terminal2: viewport exact is gone, now pin

This commit is contained in:
Mitchell Hashimoto
2024-03-05 10:08:50 -08:00
parent fb1a64b6a9
commit 2837a95d4b

View File

@ -141,10 +141,10 @@ pub const Viewport = union(enum) {
/// back in the scrollback history.
top,
/// The viewport is pinned to an exact row offset. If this page is
/// deleted (i.e. due to pruning scrollback), then the viewport will
/// stick to the top.
exact: RowOffset,
/// The viewport is pinned to a tracked pin. The tracked pin is ALWAYS
/// s.viewport_pin hence this has no value. We force that value to prevent
/// allocations.
pin,
};
/// Initialize the page. The top of the first page in the list is always the
@ -208,6 +208,12 @@ pub fn init(
PagePool.item_size * 2,
);
// We always track our viewport pin to ensure this is never an allocation
const viewport_pin = try pool.pins.create();
var tracked_pins: PinSet = .{};
errdefer tracked_pins.deinit(pool.alloc);
try tracked_pins.putNoClobber(pool.alloc, viewport_pin, {});
return .{
.cols = cols,
.rows = rows,
@ -216,9 +222,9 @@ pub fn init(
.pages = page_list,
.page_size = page_size,
.max_size = max_size_actual,
.tracked_pins = .{},
.tracked_pins = tracked_pins,
.viewport = .{ .active = {} },
.viewport_pin = try pool.pins.create(),
.viewport_pin = viewport_pin,
};
}
@ -357,17 +363,14 @@ pub fn clonePool(
return result;
}
/// Returns the viewport for the given offset, prefering to pin to
/// "active" if the offset is within the active area.
fn viewportForOffset(self: *const PageList, offset: RowOffset) Viewport {
// If the offset is on the active page, then we pin to active
// if our row idx is beyond the active row idx.
const active = self.getTopLeft(.active);
if (offset.page == active.page) {
if (offset.row_offset >= active.row_offset) {
return .{ .active = {} };
}
} else {
/// Returns the viewport for the given pin, prefering to pin to
/// "active" if the pin is within the active area.
fn pinIsActive(self: *const PageList, p: Pin) bool {
// If the pin is in the active page, then we can quickly determine
// if we're beyond the end.
const active = self.getTopLeft2(.active);
if (p.page == active.page) return p.y >= active.y;
var page_ = active.page.next;
while (page_) |page| {
// This loop is pretty fast because the active area is
@ -377,12 +380,11 @@ fn viewportForOffset(self: *const PageList, offset: RowOffset) Viewport {
// A page forward in the active area is our page, so we're
// definitely in the active area.
if (page == offset.page) return .{ .active = {} };
if (page == p.page) return true;
page_ = page.next;
}
}
return .{ .exact = offset };
return false;
}
/// Resize options
@ -1245,11 +1247,11 @@ pub fn scroll(self: *PageList, behavior: Scroll) void {
.delta_row => |n| {
if (n == 0) return;
const top = self.getTopLeft(.viewport);
const offset: RowOffset = if (n < 0) switch (top.backwardOverflow(@intCast(-n))) {
const top = self.getTopLeft2(.viewport);
const p: Pin = if (n < 0) switch (top.upOverflow(@intCast(-n))) {
.offset => |v| v,
.overflow => |v| v.end,
} else switch (top.forwardOverflow(@intCast(n))) {
} else switch (top.downOverflow(@intCast(n))) {
.offset => |v| v,
.overflow => |v| v.end,
};
@ -1261,7 +1263,14 @@ pub fn scroll(self: *PageList, behavior: Scroll) void {
// But in a terminal when you get to the bottom and back into the
// active area, you usually expect that the viewport will now
// follow the active area.
self.viewport = self.viewportForOffset(offset);
if (self.pinIsActive(p)) {
self.viewport = .{ .active = {} };
return;
}
// Pin is not active so we need to track it.
self.viewport_pin.* = p;
self.viewport = .{ .pin = {} };
},
}
}
@ -1438,16 +1447,6 @@ pub fn eraseRows(
}
}
// If our viewport is on this page and the offset is beyond
