A new centered panel type that is sized

Author: kovidgoyal

docs/changelog.rst

@@ -121,6 +121,8 @@ Detailed list of changes
 
 - A new setting :opt:`remember_window_position` to optionally use the position of the last closed kitty OS Window as the position of the first kitty OS Window when running a new kitty instance (:pull:`8601`)
 
+- Panel kitten: A new ``center-sized`` value for :option:`--edge <kitty +kitten panel --edge>` to allow easily creating sized and centered panels
+
 
 0.42.0 [2025-05-11]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

glfw/cocoa_window.m

@@ -2031,6 +2031,11 @@ void _glfwPlatformDestroyWindow(_GLFWwindow* window)
                 x += width - panel_width + 1.;
                 width = panel_width;
                 break;
+            case GLFW_EDGE_CENTER_SIZED:
+                x += (width - panel_width) / 2;
+                y += (height - panel_height) / 2;
+                width = panel_width; height = panel_height;
+                break;
             default:  // top left
                 y += height - panel_height + 1.;
                 height = panel_height; width = panel_width;
@@ -2040,8 +2045,10 @@ void _glfwPlatformDestroyWindow(_GLFWwindow* window)
         if (height < 1.) height = NSWidth(screen.visibleFrame);
     }
 
-    x += config.requested_left_margin; width -= config.requested_left_margin + config.requested_right_margin;
-    y += config.requested_bottom_margin; height -= config.requested_top_margin + config.requested_bottom_margin;
+    if (config.edge != GLFW_EDGE_CENTER_SIZED) {
+        x += config.requested_left_margin; width -= config.requested_left_margin + config.requested_right_margin;
+        y += config.requested_bottom_margin; height -= config.requested_top_margin + config.requested_bottom_margin;
+    }
 
     [nswindow setAnimationBehavior:animation_behavior];
     [nswindow setLevel:level];

glfw/glfw3.h

@@ -1302,7 +1302,7 @@ typedef struct GLFWkeyevent
 
 typedef enum { GLFW_LAYER_SHELL_NONE, GLFW_LAYER_SHELL_BACKGROUND, GLFW_LAYER_SHELL_PANEL, GLFW_LAYER_SHELL_TOP, GLFW_LAYER_SHELL_OVERLAY } GLFWLayerShellType;
 
-typedef enum { GLFW_EDGE_TOP, GLFW_EDGE_BOTTOM, GLFW_EDGE_LEFT, GLFW_EDGE_RIGHT, GLFW_EDGE_CENTER, GLFW_EDGE_NONE } GLFWEdge;
+typedef enum { GLFW_EDGE_TOP, GLFW_EDGE_BOTTOM, GLFW_EDGE_LEFT, GLFW_EDGE_RIGHT, GLFW_EDGE_CENTER, GLFW_EDGE_NONE, GLFW_EDGE_CENTER_SIZED } GLFWEdge;
 
 typedef enum { GLFW_FOCUS_NOT_ALLOWED, GLFW_FOCUS_EXCLUSIVE, GLFW_FOCUS_ON_DEMAND} GLFWFocusPolicy;
 

glfw/wl_window.c

@@ -1028,12 +1028,13 @@ layer_set_properties(const _GLFWwindow *window, bool during_creation, uint32_t w
                     if (!config.override_exclusive_zone) exclusive_zone = width;
                     break;
                 case GLFW_EDGE_CENTER:
-                    which_anchor = ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT | ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT | ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP | ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM;
+                    break;
+                case GLFW_EDGE_CENTER_SIZED:
+                    panel_width = width; panel_height = height;
                     break;
                 case GLFW_EDGE_NONE:
                     which_anchor = ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT | ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP;
-                    panel_width = width;
-                    panel_height = height;
+                    panel_width = width; panel_height = height;
                     break;
             }
     }

glfw/x11_window.c

@@ -606,6 +606,11 @@ calculate_layer_geometry(_GLFWwindow *window) {
             ans.width = m.width - config.requested_right_margin - config.requested_left_margin;
             ans.struts[s.bottom] = ans.height; ans.struts[s.bottom_end_x] = ans.width;
             break;
+        case GLFW_EDGE_CENTER_SIZED:
+            ans.needs_strut = false;
+            ans.x = (m.width - ans.width) / 2;
+            ans.y = (m.height - ans.height) / 2;
+            break;
         default:
             ans.needs_strut = false;
             ans.x = m.x + config.requested_left_margin;

