Add result highlighting to code preview

src/app/codePreview.tsx

@@ -14,8 +14,9 @@ import { Cross1Icon, FileIcon } from "@radix-ui/react-icons";
 import { Scrollbar } from "@radix-ui/react-scroll-area";
 import { vim } from "@replit/codemirror-vim";
 import CodeMirror, { ReactCodeMirrorRef } from '@uiw/react-codemirror';
+import { ArrowDown, ArrowUp } from "lucide-react";
 import { useTheme } from "next-themes";
-import { useEffect, useMemo, useRef, useState } from "react";
+import { useCallback, useEffect, useMemo, useRef, useState } from "react";
 
 export interface CodePreviewFile {
     content: string;
@@ -26,16 +27,22 @@ export interface CodePreviewFile {
 interface CodePreviewProps {
     file?: CodePreviewFile;
     keymapType: "default" | "vim";
+    selectedMatchIndex: number;
+    onSelectedMatchIndexChange: (index: number) => void;
     onClose: () => void;
 }
 
 export const CodePreview = ({
     file,
     keymapType,
+    selectedMatchIndex,
+    onSelectedMatchIndexChange,
     onClose,
 }: CodePreviewProps) => {
     const editorRef = useRef<ReactCodeMirrorRef>(null);
+
     const { theme: _theme, systemTheme } = useTheme();
+
     const theme = useMemo(() => {
         if (_theme === "system") {
             return systemTheme ?? "light";
@@ -59,16 +66,42 @@ export const CodePreview = ({
         [keymapType]
     );
 
+    const extensions = useMemo(() => {
+        return [
+            keymapExtension,
+            gutterWidthExtension,
+            javascript(),
+            searchResultHighlightExtension(),
+            search({
+                top: true,
+            }),
+            EditorView.updateListener.of(update => {
+                const width = update.view.plugin(gutterWidthExtension)?.width;
+                if (width) {
+                    setGutterWidth(width);
+                }
+            }),
+        ];
+    }, [keymapExtension]);
+
     useEffect(() => {
         if (!file || !editorRef.current?.view) {
             return;
         }
 
-        markMatches(file.matches, editorRef.current.view);
-    }, [file?.matches]);
+        markMatches(selectedMatchIndex, file.matches, editorRef.current.view);
+    }, [file?.matches, selectedMatchIndex]);
+
+    const onUpClicked = useCallback(() => {
+        onSelectedMatchIndexChange(selectedMatchIndex - 1);
+    }, [selectedMatchIndex]);
+
+    const onDownClicked = useCallback(() => {
+        onSelectedMatchIndexChange(selectedMatchIndex + 1);
+    }, [selectedMatchIndex]);
 
     return (
-        <div className="h-full">
+        <div className="flex flex-col h-full">
             <div className="flex flex-row bg-cyan-200 dark:bg-cyan-900 items-center justify-between pr-3">
                 <div className="flex flex-row">
                     <div
@@ -79,34 +112,43 @@ export const CodePreview = ({
                     </div>
                     <span>{file?.filepath}</span>
                 </div>
-                <Button variant="ghost" size="icon" className="h-6 w-6">
-                    <Cross1Icon
-                        className="h-4 w-4"
+                <div className="flex flex-row gap-1 items-center">
+                    <p className="text-sm">{`${selectedMatchIndex + 1} of ${file?.matches.length}`}</p>
+                    <Button
+                        variant="ghost"
+                        size="icon"
+                        className="h-6 w-6"
+                        disabled={selectedMatchIndex === 0}
+                        onClick={onUpClicked}
+                    >
+                        <ArrowUp className="h-4 w-4" />
+                    </Button>
+                    <Button
+                        variant="ghost"
+                        size="icon"
+                        className="h-6 w-6"
+                        onClick={onDownClicked}
+                        disabled={file ? selectedMatchIndex === file?.matches.length - 1 : true}
+                    >
+                        <ArrowDown className="h-4 w-4" />
+                    </Button>
+                    <Button
+                        variant="ghost"
+                        size="icon"
+                        className="h-6 w-6"
                         onClick={onClose}
-                    />
-                </Button>
+                    >
+                        <Cross1Icon className="h-4 w-4" />
+                    </Button>
+                </div>
             </div>
-            <ScrollArea className="h-full overflow-y-auto">
+            <ScrollArea className="h-full overflow-auto flex-1">
                 <CodeMirror
                     ref={editorRef}
                     readOnly={true}
                     value={file?.content}
                     theme={theme === "dark" ? "dark" : "light"}
-                    extensions={[
-                        keymapExtension,
-                        gutterWidthExtension,
-                        javascript(),
-                        searchResultHighlightExtension(),
-                        search({
-                            top: true,
-                        }),
-                        EditorView.updateListener.of(update => {
-                            const width = update.view.plugin(gutterWidthExtension)?.width;
-                            if (width) {
-                                setGutterWidth(width);
-                            }
-                        })
-                    ]}
+                    extensions={extensions}
                 />
                 <Scrollbar orientation="vertical" />
             </ScrollArea>

