Wiresheet: arrow keys nudge selected boxes one grid step

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app_state.py

@@ -8,7 +8,7 @@ so later rebinding would only ever be seen by the module that did it.
 import configparser
 import os
 
-VERSION = "0.0.0.178"
+VERSION = "0.0.0.179"
 PROPERTIES_FILE = os.path.join(os.path.dirname(os.path.abspath(__file__)), "editor.properties")
 DEFAULT_GRID_SIZE = 10
 DEFAULT_ADD_TIMESTAMP = True

main.py

@@ -2241,6 +2241,39 @@ def on_canvas_release(event):
     wiresheet.redraw_links()
 
 
+def nudge_selected_boxes(dx, dy):
+    """Arrow keys: moves every selected box one meta step, as one undoable move."""
+    canvas = app_state.canvas
+    tags = [t for t in app_state.selected_canvas_tags if t in app_state.canvas_comp_map]
+    if not tags or app_state.drag_data.get("tag"):
+        return "break"
+    step = app_state.meta_scale * app_state.zoom
+    margin = wiresheet.layout_margin(app_state.meta_scale) * app_state.zoom
+    limit = wiresheet.META_COORD_MAX * step
+    origins = {t: wiresheet.get_box_origin(t) for t in tags}
+    if any(o is None for o in origins.values()):
+        return "break"
+    # The group stops as one at the margin strip and the sheet's far edge.
+    shift_x = min(limit - max(o[0] for o in origins.values()),
+                  max(margin - min(o[0] for o in origins.values()), dx * step))
+    shift_y = min(limit - max(o[1] for o in origins.values()),
+                  max(margin - min(o[1] for o in origins.values()), dy * step))
+    if not shift_x and not shift_y:
+        return "break"
+
+    # Moved on the canvas, then written back exactly as a finished mouse drag is.
+    group = []
+    for tag in tags:
+        comp = app_state.canvas_comp_map[tag]
+        meta_prop = comp.find("prop[@name='meta']")
+        group.append({"tag": tag, "origin": origins[tag],
+                      "meta_before": meta_prop.get("val") if meta_prop is not None else None})
+        canvas.move(tag, shift_x, shift_y)
+    app_state.drag_data.update(tag=tags[0], group=group, moved=True, collapse_to=None)
+    on_canvas_release(None)
+    return "break"
+
+
 def fit_tree_column(tree):
     """Sizes a Treeview's tree column to its widest visible row.
 
@@ -3830,6 +3863,11 @@ link_drag.install(canvas, on_canvas_right_click,
                   on_canvas_click, on_canvas_drag, on_canvas_release,
                   link_dialog=open_link_dialog, select_boxes=select_canvas_boxes)
 canvas.bind("<ButtonPress-2>", on_canvas_right_click)
+# A click gives the sheet the keyboard, so the arrows nudge its selected boxes rather
+# than walking whatever tree or list last had focus.
+canvas.bind("<ButtonPress-1>", lambda e: canvas.focus_set(), add="+")
+for _key, _dx, _dy in (("Left", -1, 0), ("Right", 1, 0), ("Up", 0, -1), ("Down", 0, 1)):
+    canvas.bind(f"<{_key}>", lambda e, dx=_dx, dy=_dy: nudge_selected_boxes(dx, dy))
 canvas.bind("<Double-1>", on_canvas_double_click)
 
 # Wheel zoom. Windows and macOS report a delta; X11 sends button 4 and 5 instead.