ui: screens: iobus/power: make the button legend responsive to output status

For these two screens it is rather easy to make the legend dynamic.
For other screens it is a bit more complicated, so only do these two first.

Signed-off-by: Leonard Göhrs <[email protected]>

Author: hnez

src/ui/screens/iobus.rs

@@ -56,7 +56,6 @@ impl ActivatableScreen for IoBusScreen {
 
         display.with_lock(|target| {
             draw_border(target, "IOBus", SCREEN_TYPE);
-            draw_button_legend(target, "Toggle", "Screen");
 
             Text::new("CAN Status:", row_anchor(0), ui_text_style)
                 .draw(target)
@@ -134,6 +133,21 @@ impl ActivatableScreen for IoBusScreen {
             )
         });
 
+        widgets.push(|display| {
+            DynamicWidget::button_legend(
+                ui.res.regulators.iobus_pwr_en.clone(),
+                display,
+                |state: &bool| {
+                    let lower = match *state {
+                        false => "Turn On",
+                        true => "Turn Off",
+                    };
+
+                    (lower.into(), "Screen".into())
+                },
+            )
+        });
+
         let iobus_pwr_en = ui.res.regulators.iobus_pwr_en.clone();
 
         let active = Active {

src/ui/screens/power.rs

@@ -56,10 +56,7 @@ impl ActivatableScreen for PowerScreen {
     }
 
     fn activate(&mut self, ui: &Ui, display: Display) -> Box<dyn ActiveScreen> {
-        display.with_lock(|target| {
-            draw_border(target, "DUT Power", SCREEN_TYPE);
-            draw_button_legend(target, "Toggle", "Screen");
-        });
+        display.with_lock(|target| draw_border(target, "DUT Power", SCREEN_TYPE));
 
         let mut widgets = WidgetContainer::new(display);
 
@@ -135,6 +132,21 @@ impl ActivatableScreen for PowerScreen {
             )
         });
 
+        widgets.push(|display| {
+            DynamicWidget::button_legend(
+                ui.res.dut_pwr.state.clone(),
+                display,
+                |state: &OutputState| {
+                    let lower = match state {
+                        OutputState::On => "Turn Off",
+                        _ => "Turn On",
+                    };
+
+                    (lower.into(), "Screen".into())
+                },
+            )
+        });
+
         let power_state = ui.res.dut_pwr.state.clone();
         let power_request = ui.res.dut_pwr.request.clone();
 

src/ui/widgets.rs

@@ -318,6 +318,27 @@ impl<T: Serialize + DeserializeOwned + Send + Sync + Clone + 'static> DynamicWid
         )
     }
 
+    /// Draw a dynamic button legend
+    ///
+    /// Sometimes you want to draw different button legend text based on
+    /// external input. For example change from "Turn On" to "Turn Off" when
+    /// the status of the controlled value changes.
+    pub fn button_legend(
+        topic: Arc<Topic<T>>,
+        display: Arc<Display>,
+        format_fn: fn(&T) -> (String, String),
+    ) -> Self {
+        Self::new(
+            topic,
+            display,
+            Box::new(move |msg, target| {
+                let (lower, upper) = format_fn(msg);
+
+                Some(draw_button_legend(target, &lower, &upper))
+            }),
+        )
+    }
+
     /// Draw self-updating text with configurable alignment
     pub fn text_aligned(
         topic: Arc<Topic<T>>,