Files
kitty/kittens/choose_files/image_preview.go
2025-10-07 13:30:28 +05:30

120 lines
3.1 KiB
Go

package choose_files
import (
"fmt"
"io/fs"
"path/filepath"
"sync"
"sync/atomic"
"github.com/kovidgoyal/kitty/tools/disk_cache"
"github.com/kovidgoyal/kitty/tools/utils"
)
var _ = fmt.Print
var dc_size atomic.Int64
var preview_cache = sync.OnceValues(func() (*disk_cache.DiskCache, error) {
cdir := utils.CacheDir()
cdir = filepath.Join(cdir, "choose-files")
return disk_cache.NewDiskCache(cdir, dc_size.Load())
})
type PreviewRenderer interface {
Render(string) (map[string][]byte, error)
Show(h *Handler, abspath string, metadata fs.FileInfo, x, y, width, height int, cached_data map[string]string)
}
type render_data struct {
cached_data map[string]string
err error
}
type ImagePreview struct {
abspath, cache_key string
metadata fs.FileInfo
disk_cache *disk_cache.DiskCache
cached_data map[string]string
render_err Preview
render_channel chan render_data
renderer PreviewRenderer
file_metadata_preview Preview
WakeupMainThread func() bool
}
func (p ImagePreview) IsValidForColorScheme(bool) bool { return true }
func (p ImagePreview) Render(h *Handler, x, y, width, height int) {
if p.render_channel == nil {
if p.render_err == nil {
p.renderer.Show(h, p.abspath, p.metadata, x, y, width, height, p.cached_data)
} else {
p.render_err.Render(h, x, y, width, height)
}
return
}
select {
case hd := <-p.render_channel:
p.render_channel = nil
p.cached_data = hd.cached_data
p.render_err = NewErrorPreview(fmt.Errorf("Failed to render the preview with error: %w", hd.err))
p.Render(h, x, y, width, height)
return
default:
}
if p.file_metadata_preview == nil {
p.file_metadata_preview = NewFileMetadataPreview(p.abspath, p.metadata)
}
p.file_metadata_preview.Render(h, x, y, width, height)
}
func (p *ImagePreview) start_rendering() {
defer func() {
p.WakeupMainThread()
}()
ans := p.disk_cache.Get(p.cache_key)
if len(ans) > 0 {
p.render_channel <- render_data{ans, nil}
return
}
rdata, err := p.renderer.Render(p.abspath)
if err != nil {
p.render_channel <- render_data{nil, err}
} else {
ans, err = p.disk_cache.Add(p.cache_key, rdata)
p.render_channel <- render_data{utils.IfElse(err == nil, ans, nil), err}
}
}
type ImagePreviewRenderer uint
func (p ImagePreviewRenderer) Render(abspath string) (ans map[string][]byte, err error) {
return
}
func (p ImagePreviewRenderer) Show(h *Handler, abspath string, metadata fs.FileInfo, x, y, width, height int, cached_data map[string]string) {
}
func NewImagePreview(
abspath string, metadata fs.FileInfo, opts Settings, WakeupMainThread func() bool, r PreviewRenderer,
) (Preview, error) {
dc_size.Store(opts.DiskCacheSize())
ans := &ImagePreview{
abspath: abspath, metadata: metadata, render_channel: make(chan render_data),
WakeupMainThread: WakeupMainThread, renderer: r,
}
if dc, err := preview_cache(); err != nil {
return nil, err
} else {
ans.disk_cache = dc
}
if key, err := disk_cache.KeyForPath(abspath); err != nil {
return nil, err
} else {
ans.cache_key = key
}
go ans.start_rendering()
return ans, nil
}