Add tests for basic layout operations

kitty/layout.py

@@ -126,6 +126,10 @@ class Layout:
         return active_window_idx
 
     def remove_window(self, all_windows, window, current_active_window_idx):
+        try:
+            active_window = all_windows[current_active_window_idx]
+        except Exception:
+            active_window = window
         all_windows.remove(window)
         active_window_idx = None
         if window.overlay_for is not None:
@@ -134,7 +138,10 @@ class Layout:
                 active_window_idx = i
                 all_windows[i].overlay_window_id = None
         if active_window_idx is None:
-            active_window_idx = max(0, min(current_active_window_idx, len(all_windows) - 1))
+            if active_window is window:
+                active_window_idx = max(0, min(current_active_window_idx, len(all_windows) - 1))
+            else:
+                active_window_idx = idx_for_id(active_window.id, all_windows)
         if all_windows:
             self(all_windows, active_window_idx)
         self.set_active_window(all_windows, active_window_idx)
@@ -175,6 +182,7 @@ class Layout:
             windows = all_windows
         self.update_visibility(all_windows, active_window, overlaid_windows)
         self.do_layout(windows, active_window_idx)
+        return idx_for_id(active_window.id, all_windows)
 
     # Utils {{{
     def xlayout(self, num):

kitty/tabs.py

@@ -93,7 +93,7 @@ class Tab:  # {{{
 
     def relayout(self):
         if self.windows:
-            self.current_layout(self.windows, self.active_window_idx)
+            self.active_window_idx = self.current_layout(self.windows, self.active_window_idx)
         self.relayout_borders()
 
     def relayout_borders(self):

kitty_tests/layout.py

@@ -0,0 +1,111 @@
+#!/usr/bin/env python
+# vim:fileencoding=utf-8
+# License: GPL v3 Copyright: 2018, Kovid Goyal <kovid at kovidgoyal.net>
+
+from . import BaseTest
+from kitty.config import defaults
+from kitty.layout import Stack, Horizontal
+
+
+class Window:
+
+    def __init__(self, win_id, overlay_for=None, overlay_window_id=None):
+        self.id = win_id
+        self.overlay_for = overlay_for
+        self.overlay_window_id = overlay_window_id
+        self.is_visible_in_layout = True
+
+    def set_visible_in_layout(self, idx, val):
+        self.is_visible_in_layout = bool(val)
+
+    def set_geometry(self, idx, geometry):
+        self.geometry = geometry
+
+
+def create_layout(cls, opts=None, border_width=2):
+    if opts is None:
+        opts = defaults
+    ans = cls(1, 1, opts, border_width)
+    ans.set_active_window_in_os_window = lambda idx: None
+    ans.swap_windows_in_os_window = lambda a, b: None
+    return ans
+
+
+def create_windows(num=5):
+    return [Window(i + 1) for i in range(num)]
+
+
+class TestLayout(BaseTest):
+
+    def do_ops_test(self, q):
+        windows = create_windows()
+
+        def ids():
+            return [w.id for w in windows]
+
+        def visible_ids():
+            return {w.id for w in windows if w.is_visible_in_layout}
+
+        def expect_ids(*a):
+            self.assertEqual(tuple(ids()), a)
+
+        def check_visible():
+            if q.only_active_window_visible:
+                self.ae(visible_ids(), {windows[active_window_idx].id})
+            else:
+                self.ae(visible_ids(), set(ids()))
+
+        active_window_idx = 0
+        # Test layout
+        self.ae(q(windows, active_window_idx), active_window_idx)
+        expect_ids(*range(1, len(windows)+1))
+        check_visible()
+        # Test nth_window
+        for i in range(len(windows)):
+            active_window_idx = q.nth_window(windows, i)
+            self.ae(active_window_idx, i)
+            expect_ids(*range(1, len(windows)+1))
+            check_visible()
+        # Test next_window
+        for i in range(2 * len(windows)):
+            expected = (active_window_idx + 1) % len(windows)
+            active_window_idx = q.next_window(windows, active_window_idx)
+            self.ae(active_window_idx, expected)
+            expect_ids(*range(1, len(windows)+1))
+            check_visible()
+        # Test move_window
+        active_window_idx = 0
+        active_window_idx = q.move_window(windows, active_window_idx, 3)
+        self.ae(active_window_idx, 3)
+        expect_ids(4, 2, 3, 1, 5)
+        check_visible()
+        q.move_window(windows, 0, 3)
+        expect_ids(*range(1, len(windows)+1))
+        check_visible()
+        # Test add_window
+        active_window_idx = q.add_window(windows, Window(6), active_window_idx)
+        self.ae(active_window_idx, 5)
+        expect_ids(*range(1, len(windows)+1))
+        check_visible()
+        # Test remove_window
+        active_window_idx = 3
+        expected = active_window_idx
+        active_window_idx = q.remove_window(windows, windows[active_window_idx], active_window_idx)
+        self.ae(active_window_idx, expected)
+        check_visible()
+        expect_ids(1, 2, 3, 5, 6)
+        w = windows[active_window_idx]
+        active_window_idx = q.remove_window(windows, windows[0], active_window_idx)
+        self.ae(active_window_idx, windows.index(w))
+        check_visible()
+        expect_ids(2, 3, 5, 6)
+        # Test set_active_window
+        for i in range(len(windows)):
+            active_window_idx = q.set_active_window(windows, i)
+            self.ae(i, active_window_idx)
+            check_visible()
+
+    def test_layout_operations(self):
+        for layout_class in Stack, Horizontal:
+            q = create_layout(Stack)
+            self.do_ops_test(q)