Rework spectrum/console UI clearing and resetting.

firmware/application/ui_spectrum.hpp

@@ -40,6 +40,10 @@ namespace spectrum {
 
 class FrequencyScale : public Widget {
 public:
+	void on_show() override {
+		clear();
+	}
+
 	void set_spectrum_sampling_rate(const uint32_t new_sampling_rate, const size_t new_spectrum_bins) {
 		if( (spectrum_sampling_rate != new_sampling_rate) ||
 			(spectrum_bins != new_spectrum_bins) ) {
@@ -75,12 +79,6 @@ public:
 		draw_frequency_ticks(painter, r);
 	}
 
-	void clear() {
-		spectrum_sampling_rate = 0;
-		spectrum_bins = 0;
-		set_dirty();
-	}
-
 private:
 	static constexpr Dim filter_band_height = 4;
 
@@ -89,6 +87,12 @@ private:
 	uint32_t channel_filter_pass_frequency { 0 };
 	uint32_t channel_filter_stop_frequency { 0 };
 
+	void clear() {
+		spectrum_sampling_rate = 0;
+		spectrum_bins = 0;
+		set_dirty();
+	}
+
 	void clear_background(Painter& painter, const Rect r) {
 		painter.fill_rectangle(r, Color::black());
 	}
@@ -187,6 +191,8 @@ private:
 class WaterfallView : public Widget {
 public:
 	void on_show() override {
+		clear();
+
 		const auto screen_r = screen_rect();
 		display.scroll_set_area(screen_r.top(), screen_r.bottom());
 	}
@@ -203,13 +209,6 @@ public:
 		(void)painter;
 	}
 
-	void clear() {
-		display.fill_rectangle(
-			screen_rect(),
-			Color::black()
-		);
-	}
-
 	void on_channel_spectrum(
 		const ChannelSpectrum& spectrum
 	) {
@@ -233,6 +232,14 @@ public:
 			pixel_row
 		);
 	}
+
+private:
+	void clear() {
+		display.fill_rectangle(
+			screen_rect(),
+			Color::black()
+		);
+	}
 };
 
 class WaterfallWidget : public View {
@@ -273,11 +280,6 @@ public:
 		(void)painter;
 	}
 
-	void clear() {
-		waterfall_view.clear();
-		frequency_scale.clear();
-	}
-
 private:
 	WaterfallView waterfall_view;
 	FrequencyScale frequency_scale;