choose_files: start work on image previews

kittens/choose_files/image_preview.go

@@ -0,0 +1,50 @@
+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 ImagePreview struct {
+	abspath, cache_key string
+	disk_cache         *disk_cache.DiskCache
+}
+
+func (p ImagePreview) IsValidForColorScheme(bool) bool { return true }
+
+func (p ImagePreview) Render(h *Handler, x, y, width, height int) {
+	offset := 0
+	offset += h.render_wrapped_text_in_region("Rendering image, please wait...", x, y, width, height, true)
+}
+
+func NewImagePreview(abspath string, metadata fs.FileInfo, opts Settings) (Preview, error) {
+	dc_size.Store(opts.DiskCacheSize())
+	ans := &ImagePreview{abspath: abspath}
+	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
+	}
+	return ans, nil
+}

kittens/choose_files/main.go

@@ -123,6 +123,7 @@ type State struct {
 	display_title                       bool
 	pygments_style, dark_pygments_style string
 	syntax_aliases                      map[string]string
+	max_disk_cache_size                 int64
 
 	selections    []string
 	current_idx   CollectionIndex
@@ -131,6 +132,7 @@ type State struct {
 	redraw_needed bool
 }
 
+func (s State) DiskCacheSize() int64                  { return s.max_disk_cache_size }
 func (s State) HighlightStyles() (string, string)     { return s.pygments_style, s.dark_pygments_style }
 func (s State) SyntaxAliases() map[string]string      { return s.syntax_aliases }
 func (s State) DisplayTitle() bool                    { return s.display_title }
@@ -718,6 +720,7 @@ func (h *Handler) set_state_from_config(conf *Config, opts *Options) (err error)
 	h.state.pygments_style = conf.Pygments_style
 	h.state.dark_pygments_style = conf.Dark_pygments_style
 	h.state.syntax_aliases = conf.Syntax_aliases
+	h.state.max_disk_cache_size = int64(conf.Cache_size * (1024 * 1024 * 1024))
 	return
 }
 

kittens/choose_files/main.py

@@ -61,6 +61,11 @@ builtin styles <https://pygments.org/styles/>` for a list of schemes.
 This sets the colors used for dark color schemes, use :opt:`pygments_style` to change the
 colors for light color schemes.''')
 
+opt('cache_size', '0.5', option_type='positive_float', long_text='''
+The maximum size of the disk cache, in gigabytes, used for previews. Zero or negative values
+mean no limit.
+''')
+
 opt('syntax_aliases', 'pyj:py pyi:py recipe:py', ctype='strdict_ _:', option_type='syntax_aliases',
     long_text='''
 File extension aliases for syntax highlight. For example, to syntax highlight

kittens/choose_files/preview.go

@@ -297,6 +297,13 @@ func (pm *PreviewManager) preview_for(abspath string, ftype fs.FileMode) (ans Pr
 		pm.highlight_file_async(abspath, ch)
 		return NewTextFilePreview(abspath, s, ch, pm.highlighter.Sanitize)
 	}
+	if strings.HasPrefix(mt, "image/") {
+		ans, err := NewImagePreview(abspath, s, pm.settings)
+		if err != nil {
+			return NewErrorPreview(err)
+		}
+		return ans
+	}
 	return NewFileMetadataPreview(abspath, s)
 }
 

kittens/choose_files/scan.go

@@ -634,6 +634,7 @@ type Settings interface {
 	GlobalIgnores() ignorefiles.IgnoreFile
 	HighlightStyles() (string, string)
 	SyntaxAliases() map[string]string
+	DiskCacheSize() int64
 }
 
 type ResultManager struct {