terminal/new: eraseRows

src/terminal/new/PageList.zig

@@ -488,12 +488,26 @@ pub const RowChunkIterator = struct {
 ///
 /// This is a more efficient way to iterate through the data in a region,
 /// since you can do simple pointer math and so on.
+///
+/// If bl_pt is non-null, iteration will stop at the bottom left point
+/// (inclusive). If bl_pt is null, the entire region specified by the point
+/// tag will be iterated over. tl_pt and bl_pt must be the same tag, and
+/// bl_pt must be greater than or equal to tl_pt.
 pub fn rowChunkIterator(
     self: *const PageList,
     tl_pt: point.Point,
+    bl_pt: ?point.Point,
 ) RowChunkIterator {
+    // TODO: bl_pt assertions
+
     const tl = self.getTopLeft(tl_pt);
-    const limit: RowChunkIterator.Limit = switch (tl_pt) {
+    const limit: RowChunkIterator.Limit = limit: {
+        if (bl_pt) |pt| {
+            const bl = self.getTopLeft(pt);
+            break :limit .{ .row = bl.forward(pt.coord().y).? };
+        }
+
+        break :limit switch (tl_pt) {
             // These always go to the end of the screen.
             .screen, .active => .{ .none = {} },
 
@@ -504,6 +518,7 @@ pub fn rowChunkIterator(
             // to calculate but also more rare of a thing to iterate over.
             .history => .{ .row = self.getTopLeft(.active) },
         };
+    };
 
     return .{ .row = tl.forward(tl_pt.coord().y), .limit = limit };
 }
@@ -1040,7 +1055,7 @@ test "PageList rowChunkIterator single page" {
     try testing.expect(s.pages.first.?.next == null);
 
     // Iterate the active area
-    var it = s.rowChunkIterator(.{ .active = .{} });
+    var it = s.rowChunkIterator(.{ .active = .{} }, null);
     {
         const chunk = it.next().?;
         try testing.expect(chunk.page == s.pages.first.?);
@@ -1068,7 +1083,7 @@ test "PageList rowChunkIterator two pages" {
     try testing.expect(try s.grow() != null);
 
     // Iterate the active area
-    var it = s.rowChunkIterator(.{ .active = .{} });
+    var it = s.rowChunkIterator(.{ .active = .{} }, null);
     {
         const chunk = it.next().?;
         try testing.expect(chunk.page == s.pages.first.?);
@@ -1102,7 +1117,7 @@ test "PageList rowChunkIterator history two pages" {
     try testing.expect(try s.grow() != null);
 
     // Iterate the active area
-    var it = s.rowChunkIterator(.{ .history = .{} });
+    var it = s.rowChunkIterator(.{ .history = .{} }, null);
     {
         const active_tl = s.getTopLeft(.active);
         const chunk = it.next().?;

src/terminal/new/Screen.zig

@@ -277,10 +277,11 @@ pub fn scroll(self: *Screen, behavior: Scroll) void {
     }
 }
 
-/// Erase the active area of the screen from y=0 to rows-1. The cells
-/// are blanked using the given blank cell.
-pub fn eraseActive(self: *Screen) void {
-    var it = self.pages.rowChunkIterator(.{ .active = .{} });
+// Erase the region specified by tl and bl, inclusive. Erased cells are
+// colored with the current style background color. This will erase all
+// cells in the rows.
+pub fn eraseRows(self: *Screen, tl: point.Point, bl: ?point.Point) void {
+    var it = self.pages.rowChunkIterator(tl, bl);
     while (it.next()) |chunk| {
         for (chunk.rows()) |*row| {
             const cells_offset = row.cells;
@@ -345,6 +346,20 @@ pub fn eraseCells(
     @memset(cells, self.blankCell());
 }
 
+/// Erase cells but only if they are not protected.
+pub fn eraseUnprotectedCells(
+    self: *Screen,
+    page: *Page,
+    row: *Row,
+    cells: []Cell,
+) void {
+    for (cells) |*cell| {
+        if (cell.protected) continue;
+        const cell_multi: [*]Cell = @ptrCast(cell);
+        self.eraseCells(page, row, cell_multi[0..1]);
+    }
+}
+
 /// Returns the blank cell to use when doing terminal operations that
 /// require preserving the bg color.
 fn blankCell(self: *const Screen) Cell {
@@ -743,7 +758,7 @@ test "Screen style reset with unset" {
     try testing.expectEqual(@as(usize, 0), page.styles.count(page.memory));
 }
 
-test "Screen eraseActive one line" {
+test "Screen eraseRows active one line" {
     const testing = std.testing;
     const alloc = testing.allocator;
 
@@ -751,13 +766,13 @@ test "Screen eraseActive one line" {
     defer s.deinit();
 
     try s.testWriteString("hello, world");
-    s.eraseActive();
+    s.eraseRows(.{ .active = .{} }, null);
     const str = try s.dumpStringAlloc(alloc, .{ .screen = .{} });
     defer alloc.free(str);
     try testing.expectEqualStrings("", str);
 }
 
-test "Screen eraseActive multi line" {
+test "Screen eraseRows active multi line" {
     const testing = std.testing;
     const alloc = testing.allocator;
 
@@ -765,13 +780,13 @@ test "Screen eraseActive multi line" {
     defer s.deinit();
 
     try s.testWriteString("hello\nworld");
-    s.eraseActive();
+    s.eraseRows(.{ .active = .{} }, null);
     const str = try s.dumpStringAlloc(alloc, .{ .screen = .{} });
     defer alloc.free(str);
     try testing.expectEqualStrings("", str);
 }
 
-test "Screen eraseActive styled line" {
+test "Screen eraseRows active styled line" {
     const testing = std.testing;
     const alloc = testing.allocator;
 
@@ -786,7 +801,7 @@ test "Screen eraseActive styled line" {
     const page = s.cursor.page_offset.page.data;
     try testing.expectEqual(@as(usize, 1), page.styles.count(page.memory));
 
-    s.eraseActive();
+    s.eraseRows(.{ .active = .{} }, null);
 
     // We should have none because active cleared it
     try testing.expectEqual(@as(usize, 0), page.styles.count(page.memory));