add auto-fit on double-click for table column/row dividers, row/col indicators on focus

src/EditorView.swift

@@ -331,6 +331,12 @@ class MarkdownTableView: NSView, NSTextFieldDelegate {
     private let defaultCellHeight: CGFloat = 26
     private let dividerHitZone: CGFloat = 6
 
+    private let indicatorRowHeight: CGFloat = 20
+    private let indicatorColWidth: CGFloat = 30
+    private var indicatorsVisible = false
+    private var indicatorContainer: NSView?
+    private var focusMonitor: Any?
+
     private enum DragMode { case none, column(Int), row(Int) }
     private var dragMode: DragMode = .none
     private var dragStartPoint: NSPoint = .zero
@@ -348,10 +354,17 @@ class MarkdownTableView: NSView, NSTextFieldDelegate {
         initSizes(width: width)
         buildGrid()
         setupTrackingArea()
+        setupFocusMonitoring()
     }
 
     required init?(coder: NSCoder) { fatalError() }
 
+    deinit {
+        if let monitor = focusMonitor {
+            NotificationCenter.default.removeObserver(monitor)
+        }
+    }
+
     private func initSizes(width: CGFloat) {
         let colCount = table.headers.count
         guard colCount > 0 else { return }
@@ -389,25 +402,30 @@ class MarkdownTableView: NSView, NSTextFieldDelegate {
 
     private func buildGrid() {
         subviews.forEach { $0.removeFromSuperview() }
+        indicatorContainer = nil
         cellFields = []
 
         let colCount = table.headers.count
         guard colCount > 0 else { return }
         let th = totalHeight
-        let totalWidth = columnX(for: colCount) + 1
+        let ox = indicatorOffset
+        let oy = indicatorTopOffset
+        let gridWidth = columnX(for: colCount) + 1
+        let fullWidth = gridWidth + ox
+        let fullHeight = th + oy
 
-        frame.size = NSSize(width: totalWidth, height: th)
+        frame.size = NSSize(width: fullWidth, height: fullHeight)
 
-        let headerBg = NSView(frame: NSRect(x: 0, y: th - rowHeights[0], width: totalWidth, height: rowHeights[0]))
+        let headerBg = NSView(frame: NSRect(x: ox, y: th - rowHeights[0] + oy, width: gridWidth, height: rowHeights[0]))
         headerBg.wantsLayer = true
         headerBg.layer?.backgroundColor = Theme.current.surface0.cgColor
         addSubview(headerBg)
 
         var headerFields: [NSTextField] = []
         for (col, header) in table.headers.enumerated() {
-            let x = columnX(for: col)
+            let x = columnX(for: col) + ox
             let h = rowHeights[0]
-            let field = makeCell(text: header, frame: NSRect(x: x, y: th - h + 2, width: columnWidths[col], height: h - 4), isHeader: true, row: -1, col: col)
+            let field = makeCell(text: header, frame: NSRect(x: x, y: th - h + 2 + oy, width: columnWidths[col], height: h - 4), isHeader: true, row: -1, col: col)
             addSubview(field)
             headerFields.append(field)
         }
@@ -415,17 +433,17 @@ class MarkdownTableView: NSView, NSTextFieldDelegate {
 
         for (rowIdx, row) in table.rows.enumerated() {
             var rowFields: [NSTextField] = []
-            let y = rowY(for: rowIdx + 1)
+            let y = rowY(for: rowIdx + 1) + oy
             let h = rowHeights[rowIdx + 1]
             for (col, cell) in row.enumerated() where col < colCount {
-                let x = columnX(for: col)
+                let x = columnX(for: col) + ox
                 let field = makeCell(text: cell, frame: NSRect(x: x, y: y + 2, width: columnWidths[col], height: h - 4), isHeader: false, row: rowIdx, col: col)
                 addSubview(field)
                 rowFields.append(field)
             }
             while rowFields.count < colCount {
                 let col = rowFields.count
-                let x = columnX(for: col)
+                let x = columnX(for: col) + ox
                 let field = makeCell(text: "", frame: NSRect(x: x, y: y + 2, width: columnWidths[col], height: h - 4), isHeader: false, row: rowIdx, col: col)
                 addSubview(field)
                 rowFields.append(field)
@@ -435,19 +453,23 @@ class MarkdownTableView: NSView, NSTextFieldDelegate {
 
