terminal/new: save cursor, protected modes

src/terminal/Terminal.zig

@@ -5334,6 +5334,7 @@ test "Terminal: eraseChars wide character" {
     }
 }
 
+// X
 test "Terminal: eraseChars protected attributes respected with iso" {
     const alloc = testing.allocator;
     var t = try init(alloc, 5, 5);
@@ -5351,6 +5352,7 @@ test "Terminal: eraseChars protected attributes respected with iso" {
     }
 }
 
+// X
 test "Terminal: eraseChars protected attributes ignored with dec most recent" {
     const alloc = testing.allocator;
     var t = try init(alloc, 5, 5);
@@ -5370,6 +5372,7 @@ test "Terminal: eraseChars protected attributes ignored with dec most recent" {
     }
 }
 
+// X
 test "Terminal: eraseChars protected attributes ignored with dec set" {
     const alloc = testing.allocator;
     var t = try init(alloc, 5, 5);
@@ -5592,6 +5595,23 @@ test "Terminal: saveCursor resize" {
     }
 }
 
+// X
+test "Terminal: saveCursor protected pen" {
+    const alloc = testing.allocator;
+    var t = try init(alloc, 10, 5);
+    defer t.deinit(alloc);
+
+    t.setProtectedMode(.iso);
+    try testing.expect(t.screen.cursor.pen.attrs.protected);
+    t.setCursorPos(1, 10);
+    t.saveCursor();
+    t.setProtectedMode(.off);
+    try testing.expect(!t.screen.cursor.pen.attrs.protected);
+    t.restoreCursor();
+    try testing.expect(t.screen.cursor.pen.attrs.protected);
+}
+
+// X
 test "Terminal: setProtectedMode" {
     const alloc = testing.allocator;
     var t = try init(alloc, 3, 3);

src/terminal/new/Screen.zig

@@ -3,6 +3,7 @@ const Screen = @This();
 const std = @import("std");
 const Allocator = std.mem.Allocator;
 const assert = std.debug.assert;
+const ansi = @import("../ansi.zig");
 const sgr = @import("../sgr.zig");
 const unicode = @import("../../unicode/main.zig");
 const PageList = @import("PageList.zig");
@@ -25,6 +26,13 @@ cursor: Cursor,
 /// The saved cursor
 saved_cursor: ?SavedCursor = null,
 
+/// The current or most recent protected mode. Once a protection mode is
+/// set, this will never become "off" again until the screen is reset.
+/// The current state of whether protection attributes should be set is
+/// set on the Cell pen; this is only used to determine the most recent
+/// protection mode since some sequences such as ECH depend on this.
+protected_mode: ansi.ProtectedMode = .off,
+
 /// The cursor position.
 pub const Cursor = struct {
     // The x/y position within the viewport.
@@ -35,6 +43,10 @@ pub const Cursor = struct {
     /// next character print will force a soft-wrap.
     pending_wrap: bool = false,
 
+    /// The protected mode state of the cursor. If this is true then
+    /// all new characters printed will have the protected state set.
+    protected: bool = false,
+
     /// The currently active style. This is the concrete style value
     /// that should be kept up to date. The style ID to use for cell writing
     /// is below.
@@ -58,6 +70,7 @@ pub const SavedCursor = struct {
     x: size.CellCountInt,
     y: size.CellCountInt,
     style: style.Style,
+    protected: bool,
     pending_wrap: bool,
     origin: bool,
     // TODO

src/terminal/new/Terminal.zig

@@ -544,6 +544,7 @@ fn printCell(
         .content = .{ .codepoint = c },
         .style_id = self.screen.cursor.style_id,
         .wide = wide,
+        .protected = self.screen.cursor.protected,
     };
 
