1 files changed, 144 insertions, 0 deletions
diff --git a/gui/internal/ui/window.go b/gui/internal/ui/window.go
new file mode 100644
index 0000000..e35a363
--- /dev/null
+++ b/gui/internal/ui/window.go
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+// Package ui is krino-gui's GTK4 layer: it renders what package model
+// holds and forwards what the user does back to it. It makes no decisions
+// of its own (GUI design §1.2).
+package ui
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/diamondburned/gotk4/pkg/gtk/v4"
+
+	"krino/gui/internal/model"
+	"krino/internal/engine"
+	"krino/internal/xdg"
+)
+
+// Window is krino-gui's one window: three tabs, and a status bar.
+type Window struct {
+	app *gtk.Application
+	win *gtk.ApplicationWindow
+
+	engine *engine.Engine
+	sess   *engine.Session
+
+	plan   *planView
+	status *gtk.Label
+}
+
+// NewWindow builds the window for e; the session is the run everything in
+// it goes through.
+func NewWindow(app *gtk.Application, e *engine.Engine, sess *engine.Session) *Window {
+	w := &Window{app: app, engine: e, sess: sess}
+	w.win = gtk.NewApplicationWindow(app)
+	w.win.SetTitle("krino")
+	w.win.SetDefaultSize(1000, 640)
+
+	notebook := gtk.NewNotebook()
+	w.plan = newPlanView(w)
+	notebook.AppendPage(w.plan.root, gtk.NewLabel("Plan"))
+	notebook.AppendPage(placeholder("History and undo arrives with the next milestone."), gtk.NewLabel("History & undo"))
+	notebook.AppendPage(placeholder("The rules editor arrives with a later milestone."), gtk.NewLabel("Rules"))
+
+	w.status = gtk.NewLabel("")
+	w.status.SetXAlign(0)
+	w.status.SetMarginStart(8)
+	w.status.SetMarginEnd(8)
+	w.status.SetMarginTop(4)
+	w.status.SetMarginBottom(4)
+
+	box := gtk.NewBox(gtk.OrientationVertical, 0)
+	notebook.SetVExpand(true)
+	box.Append(notebook)
+	box.Append(gtk.NewSeparator(gtk.OrientationHorizontal))
+	box.Append(w.status)
+	w.win.SetChild(box)
+	// Closing the window releases whatever directory lock the open plan
+	// holds, rather than leaving a lock file for the next run to find.
+	w.win.ConnectCloseRequest(func() bool {
+		w.plan.closeTab()
+		return false
+	})
+	return w
+}
+
+// Show puts the window on screen.
+func (w *Window) Show() { w.win.Show() }
+
+// setStatus writes the line at the bottom of the window.
+func (w *Window) setStatus(format string, args ...any) {
+	w.status.SetText(fmt.Sprintf(format, args...))
+}
+
+// placeholder is the page of a tab that is not built yet.
+func placeholder(text string) gtk.Widgetter {
+	l := gtk.NewLabel(text)
+	l.SetVExpand(true)
+	return l
+}
+
+// escape returns text as it is safe to show: control, bidirectional and
+// separator characters are written as escapes, the way the terminal
+// front end does it (spec §15.1), so a hostile file name cannot reorder or
+// restyle the window. GTK labels are set as plain text, never as markup.
+func escape(s string) string {
+	var b strings.Builder
+	for _, r := range s {
+		switch {
+		case r == '\t':
+			b.WriteString("\\t")
+		case r < 0x20, r == 0x7f, r >= 0x80 && r <= 0x9f,
+			r == 0x061c, r >= 0x200e && r <= 0x200f, r >= 0x202a && r <= 0x202e,
+			r >= 0x2066 && r <= 0x2069, r == 0x2028, r == 0x2029:
+			fmt.Fprintf(&b, "\\u%04x", r)
+		default:
+			b.WriteRune(r)
+		}
+	}
+	return b.String()
+}
+
+// runInBackground runs work off the main loop and hands its result back to
+// the GTK thread with done. GTK may only be touched from the main loop.
+func runInBackground(work func(context.Context) error, done func(error)) context.CancelFunc {
+	ctx, cancel := context.WithCancel(context.Background())
+	go func() {
+		err := work(ctx)
+		idleAdd(func() { done(err) })
+	}()
+	return cancel
+}
+
+// rowLabel is the middle cell of a row: what would happen to the file and
+// where it would land, or - when nothing would - why not. Destinations
+// inside root are shown relative to it, as the plan's own output does.
+func rowLabel(r model.Row, root string) string {
+	if len(r.Steps) == 0 {
+		return strings.Join(r.Warnings, "; ")
+	}
+	var parts []string
+	for _, s := range r.Steps {
+		switch {
+		case s.Skip != "":
+			parts = append(parts, s.Kind.String()+" skipped: "+s.Skip)
+		case s.Dst == "":
+			parts = append(parts, s.Kind.String())
+		default:
+			parts = append(parts, s.Kind.String()+" "+shorten(s.Dst, root))
+		}
+	}
+	return strings.Join(parts, ", ")
+}
+
+// shorten writes a destination inside root relative to it, and any other
+// with ~ for the home directory.
+func shorten(dst, root string) string {
+	if root != "" && strings.HasPrefix(dst, root+string(os.PathSeparator)) {
+		return dst[len(root)+1:]
+	}
+	return xdg.Abbrev(dst)
+}