Make help page work again

src/kitty.rs

@@ -20,6 +20,12 @@ use ratatui::prelude::Rect;
 
 use crate::converter::MaybeTransferred;
 
+pub enum KittyDisplay<'tui> {
+	NoChange,
+	ClearImages,
+	DisplayImages(Vec<(usize, &'tui mut MaybeTransferred, Rect)>)
+}
+
 pub struct DbgWriter<W: Write> {
 	w: W,
 	#[cfg(debug_assertions)]
@@ -82,7 +88,7 @@ pub async fn do_shms_work(ev_stream: &mut EventStream) -> bool {
 }
 
 pub async fn display_kitty_images<'es>(
-	images: Vec<(usize, &mut MaybeTransferred, Rect)>,
+	display: KittyDisplay<'_>,
 	ev_stream: &'es mut EventStream
 ) -> Result<
 	(),
@@ -92,6 +98,9 @@ pub async fn display_kitty_images<'es>(
 		TransmitError<<&'es mut EventStream as AsyncInputReader>::Error>
 	)
 > {
+	let images = match display {
+		KittyDisplay::NoChange => return Ok(()),
+		KittyDisplay::DisplayImages(_) | KittyDisplay::ClearImages => {
 			run_action(
 				Action::Delete(DeleteConfig {
 					effect: ClearOrDelete::Clear,
@@ -102,6 +111,14 @@ pub async fn display_kitty_images<'es>(
 			.await
 			.map_err(|e| (vec![], "Couldn't clear previous images", e))?;
 
+			let KittyDisplay::DisplayImages(images) = display else {
+				return Ok(());
+			};
+
+			images
+		}
+	};
+
 	let mut err = None;
 	for (page_num, img, area) in images {
 		let config = DisplayConfig::default();

src/main.rs

@@ -29,7 +29,7 @@ use ratatui_image::picker::{Picker, ProtocolType};
 use tdf::{
 	PrerenderLimit,
 	converter::{ConvertedPage, ConverterMsg, run_conversion_loop},
-	kitty::{display_kitty_images, do_shms_work, run_action},
+	kitty::{KittyDisplay, display_kitty_images, do_shms_work, run_action},
 	renderer::{self, RenderError, RenderInfo, RenderNotif},
 	tui::{BottomMessage, InputAction, MessageSetting, Tui}
 };
@@ -422,12 +422,11 @@ async fn enter_redraw_loop(
 		}
 
 		if needs_redraw {
-			let mut to_display = vec![];
+			let mut to_display = KittyDisplay::NoChange;
 			term.draw(|f| {
 				to_display = tui.render(f, &main_area);
 			})?;
 
-			if !to_display.is_empty() {
 			let maybe_err = display_kitty_images(to_display, &mut ev_stream).await;
 
 			if let Err((to_replace, err_desc, enum_err)) = maybe_err {
@@ -451,7 +450,6 @@ async fn enter_redraw_loop(
 					to_renderer.send(RenderNotif::PageNeedsReRender(page_num))?;
 				}
 			}
-			}
 
 			execute!(stdout().lock(), EndSynchronizedUpdate)?;
 		}

src/tui.rs

@@ -24,6 +24,7 @@ use ratatui_image::Image;
 
 use crate::{
 	converter::{ConvertedImage, MaybeTransferred},
+	kitty::KittyDisplay,
 	renderer::{RenderError, fill_default},
 	skip::Skip
 };
@@ -133,10 +134,10 @@ impl Tui {
 		&'s mut self,
 		frame: &mut Frame<'_>,
 		full_layout: &RenderLayout
-	) -> Vec<(usize, &'s mut MaybeTransferred, Rect)> {
+	) -> KittyDisplay<'s> {
 		if self.showing_help_msg {
 			self.render_help_msg(frame);
-			return vec![];
+			return KittyDisplay::ClearImages;
 		}
 
 		if let Some((top_area, bottom_area)) = full_layout.top_and_bottom {
@@ -243,7 +244,7 @@ impl Tui {
 			// be written and set to skip it so that ratatui doesn't spend a lot of time diffing it
 			// each re-render
 			frame.render_widget(Skip::new(true), img_area);
-			vec![]
+			KittyDisplay::NoChange
 		} else {
 			// here we calculate how many pages can fit in the available area.
 			let mut test_area_w = img_area.width;
@@ -279,7 +280,7 @@ impl Tui {
 			if page_widths.is_empty() {
 				// If none are ready to render, just show the loading thing
 				Self::render_loading_in(frame, img_area);
-				vec![]
+				KittyDisplay::ClearImages
 			} else {
 				execute!(stdout(), BeginSynchronizedUpdate).unwrap();
 
@@ -306,7 +307,7 @@ impl Tui {
 				// then the whole diffing thing messes it up
 				self.last_render.rect = size;
 
-				to_display
+				KittyDisplay::DisplayImages(to_display)
 			}
 		}
 	}