Add Kitty window and tab chooser with previews

.config/kitty/choose_tab.py

@@ -0,0 +1,121 @@
+"""Choose a tab grouped by native Kitty window, and focus its window."""
+
+import json
+
+from kittens.tui.handler import result_handler
+from kitty.fast_data_types import get_os_window_title
+
+
+def main(args):
+    pass
+
+
+def snapshot_tab(tab, boss):
+    """Capture before opening the chooser, without focusing or relaying out tabs."""
+    panes = []
+    active = tab.active_window
+    try:
+        groups = list(tab.windows.iter_all_layoutable_groups(only_visible=True))
+    except Exception:
+        groups = []
+    for group in groups:
+        window = boss.window_id_map.get(group.active_window_id)
+        if window is None:
+            continue
+        try:
+            geometry = window.geometry
+            pane = dict(id=window.id, title=window.title,
+                        active=window is active,
+                        rect=[geometry.left, geometry.top, geometry.right, geometry.bottom],
+                        lines=None)
+        except Exception:
+            continue
+        try:
+            pane['lines'] = [window.screen.visual_line(i).as_ansi()
+                             for i in range(window.screen.lines)]
+        except Exception:
+            pass
+        panes.append(pane)
+    return dict(title=tab.name or tab.title, panes=panes)
+
+
+@result_handler(no_ui=True)
+def handle_result(args, answer, target_window_id, boss):
+    source = boss.window_id_map.get(target_window_id)
+    current = source.tabref() if source is not None else boss.active_tab
+
+    def chosen(tab_id):
+        if not isinstance(tab_id, int):
+            return
+        for tab in boss.all_tabs:
+            if tab.id == tab_id:
+                window = tab.active_window
+                if window is not None:
+                    boss.set_active_window(window, switch_os_window_if_needed=True)
+                return
+
+    entries = []
+    snapshots = {}
+    for index, (os_window_id, manager) in enumerate(boss.os_window_map.items(), 1):
+        tabs = list(manager)
+        active = manager.active_tab
+        if not tabs or active is None:
+            continue
+        count = len(tabs)
+        title = get_os_window_title(os_window_id) or f"Window {index}"
+        label = f"- {title}: {count} {'tab' if count == 1 else 'tabs'}"
+        if current in tabs:
+            label += " (current)"
+        tab_ids = [tab.id for tab in tabs]
+        entries.append(dict(kind='window', label=label, tab_id=active.id,
+                            tabs=tab_ids, title=title))
+        for tab_index, tab in enumerate(tabs, 1):
+            branch = "└─>" if tab_index == count else "├─>"
+            marker = "*" if tab is active else ""
+            label = f"{branch} {tab_index}: {tab.name or tab.title}{marker}"
+            if tab.num_window_groups > 1:
+                label += f" [{tab.num_window_groups} panes]"
+            entries.append(dict(kind='tab', label=label, tab_id=tab.id,
+                                title=tab.name or tab.title))
+            snapshots[str(tab.id)] = snapshot_tab(tab, boss)
+    selected = None
+
+    def done(answer, target_window_id, boss):
+        nonlocal selected
+        selected = answer
+
+    # Kittens overlay one pane. Temporarily use stack to fill the tab, keeping
+    # the original layout object (including its split tree and size biases).
+    layout_state = None
+    chooser_layout = None
+    if current is not None and current.current_layout.name != 'stack':
+        layout_state = (current.current_layout, current._current_layout_name,
+                        current._last_used_layout)
+
+    def restore_layout():
+        if (layout_state is not None and current in boss.all_tabs
+                and current.current_layout is chooser_layout):
+            current.current_layout, current._current_layout_name, current._last_used_layout = layout_state
+            current.mark_tab_bar_dirty()
+            current.relayout()
+
+    def removed(target_window_id, boss):
+        restore_layout()
+        chosen(selected)
+
+    try:
+        if layout_state is not None:
+            current._set_current_layout('stack')
+            chooser_layout = current.current_layout
+            current.relayout()
+        overlay = boss.run_kitten_with_metadata(
+            "window_picker.py", args=tuple(args[1:]),
+            input_data=json.dumps(dict(entries=entries, snapshots=snapshots)),
+            window=source,
+            custom_callback=done, action_on_removal=removed,
+        )
+        if overlay is None:
+            restore_layout()
+    except Exception:
+        restore_layout()
+        raise