feat(vscode): selection style

packages/vscode/package.json

@@ -60,6 +60,11 @@
           "type": "boolean",
           "default": true,
           "description": "Enable/disable color preview decorations"
+        },
+        "unocss.selectionStyle": {
+          "type": "boolean",
+          "default": true,
+          "description": "Enable/disable selection style decorations"
         }
       }
     }

packages/vscode/src/index.ts

@@ -6,6 +6,7 @@ import { log } from './log'
 import { registerAnnotations } from './annotation'
 import { registerAutoComplete } from './autocomplete'
 import { ContextLoader } from './contextLoader'
+import { registerSelectionStyle } from './selectionStyle'
 
 export async function activate(ext: ExtensionContext) {
   log.appendLine(`⚪️ UnoCSS for VS Code v${version}\n`)
@@ -50,6 +51,7 @@ export async function activate(ext: ExtensionContext) {
 
   registerAutoComplete(cwd, contextLoader, ext)
   registerAnnotations(cwd, contextLoader, status, ext)
+  registerSelectionStyle(cwd, contextLoader)
 }
 
 export function deactivate() {}

packages/vscode/src/selectionStyle.ts

@@ -0,0 +1,90 @@
+import { MarkdownString, Position, Range, window, workspace } from 'vscode'
+import parserCSS from 'prettier/parser-postcss'
+import prettier from 'prettier/standalone'
+import type { TextEditorSelectionChangeEvent } from 'vscode'
+import { regexScopePlaceholder } from '@unocss/core'
+import { log } from './log'
+import { throttle } from './utils'
+import type { ContextLoader } from './contextLoader'
+import { getMatchedPositionsFromCode } from './integration'
+
+export async function registerSelectionStyle(cwd: string, contextLoader: ContextLoader) {
+  const hasSelectionStyle = (): boolean => workspace.getConfiguration().get('unocss.selectionStyle') ?? true
+
+  const integrationDecoration = window.createTextEditorDecorationType({})
+
+  async function selectionStyle(editor: TextEditorSelectionChangeEvent) {
+    try {
+      if (!hasSelectionStyle())
+        return reset()
+
+      const doc = editor.textEditor.document
+      if (!doc)
+        return reset()
+
+      const id = doc.uri.fsPath
+      const selection = editor.textEditor.selection
+      const range = new Range(
+        new Position(selection.start.line, selection.start.character),
+        new Position(selection.end.line, selection.end.character),
+      )
+      let code = editor.textEditor.document.getText(range).trim()
+      if (!code.startsWith('<'))
+        code = `<div ${code}`
+      if (!code.endsWith('>'))
+        code = `${code} >`
+      const ctx = await contextLoader.resolveContext(code, id) || (await contextLoader.resolveClosestContext(code, id))
+      const result = await getMatchedPositionsFromCode(ctx.uno, code)
+      if (!result.length)
+        return reset()
+
+      const uniqMap = new Map<string, string>()
+      for (const [start, end, className] of result)
+        uniqMap.set(`${start}-${end}`, className)
+
+      const classNamePlaceholder = '___'
+      const sheetMap = new Map<string, string>()
+      await Promise.all(Array.from(uniqMap.values())
+        .map(async (name) => {
+          const tokens = await ctx.uno.parseToken(name, classNamePlaceholder) || []
+          tokens.forEach((token) => {
+            if (token[1] && token[2]) {
+              const key = token[1]
+                .replace(`.${classNamePlaceholder}`, '&')
+                .replace(regexScopePlaceholder, ' ')
+                .trim()
+              sheetMap.set(key, (sheetMap.get(key) || '') + token[2])
+            }
+          })
+        }),
+      )
+
+      const css = Array.from(sheetMap.keys())
+        .sort()
+        .map(key => `${key}{${sheetMap.get(key)}}`)
+        .join('\n')
+
+      const prettified = prettier.format(css, {
+        parser: 'css',
+        plugins: [parserCSS],
+      })
+
+      editor.textEditor.setDecorations(integrationDecoration, [{
+        range,
+        get hoverMessage() {
+          return new MarkdownString(`UnoCSS utilities in the selection will be equivalent to:\n\`\`\`css\n${prettified.trim()}\n\`\`\``)
+        },
+      }])
+
+      function reset() {
+        editor.textEditor.setDecorations(integrationDecoration, [])
+      }
+    }
+    catch (e) {
+      log.appendLine('⚠️ Error on selectionStyle')
+      log.appendLine(String(e))
+    }
+  }
+
+  window.onDidChangeTextEditorSelection(throttle(selectionStyle, 200))
+}

packages/vscode/src/utils.ts

@@ -9,15 +9,15 @@ import { colorToString } from '@unocss/preset-mini/utils'
 export function throttle<T extends ((...args: any) => any)>(func: T, timeFrame: number): T {
   let lastTime = 0
   let timer: any
-  return function () {
+  return function (...args) {
     const now = Date.now()
     clearTimeout(timer)
     if (now - lastTime >= timeFrame) {
       lastTime = now
-      return func()
+      return func(...args)
     }
     else {
-      timer = setTimeout(func, timeFrame)
+      timer = setTimeout(func, timeFrame, ...args)
     }
   } as T
 }