fix mascot

README.md

@@ -304,13 +304,13 @@ showing every repeated `COMMENTED` event.
 `viewer_label = "login"` shows your GitHub username like every other author.
 Set it to `"you"` to replace your username with `@you` throughout the UI.
 
-Difflet is disabled by default. Set `mascot = true` to keep it visible to the
-right next to the active view's naturally sized header, separated by a
-small gap. On normal terminal widths Difflet is centered horizontally and the
-header uses the space to its left. When centering would make the header too
-narrow, Difflet falls back to a small right-edge inset. Header information
-wraps when the combined header and mascot do not fit. The layout adds only the
-vertical rows required to display the four-line mascot.
+Difflet is disabled by default. Set `mascot = true` to show it on the pull
+request picker, dashboard, and thread screens. On the dashboard it is centered
+beside the first metadata rows so it does not add whitespace below the pull
+request title. Editor and popup views hide it to preserve their full usable
+height. On other supported screens Difflet sits to the right of the naturally
+sized header. Header information wraps when the combined header and mascot do
+not fit.
 `mascot_animated` controls brief loading, blink, success, and error motion
 independently from `mascot_expressive`, which permits stronger emotional
 faces. Disabling animation leaves the appropriate final state visible.

difflet_test.go

@@ -196,6 +196,173 @@ func TestDiffletDisabledPreservesViewExactly(t *testing.T) {
 	}
 }
 