kittens/panel/main.py

@@ -13,6 +13,7 @@
 from kitty.fast_data_types import (
     GLFW_EDGE_BOTTOM,
     GLFW_EDGE_CENTER,
+    GLFW_EDGE_CENTER_SIZED,
     GLFW_EDGE_LEFT,
     GLFW_EDGE_NONE,
     GLFW_EDGE_RIGHT,
@@ -66,7 +67,8 @@ def layer_shell_config(opts: PanelCLIOptions) -> LayerShellConfig:
     }.get(opts.layer, GLFW_LAYER_SHELL_PANEL)
     ltype = GLFW_LAYER_SHELL_BACKGROUND if opts.edge == 'background' else ltype
     edge = {
-        'top': GLFW_EDGE_TOP, 'bottom': GLFW_EDGE_BOTTOM, 'left': GLFW_EDGE_LEFT, 'right': GLFW_EDGE_RIGHT, 'center': GLFW_EDGE_CENTER, 'none': GLFW_EDGE_NONE
+        'top': GLFW_EDGE_TOP, 'bottom': GLFW_EDGE_BOTTOM, 'left': GLFW_EDGE_LEFT, 'right': GLFW_EDGE_RIGHT,
+        'center': GLFW_EDGE_CENTER, 'none': GLFW_EDGE_NONE, 'center-sized': GLFW_EDGE_CENTER_SIZED,
     }.get(opts.edge, GLFW_EDGE_TOP)
     focus_policy = {
         'not-allowed': GLFW_FOCUS_NOT_ALLOWED, 'exclusive': GLFW_FOCUS_EXCLUSIVE, 'on-demand': GLFW_FOCUS_ON_DEMAND

kitty/fast_data_types.pyi

@@ -25,6 +25,7 @@ GLFW_EDGE_BOTTOM: int
 GLFW_EDGE_LEFT: int
 GLFW_EDGE_RIGHT: int
 GLFW_EDGE_CENTER: int
+GLFW_EDGE_CENTER_SIZED: int
 GLFW_EDGE_NONE: int
 GLFW_FOCUS_NOT_ALLOWED: int
 GLFW_FOCUS_EXCLUSIVE: int

kitty/glfw-wrapper.h

@@ -1231,7 +1231,7 @@ edge_spacing(GLFWEdge which) {
         case GLFW_EDGE_BOTTOM: edge = "bottom"; break;
         case GLFW_EDGE_LEFT: edge = "left"; break;
         case GLFW_EDGE_RIGHT: edge = "right"; break;
-        case GLFW_EDGE_CENTER: case GLFW_EDGE_NONE: return 0;
+        case GLFW_EDGE_CENTER: case GLFW_EDGE_NONE: case GLFW_EDGE_CENTER_SIZED: return 0;
     }
     if (!edge_spacing_func) {
         log_error("Attempt to call edge_spacing() without first setting edge_spacing_func");
@@ -2690,6 +2690,7 @@ init_glfw(PyObject *m) {
     ADDC(GLFW_LAYER_SHELL_NONE); ADDC(GLFW_LAYER_SHELL_PANEL); ADDC(GLFW_LAYER_SHELL_BACKGROUND); ADDC(GLFW_LAYER_SHELL_TOP); ADDC(GLFW_LAYER_SHELL_OVERLAY);
     ADDC(GLFW_FOCUS_NOT_ALLOWED); ADDC(GLFW_FOCUS_EXCLUSIVE); ADDC(GLFW_FOCUS_ON_DEMAND);
     ADDC(GLFW_EDGE_TOP); ADDC(GLFW_EDGE_BOTTOM); ADDC(GLFW_EDGE_LEFT); ADDC(GLFW_EDGE_RIGHT); ADDC(GLFW_EDGE_CENTER); ADDC(GLFW_EDGE_NONE);
+    ADDC(GLFW_EDGE_CENTER_SIZED);
     ADDC(GLFW_COLOR_SCHEME_NO_PREFERENCE); ADDC(GLFW_COLOR_SCHEME_DARK); ADDC(GLFW_COLOR_SCHEME_LIGHT);
 
     /* start glfw functional keys (auto generated by gen-key-constants.py do not edit) */

kitty/glfw.c

@@ -601,20 +601,21 @@ def build_panel_cli_spec(defaults: dict[str, str]) -> str:
 
 
 --edge
-choices=top,bottom,left,right,background,center,none
+choices=top,bottom,left,right,background,center,center-sized,none
 default={edge}
 Which edge of the screen to place the panel on. Note that some window managers
 (such as i3) do not support placing docked windows on the left and right edges.
 The value :code:`background` means make the panel the "desktop wallpaper".
 Note that when using sway if you set a background in your sway config it will
 cover the background drawn using this kitten.
-Additionally, there are two more values: :code:`center` and :code:`none`.
+Additionally, there are three more values: :code:`center`, :code:`center-sized` and :code:`none`.
 The value :code:`center` anchors the panel to all sides and covers the entire
 display (on macOS the part of the display not covered by titlebar and dock).
 The panel can be shrunk and placed using the margin parameters.
 The value :code:`none` anchors the panel to the top left corner and should be
 placed and using the margin parameters. Its size is set by :option:`--lines`
-and :option:`--columns`.
+and :option:`--columns`. The value :code:`center-sized` is just like :code:`none` except
+that the panel is centered instead of in the top left corner and the margins have no effect.
 
 
 --layer