ghostty/src/terminal/new/Screen.zig
2024-03-22 20:27:29 -07:00

626 lines
19 KiB
Zig

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");
const pagepkg = @import("page.zig");
const point = @import("point.zig");
const size = @import("size.zig");
const style = @import("style.zig");
const Page = pagepkg.Page;
/// The general purpose allocator to use for all memory allocations.
/// Unfortunately some screen operations do require allocation.
alloc: Allocator,
/// The list of pages in the screen.
pages: PageList,
/// The current cursor position
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.
x: size.CellCountInt,
y: size.CellCountInt,
/// The "last column flag (LCF)" as its called. If this is set then the
/// 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.
style: style.Style = .{},
/// The currently active style ID. The style is page-specific so when
/// we change pages we need to ensure that we update that page with
/// our style when used.
style_id: style.Id = style.default_id,
style_ref: ?*size.CellCountInt = null,
/// The pointers into the page list where the cursor is currently
/// located. This makes it faster to move the cursor.
page_offset: PageList.RowOffset,
page_row: *pagepkg.Row,
page_cell: *pagepkg.Cell,
};
/// Saved cursor state.
pub const SavedCursor = struct {
x: size.CellCountInt,
y: size.CellCountInt,
style: style.Style,
protected: bool,
pending_wrap: bool,
origin: bool,
// TODO
//charset: CharsetState,
};
/// Initialize a new screen.
pub fn init(
alloc: Allocator,
cols: size.CellCountInt,
rows: size.CellCountInt,
max_scrollback: usize,
) !Screen {
// Initialize our backing pages.
var pages = try PageList.init(alloc, cols, rows, max_scrollback);
errdefer pages.deinit();
// The active area is guaranteed to be allocated and the first
// page in the list after init. This lets us quickly setup the cursor.
// This is MUCH faster than pages.rowOffset.
const page_offset: PageList.RowOffset = .{
.page = pages.pages.first.?,
.row_offset = 0,
};
const page_rac = page_offset.rowAndCell(0);
return .{
.alloc = alloc,
.pages = pages,
.cursor = .{
.x = 0,
.y = 0,
.page_offset = page_offset,
.page_row = page_rac.row,
.page_cell = page_rac.cell,
},
};
}
pub fn deinit(self: *Screen) void {
self.pages.deinit();
}
pub fn cursorCellRight(self: *Screen, n: size.CellCountInt) *pagepkg.Cell {
assert(self.cursor.x + n < self.pages.cols);
const cell: [*]pagepkg.Cell = @ptrCast(self.cursor.page_cell);
return @ptrCast(cell + n);
}
pub fn cursorCellLeft(self: *Screen, n: size.CellCountInt) *pagepkg.Cell {
assert(self.cursor.x >= n);
const cell: [*]pagepkg.Cell = @ptrCast(self.cursor.page_cell);
return @ptrCast(cell - n);
}
pub fn cursorCellEndOfPrev(self: *Screen) *pagepkg.Cell {
assert(self.cursor.y > 0);
const page_offset = self.cursor.page_offset.backward(1).?;
const page_rac = page_offset.rowAndCell(self.pages.cols - 1);
return page_rac.cell;
}
/// Move the cursor right. This is a specialized function that is very fast
/// if the caller can guarantee we have space to move right (no wrapping).
pub fn cursorRight(self: *Screen, n: size.CellCountInt) void {
assert(self.cursor.x + n < self.pages.cols);
const cell: [*]pagepkg.Cell = @ptrCast(self.cursor.page_cell);
self.cursor.page_cell = @ptrCast(cell + n);
self.cursor.x += n;
}
/// Move the cursor left.
pub fn cursorLeft(self: *Screen, n: size.CellCountInt) void {
assert(self.cursor.x >= n);
const cell: [*]pagepkg.Cell = @ptrCast(self.cursor.page_cell);
self.cursor.page_cell = @ptrCast(cell - n);
self.cursor.x -= n;
}
/// Move the cursor up.
///
/// Precondition: The cursor is not at the top of the screen.
pub fn cursorUp(self: *Screen, n: size.CellCountInt) void {
assert(self.cursor.y >= n);
const page_offset = self.cursor.page_offset.backward(n).?;
const page_rac = page_offset.rowAndCell(self.cursor.x);
self.cursor.page_offset = page_offset;
self.cursor.page_row = page_rac.row;
self.cursor.page_cell = page_rac.cell;
self.cursor.y -= n;
}
pub fn cursorRowUp(self: *Screen, n: size.CellCountInt) *pagepkg.Row {
assert(self.cursor.y >= n);
const page_offset = self.cursor.page_offset.backward(n).?;
const page_rac = page_offset.rowAndCell(self.cursor.x);
return page_rac.row;
}
/// Move the cursor down.
