Progress bar

[EmbersArc]

Closes #496.

simplescreenrecorder-2021-06-26_22.56.43.mp4

[parasyte]

The animation looks awesome! I think I like it a little better with the selection background and text colors. What do you think?

The diff is:

diff --git a/egui_demo_lib/src/apps/demo/progress_bar.rs b/egui_demo_lib/src/apps/demo/progress_bar.rs
index f0cb976..f37120f 100644
--- a/egui_demo_lib/src/apps/demo/progress_bar.rs
+++ b/egui_demo_lib/src/apps/demo/progress_bar.rs
@@ -72,11 +72,7 @@ impl Widget for ProgressBar {
             ),
         );
 
-        let (dark, bright) = if visuals.dark_mode {
-            (0.2, 0.3)
-        } else {
-            (0.8, 0.9)
-        };
+        let (dark, bright) = (0.8, 1.0);
         let color_factor = if animate {
             ui.ctx().request_repaint();
             lerp(dark..=bright, ui.input().time.cos().abs())
@@ -87,7 +83,7 @@ impl Widget for ProgressBar {
         ui.painter().rect(
             inner_rect,
             corner_radius,
-            Color32::from_gray((color_factor * 255.0) as u8),
+            Color32::from(Rgba::from(visuals.selection.bg_fill) * color_factor as f32),
             Stroke::none(),
         );
 
@@ -119,7 +115,9 @@ impl Widget for ProgressBar {
                 Align2::LEFT_CENTER,
                 text,
                 TextStyle::Button,
-                visuals.text_color(),
+                visuals
+                    .override_text_color
+                    .unwrap_or(visuals.selection.stroke.color),
             );
         }
 

Also, shouldn't the widget be included in egui::widgets and not just the demo lib?

[EmbersArc]

@parasyte Much better! I applied the suggestions.

[emilk]

This looks really good!

[emilk]

It is an interesting question what the default should be here.

It wastes some CPU in reactive mode using eframe, but basically anywhere else it is nice with an animation.

In the future we may want to have a global egui option for "do you want animations or not?", but for now... either false or true work for me to be honest.

[EmbersArc]

The animation now plays on hover, I'll leave it up to you to decide whether it should be animated by default.

[emilk]

This can easily overflow the size of the progress bar, which would look pretty ugly.

I think we either should either:

• measure the text (https://docs.rs/egui/0.13.0/egui/struct.Painter.html#method.layout_no_wrap) and use it as a minimum width of the widget
• clip the text (https://docs.rs/egui/0.13.0/egui/struct.Painter.html#method.sub_region)

[EmbersArc]

Good point, the text now gets clipped in 1d0d86f.

[emilk]

This seems like something so common that we should have a helper for it, e.g. .show_percentage()

[EmbersArc]

Added in 1d0d86f

[emilk]

Wonderful - thank you!