dirtree: add dirtree-collapse config setting

Adds a setting to the configuration to configure at which level the
folders in the dirtree are collapsed by default.

In my case, this is useful because my organisation has some rather deep
nesting in the folder structure, and a _lot_ of folders, and this way I
can keep my dirtree uncluttered while still having all folders there if
I need them.

Signed-off-by: Sijmen <me@sijman.nl>

CHANGELOG.md

@@ -11,6 +11,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Import/Export mbox files with `:import-mbox` and `:export-mbox`.
 - `address-book-cmd` can now also be specified in `accounts.conf`.
 - Run `check-mail-cmd` with `:check-mail`.
+- Configurable default collapse depth for directory tree.
 
 ### Changed
 

config/aerc.conf

@@ -103,6 +103,12 @@ dirlist-delay=200ms
 # Default: false
 dirlist-tree=false
 
+# If dirlist-tree is enabled, set level at which folders are collapsed by
+# default. Set to 0 to disable.
+#
+# Default: 0
+dirlist-collapse=0
+
 # List of space-separated criteria to sort the messages by, see *sort*
 # command in *aerc*(1) for reference. Prefixing a criterion with "-r "
 # reverses that criterion.

config/config.go

@@ -62,6 +62,7 @@ type UIConfig struct {
 	DirListFormat       string        `ini:"dirlist-format"`
 	DirListDelay        time.Duration `ini:"dirlist-delay"`
 	DirListTree         bool          `ini:"dirlist-tree"`
+	DirListCollapse     int           `ini:"dirlist-collapse"`
 	Sort                []string      `delim:" "`
 	NextMessageOnDelete bool          `ini:"next-message-on-delete"`
 	CompletionDelay     time.Duration `ini:"completion-delay"`

widgets/dirtree.go

@@ -327,7 +327,7 @@ func (dt *DirectoryTree) buildTree() {
 	copy(dt.treeDirs, dt.dirs)
 
 	root := &types.Thread{Uid: 0}
-	buildTree(root, sTree, 0xFFFFFF)
+	dt.buildTreeNode(root, sTree, 0xFFFFFF, 1)
 
 	threads := make([]*types.Thread, 0)
 
@@ -373,7 +373,7 @@ func (dt *DirectoryTree) buildTree() {
 	}
 }
 
-func buildTree(node *types.Thread, stree [][]string, defaultUid uint32) {
+func (dt *DirectoryTree) buildTreeNode(node *types.Thread, stree [][]string, defaultUid uint32, depth int) {
 	m := make(map[string][][]string)
 	for _, branch := range stree {
 		if len(branch) > 1 {
@@ -398,7 +398,10 @@ func buildTree(node *types.Thread, stree [][]string, defaultUid uint32) {
 		}
 		nextNode := &types.Thread{Uid: uid}
 		node.AddChild(nextNode)
-		buildTree(nextNode, next, defaultUid)
+		if dt.UiConfig().DirListCollapse != 0 {
+			node.Hidden = depth > dt.UiConfig().DirListCollapse
+		}
+		dt.buildTreeNode(nextNode, next, defaultUid, depth+1)
 	}
 }