///
/// Precondition: The cursor is not at the bottom of the screen.
pub fn cursorDown(self: *Screen, n: size.CellCountInt) void {
assert(self.cursor.y + n < self.pages.rows);
// We move the offset into our page list to the next row and then
// get the pointers to the row/cell and set all the cursor state up.
const page_offset = self.cursor.page_offset.forward(n).?;
const page_rac = page_offset.rowAndCell(self.cursor.x);
self.cursor.page_offset = page_offset;
self.cursor.page_row = page_rac.row;
self.cursor.page_cell = page_rac.cell;
// Y of course increases
self.cursor.y += n;
}
/// Move the cursor to some absolute horizontal position.
pub fn cursorHorizontalAbsolute(self: *Screen, x: size.CellCountInt) void {
assert(x < self.pages.cols);
const page_rac = self.cursor.page_offset.rowAndCell(x);
self.cursor.page_cell = page_rac.cell;
self.cursor.x = x;
}
/// Move the cursor to some absolute position.
pub fn cursorAbsolute(self: *Screen, x: size.CellCountInt, y: size.CellCountInt) void {
assert(x < self.pages.cols);
assert(y < self.pages.rows);
const page_offset = if (y < self.cursor.y)
self.cursor.page_offset.backward(self.cursor.y - y).?
else if (y > self.cursor.y)
self.cursor.page_offset.forward(y - self.cursor.y).?
else
self.cursor.page_offset;
const page_rac = page_offset.rowAndCell(x);
self.cursor.page_offset = page_offset;
self.cursor.page_row = page_rac.row;
self.cursor.page_cell = page_rac.cell;
self.cursor.x = x;
self.cursor.y = y;
}
/// Scroll the active area and keep the cursor at the bottom of the screen.
/// This is a very specialized function but it keeps it fast.
pub fn cursorDownScroll(self: *Screen) !void {
assert(self.cursor.y == self.pages.rows - 1);
// Grow our pages by one row. The PageList will handle if we need to
// allocate, prune scrollback, whatever.
_ = try self.pages.grow();
const page_offset = self.cursor.page_offset.forward(1).?;
const page_rac = page_offset.rowAndCell(self.cursor.x);
self.cursor.page_offset = page_offset;
self.cursor.page_row = page_rac.row;
self.cursor.page_cell = page_rac.cell;
// The newly created line needs to be styled according to the bg color
// if it is set.
if (self.cursor.style_id != style.default_id) {
if (self.cursor.style.bgCell()) |blank_cell| {
const cell_current: [*]pagepkg.Cell = @ptrCast(self.cursor.page_cell);
const cells = cell_current - self.cursor.x;
@memset(cells[0..self.pages.cols], blank_cell);
}
}
}
/// Options for scrolling the viewport of the terminal grid. The reason
/// we have this in addition to PageList.Scroll is because we have additional
/// scroll behaviors that are not part of the PageList.Scroll enum.
pub const Scroll = union(enum) {
/// For all of these, see PageList.Scroll.
active,
top,
delta_row: isize,
};
/// Scroll the viewport of the terminal grid.
pub fn scroll(self: *Screen, behavior: Scroll) void {
switch (behavior) {
.active => self.pages.scroll(.{ .active = {} }),
.top => self.pages.scroll(.{ .top = {} }),
.delta_row => |v| self.pages.scroll(.{ .delta_row = v }),
}
}
/// Set a style attribute for the current cursor.
///
/// This can cause a page split if the current page cannot fit this style.
/// This is the only scenario an error return is possible.