+func TestDiffletDashboardIsCenteredBesideMetadata(t *testing.T) {
+	app := NewAppWithSettings(
+		&recordingService{}, "owner", "repository", false, 10, 10,
+		AppSettings{Mascot: true},
+	)
+	app.screen = dashboardScreen
+	app.loading = false
+	app.details = PRDetails{
+		PullRequest: PullRequest{
+			RepoWithOwner: "owner/repository", Number: 42,
+			Title: "A useful title", Author: "alice",
+		},
+		HeadRef: "feature", BaseRef: "main",
+	}
+	updated, _ := app.Update(tea.WindowSizeMsg{Width: 80, Height: 24})
+	app = updated.(App)
+
+	rendered := strings.Split(app.View(), "\n")
+	headerHeight := len(app.dashboardHeaderLines())
+	if strings.TrimSpace(ansi.Strip(rendered[headerHeight])) == "" {
+		t.Fatal("dashboard left a blank row between its title and metadata")
+	}
+	for row, mascotLine := range (DiffletFrame{Expression: DiffletIdle}).lines() {
+		plain := ansi.Strip(rendered[headerHeight+row])
+		mascotText := strings.TrimRight(mascotLine, " ")
+		mascotIndex := strings.Index(plain, mascotText)
+		left := -1
+		if mascotIndex >= 0 {
+			left = lipgloss.Width(plain[:mascotIndex])
+		}
+		if left != (app.width-diffletWidth)/2 {
+			t.Fatalf("row %d mascot starts at %d, want centered position %d: %q",
+				row, left, (app.width-diffletWidth)/2, plain)
+		}
+	}
+	for row, label := range []string{"author", "branches", "review"} {
+		if !strings.Contains(ansi.Strip(rendered[headerHeight+row]), label) {
+			t.Fatalf("dashboard row %d does not place %q beside mascot: %q",
+				row, label, ansi.Strip(rendered[headerHeight+row]))
+		}
+	}
+}
+
+func TestDiffletIsHiddenInEditorAndPopups(t *testing.T) {
+	app := NewAppWithSettings(
+		&recordingService{}, "owner", "repository", false, 10, 10,
+		AppSettings{Mascot: true},
+	)
+	app.screen = dashboardScreen
+	app.loading = false
+	app.details = PRDetails{PullRequest: PullRequest{
+		RepoWithOwner: "owner/repository", Number: 42, Title: "Title",
+	}}
+	updated, _ := app.Update(tea.WindowSizeMsg{Width: 80, Height: 24})
+	app = updated.(App)
+
+	for _, mode := range []writeMode{writePREdit, writeReplyConfirm} {
+		app.writeMode = mode
+		if got, want := app.View(), app.viewContent(); got != want {
+			t.Fatalf("write mode %d changed by enabled mascot:\ngot:\n%q\nwant:\n%q",
+				mode, got, want)
+		}
+		if strings.Contains(ansi.Strip(app.View()), "▄███████▄") {
+			t.Fatalf("write mode %d displayed the mascot", mode)
+		}
+	}
+	app.writeMode = writeNone
+	app.helpVisible = true
+	if got, want := app.View(), app.viewContent(); got != want {
+		t.Fatalf("help popup changed by enabled mascot:\ngot:\n%q\nwant:\n%q", got, want)
+	}
+}
+
+func TestDiffletEnabledEditorCanRevealLastDescriptionRow(t *testing.T) {
+	app := NewAppWithSettings(
+		&recordingPRService{}, "owner", "repository", false, 10, 10,
+		AppSettings{Mascot: true},
+	)
+	app.screen = dashboardScreen
+	app.loading = false
+	app.width, app.height = 50, 12
+	app.details = PRDetails{
+		PullRequest: PullRequest{
+			ID: "pr", RepoWithOwner: "owner/repository", Number: 42,
+			Title: "Title",
+		},
+		BaseRef: "main",
+		Body:    strings.Repeat("description row\n", 20) + "LAST DESCRIPTION ROW",
+		Permissions: ViewerPermissions{
+			CanUpdatePR: true,
+		},
+	}
+	app.startPREdit()
+	app.prEditEditors[prEditBodyField].Cursor =
+		len([]rune(app.prEditEditors[prEditBodyField].Text))
+	app.ensurePREditCursorVisible()
+
+	rendered := ansi.Strip(app.View())
+	if !strings.Contains(rendered, "LAST DESCRIPTION ROW") {
+		t.Fatalf("last description row is outside the editor viewport:\n%s", rendered)
+	}
+	if strings.Contains(rendered, "▄███████▄") {
+		t.Fatal("editor displayed the mascot instead of using its full height")
+	}
+}
+
+func TestDashboardDiffletRemainsCenteredAtNarrowWidths(t *testing.T) {
+	mascot := (DiffletFrame{Expression: DiffletIdle}).lines()
+	metadata := []string{"author", "branches", "review", "checks"}
+	for width := diffletWidth; width < 20; width++ {
+		rendered := renderDashboardMetadataWithDifflet(metadata, mascot, width)
+		for row, mascotLine := range mascot {
+			mascotText := strings.TrimRight(mascotLine, " ")
+			var mascotRow string
+			for _, line := range rendered {
+				if strings.Contains(line, mascotText) {
+					mascotRow = line
+					break
+				}
+			}
+			index := strings.Index(mascotRow, mascotText)
+			left := -1
+			if index >= 0 {
+				left = lipgloss.Width(mascotRow[:index])
+			}
+			if want := max(0, (width-diffletWidth)/2); left != want {
+				t.Fatalf("width %d row %d mascot starts at %d, want %d: %q",
+					width, row, left, want, mascotRow)
+			}
+		}
+	}
+}
+
+func TestDashboardLoadingDiffletIsCentered(t *testing.T) {
+	app := NewAppWithSettings(
+		&recordingService{}, "owner", "repository", false, 10, 10,
+		AppSettings{Mascot: true},
+	)
+	app.screen = dashboardScreen
+	app.loading = true
+	app.details = PRDetails{PullRequest: PullRequest{
+		RepoWithOwner: "owner/repository", Number: 42, Title: "Title",
+	}}
+	updated, _ := app.Update(tea.WindowSizeMsg{Width: 80, Height: 24})
+	app = updated.(App)
+
+	rendered := strings.Split(app.View(), "\n")
+	mascotLine := strings.TrimRight((DiffletFrame{Expression: DiffletIdle}).lines()[0], " ")
+	for row, line := range rendered {
+		plain := ansi.Strip(line)
+		index := strings.Index(plain, mascotLine)
+		if index < 0 {
+			continue
+		}
+		if left := lipgloss.Width(plain[:index]); left != (app.width-diffletWidth)/2 {
+			t.Fatalf("loading mascot starts at %d, want %d: %q",
+				left, (app.width-diffletWidth)/2, plain)
+		}
+		if row != len(app.dashboardHeaderLines()) {
+			t.Fatalf("loading mascot begins on row %d, want %d",
+				row, len(app.dashboardHeaderLines()))
+		}
+		return
+	}
+	t.Fatal("loading dashboard did not display the mascot")
+}
+
 func TestDiffletHeaderMeasurementMatchesRenderedHeader(t *testing.T) {
 	tests := []struct {
 		name   string

tui.go

@@ -1874,7 +1874,7 @@ func (m App) dashboardViewportHeight() int {
 }
 
 func (m App) dashboardMaxScroll() int {
-	return max(0, len(m.dashboardLines())-m.dashboardViewportHeight())
+	return max(0, len(m.dashboardDisplayLines())-m.dashboardViewportHeight())
 }
 
 func (m App) detailPaneSize() (int, int) {
@@ -1924,6 +1924,12 @@ func (m App) View() string {
 	if len(mascot) != diffletHeight {
 		return m.viewContent()
 	}
+	if m.diffletHiddenForCurrentView() {
+		return m.viewContent()
+	}
+	if m.screen == dashboardScreen {
+		return m.viewDashboardWithLines(m.dashboardLinesWithDifflet(mascot))
+	}
 	gap := diffletGap
 	headerWidth := diffletHeaderWidth(m.width)
 	if headerWidth < 1 {
@@ -1959,11 +1965,15 @@ func (m App) View() string {
 	)
 }
 
