From 4753d656e7af7d586236f6913864b156ce12ded4 Mon Sep 17 00:00:00 2001
From: Lucas Kent <rubickent@gmail.com>
Date: Sun, 20 Mar 2022 19:11:38 +1100
Subject: [PATCH] Add Plot::allow_scroll

---
 CHANGELOG.md                                |  1 +
 egui/src/widgets/plot/mod.rs                | 16 +++++++++++++---
 egui_demo_lib/src/apps/demo/context_menu.rs |  4 ++++
 3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6678da2cb1b5..01c51ff87d9b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,7 @@ NOTE: [`epaint`](epaint/CHANGELOG.md), [`eframe`](eframe/CHANGELOG.md), [`egui_w
 ## Unreleased
 
 ### Added ⭐
+* Added `Plot::allow_scroll`, `Plot::allow_zoom` no longer affects scrolling ([#1382](https://github.com/emilk/egui/pull/1382)).
 * Added `Shape::Callback` for backend-specific painting ([#1351](https://github.com/emilk/egui/pull/1351)).
 * Added `Frame::canvas` ([#1362](https://github.com/emilk/egui/pull/1362)).
 * `Context::request_repaint` will wake up UI thread, if integrations has called `Context::set_request_repaint_callback` ([#1366](https://github.com/emilk/egui/pull/1366)).
diff --git a/egui/src/widgets/plot/mod.rs b/egui/src/widgets/plot/mod.rs
index 3885fc1178cb..bcc5527182d0 100644
--- a/egui/src/widgets/plot/mod.rs
+++ b/egui/src/widgets/plot/mod.rs
@@ -164,6 +164,7 @@ pub struct Plot {
     center_y_axis: bool,
     allow_zoom: bool,
     allow_drag: bool,
+    allow_scroll: bool,
     min_auto_bounds: PlotBounds,
     margin_fraction: Vec2,
     allow_boxed_zoom: bool,
@@ -196,6 +197,7 @@ impl Plot {
             center_y_axis: false,
             allow_zoom: true,
             allow_drag: true,
+            allow_scroll: true,
             min_auto_bounds: PlotBounds::NOTHING,
             margin_fraction: Vec2::splat(0.05),
             allow_boxed_zoom: true,
@@ -287,6 +289,12 @@ impl Plot {
         self
     }
 
+    /// Whether to allow scrolling in the plot. Default: `true`.
+    pub fn allow_scroll(mut self, on: bool) -> Self {
+        self.allow_scroll = on;
+        self
+    }
+
     /// Set the side margin as a fraction of the plot size.
     ///
     /// For instance, a value of `0.1` will add 10% space on both sides.
@@ -434,6 +442,7 @@ impl Plot {
             center_x_axis,
             center_y_axis,
             allow_zoom,
+            allow_scroll,
             allow_drag,
             allow_boxed_zoom,
             boxed_zoom_pointer_button: boxed_zoom_pointer,
@@ -660,8 +669,8 @@ impl Plot {
             }
         }
 
-        if allow_zoom {
-            if let Some(hover_pos) = response.hover_pos() {
+        if let Some(hover_pos) = response.hover_pos() {
+            if allow_zoom {
                 let zoom_factor = if data_aspect.is_some() {
                     Vec2::splat(ui.input().zoom_delta())
                 } else {
@@ -671,7 +680,8 @@ impl Plot {
                     transform.zoom(zoom_factor, hover_pos);
                     auto_bounds = false;
                 }
-
+            }
+            if allow_scroll {
                 let scroll_delta = ui.input().scroll_delta;
                 if scroll_delta != Vec2::ZERO {
                     transform.translate_bounds(-scroll_delta);
diff --git a/egui_demo_lib/src/apps/demo/context_menu.rs b/egui_demo_lib/src/apps/demo/context_menu.rs
index 4476c1ec021b..9bd6f2dd0869 100644
--- a/egui_demo_lib/src/apps/demo/context_menu.rs
+++ b/egui_demo_lib/src/apps/demo/context_menu.rs
@@ -21,6 +21,7 @@ pub struct ContextMenus {
     show_axes: [bool; 2],
     allow_drag: bool,
     allow_zoom: bool,
+    allow_scroll: bool,
     center_x_axis: bool,
     center_y_axis: bool,
     width: f32,
@@ -34,6 +35,7 @@ impl Default for ContextMenus {
             show_axes: [true, true],
             allow_drag: true,
             allow_zoom: true,
+            allow_scroll: true,
             center_x_axis: false,
             center_y_axis: false,
             width: 400.0,
@@ -99,6 +101,7 @@ impl super::View for ContextMenus {
                     ui.end_row();
                     if ui.checkbox(&mut self.allow_drag, "Drag").changed()
                         || ui.checkbox(&mut self.allow_zoom, "Zoom").changed()
+                        || ui.checkbox(&mut self.allow_scroll, "Scroll").changed()
                     {
                         ui.close_menu();
                     }
@@ -128,6 +131,7 @@ impl ContextMenus {
             .show_axes(self.show_axes)
             .allow_drag(self.allow_drag)
             .allow_zoom(self.allow_zoom)
+            .allow_scroll(self.allow_scroll)
             .center_x_axis(self.center_x_axis)
             .center_x_axis(self.center_y_axis)
             .width(self.width)