support the open-icon of folder (#34168)

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

routers/web/repo/treelist.go

@@ -4,6 +4,7 @@
 package repo
 
 import (
+	"html/template"
 	"net/http"
 	"strings"
 
@@ -67,7 +68,7 @@ type WebDiffFileItem struct {
 	EntryMode   string
 	IsViewed    bool
 	Children    []*WebDiffFileItem
-	// TODO: add icon support in the future
+	FileIcon    template.HTML
 }
 
 // WebDiffFileTree is used by frontend, check the field names in frontend before changing
@@ -77,7 +78,7 @@ type WebDiffFileTree struct {
 
 // transformDiffTreeForWeb transforms a gitdiff.DiffTree into a WebDiffFileTree for Web UI rendering
 // it also takes a map of file names to their viewed state, which is used to mark files as viewed
-func transformDiffTreeForWeb(diffTree *gitdiff.DiffTree, filesViewedState map[string]pull_model.ViewedState) (dft WebDiffFileTree) {
+func transformDiffTreeForWeb(renderedIconPool *fileicon.RenderedIconPool, diffTree *gitdiff.DiffTree, filesViewedState map[string]pull_model.ViewedState) (dft WebDiffFileTree) {
 	dirNodes := map[string]*WebDiffFileItem{"": &dft.TreeRoot}
 	addItem := func(item *WebDiffFileItem) {
 		var parentPath string
@@ -110,6 +111,7 @@ func transformDiffTreeForWeb(diffTree *gitdiff.DiffTree, filesViewedState map[st
 		item := &WebDiffFileItem{FullName: file.HeadPath, DiffStatus: file.Status}
 		item.IsViewed = filesViewedState[item.FullName] == pull_model.Viewed
 		item.NameHash = git.HashFilePathForWebUI(item.FullName)
+		item.FileIcon = fileicon.RenderEntryIconHTML(renderedIconPool, &fileicon.EntryInfo{FullName: file.HeadPath, EntryMode: file.HeadMode})
 
 		switch file.HeadMode {
 		case git.EntryModeTree: