Files
yellowjacket/backend/frontendutil/frontendutil.go
T
yonluandClaude Opus 5 4471db3aef feat(wails): move the Go side to v3
Phases 2 and 3 of plan 009, plus the parts of phase 1 that could not
land before them. Nothing in the tree imports wails/v2 any more; all
three lint and test configurations are green and `go build .` produces
a running binary.

The point of the migration is one file. backend/events/emit.go probed
ctx.Value("events") — a v2-*private* context key — to decide whether
emitting was safe, because runtime.EventsEmit called log.Fatalf on a
context without the runtime and took the process down with it. v3's
emit takes no context, so that is now application.Get() == nil. D1
held: events.Emit keeps its ctx as the WithSink test seam, and all 45
call sites and 7 test files are untouched.

The bootstrap splits into application.New + Window.NewWithOptions +
Run. Ten bound services implement ServiceStartup instead of being
handed a context by hand from OnStartup, which also stops ten
SetContext methods being exported as bindings. jobs.Registry and
explore.SearchIndex keep theirs — neither is bound, so converting them
would be churn for no binding removed.

Four things differed from the plan and are written up in it: GPU policy
moved to the per-window LinuxWindow options rather than surviving on
LinuxOptions; there is no OnStartup/OnDomReady option, so app-level
wiring hangs off ApplicationStarted; application.NewService is generic,
so FEBindings []any could not survive (the binding generator is a
static analyser and would have seen nothing); and the quit veto had to
be restructured, because v3's dialog answers on a callback rather than
returning the button, so ShouldQuit vetoes, asks, and quits again from
the callback.

Window state saving moves to a WindowClosing hook — the size has to be
read while the window still exists, and v3's OnShutdown has neither
context nor window. backend/logging is deleted rather than ported:
v3 takes a *slog.Logger directly, so the v2 logger.Logger adapter had
no caller left.

Phase 1's tail rides along, now that it can: the Makefile's wails
invocations, all 50 webkit2_41 sites, lefthook, both packaging recipes
and ci.yml's apt lists. v3 builds against GTK4 + WebKitGTK 6.0, which
Arch and ubuntu:24.04 both ship, so the tag is a deletion rather than
a translation.

Phase 4 is next and the branch is not usable until it lands: the app
builds, but frontend/wailsjs/ is v2's tree and nothing regenerates it,
so the frontend cannot reach the backend yet.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UDCbcCZQepnpSQYJ6SxxZm
2026-08-14 14:01:02 -04:00

123 lines
3.1 KiB
Go

// Package frontendutil provides Go functions bound to the frontend.
package frontendutil
import (
"context"
"errors"
"fmt"
"log/slog"
"os"
"github.com/wailsapp/wails/v3/pkg/application"
)
// ErrNoRuntime is returned when a dialog is asked for with no running
// application to parent it to — under test, or after shutdown.
var ErrNoRuntime = errors.New("no Wails runtime to show a dialog")
// FrontendUtil provides frontend-bound Go functions.
type FrontendUtil struct {
ctx context.Context
}
// NewFrontendUtil creates a new FrontendUtil instance.
func NewFrontendUtil() (*FrontendUtil, error) {
return &FrontendUtil{}, nil
}
// ServiceStartup is v3's service lifecycle hook: it runs once the
// runtime exists, and ctx is cancelled when the app shuts down. It
// replaces v2's SetContext, which had to be called by hand from
// OnStartup and was exported, so it was also bound to the frontend.
func (fe *FrontendUtil) ServiceStartup(
ctx context.Context,
_ application.ServiceOptions,
) error {
fe.ctx = ctx
return nil
}
// DirectoryPicker opens a directory selection dialog.
//
// v3 has no separate directory dialog: it is the file dialog told to
// choose directories and not files.
func (fe *FrontendUtil) DirectoryPicker() (string, error) {
app := application.Get()
if app == nil {
return "", ErrNoRuntime
}
slog.Default().Info("selecting a directory")
dir, err := app.Dialog.OpenFile().
CanChooseDirectories(true).
CanChooseFiles(false).
PromptForSingleSelection()
if err != nil {
return "", fmt.Errorf(
"could not open directory dialog\n%w", err,
)
}
return dir, nil
}
// PlaylistFilePicker opens a file selection dialog filtered
// to M3U/M3U8 playlist files. Multiple files may be selected.
func (fe *FrontendUtil) PlaylistFilePicker() (
[]string,
error,
) {
app := application.Get()
if app == nil {
return nil, ErrNoRuntime
}
slog.Default().Info("selecting playlist files")
files, err := app.Dialog.OpenFile().
SetTitle("Import Playlist").
AddFilter("Playlist Files (*.m3u, *.m3u8)", "*.m3u;*.m3u8").
PromptForMultipleSelection()
if err != nil {
return nil, fmt.Errorf(
"could not open file dialog: %w", err,
)
}
return files, nil
}
// ImageFilePicker opens a file selection dialog filtered to image
// files (JPEG, PNG). Returns the selected file path, or empty
// string if the user cancelled.
func (fe *FrontendUtil) ImageFilePicker() (string, error) {
app := application.Get()
if app == nil {
return "", ErrNoRuntime
}
file, err := app.Dialog.OpenFile().
SetTitle("Select Cover Art").
AddFilter("Image Files (*.jpg, *.jpeg, *.png)", "*.jpg;*.jpeg;*.png").
PromptForSingleSelection()
if err != nil {
return "", fmt.Errorf("could not open file dialog: %w", err)
}
return file, nil
}
// ReadFile reads a file from disk and returns its contents.
// Used by the frontend to read cover art image files selected
// via ImageFilePicker.
func (fe *FrontendUtil) ReadFile(path string) ([]byte, error) {
data, err := os.ReadFile(path)
if err != nil {
return nil, fmt.Errorf("read file %q: %w", path, err)
}
return data, nil
}