vt: ghostty_terminal_resize

include/ghostty/vt/terminal.h

@@ -118,6 +118,24 @@ GhosttyResult ghostty_terminal_new(const GhosttyAllocator* allocator,
  */
 void ghostty_terminal_free(GhosttyTerminal terminal);
 
+/**
+ * Resize the terminal to the given dimensions.
+ *
+ * Changes the number of columns and rows in the terminal. The primary
+ * screen will reflow content if wraparound mode is enabled; the alternate
+ * screen does not reflow. If the dimensions are unchanged, this is a no-op.
+ *
+ * @param terminal The terminal handle (NULL returns GHOSTTY_INVALID_VALUE)
+ * @param cols New width in cells (must be greater than zero)
+ * @param rows New height in cells (must be greater than zero)
+ * @return GHOSTTY_SUCCESS on success, or an error code on failure
+ *
+ * @ingroup terminal
+ */
+GhosttyResult ghostty_terminal_resize(GhosttyTerminal terminal,
+                                      uint16_t cols,
+                                      uint16_t rows);
+
 /**
  * Write VT-encoded data to the terminal for processing.
  *

src/lib_vt.zig

@@ -145,6 +145,7 @@ comptime {
         @export(&c.sgr_attribute_value, .{ .name = "ghostty_sgr_attribute_value" });
         @export(&c.terminal_new, .{ .name = "ghostty_terminal_new" });
         @export(&c.terminal_free, .{ .name = "ghostty_terminal_free" });
+        @export(&c.terminal_resize, .{ .name = "ghostty_terminal_resize" });
         @export(&c.terminal_vt_write, .{ .name = "ghostty_terminal_vt_write" });
         @export(&c.terminal_scroll_viewport, .{ .name = "ghostty_terminal_scroll_viewport" });
 

src/terminal/c/main.zig

@@ -55,6 +55,7 @@ pub const paste_is_safe = paste.is_safe;
 
 pub const terminal_new = terminal.new;
 pub const terminal_free = terminal.free;
+pub const terminal_resize = terminal.resize;
 pub const terminal_vt_write = terminal.vt_write;
 pub const terminal_scroll_viewport = terminal.scroll_viewport;
 

src/terminal/c/terminal.zig

@@ -82,6 +82,17 @@ pub fn scroll_viewport(
     });
 }
 
+pub fn resize(
+    terminal_: Terminal,
+    cols: size.CellCountInt,
+    rows: size.CellCountInt,
+) callconv(.c) Result {
+    const t = terminal_ orelse return .invalid_value;
+    if (cols == 0 or rows == 0) return .invalid_value;
+    t.resize(t.gpa(), cols, rows) catch return .out_of_memory;
+    return .success;
+}
+
 pub fn free(terminal_: Terminal) callconv(.c) void {
     const t = terminal_ orelse return;
 
@@ -192,6 +203,45 @@ test "scroll_viewport null" {
     scroll_viewport(null, .{ .tag = .top, .value = undefined });
 }
 
+test "resize" {
+    var t: Terminal = null;
+    try testing.expectEqual(Result.success, new(
+        &lib_alloc.test_allocator,
+        &t,
+        .{
+            .cols = 80,
+            .rows = 24,
+            .max_scrollback = 10_000,
+        },
+    ));
+    defer free(t);
+
+    try testing.expectEqual(Result.success, resize(t, 40, 12));
+    try testing.expectEqual(40, t.?.cols);
+    try testing.expectEqual(12, t.?.rows);
+}
+
+test "resize null" {
+    try testing.expectEqual(Result.invalid_value, resize(null, 80, 24));
+}
+
+test "resize invalid value" {
+    var t: Terminal = null;
+    try testing.expectEqual(Result.success, new(
+        &lib_alloc.test_allocator,
+        &t,
+        .{
+            .cols = 80,
+            .rows = 24,
+            .max_scrollback = 10_000,
+        },
+    ));
+    defer free(t);
+
+    try testing.expectEqual(Result.invalid_value, resize(t, 0, 24));
+    try testing.expectEqual(Result.invalid_value, resize(t, 80, 0));
+}
+
 test "vt_write" {
     var t: Terminal = null;
     try testing.expectEqual(Result.success, new(