From da7bf1ca587f66857b496f707bc3271cf366fcd3 Mon Sep 17 00:00:00 2001
From: tv <tv@shackspace.de>
Date: Sat, 31 Jan 2015 17:04:49 +0100
Subject: toggleTagAtCursor: sync modification

Synchronize modification of tags between Message and SearchResult.
---
 TreeZipperUtils.hs | 40 ++++++++++++++++++++++++++++++++++++++++
 test5.hs           | 11 +++++++----
 2 files changed, 47 insertions(+), 4 deletions(-)

diff --git a/TreeZipperUtils.hs b/TreeZipperUtils.hs
index b6410a3..0c6dc00 100644
--- a/TreeZipperUtils.hs
+++ b/TreeZipperUtils.hs
@@ -1,5 +1,6 @@
 module TreeZipperUtils where
 
+import Data.Maybe
 import Data.Tree
 import Data.Tree.Zipper
 
@@ -10,3 +11,42 @@ path loc = toParent loc : parents loc
 -- Return parent stack compatible form of loc.
 toParent :: TreePos Full a -> (Forest a, a, Forest a)
 toParent loc = (before loc, label loc, after loc)
+
+
+modifyFirstParentLabelWhere
+    :: (a -> Bool)
+    -> (a -> a)
+    -> TreePos Full a
+    -> TreePos Full a
+modifyFirstParentLabelWhere p f loc0 =
+    case parent loc0 of
+        Nothing -> loc0
+        Just loc0' -> go (byChildIndex loc0) loc0'
+  where
+
+    go rewind loc =
+        if p (label loc)
+            then
+                rewind (modifyLabel f loc)
+            else
+                case parent loc of
+                    Nothing -> rewind loc
+                    Just loc' ->
+                        go (rewind . byChildIndex loc) loc'
+
+    -- generator for a rewind step
+    byChildIndex :: TreePos Full a -> (TreePos Full a -> TreePos Full a)
+    byChildIndex loc =
+        -- The use of fromJust is safe here because we're only modifying
+        -- labels and not the tree structure and thus the index is valid.
+        fromJust . childAt (childIndex loc)
+
+
+-- XXX This could be named more general, like countPrevSiblings?
+-- XXX Can we kill the recursion?
+childIndex :: TreePos Full a -> Int
+childIndex =
+    go 0
+  where
+    go index =
+        maybe index (go $ index + 1) . prev
diff --git a/test5.hs b/test5.hs
index 4133e76..3075b0a 100644
--- a/test5.hs
+++ b/test5.hs
@@ -35,6 +35,7 @@ import TagUtils
 import Trammel
 import TreeSearch
 import TreeView
+import TreeZipperUtils (modifyFirstParentLabelWhere)
 import Utils
 
 
@@ -430,19 +431,21 @@ toggleTagAtCursor tag q@State{..} = case Z.label cursor of
                     else AddTag
             tagOps = [tagOp tag]
         Notmuch.notmuchTag tagOps sr
-        -- TODO reload or patch whole thread
-        let cursor' = Z.modifyTree (patchRootLabelTags tagOps) cursor
+        let cursor' = Z.modifyTree (patchTreeTags tagOps) cursor
         return q { cursor = cursor' }
 
     TVMessage m -> do
-        -- TODO modify search result tags
         let tagOp =
                 if tag `elem` Notmuch.messageTags m
                     then DelTag
                     else AddTag
             tagOps = [tagOp tag]
         Notmuch.notmuchTag tagOps m
-        let cursor' = Z.modifyTree (patchRootLabelTags tagOps) cursor
+        let cursor' =
+                -- TODO this needs a nice name
+                modifyFirstParentLabelWhere isTVSearchResult f $
+                Z.modifyLabel f cursor
+            f = patchTags tagOps
         return q { cursor = cursor' }
 
     _ -> return q { flashMessage = "nothing happened" }
-- 
cgit v1.2.3