From a78febec6c9d62afd0bb86c34ff5465c91bd299c Mon Sep 17 00:00:00 2001
From: xenia <xenia.agda@gmail.com>
Date: Sun, 12 Nov 2023 17:26:31 +0100
Subject: [PATCH] Highlight current node

---
 rc/tree.kak    | 31 ++++++++++++++++++++++++++++++-
 src/kakoune.rs | 26 ++++++++++++++++++++++++++
 src/main.rs    |  8 ++++++++
 3 files changed, 64 insertions(+), 1 deletion(-)

diff --git a/rc/tree.kak b/rc/tree.kak
index 2c11a10..5cfcb69 100644
--- a/rc/tree.kak
+++ b/rc/tree.kak
@@ -9,6 +9,11 @@ declare-option str tree_log "/tmp/kak-tree.log"
 # Option to store draft of the current buffer before passing to shell.
 declare-option -hidden str tree_draft
 
+declare-option str tree_highlight_style "black,blue"
+
+declare-option -hidden range-specs tree_highlight
+add-highlighter global/tree_highlight ranges tree_highlight
+
 define-command -hidden tree-command -params 1..2 -docstring %{
     tree-command <OP_TYPE> [<OP_PARAMS>]
     Send request to kak-tree and evaluate response.
@@ -74,6 +79,30 @@ define-command tree-select-first-child -params ..1 -docstring %{
     Select the first immediate visible children or the first descendant matching KIND when provided.
 } %{
     tree-command-with-optional-kind SelectChildren %arg{1}
-    execute-keys <space>
+    execute-keys ,
+}
+
+define-command tree-node-highlight -docstring %{
+    tree-node-highlight
+    Highlight the current node using the tree_highlight_style face
+} %{ tree-command HighlightCurrentNode }
+
+define-command tree-node-clear-highlight -docstring %{
+    tree-node-clear-highlight
+    Removes any highlight
+} %{ set-option buffer tree_highlight %val{timestamp} }
+
+define-command tree-always-highlight -docstring %{
+    Highlight the current node at all times, as the cursor moves
+} %{
+    hook -group tree-always-highlight global RawKey .* tree-node-highlight
+    tree-node-highlight
+}
+
+define-command tree-always-highlight-disable -docstring %{
+    Stop highlighting the cursor
+} %{
+    remove-hooks global tree-always-highlight
+    tree-node-clear-highlight
 }
 
diff --git a/src/kakoune.rs b/src/kakoune.rs
index 1bc881b..7a2b03c 100644
--- a/src/kakoune.rs
+++ b/src/kakoune.rs
@@ -9,6 +9,32 @@ pub fn select_ranges(buffer: &[String], ranges: &[Range]) -> String {
     }
 }
 
+pub fn highlight_ranges(buffer: &[String], ranges: &[Range]) -> String {
+    format!("set-option buffer tree_highlight %val{{timestamp}} {}", ranges_to_range_desc(&buffer, &ranges, "%opt{tree_highlight_style}".to_string()))
+}
+
+pub fn ranges_to_range_desc(buffer: &[String], ranges: &[Range], string: String) -> String {
+    ranges
+        .iter()
+        .map(|range| {
+            let mut end_row = range.end_point.row;
+            let mut end_column = range.end_point.column;
+            if end_column > 0 {
+                end_column -= 1;
+            } else {
+                end_row -= 1;
+                end_column = 1_000_000;
+            }
+            format!(
+                "\"{},{}|{}\"",
+                point_to_kak_coords(buffer, range.start_point),
+                point_to_kak_coords(buffer, Point::new(end_row, end_column)),
+                string,
+            )
+        })
+        .join(" ")
+}
+
 pub fn ranges_to_selections_desc(buffer: &[String], ranges: &[Range]) -> String {
     ranges
         .iter()
diff --git a/src/main.rs b/src/main.rs
index 6fdec86..7cf98f2 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -23,6 +23,7 @@ struct Request {
 #[serde(tag = "type")]
 enum Op {
     NodeSExp,
+    HighlightCurrentNode,
     SelectChildren { kind: Option<String> },
     SelectNextNode { kind: Option<String> },
     SelectParentNode { kind: Option<String> },
@@ -181,6 +182,13 @@ fn handle_request(config: &Config, request: &Request) -> String {
             let node = tree::shrink_to_range(tree.root_node(), &ranges[0]);
             format!("info '{}'", node.to_sexp())
         }
+        Op::HighlightCurrentNode => {
+            for range in &ranges {
+                let node = tree::shrink_to_range(tree.root_node(), range);
+                new_ranges.push(node.range());
+            }
+            kakoune::highlight_ranges(&buffer, &new_ranges)
+        }
     }
 }