     // Handle the style ref count handling
@@ -783,6 +784,7 @@ pub fn saveCursor(self: *Terminal) void {
         .x = self.screen.cursor.x,
         .y = self.screen.cursor.y,
         .style = self.screen.cursor.style,
+        .protected = self.screen.cursor.protected,
         .pending_wrap = self.screen.cursor.pending_wrap,
         .origin = self.modes.get(.origin),
         //TODO
@@ -799,6 +801,7 @@ pub fn restoreCursor(self: *Terminal) !void {
         .x = 0,
         .y = 0,
         .style = .{},
+        .protected = false,
         .pending_wrap = false,
         .origin = false,
         // TODO
@@ -814,12 +817,36 @@ pub fn restoreCursor(self: *Terminal) !void {
     //self.screen.charset = saved.charset;
     self.modes.set(.origin, saved.origin);
     self.screen.cursor.pending_wrap = saved.pending_wrap;
+    self.screen.cursor.protected = saved.protected;
     self.screen.cursorAbsolute(
         @min(saved.x, self.cols - 1),
         @min(saved.y, self.rows - 1),
     );
 }
 
+/// Set the character protection mode for the terminal.
+pub fn setProtectedMode(self: *Terminal, mode: ansi.ProtectedMode) void {
+    switch (mode) {
+        .off => {
+            self.screen.cursor.protected = false;
+
+            // screen.protected_mode is NEVER reset to ".off" because
+            // logic such as eraseChars depends on knowing what the
+            // _most recent_ mode was.
+        },
+
+        .iso => {
+            self.screen.cursor.protected = true;
+            self.screen.protected_mode = .iso;
+        },
+
+        .dec => {
+            self.screen.cursor.protected = true;
+            self.screen.protected_mode = .dec;
+        },
+    }
+}
+
 /// Horizontal tab moves the cursor to the next tabstop, clearing
 /// the screen to the left the tabstop.
 pub fn horizontalTab(self: *Terminal) !void {
@@ -1441,6 +1468,12 @@ pub fn deleteChars(self: *Terminal, count: usize) void {
 pub fn eraseChars(self: *Terminal, count_req: usize) void {
     const count = @max(count_req, 1);
 
+    // This resets the soft-wrap of this line
+    self.screen.cursor.page_row.wrap = false;
+
+    // This resets the pending wrap state
+    self.screen.cursor.pending_wrap = false;
+
     // Our last index is at most the end of the number of chars we have
     // in the current line.
     const end = end: {
@@ -1459,38 +1492,32 @@ pub fn eraseChars(self: *Terminal, count_req: usize) void {
 
     // Clear the cells
     const cells: [*]Cell = @ptrCast(self.screen.cursor.page_cell);
+
+    // If we never had a protection mode, then we can assume no cells
+    // are protected and go with the fast path. If the last protection
+    // mode was not ISO we also always ignore protection attributes.
+    if (self.screen.protected_mode != .iso) {
         self.blankCells(
             &self.screen.cursor.page_offset.page.data,
             self.screen.cursor.page_row,
             cells[0..end],
         );
+        return;
+    }
 
-    // This resets the soft-wrap of this line
-    self.screen.cursor.page_row.wrap = false;
-
-    // This resets the pending wrap state
-    self.screen.cursor.pending_wrap = false;
-
-    // TODO: protected mode, see below for old logic
-    //
-    // const pen: Screen.Cell = .{
-    //     .bg = self.screen.cursor.pen.bg,
-    // };
-    //
-    // // If we never had a protection mode, then we can assume no cells
-    // // are protected and go with the fast path. If the last protection
-    // // mode was not ISO we also always ignore protection attributes.
-    // if (self.screen.protected_mode != .iso) {
-    //     row.fillSlice(pen, self.screen.cursor.x, end);
-    // }
-    //
-    // // We had a protection mode at some point. We must go through each
-    // // cell and check its protection attribute.
-    // for (self.screen.cursor.x..end) |x| {
-    //     const cell = row.getCellPtr(x);
-    //     if (cell.attrs.protected) continue;
-    //     cell.* = pen;
-    // }
+    // SLOW PATH
+    // We had a protection mode at some point. We must go through each
+    // cell and check its protection attribute.
+    for (0..end) |x| {
+        const cell_multi: [*]Cell = @ptrCast(cells + x);
+        const cell: *Cell = @ptrCast(&cell_multi[0]);
+        if (cell.protected) continue;
+        self.blankCells(
+            &self.screen.cursor.page_offset.page.data,
+            self.screen.cursor.page_row,
+            cell_multi[0..1],
+        );
+    }
 }
 
