Fix vertical slider up/down keys and add a line in the changelog

Follow-up to https://github.com/emilk/egui/pull/875

CHANGELOG.md

@@ -13,6 +13,7 @@ NOTE: [`epaint`](epaint/CHANGELOG.md), [`eframe`](eframe/CHANGELOG.md), [`egui_w
 * Most widgets containing text (`Label`, `Button` etc) now supports rich text ([#855](https://github.com/emilk/egui/pull/855)).
 * When using a custom font you can now specify a font index ([#873](https://github.com/emilk/egui/pull/873)).
 * You can now read the plot coordinates of the mouse when building a `Plot` ([#766](https://github.com/emilk/egui/pull/766)).
+* Add vertical sliders with `Slider::new(…).vertical()` ([#875](https://github.com/emilk/egui/pull/875)).
 
 ### Changed 🔧
 * Unifiy the four `Memory` data buckets (`data`, `data_temp`, `id_data` and `id_data_temp`) into a single `Memory::data`, with a new interface ([#836](https://github.com/emilk/egui/pull/836)).
@@ -31,11 +32,12 @@ NOTE: [`epaint`](epaint/CHANGELOG.md), [`eframe`](eframe/CHANGELOG.md), [`egui_w
 * Removed `egui::paint` (use `egui::epaint` instead).
 
 ### Contributors 🙏
+* [5225225](https://github.com/5225225): ([#849](https://github.com/emilk/egui/pull/849)).
+* [B-Reif](https://github.com/B-Reif) ([#875](https://github.com/emilk/egui/pull/875)).
+* [EmbersArc](https://github.com/EmbersArc): ([#766](https://github.com/emilk/egui/pull/766)).
 * [mankinskin](https://github.com/mankinskin) ([#543](https://github.com/emilk/egui/pull/543))
 * [sumibi-yakitori](https://github.com/sumibi-yakitori) ([#830](https://github.com/emilk/egui/pull/830))
-* [5225225](https://github.com/5225225): ([#849](https://github.com/emilk/egui/pull/849)).
 * [t18b219k](https://github.com/t18b219k): ([#868](https://github.com/emilk/egui/pull/868)).
-* [EmbersArc](https://github.com/EmbersArc): ([#766](https://github.com/emilk/egui/pull/766)).
 
 
 ## 0.15.0 - 2021-10-24 - Syntax highlighting and hscroll

egui/src/widgets/slider.rs

@@ -315,8 +315,15 @@ impl<'a> Slider<'a> {
         response.widget_info(|| WidgetInfo::slider(value, &self.text));
 
         if response.has_focus() {
-            let increment = ui.input().num_presses(self.key_increment());
+            let (dec_key, inc_key) = match self.orientation {
-            let decrement = ui.input().num_presses(self.key_decrement());
+                SliderOrientation::Horizontal => (Key::ArrowLeft, Key::ArrowRight),
+                // Note that this is for moving the slider position,
+                // so up = decrement y coordinate:
+                SliderOrientation::Vertical => (Key::ArrowUp, Key::ArrowDown),
+            };
+
+            let decrement = ui.input().num_presses(dec_key);
+            let increment = ui.input().num_presses(inc_key);
             let kb_step = increment as f32 - decrement as f32;
 
             if kb_step != 0.0 {
@@ -394,20 +401,6 @@ impl<'a> Slider<'a> {
         }
     }
 
-    fn key_increment(&self) -> Key {
-        match self.orientation {
-            SliderOrientation::Horizontal => Key::ArrowRight,
-            SliderOrientation::Vertical => Key::ArrowUp,
-        }
-    }
-
-    fn key_decrement(&self) -> Key {
-        match self.orientation {
-            SliderOrientation::Horizontal => Key::ArrowLeft,
-            SliderOrientation::Vertical => Key::ArrowDown,
-        }
-    }
-
     fn rail_rect(&self, rect: &Rect, radius: f32) -> Rect {
         match self.orientation {
             SliderOrientation::Horizontal => Rect::from_min_max(

egui_demo_lib/src/apps/demo/sliders.rs

@@ -132,13 +132,15 @@ impl super::View for Sliders {
             ui.label("Slider type:");
             ui.radio_value(integer, true, "i32");
             ui.radio_value(integer, false, "f64");
-        });
+        })
+        .response
+        .on_hover_text("All numeric types (f32, usize, …) are supported.");
+
         ui.horizontal(|ui| {
             ui.label("Slider orientation:");
             ui.radio_value(vertical, false, "Horizontal");
             ui.radio_value(vertical, true, "Vertical");
         });
-        ui.label("(f32, usize etc are also possible)");
         ui.add_space(8.0);
 
         ui.checkbox(logarithmic, "Logarithmic");