Work on faces panel

kittens/choose_fonts/faces.go

@@ -4,30 +4,97 @@ import (
 	"fmt"
 	"kitty/tools/tui/loop"
 	"kitty/tools/utils"
+	"math"
+	"sync"
 )
 
 var _ = fmt.Print
 
+type faces_settings struct {
+	font_family, bold_font, italic_font, bold_italic_font string
+}
+
+type faces_preview_key struct {
+	settings      faces_settings
+	width, height int
+}
+
 type faces struct {
 	handler *handler
 
-	family   string
-	settings struct {
-		font_family, bold_font, italic_font, bold_italic_font string
-	}
+	family              string
+	settings            faces_settings
+	preview_cache       map[faces_preview_key]map[string]string
+	preview_cache_mutex sync.Mutex
 }
 
 func (self *faces) draw_screen() (err error) {
-	self.handler.lp.SetCursorVisible(false)
-	sz, _ := self.handler.lp.ScreenSize()
-	lines := []string{self.handler.format_title(self.family, 0), ""}
-	_, _, str := self.handler.render_lines.InRectangle(lines, 0, 0, int(sz.WidthCells), int(sz.HeightCells), &self.handler.mouse_state, self.on_click)
-	self.handler.lp.QueueWriteString(str)
+	lp := self.handler.lp
+	lp.SetCursorVisible(false)
+	sz, _ := lp.ScreenSize()
+	styled := lp.SprintStyled
+	lines := []string{
+		self.handler.format_title(self.family, 0), "",
+		fmt.Sprintf("Press %s to select this font, %s to go back to the font list or any of the highlighted keys below to fine-tune the appearance of the individual font styles.", styled("fg=green", "Enter"), styled("fg=red", "Esc")), "",
+	}
+	_, y, str := self.handler.render_lines.InRectangle(lines, 0, 0, int(sz.WidthCells), int(sz.HeightCells), &self.handler.mouse_state, self.on_click)
+
+	lp.QueueWriteString(str)
+
+	num_lines_per_font := ((int(sz.HeightCells) - y - 1) / 4) - 2
+	num_lines_needed := int(math.Ceil(100. / float64(sz.WidthCells)))
+	num_lines := max(1, min(num_lines_per_font, num_lines_needed))
+	key := faces_preview_key{settings: self.settings, width: int(sz.WidthCells * sz.CellWidth), height: int(sz.CellHeight) * num_lines}
+	self.preview_cache_mutex.Lock()
+	defer self.preview_cache_mutex.Unlock()
+	previews := self.preview_cache[key]
+	if previews == nil {
+		self.preview_cache[key] = make(map[string]string)
+		self.preview_cache[key]["in_flight"] = "yes"
+		go func() {
+			var r map[string]string
+			s := key.settings
+			self.handler.set_worker_error(kitty_font_backend.query("render_family_samples", map[string]any{
+				"text_style": self.handler.text_style, "font_family": s.font_family,
+				"bold_font": s.bold_font, "italic_font": s.italic_font, "bold_italic_font": s.bold_italic_font,
+				"width": key.width, "height": key.height, "output_dir": self.handler.temp_dir,
+			}, &r))
+			self.preview_cache_mutex.Lock()
+			defer self.preview_cache_mutex.Unlock()
+			r["in_flight"] = "no"
+			self.preview_cache[key] = r
+			self.handler.lp.WakeupMainThread()
+		}()
+		return
+	}
+	if previews["in_flight"] == "yes" {
+		return
+	}
+
+	slot := 0
+	d := func(setting, title, setting_val string) {
+		if int(sz.HeightCells)-y < num_lines+1 {
+			return
+		}
+		lp.MoveCursorTo(1, y+1)
+		lp.QueueWriteString(title + fmt.Sprintf(" (%s %s)", setting, setting_val))
+		y += 1
+		lp.MoveCursorTo(1, y+1)
+		self.handler.graphics_manager.display_image(slot, previews[setting], key.width, key.height)
+		slot++
+		y += num_lines + 1
+	}
+	d(`font_family`, styled("fg=magenta bold", "R")+`egular`, key.settings.font_family)
+	d(`bold_font`, styled("fg=magenta bold", "B")+`old`, key.settings.bold_font)
+	d(`italic_font`, styled("fg=magenta bold", "I")+`talic`, key.settings.italic_font)
+	d(`bold_italic_font`, "B"+styled("fg=magenta bold", "o")+`ld-Italic`, key.settings.bold_italic_font)
+
 	return
 }
 
 func (self *faces) initialize(h *handler) (err error) {
 	self.handler = h
+	self.preview_cache = make(map[faces_preview_key]map[string]string)
 	return
 }