fix: default to changing y axis when changing data aspect

[saecki]

Closes #2077.

@cessen @DusterTheFirst Can you guys check if I broke anything in this PR?

[saecki]

Ok so that definitely broke something

[saecki]

This feels a little bit inconsistent, but I've found it to actually work quite well, though other suggestions are welcome.
If auto_bounds is active, changing the data_aspect works as before.
If auto_bounds is inactive, changing the data_aspect only changes the y-axis.

Screencast.from.2022-09-26.17.59.43.webm

[emilk]

There are now merge conflicts with #2029, but it should be pretty trivial to fix if you merge in master and apply:

index a517db1e..86faad9a 100644
--- a/crates/egui/src/widgets/plot/mod.rs
+++ b/crates/egui/src/widgets/plot/mod.rs
@@ -79,6 +79,13 @@ struct AxisBools {
     y: bool,
 }
 
+impl AxisBools {
+    #[inline]
+    pub fn any(&self) -> bool {
+        self.x || self.y
+    }
+}
+
 impl From<bool> for AxisBools {
     fn from(val: bool) -> Self {
         AxisBools { x: val, y: val }

[saecki]

Rebased onto master and applied the patch

[emilk]

thanks!

[Zoxc]

Note that the auto_bounds variable is something entirely different after #2029 and it doesn't seem to make sense with the use in this PR.