         let totalRows = 1 + table.rows.count
         for i in 1..<colCount {
-            let x = columnX(for: i) - 1
+            let x = columnX(for: i) - 1 + ox
-            let line = NSView(frame: NSRect(x: x, y: 0, width: 1, height: th))
+            let line = NSView(frame: NSRect(x: x, y: oy, width: 1, height: th))
             line.wantsLayer = true
             line.layer?.backgroundColor = Theme.current.surface2.cgColor
             addSubview(line)
         }
         for i in 0..<totalRows {
-            let lineY = (i == 0) ? th - rowHeights[0] : rowY(for: i)
+            let lineY = ((i == 0) ? th - rowHeights[0] : rowY(for: i)) + oy
-            let line = NSView(frame: NSRect(x: 0, y: lineY, width: totalWidth, height: 1))
+            let line = NSView(frame: NSRect(x: ox, y: lineY, width: gridWidth, height: 1))
             line.wantsLayer = true
             line.layer?.backgroundColor = Theme.current.surface2.cgColor
             addSubview(line)
         }
+
+        if indicatorsVisible {
+            buildIndicators()
+        }
     }
 
     private func makeCell(text: String, frame: NSRect, isHeader: Bool, row: Int, col: Int) -> NSTextField {
@@ -474,17 +496,131 @@ class MarkdownTableView: NSView, NSTextFieldDelegate {
         return field
     }
 
+    // MARK: - Column letter helper
+
+    private func columnLetter(for index: Int) -> String {
+        var n = index
+        var result = ""
+        repeat {
+            result = String(UnicodeScalar(65 + (n % 26))!) + result
+            n = n / 26 - 1
+        } while n >= 0
+        return result
+    }
+
+    // MARK: - Indicators
+
+    private var indicatorOffset: CGFloat {
+        indicatorsVisible ? indicatorColWidth : 0
+    }
+
+    private var indicatorTopOffset: CGFloat {
+        indicatorsVisible ? indicatorRowHeight : 0
+    }
+
+    private func buildIndicators() {
+        indicatorContainer?.removeFromSuperview()
+
+        let container = NSView(frame: bounds)
+        container.wantsLayer = true
+        container.alphaValue = indicatorsVisible ? 1 : 0
+        addSubview(container)
+        indicatorContainer = container
+
+        let colCount = table.headers.count
+        let totalRows = 1 + table.rows.count
+        let th = totalHeight + indicatorTopOffset
+        let indicatorBg = Theme.current.surface0
+
+        let corner = NSView(frame: NSRect(x: 0, y: th - indicatorRowHeight, width: indicatorColWidth, height: indicatorRowHeight))
+        corner.wantsLayer = true
+        corner.layer?.backgroundColor = indicatorBg.cgColor
+        container.addSubview(corner)
+
+        for col in 0..<colCount {
+            let x = indicatorColWidth + columnX(for: col)
+            let label = NSTextField(labelWithString: columnLetter(for: col))
+            label.font = NSFont.systemFont(ofSize: 10, weight: .medium)
+            label.textColor = Theme.current.overlay2
+            label.alignment = .center
+            label.frame = NSRect(x: x, y: th - indicatorRowHeight, width: columnWidths[col], height: indicatorRowHeight)
+            label.wantsLayer = true
+            label.layer?.backgroundColor = indicatorBg.cgColor
+            container.addSubview(label)
+        }
+
+        for row in 0..<totalRows {
+            let y = rowY(for: row)
+            let label = NSTextField(labelWithString: "\(row + 1)")
+            label.font = NSFont.systemFont(ofSize: 10, weight: .medium)
+            label.textColor = Theme.current.overlay2
+            label.alignment = .center
+            label.frame = NSRect(x: 0, y: y, width: indicatorColWidth, height: rowHeights[row])
+            label.wantsLayer = true
+            label.layer?.backgroundColor = indicatorBg.cgColor
+            container.addSubview(label)
+        }
+    }
+
+    private func showIndicators() {
+        guard !indicatorsVisible else { return }
+        indicatorsVisible = true
+        buildGrid()
+        NSAnimationContext.runAnimationGroup { ctx in
+            ctx.duration = 0.2
+            self.indicatorContainer?.animator().alphaValue = 1
+        }
+    }
+
+    private func hideIndicators() {
+        guard indicatorsVisible else { return }
+        NSAnimationContext.runAnimationGroup({ ctx in
+            ctx.duration = 0.2
+            self.indicatorContainer?.animator().alphaValue = 0
+        }, completionHandler: { [weak self] in
+            guard let self = self else { return }
+            self.indicatorsVisible = false
+            self.buildGrid()
+        })
+    }
+
+    private func setupFocusMonitoring() {
+        focusMonitor = NotificationCenter.default.addObserver(
+            forName: NSWindow.didUpdateNotification,
+            object: nil,
+            queue: .main
+        ) { [weak self] _ in
+            self?.checkFocusState()
+        }
+    }
+
+    private func checkFocusState() {
+        guard let w = window else { return }
+        let fr = w.firstResponder
+        let hasFocusedCell = cellFields.joined().contains { field in
+            fr === field || (fr as? NSTextView)?.delegate === field
+        }
+        if hasFocusedCell && !indicatorsVisible {
+            showIndicators()
+        } else if !hasFocusedCell && indicatorsVisible && !mouseInside {
+            hideIndicators()
+        }
+    }
+
+    private var mouseInside = false
+
     // MARK: - Resize hit detection
 
