fix(blockwise-visual): handle double-width chars and tabs (#1596)

* improve: the selection direction is consistent with nvim

* test: fix blockwise visual test

* refactor: use ternary

runtime/lua/vscode-neovim/internal.lua

@@ -115,4 +115,51 @@ do
   end
 end
 
+---display-col to col
+---@param line string
+---@param discol number
+local function discol_to_col(line, discol)
+  if discol == 0 then
+    return 0
+  end
+
+  local col = 0
+  local max_col = vim.fn.strcharlen(line)
+
+  local min_distance = math.huge
+  local nearest_col = 0
+
+  while col <= max_col do
+    local curr_col = math.floor((col + max_col) / 2)
+    local curr_discol = fn.strdisplaywidth(fn.strcharpart(line, 0, curr_col))
+    if curr_discol == discol then
+      return curr_col
+    elseif curr_discol > discol then
+      max_col = curr_col - 1
+    else
+      col = curr_col + 1
+    end
+
+    local curr_distance = math.abs(curr_discol - discol)
+    if curr_distance < min_distance then
+      min_distance = curr_distance
+      nearest_col = curr_col
+    elseif curr_distance == min_distance and curr_col < nearest_col then
+      nearest_col = curr_col
+    end
+  end
+  return nearest_col
+end
+
+function M.handle_blockwise_selection(lines, start_discol, end_discol)
+  local result = {}
+  for _, line in ipairs(lines) do
+    table.insert(result, {
+      discol_to_col(line, start_discol),
+      discol_to_col(line, end_discol),
+    })
+  end
+  return result
+end
+
 return M

src/cursor_manager.ts

@@ -3,6 +3,7 @@ import {
     commands,
     Disposable,
     Position,
+    Range,
     Selection,
     TextEditor,
     TextEditorCursorStyle,
@@ -420,7 +421,6 @@ export class CursorManager implements Disposable {
         anchor: Position | undefined,
     ): Promise<Selection[]> => {
         const doc = editor.document;
-
         if (!anchor) {
             const anchorNvim = await this.client.callFunction("getpos", ["v"]);
             anchor = convertVimPositionToEditorPosition(editor, new Position(anchorNvim[1] - 1, anchorNvim[2] - 1));
@@ -437,50 +437,71 @@ export class CursorManager implements Disposable {
         // we hide the real cursor and use a highlight decorator for the fake cursor
         switch (mode.visual) {
             case "char":
-                if (anchor.isBeforeOrEqual(active))
-                    return [
-                        new Selection(
-                            anchor,
-                            new Position(active.line, Math.min(active.character + 1, activeLineLength)),
-                        ),
-                    ];
-                else
-                    return [
-                        new Selection(
-                            new Position(anchor.line, Math.min(anchor.character + 1, anchorLineLength)),
-                            active,
-                        ),
-                    ];
+                return [
+                    anchor.isBeforeOrEqual(active)
+                        ? new Selection(
+                              anchor,
+                              new Position(active.line, Math.min(active.character + 1, activeLineLength)),
+                          )
+                        : new Selection(
+                              new Position(anchor.line, Math.min(anchor.character + 1, anchorLineLength)),
+                              active,
+                          ),
+                ];
             case "line":
-                if (anchor.line <= active.line) return [new Selection(anchor.line, 0, active.line, activeLineLength)];
-                else return [new Selection(anchor.line, anchorLineLength, active.line, 0)];
+                return [
+                    anchor.line <= active.line
+                        ? new Selection(anchor.line, 0, active.line, activeLineLength)
+                        : new Selection(anchor.line, anchorLineLength, active.line, 0),
+                ];
             case "block": {
-                const selections: Selection[] = [];
-                // we want the first selection to be on the cursor line, so that a single-line selection will properly trigger word highlight
-                const before = anchor.line < active.line;
-                for (
-                    let line = active.line;
-                    before ? line >= anchor.line : line <= anchor.line;
-                    before ? line-- : line++
-                ) {
-                    // skip lines that don't contain the block selection, except if it contains the cursor
-                    const docLine = doc.lineAt(line);
-                    if (
-                        docLine.range.end.character > Math.min(anchor.character, active.character) ||
-                        line === active.line
-                    ) {
-                        // selections go left to right for simplicity, and don't go past the end of the line
-                        selections.push(
-                            new Selection(
-                                line,
-                                Math.min(anchor.character, active.character),
-                                line,
-                                Math.min(Math.max(anchor.character, active.character) + 1, docLine.range.end.character),
-                            ),
-                        );
-                    }
+                const getDisplayWidth = async (...pos: Position[]) => {
+                    const parts = pos.map((p) => {
+                        const textRange = doc.validateRange(new Range(p.line, 0, p.line, p.character));
+                        return doc.getText(textRange);
+                    });
+                    return this.client.lua(
+                        `
+                   return (function(parts)
+                        return vim.tbl_map(function(part) return vim.fn.strdisplaywidth(part) end, parts)
+                    end)(...)
+                    `,
+                        [parts],
+                    ) as Promise<number[]>;
+                };
+
+                const [anchorDisCol, activeDisCol] = await getDisplayWidth(anchor, active);
+                const [startDisCol, endDisCol] = [
+                    Math.min(anchorDisCol, activeDisCol),
+                    Math.max(anchorDisCol, activeDisCol),
+                ];
+
+                const lines = [];
+                const startLine = Math.min(active.line, anchor.line);
+                const endLine = Math.max(active.line, anchor.line);
+                for (let line = startLine; line <= endLine; line++) {
+                    lines.push(doc.lineAt(line).text);
                 }
-                return selections;
+                const _code = 'return require"vscode-neovim.internal".handle_blockwise_selection(...)';
+                const ret = (await this.client.lua(_code, [lines, startDisCol, endDisCol])) as [number, number][];
+
+                const ranges: Range[] = [];
+                ret.forEach(([startChar, endChar], idx) => {
+                    const line = idx + startLine;
+                    const lineRange = doc.lineAt(line).range;
+                    const range = lineRange.intersection(new Range(line, startChar, line, endChar));
+                    if (range && (range.start.isBefore(lineRange.end) || line === active.line)) ranges.push(range);
+                });
+
+                // correct the orientation
+                const selections = ranges.map((r) => {
+                    const range = doc.validateRange(new Range(r.start, r.end.translate(0, 1)));
+                    return activeDisCol >= anchorDisCol
+                        ? new Selection(range.start, range.end)
+                        : new Selection(range.end, range.start);
+                });
+                // Make sure word highlighting is triggered correctly
+                return anchor.isBeforeOrEqual(active) ? selections.reverse() : selections;
             }
         }
     };

src/test/suite/visual-modes.test.ts

@@ -237,7 +237,7 @@ describe("Visual modes test", () => {
         await sendVSCodeKeys("0");
         await assertContent(
             {
-                vsCodeSelections: [new vscode.Selection(0, 0, 0, 7), new vscode.Selection(1, 0, 1, 7)],
+                vsCodeSelections: [new vscode.Selection(0, 7, 0, 0), new vscode.Selection(1, 7, 1, 0)],
             },
             client,
         );
@@ -271,7 +271,7 @@ describe("Visual modes test", () => {
         await sendVSCodeKeys("j");
         await assertContent(
             {
-                vsCodeSelections: [new vscode.Selection(1, 1, 1, 1), new vscode.Selection(0, 1, 0, 3)],
+                vsCodeSelections: [new vscode.Selection(1, 1, 1, 1), new vscode.Selection(0, 3, 0, 1)],
             },
             client,
         );