 /// Blank the given cells. The cells must be long to the given row and page.
@@ -3560,6 +3587,59 @@ test "Terminal: eraseChars handles refcounted styles" {
     try testing.expectEqual(@as(usize, 0), page.styles.count(page.memory));
 }
 
+test "Terminal: eraseChars protected attributes respected with iso" {
+    const alloc = testing.allocator;
+    var t = try init(alloc, 5, 5);
+    defer t.deinit(alloc);
+
+    t.setProtectedMode(.iso);
+    for ("ABC") |c| try t.print(c);
+    t.setCursorPos(1, 1);
+    t.eraseChars(2);
+
+    {
+        const str = try t.plainString(testing.allocator);
+        defer testing.allocator.free(str);
+        try testing.expectEqualStrings("ABC", str);
+    }
+}
+
+test "Terminal: eraseChars protected attributes ignored with dec most recent" {
+    const alloc = testing.allocator;
+    var t = try init(alloc, 5, 5);
+    defer t.deinit(alloc);
+
+    t.setProtectedMode(.iso);
+    for ("ABC") |c| try t.print(c);
+    t.setProtectedMode(.dec);
+    t.setProtectedMode(.off);
+    t.setCursorPos(1, 1);
+    t.eraseChars(2);
+
+    {
+        const str = try t.plainString(testing.allocator);
+        defer testing.allocator.free(str);
+        try testing.expectEqualStrings("  C", str);
+    }
+}
+
+test "Terminal: eraseChars protected attributes ignored with dec set" {
+    const alloc = testing.allocator;
+    var t = try init(alloc, 5, 5);
+    defer t.deinit(alloc);
+
+    t.setProtectedMode(.dec);
+    for ("ABC") |c| try t.print(c);
+    t.setCursorPos(1, 1);
+    t.eraseChars(2);
+
+    {
+        const str = try t.plainString(testing.allocator);
+        defer testing.allocator.free(str);
+        try testing.expectEqualStrings("  C", str);
+    }
+}
+
 test "Terminal: reverseIndex" {
     const alloc = testing.allocator;
     var t = try init(alloc, 2, 5);
@@ -5586,3 +5666,34 @@ test "Terminal: saveCursor origin mode" {
         try testing.expectEqualStrings("X", str);
     }
 }
+
+test "Terminal: saveCursor protected pen" {
+    const alloc = testing.allocator;
+    var t = try init(alloc, 10, 5);
+    defer t.deinit(alloc);
+
+    t.setProtectedMode(.iso);
+    try testing.expect(t.screen.cursor.protected);
+    t.setCursorPos(1, 10);
+    t.saveCursor();
+    t.setProtectedMode(.off);
+    try testing.expect(!t.screen.cursor.protected);
+    try t.restoreCursor();
+    try testing.expect(t.screen.cursor.protected);
+}
+
+test "Terminal: setProtectedMode" {
+    const alloc = testing.allocator;
+    var t = try init(alloc, 3, 3);
+    defer t.deinit(alloc);
+
+    try testing.expect(!t.screen.cursor.protected);
+    t.setProtectedMode(.off);
+    try testing.expect(!t.screen.cursor.protected);
+    t.setProtectedMode(.iso);
+    try testing.expect(t.screen.cursor.protected);
+    t.setProtectedMode(.dec);
+    try testing.expect(t.screen.cursor.protected);
+    t.setProtectedMode(.off);
+    try testing.expect(!t.screen.cursor.protected);
+}

src/terminal/new/page.zig

@@ -537,7 +537,10 @@ pub const Cell = packed struct(u64) {
     /// and spacer properties of a cell.
     wide: Wide = .narrow,
 
-    _padding: u20 = 0,
+    /// Whether this was written with the protection flag set.
+    protected: bool = false,
+
+    _padding: u19 = 0,
 
     pub const ContentTag = enum(u2) {
         /// A single codepoint, could be zero to be empty cell.