-func (m App) diffletHeaderLineCount() (int, bool) {
-	if m.helpVisible ||
+func (m App) diffletHiddenForCurrentView() bool {
+	return m.helpVisible ||
 		(m.aiMode != aiNone && m.aiMode != aiDiscussion) ||
-		(m.writeMode != writeNone && m.writeMode != writeReply && m.writeMode != writePREdit) ||
-		m.screen == healthScreen {
+		(m.writeMode != writeNone && m.writeMode != writeReply) ||
+		m.screen == healthScreen
+}
+
+func (m App) diffletHeaderLineCount() (int, bool) {
+	if m.diffletHiddenForCurrentView() {
 		return 0, false
 	}
 	switch m.screen {
@@ -1973,9 +1983,6 @@ func (m App) diffletHeaderLineCount() (int, bool) {
 		if m.scroll > 0 {
 			return 0, false
 		}
-		if m.writeMode == writePREdit {
-			return 1, true
-		}
 		return len(m.dashboardHeaderLines()), true
 	case threadScreen:
 		return len(m.threadTopLines()), true
@@ -2563,7 +2570,10 @@ func groupedPRRows(prs []PullRequest, selected int) ([]prListRow, int) {
 }
 
 func (m App) viewDashboard() string {
-	lines := m.dashboardLines()
+	return m.viewDashboardWithLines(m.dashboardLines())
+}
+
+func (m App) viewDashboardWithLines(lines []string) string {
 	viewportHeight := m.dashboardViewportHeight()
 	maxScroll := max(0, len(lines)-viewportHeight)
 	scroll := min(m.scroll, maxScroll)
@@ -2594,6 +2604,69 @@ func (m App) viewDashboard() string {
 	return view
 }
 
+func (m App) dashboardDisplayLines() []string {
+	mascot := m.difflet.frameLines()
+	if len(mascot) == diffletHeight && !m.diffletHiddenForCurrentView() {
+		return m.dashboardLinesWithDifflet(mascot)
+	}
+	return m.dashboardLines()
+}
+
+func (m App) dashboardLinesWithDifflet(mascot []string) []string {
+	lines := m.dashboardLines()
+	headerLines := len(m.dashboardHeaderLines())
+	metadataStart := headerLines + 1
+	if headerLines >= len(lines) ||
+		strings.TrimSpace(ansi.Strip(lines[headerLines])) != "" {
+		return lines
+	}
+	if len(lines) < metadataStart+diffletHeight {
+		result := append([]string(nil), lines[:headerLines]...)
+		result = append(result, centeredDiffletLines(mascot, m.width)...)
+		return append(result, lines[metadataStart:]...)
+	}
+	band := renderDashboardMetadataWithDifflet(
+		lines[metadataStart:metadataStart+diffletHeight],
+		mascot,
+		m.width,
+	)
+	result := append([]string(nil), lines[:headerLines]...)
+	result = append(result, band...)
+	return append(result, lines[metadataStart+diffletHeight:]...)
+}
+
+func renderDashboardMetadataWithDifflet(metadata, mascot []string, width int) []string {
+	mascotLeft := max(0, (width-diffletWidth)/2)
+	if width <= diffletWidth || mascotLeft < diffletGap {
+		centered := centeredDiffletLines(mascot, width)
+		return append(centered, metadata...)
+	}
+	metadataWidth := max(1, mascotLeft-diffletGap)
+	height := max(len(metadata), len(mascot))
+	rendered := make([]string, 0, height)
+	for row := range height {
+		left, right := "", ""
+		if row < len(metadata) {
+			left = ansi.Truncate(metadata[row], metadataWidth, "…")
+		}
+		if row < len(mascot) {
+			right = mascot[row]
+		}
+		rendered = append(rendered, pad(left, mascotLeft)+right)
+	}
+	return rendered
+}
+
+func centeredDiffletLines(mascot []string, width int) []string {
+	centered := make([]string, 0, len(mascot))
+	for _, line := range mascot {
+		centered = append(centered, lipgloss.PlaceHorizontal(
+			width, lipgloss.Center, line,
+		))
+	}
+	return centered
+}
+
 func (m App) viewHealth() string {
 	lines := m.healthLines()
 	viewportHeight := m.healthViewportHeight()