// our new end, shift it.
switch (self.viewport) {
.top, .active => {},
.exact => |*offset| exact: {
if (offset.page != chunk.page) break :exact;
offset.row_offset -|= scroll_amount;
},
}
// Our new size is the amount we scrolled
chunk.page.data.size.rows = @intCast(scroll_amount);
erased += chunk.end;
@ -1466,20 +1465,20 @@ pub fn eraseRows(
};
}
// If we have an exact viewport, we need to adjust for active area.
// If we have a pinned viewport, we need to adjust for active area.
switch (self.viewport) {
.active => {},
.exact => |offset| self.viewport = self.viewportForOffset(offset),
// For pin, we check if our pin is now in the active area and if so
// we move our viewport back to the active area.
.pin => if (self.pinIsActive(self.viewport_pin.*)) {
self.viewport = .{ .active = {} };
},
// For top, we move back to active if our erasing moved our
// top page into the active area.
.top => {
const vp = self.viewportForOffset(.{
.page = self.pages.first.?,
.row_offset = 0,
});
if (vp == .active) self.viewport = vp;
.top => if (self.pinIsActive(.{ .page = self.pages.first.? })) {
self.viewport = .{ .active = {} };
},
}
}
@ -1500,20 +1499,6 @@ fn erasePage(self: *PageList, page: *List.Node) void {
p.x = 0;
}
// If our viewport is pinned to this page, then we need to update it.
switch (self.viewport) {
.top, .active => {},
.exact => |*offset| {
if (offset.page == page) {
if (page.next) |next| {
offset.page = next;
} else {
self.viewport = .{ .active = {} };
}
}
},
}
// Remove the page from the linked list
self.pages.remove(page);
self.destroyPage(page);
@ -1548,6 +1533,7 @@ pub fn trackPin(self: *PageList, p: Pin) !*Pin {
/// Untrack a previously tracked pin. This will deallocate the pin.
pub fn untrackPin(self: *PageList, p: *Pin) void {
assert(p != self.viewport_pin);
if (self.tracked_pins.remove(p)) {
self.pool.pins.destroy(p);
}
@ -1755,7 +1741,7 @@ fn getTopLeft(self: *const PageList, tag: point.Tag) RowOffset {
.viewport => switch (self.viewport) {
.active => self.getTopLeft(.active),
.top => self.getTopLeft(.screen),
.exact => |v| v,
.pin => .{ .page = self.viewport_pin.page, .row_offset = self.viewport_pin.y },
},
// The active area is calculated backwards from the last page.
@ -1787,7 +1773,7 @@ fn getTopLeft2(self: *const PageList, tag: point.Tag) Pin {
.viewport => switch (self.viewport) {
.active => self.getTopLeft2(.active),
.top => self.getTopLeft2(.screen),
.exact => |v| .{ .page = v.page, .y = v.row_offset },
.pin => self.viewport_pin.*,
},
// The active area is calculated backwards from the last page.
@ -2647,7 +2633,8 @@ test "PageList erase resets viewport to active if moves within active" {
// Move our viewport to the top
s.scroll(.{ .delta_row = -@as(isize, @intCast(s.totalRows())) });
try testing.expect(s.viewport.exact.page == s.pages.first.?);
try testing.expect(s.viewport == .pin);
try testing.expect(s.viewport_pin.page == s.pages.first.?);
// Erase the entire history, we should be back to just our active set.
s.eraseRows(.{ .history = .{} }, null);
@ -2669,11 +2656,13 @@ test "PageList erase resets viewport if inside erased page but not active" {
// Move our viewport to the top
s.scroll(.{ .delta_row = -@as(isize, @intCast(s.totalRows())) });
try testing.expect(s.viewport.exact.page == s.pages.first.?);
try testing.expect(s.viewport == .pin);
try testing.expect(s.viewport_pin.page == s.pages.first.?);
// Erase the entire history, we should be back to just our active set.
s.eraseRows(.{ .history = .{} }, .{ .history = .{ .y = 2 } });
try testing.expect(s.viewport.exact.page == s.pages.first.?);
try testing.expect(s.viewport == .pin);
try testing.expect(s.viewport_pin.page == s.pages.first.?);
}
test "PageList erase resets viewport to active if top is inside active" {