src/app/page.tsx

@@ -31,6 +31,7 @@ export default function Home() {
 
     const [isCodePanelOpen, setIsCodePanelOpen] = useState(false);
     const [previewFile, setPreviewFile] = useState<CodePreviewFile | undefined>(undefined);
+    const [selectedMatchIndex, setSelectedMatchIndex] = useState(0);
 
     const [fileMatches, setFileMatches] = useState<ZoektFileMatch[]>([]);
     const [isLoading, setIsLoading] = useState(false);
@@ -104,11 +105,12 @@ export default function Home() {
                             fetch(url)
                                 .then(response => response.json())
                                 .then((body: GetSourceResponse) => {
+                                    setSelectedMatchIndex(0);
                                     setPreviewFile({
                                         content: body.content,
                                         filepath: match.FileName,
                                         matches: match.Matches,
-                                    })
+                                    });
                                     setIsCodePanelOpen(true);
                                 });
                         }}
@@ -122,6 +124,8 @@ export default function Home() {
                     <CodePreview
                         file={previewFile}
                         onClose={() => setIsCodePanelOpen(false)}
+                        selectedMatchIndex={selectedMatchIndex}
+                        onSelectedMatchIndexChange={setSelectedMatchIndex}
                         keymapType={keymapType}
                     />
                 </ResizablePanel>

src/lib/extensions/searchResultHighlightExtension.ts

@@ -1,12 +1,27 @@
-import { Extension, StateEffect, StateField, Transaction } from "@codemirror/state";
+import { EditorSelection, Extension, StateEffect, StateField, Text, Transaction } from "@codemirror/state";
 import { Decoration, DecorationSet, EditorView } from "@codemirror/view";
 import { ZoektMatch } from "../types";
 
 const matchMark = Decoration.mark({
     class: "cm-searchMatch"
 });
+const selectedMatchMark = Decoration.mark({
+    class: "cm-searchMatch cm-searchMatch-selected"
+});
+
+const setMatchState = StateEffect.define<{
+    selectedMatchIndex: number,
+    matches: ZoektMatch[],
+}>();
+
+const getMatchRange = (match: ZoektMatch, document: Text) => {
+    const line = document.line(match.LineNum);
+    const fragment = match.Fragments[0];
+    const from = line.from + fragment.Pre.length;
+    const to = from + fragment.Match.length;
+    return { from, to };
+}
 
-const setMatches = StateEffect.define<ZoektMatch[]>();
 
 const matchHighlighter = StateField.define<DecorationSet>({
     create () {
@@ -16,13 +31,13 @@ const matchHighlighter = StateField.define<DecorationSet>({
         highlights = highlights.map(transaction.changes);
 
         for (const effect of transaction.effects) {
-            if (effect.is(setMatches)) {
-                const decorations = effect.value.map(match => {
-                    const line = transaction.newDoc.line(match.LineNum);
-                    const fragment = match.Fragments[0];
-                    const from = line.from + fragment.Pre.length;
-                    const to = from + fragment.Match.length;
-                    return matchMark.range(from, to);
+            if (effect.is(setMatchState)) {
+                const { matches, selectedMatchIndex } = effect.value;
+
+                const decorations = matches.map((match, index) => {
+                    const { from, to } = getMatchRange(match, transaction.newDoc);
+                    const mark = index === selectedMatchIndex ? selectedMatchMark : matchMark;
+                    return mark.range(from, to);
                 });
 
                 highlights = Decoration.set(decorations)
@@ -37,11 +52,29 @@ const matchHighlighter = StateField.define<DecorationSet>({
 const highlightTheme = EditorView.baseTheme({
     "&light .cm-searchMatch": { backgroundColor: "#ffff0054" },
     "&dark .cm-searchMatch": { backgroundColor: "#00ffff8a" },
+    "&light .cm-searchMatch-selected": { backgroundColor: "#ff6a0054" },
+    "&dark .cm-searchMatch-selected": { backgroundColor: "#ff00ff8a" }
 });
 
-export const markMatches = (matches: ZoektMatch[], view: EditorView) => {
-    const effect: StateEffect<ZoektMatch[]> = setMatches.of(matches);
-    view.dispatch({ effects: [effect] });
+export const markMatches = (selectedMatchIndex: number, matches: ZoektMatch[], view: EditorView) => {
+    const setState = setMatchState.of({
+        selectedMatchIndex,
+        matches,
+    });
+    
+    const effects = []
+    effects.push(setState);
+
+    if (selectedMatchIndex >= 0 && selectedMatchIndex < matches.length) {
+        const match = matches[selectedMatchIndex];
+        const { from, to } = getMatchRange(match, view.state.doc);
+        const selection = EditorSelection.range(from, to);
+        effects.push(EditorView.scrollIntoView(selection, {
+            y: "start",
+        }));
+    };
+
+    view.dispatch({ effects });
     return true;
 }