pub fn setAttribute(self: *Screen, attr: sgr.Attribute) !void {
switch (attr) {
.unset => {
self.cursor.style = .{};
},
.bold => {
self.cursor.style.flags.bold = true;
},
.reset_bold => {
// Bold and faint share the same SGR code for this
self.cursor.style.flags.bold = false;
self.cursor.style.flags.faint = false;
},
.italic => {
self.cursor.style.flags.italic = true;
},
.reset_italic => {
self.cursor.style.flags.italic = false;
},
.faint => {
self.cursor.style.flags.faint = true;
},
.underline => |v| {
self.cursor.style.flags.underline = v;
},
.reset_underline => {
self.cursor.style.flags.underline = .none;
},
.underline_color => |rgb| {
self.cursor.style.underline_color = .{ .rgb = .{
.r = rgb.r,
.g = rgb.g,
.b = rgb.b,
} };
},
.@"256_underline_color" => |idx| {
self.cursor.style.underline_color = .{ .palette = idx };
},
.reset_underline_color => {
self.cursor.style.underline_color = .none;
},
.blink => {
self.cursor.style.flags.blink = true;
},
.reset_blink => {
self.cursor.style.flags.blink = false;
},
.inverse => {
self.cursor.style.flags.inverse = true;
},
.reset_inverse => {
self.cursor.style.flags.inverse = false;
},
.invisible => {
self.cursor.style.flags.invisible = true;
},
.reset_invisible => {
self.cursor.style.flags.invisible = false;
},
.strikethrough => {
self.cursor.style.flags.strikethrough = true;
},
.reset_strikethrough => {
self.cursor.style.flags.strikethrough = false;
},
.direct_color_fg => |rgb| {
self.cursor.style.fg_color = .{
.rgb = .{
.r = rgb.r,
.g = rgb.g,
.b = rgb.b,
},
};
},
.direct_color_bg => |rgb| {
self.cursor.style.bg_color = .{
.rgb = .{
.r = rgb.r,
.g = rgb.g,
.b = rgb.b,
},
};
},
.@"8_fg" => |n| {
self.cursor.style.fg_color = .{ .palette = @intFromEnum(n) };
},
.@"8_bg" => |n| {
self.cursor.style.bg_color = .{ .palette = @intFromEnum(n) };
},
.reset_fg => self.cursor.style.fg_color = .none,
.reset_bg => self.cursor.style.bg_color = .none,
.@"8_bright_fg" => |n| {
self.cursor.style.fg_color = .{ .palette = @intFromEnum(n) };
},
.@"8_bright_bg" => |n| {
self.cursor.style.bg_color = .{ .palette = @intFromEnum(n) };
},
.@"256_fg" => |idx| {
self.cursor.style.fg_color = .{ .palette = idx };
},
.@"256_bg" => |idx| {
self.cursor.style.bg_color = .{ .palette = idx };
},
.unknown => return,
}
try self.manualStyleUpdate();
}
/// Call this whenever you manually change the cursor style.
pub fn manualStyleUpdate(self: *Screen) !void {
var page = &self.cursor.page_offset.page.data;
// Remove our previous style if is unused.
if (self.cursor.style_ref) |ref| {
if (ref.* == 0) {
page.styles.remove(page.memory, self.cursor.style_id);
}
}
// If our new style is the default, just reset to that
if (self.cursor.style.default()) {
self.cursor.style_id = 0;
self.cursor.style_ref = null;
return;
}
// After setting the style, we need to update our style map.
// Note that we COULD lazily do this in print. We should look into
// if that makes a meaningful difference. Our priority is to keep print
// fast because setting a ton of styles that do nothing is uncommon
// and weird.
const md = try page.styles.upsert(page.memory, self.cursor.style);
self.cursor.style_id = md.id;
self.cursor.style_ref = &md.ref;
}
/// Dump the screen to a string. The writer given should be buffered;
/// this function does not attempt to efficiently write and generally writes
/// one byte at a time.
pub fn dumpString(
self: *const Screen,
writer: anytype,
tl: point.Point,
) !void {
var blank_rows: usize = 0;
var iter = self.pages.rowIterator(tl);
while (iter.next()) |row_offset| {
const rac = row_offset.rowAndCell(0);
const cells = cells: {
const cells: [*]pagepkg.Cell = @ptrCast(rac.cell);
break :cells cells[0..self.pages.cols];
};
if (!pagepkg.Cell.hasTextAny(cells)) {
blank_rows += 1;
continue;
}
if (blank_rows > 0) {
for (0..blank_rows) |_| try writer.writeByte('\n');
blank_rows = 0;
}
// TODO: handle wrap
blank_rows += 1;
var blank_cells: usize = 0;
for (cells) |*cell| {
// Skip spacers
switch (cell.wide) {
.narrow, .wide => {},
.spacer_head, .spacer_tail => continue,
}
// If we have a zero value, then we accumulate a counter. We
// only want to turn zero values into spaces if we have a non-zero
// char sometime later.
