pressed ^ shift_pressed;
             im->vfinger_invert_y = ctrl_pressed;
         }
         struct sc_point vfinger = inverse_point(mouse, im->screen->frame_size,

Could you confirm, please?

[rom1v]

Please review/test 7a9ea5c.

[Hubert21]

That works perfectly, thanks :)

[rom1v]

Merged into dev 🚀

[unique-EJ]

Merged into dev 🚀

@rom1v @Hubert21 👋 why is this in dev branch and not the master?
Please bring that over, with Ctrl+Shift for horizontal tilt referred to in the file /doc/shortcuts.md

... and sometimes vertical tilt does zoom, why is that? 🤔

[rom1v]

👋 why is this in dev branch and not the master?

Because it has been merged after the latest release. It will be in the next one:
https://github.com/Genymobile/scrcpy/blob/master/doc/build.md#branches

[unique-EJ]

@rom1v how is tilt not 2 finger (laptop) touchpad scroll?
and I am using scrcpy (2.7) now! 🙂 Android 14 through my laptop.

[rom1v]

how is tilt not 2 finger (laptop) touchpad scroll?

Scrcpy sends 2 fingers at the specified location to Android. The Android system reacts as it wants.