     private func columnDivider(at point: NSPoint) -> Int? {
+        let ox = indicatorOffset
         let colCount = table.headers.count
         for i in 1..<colCount {
-            let divX = columnX(for: i) - 1
+            let divX = columnX(for: i) - 1 + ox
             if abs(point.x - divX) <= dividerHitZone {
                 return i - 1
             }
         }
-        let lastX = columnX(for: colCount)
+        let lastX = columnX(for: colCount) + ox
         if abs(point.x - lastX) <= dividerHitZone {
             return colCount - 1
         }
@@ -492,13 +628,14 @@ class MarkdownTableView: NSView, NSTextFieldDelegate {
     }
 
     private func rowDivider(at point: NSPoint) -> Int? {
+        let oy = indicatorTopOffset
         let totalRows = 1 + table.rows.count
         for i in 0..<totalRows {
             let divY: CGFloat
             if i == 0 {
-                divY = totalHeight - rowHeights[0]
+                divY = totalHeight - rowHeights[0] + oy
             } else {
-                divY = rowY(for: i)
+                divY = rowY(for: i) + oy
             }
             if abs(point.y - divY) <= dividerHitZone {
                 return i
@@ -531,19 +668,34 @@ class MarkdownTableView: NSView, NSTextFieldDelegate {
         }
     }
 
+    override func mouseEntered(with event: NSEvent) {
+        mouseInside = true
+        showIndicators()
+    }
+
     override func mouseExited(with event: NSEvent) {
         NSCursor.arrow.set()
+        mouseInside = false
+        checkFocusState()
     }
 
     override func mouseDown(with event: NSEvent) {
         let pt = convert(event.locationInWindow, from: nil)
         if let col = columnDivider(at: pt) {
+            if event.clickCount == 2 {
+                autoFitColumn(col)
+                return
+            }
             dragMode = .column(col)
             dragStartPoint = pt
             dragStartSize = columnWidths[col]
             return
         }
         if let row = rowDivider(at: pt) {
+            if event.clickCount == 2 {
+                autoFitRow(row)
+                return
+            }
             dragMode = .row(row)
             dragStartPoint = pt
             dragStartSize = rowHeights[row]
@@ -576,6 +728,56 @@ class MarkdownTableView: NSView, NSTextFieldDelegate {
         dragMode = .none
     }
 
+    // MARK: - Auto-fit
+
+    private func measureColumnWidth(_ col: Int) -> CGFloat {
+        let headerFont = NSFontManager.shared.convert(Theme.editorFont, toHaveTrait: .boldFontMask)
+        let cellFont = Theme.editorFont
+
+        var maxW: CGFloat = 0
+        if col < table.headers.count {
+            let w = (table.headers[col] as NSString).size(withAttributes: [.font: headerFont]).width
+            maxW = max(maxW, w)
+        }
+        for row in table.rows {
+            guard col < row.count else { continue }
+            let w = (row[col] as NSString).size(withAttributes: [.font: cellFont]).width
+            maxW = max(maxW, w)
+        }
+        return max(maxW + 16, minColWidth)
+    }
+
+    private func measureRowHeight(_ row: Int) -> CGFloat {
+        let font: NSFont = row == 0
+            ? NSFontManager.shared.convert(Theme.editorFont, toHaveTrait: .boldFontMask)
+            : Theme.editorFont
+        let cells: [String] = row == 0 ? table.headers : (row - 1 < table.rows.count ? table.rows[row - 1] : [])
+
+        var maxH: CGFloat = 0
+        for (col, text) in cells.enumerated() where col < columnWidths.count {
+            let constrainedSize = NSSize(width: columnWidths[col], height: .greatestFiniteMagnitude)
+            let rect = (text as NSString).boundingRect(
+                with: constrainedSize,
+                options: [.usesLineFragmentOrigin],
+                attributes: [.font: font]
+            )
+            maxH = max(maxH, rect.height)
+        }
+        return max(maxH + 8, minRowHeight)
+    }
+
+    private func autoFitColumn(_ col: Int) {
+        guard col >= 0, col < columnWidths.count else { return }
+        columnWidths[col] = measureColumnWidth(col)
+        buildGrid()
+    }
+
+    private func autoFitRow(_ row: Int) {
+        guard row >= 0, row < rowHeights.count else { return }
+        rowHeights[row] = measureRowHeight(row)
+        buildGrid()
+    }
+
     // MARK: - Cell editing
 
     func controlTextDidEndEditing(_ obj: Notification) {