if (!cell.hasText()) {
blank_cells += 1;
continue;
}
if (blank_cells > 0) {
for (0..blank_cells) |_| try writer.writeByte(' ');
blank_cells = 0;
}
switch (cell.content_tag) {
.codepoint => {
try writer.print("{u}", .{cell.content.codepoint});
},
.codepoint_grapheme => {
try writer.print("{u}", .{cell.content.codepoint});
const cps = row_offset.page.data.lookupGrapheme(cell).?;
for (cps) |cp| {
try writer.print("{u}", .{cp});
}
},
else => unreachable,
}
}
}
}
pub fn dumpStringAlloc(
self: *const Screen,
alloc: Allocator,
tl: point.Point,
) ![]const u8 {
var builder = std.ArrayList(u8).init(alloc);
defer builder.deinit();
try self.dumpString(builder.writer(), tl);
return try builder.toOwnedSlice();
}
fn testWriteString(self: *Screen, text: []const u8) !void {
const view = try std.unicode.Utf8View.init(text);
var iter = view.iterator();
while (iter.nextCodepoint()) |c| {
if (self.cursor.x == self.pages.cols) {
@panic("wrap not implemented");
}
const width: usize = if (c <= 0xFF) 1 else @intCast(unicode.table.get(c).width);
if (width == 0) {
@panic("zero-width todo");
}
assert(width == 1 or width == 2);
switch (width) {
1 => {
self.cursor.page_cell.content_tag = .codepoint;
self.cursor.page_cell.content = .{ .codepoint = c };
self.cursor.x += 1;
if (self.cursor.x < self.pages.cols) {
const cell: [*]pagepkg.Cell = @ptrCast(self.cursor.page_cell);
self.cursor.page_cell = @ptrCast(cell + 1);
} else {
@panic("wrap not implemented");
}
},
2 => @panic("todo double-width"),
else => unreachable,
}
}
}
test "Screen read and write" {
const testing = std.testing;
const alloc = testing.allocator;
var s = try Screen.init(alloc, 80, 24, 1000);
defer s.deinit();
try testing.expectEqual(@as(style.Id, 0), s.cursor.style_id);
try s.testWriteString("hello, world");
const str = try s.dumpStringAlloc(alloc, .{ .screen = .{} });
defer alloc.free(str);
try testing.expectEqualStrings("hello, world", str);
}
test "Screen style basics" {
const testing = std.testing;
const alloc = testing.allocator;
var s = try Screen.init(alloc, 80, 24, 1000);
defer s.deinit();
const page = s.cursor.page_offset.page.data;
try testing.expectEqual(@as(usize, 0), page.styles.count(page.memory));
// Set a new style
try s.setAttribute(.{ .bold = {} });
try testing.expect(s.cursor.style_id != 0);
try testing.expectEqual(@as(usize, 1), page.styles.count(page.memory));
try testing.expect(s.cursor.style.flags.bold);
// Set another style, we should still only have one since it was unused
try s.setAttribute(.{ .italic = {} });
try testing.expect(s.cursor.style_id != 0);
try testing.expectEqual(@as(usize, 1), page.styles.count(page.memory));
try testing.expect(s.cursor.style.flags.italic);
}
test "Screen style reset to default" {
const testing = std.testing;
const alloc = testing.allocator;
var s = try Screen.init(alloc, 80, 24, 1000);
defer s.deinit();
const page = s.cursor.page_offset.page.data;
try testing.expectEqual(@as(usize, 0), page.styles.count(page.memory));
// Set a new style
try s.setAttribute(.{ .bold = {} });
try testing.expect(s.cursor.style_id != 0);
try testing.expectEqual(@as(usize, 1), page.styles.count(page.memory));
// Reset to default
try s.setAttribute(.{ .reset_bold = {} });
try testing.expect(s.cursor.style_id == 0);
try testing.expectEqual(@as(usize, 0), page.styles.count(page.memory));
}
test "Screen style reset with unset" {
const testing = std.testing;
const alloc = testing.allocator;
var s = try Screen.init(alloc, 80, 24, 1000);
defer s.deinit();
const page = s.cursor.page_offset.page.data;
try testing.expectEqual(@as(usize, 0), page.styles.count(page.memory));
// Set a new style
try s.setAttribute(.{ .bold = {} });
try testing.expect(s.cursor.style_id != 0);
try testing.expectEqual(@as(usize, 1), page.styles.count(page.memory));
// Reset to default
try s.setAttribute(.{ .unset = {} });
try testing.expect(s.cursor.style_id == 0);
try testing.expectEqual(@as(usize, 0), page.styles.count(page.memory));
}