Added option to disable ctrl+mousewheel zoom

[filipkilibarda]

Addressing the longstanding Ctrl+scroll zoom in/out issue, as expressed in these old requests

• https://bugs.launchpad.net/terminator/+bug/1505292
• https://bugs.launchpad.net/terminator/+bug/1638607

What problem does this PR solve?

Some laptop users (including myself) often bump the trackpad while holding Ctrl, which results in the terminal drastically zooming in and out (it's super sensitive).

The usual fix to get around this was to press Ctrl+0 to reset the zoom everytime it happened, but this often fails to restore the original symmetry among split windows in apps like vim and tmux.

Needless to say, it's also annoying having to reset zoom scale so often.

What this PR does

• Adds a checkbox to the Profiles > General section of terminator preferences
• If checked, don't run the Ctrl+mousewheel signal handler that's responsible for zooming the terminal in and out
• keyboard bindings for zooming still work

---

Thanks for taking over maintenance :) Cool to see this project active again!

[mckellyln]

@JakubVanek hi
I cannot seem to get Alt + scrollwheel to work in this terminator.
I just wanted to ask would that be in this same area of the code ?
thx,
-m

[JakubVanek]

Hi @mckellyln,

yup, the following patch prints ALT SCROLL for me:

diff --git a/terminatorlib/terminal.py b/terminatorlib/terminal.py
index 64a14bdd..0dd36570 100644
--- a/terminatorlib/terminal.py
+++ b/terminatorlib/terminal.py
@@ -1006,6 +1006,8 @@ class Terminal(Gtk.VBox):
             elif event.direction == Gdk.ScrollDirection.DOWN or SMOOTH_SCROLL_DOWN:
                 self.scroll_by_page(1)
                 return (True)
+        if event.state & Gdk.ModifierType.MOD1_MASK == Gdk.ModifierType.MOD1_MASK:
+            print("ALT SCROLL")
         return(False)
 
     def popup_menu(self, widget, event=None):

There is no ALT_MASK, but according to https://valadoc.org/gdk-3.0/Gdk.ModifierType.html the corresponding mask is mainly MOD1_MASK.

Best regards,
Jakub

[mckellyln]

Thanks. I do not get that. Something in my setup is affecting alt + wheel in my terminator.
Other apps work fine so its not the OS. I'll keep digging.
I really appreciate everyone's help on the great Terminator!

[JakubVanek]

I cannot scroll in terminator either if I have Alt pressed, so the issue is not only on your machine. However I suspect that this may not be a change in Terminator, but rather in GNOME VTE - that is a widget that effectively does the terminal emulation. It could be worked around in terminator, but some nice-to-have features might be lost for alt-scrolling that way (like smooth scrolling on a touchpad) (this is only a pure speculation though).

[mckellyln]

ok, thanks for that good info.
I will research if I can somehow re-configure my gnome/vte to allow mod1 + wheel ?
If not, then using ctrl + wheel (with these changes) for my previous alt might be a good substitute.
-m

[JakubVanek]

Works for me locally, thank you very much!

[JakubVanek]

Curiously, with zoom disabled, scrolling with Ctrl pressed seems to work fine. There seems to be something special about the Alt key.

[filipkilibarda]

Here's an ugly patch that makes it so you can scroll while holding Alt. Not sure if this is what @mckellyln meant

diff --git a/terminatorlib/terminal.py b/terminatorlib/terminal.py
index e8212197..1a67f32c 100644
--- a/terminatorlib/terminal.py
+++ b/terminatorlib/terminal.py
@@ -1001,6 +1001,8 @@ class Terminal(Gtk.VBox):
             elif event.direction == Gdk.ScrollDirection.DOWN or SMOOTH_SCROLL_DOWN:
                 self.scroll_by_page(1)
                 return (True)
+        if event.state & Gdk.ModifierType.MOD1_MASK == Gdk.ModifierType.MOD1_MASK:
+            event.state ^= Gdk.ModifierType.MOD1_MASK
         return(False)

     def popup_menu(self, widget, event=None):

There's some signal handler in the chain (not in terminator - maybe libgtk?) that aborts or ignores scrolling when Alt is pressed, so quick hack is to just turn off Alt in our signal handler, which comes first in the chain.

[mckellyln]

Thanks! I will test. What I did before is scroll 4x more with Alt+wheel then just with wheel.
So in vi or tmux or whatever I can tell alt mod is pressed while wheel is moved.
I have PgUp/Dn set up the same way ...
Perhaps its not standard but it would be awesome if there was some way to configure it on.

Update: ok, I see that you removed the alt - so scroll works but we don't know alt was pressed.
makes sense, it is better than not scrolling at all!

I really appreciate your effort on this, thank you,
-m

[filipkilibarda]

Update: ok, I see that you removed the alt - so scroll works but we don't know alt was pressed.
makes sense, it is better than not scrolling at all!

Yeah I think we would want a better solution to make this configurable. Just killing the Alt modifier seems too invasive.

Any further research would require digging through libgtk or libvte to see why Alt is handled differently.

Glad it works better though

[mattrose]

I'll take a look at this in the next few days.

[mattrose]

Found this related thing while scrolling through VTE issues:

https://gitlab.gnome.org/GNOME/vte/-/issues/241

[mattrose]

I left some feedback on the related vte bug mentioned above based on comments here and in the issue that @mckellyln raised.