migrations/egui
1
0
Fork 0
mirror of https://github.com/emilk/egui.git synced 2026-08-31 05:40:03 -04:00
Code Activity

Add rotation gesture support for trackpad sources (#7453)

Browse Source 
Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
Co-authored-by: Lucas Meurer <hi@lucasmerlin.me>
This commit is contained in:
Alan Everett
2025-09-11 06:44:17 -04:00
committed by GitHub
parent 802d307e4a
commit b0c568a78e
7 changed files with 174 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files

48
crates/egui_demo_lib/src/demo/multi_touch.rs
View File

@@ -1,5 +1,5 @@
use egui::{
Color32, Frame, Pos2, Rect, Sense, Stroke, Vec2,
Color32, Event, Frame, Pos2, Rect, Sense, Stroke, Vec2,
emath::{RectTransform, Rot2},
vec2,
};
@@ -30,7 +30,7 @@ impl crate::Demo for MultiTouch {
fn show(&mut self, ctx: &egui::Context, open: &mut bool) {
egui::Window::new(self.name())
.open(open)
.default_size(vec2(512.0, 512.0))
.default_size(vec2(544.0, 512.0))
.resizable(true)
.show(ctx, |ui| {
use crate::View as _;
@@ -45,13 +45,31 @@ impl crate::View for MultiTouch {
ui.add(crate::egui_github_link_file!());
});
ui.strong(
"This demo only works on devices with multitouch support (e.g. mobiles and tablets).",
"This demo only works on devices with multitouch support (e.g. mobiles, tablets, and trackpads).",
);
ui.separator();
ui.label("Try touch gestures Pinch/Stretch, Rotation, and Pressure with 2+ fingers.");
let relative_pointer_gesture = ui.input(|i| {
i.events.iter().any(|event| {
matches!(
event,
Event::MouseWheel { .. } | Event::Zoom { .. } | Event::Rotate { .. }
)
})
});
let num_touches = ui.input(|i| i.multi_touch().map_or(0, |mt| mt.num_touches));
ui.label(format!("Current touches: {num_touches}"));
let num_touches_str = format!("{num_touches}-finger touch");
ui.label(format!(
"Input source: {}",
if ui.input(|i| i.multi_touch().is_some()) {
num_touches_str.as_str()
} else if relative_pointer_gesture {
"cursor"
} else {
"none"
}
));
let color = if ui.visuals().dark_mode {
Color32::WHITE
@@ -83,18 +101,18 @@ impl crate::View for MultiTouch {
// check for touch input (or the lack thereof) and update zoom and scale factors, plus
// color and width:
let mut stroke_width = 1.;
if let Some(multi_touch) = ui.ctx().multi_touch() {
// This adjusts the current zoom factor and rotation angle according to the dynamic
// change (for the current frame) of the touch gesture:
self.zoom *= multi_touch.zoom_delta;
self.rotation += multi_touch.rotation_delta;
// the translation we get from `multi_touch` needs to be scaled down to the
// normalized coordinates we use as the basis for painting:
self.translation += to_screen.inverse().scale() * multi_touch.translation_delta;
// touch pressure will make the arrow thicker (not all touch devices support this):
stroke_width += 10. * multi_touch.force;
if ui.input(|i| i.multi_touch().is_some()) || relative_pointer_gesture {
ui.input(|input| {
// This adjusts the current zoom factor, rotation angle, and translation according
// to the dynamic change (for the current frame) of the touch gesture:
self.zoom *= input.zoom_delta();
self.rotation += input.rotation_delta();
self.translation += to_screen.inverse().scale() * input.translation_delta();
// touch pressure will make the arrow thicker (not all touch devices support this):
stroke_width += 10. * input.multi_touch().map_or(0.0, |touch| touch.force);
self.last_touch_time = ui.input(|i| i.time);
self.last_touch_time = input.time;
});
} else {
self.slowly_reset(ui);
}