test(scale): add automated tests, manual QA checklist, and build integration

- Automated scale tests: float tolerance, safety guard, ceilf fallback - Manual QA checklist: 8 items covering fractional, mixed-DPI, XWayland - Build: test_scale Makefile target (standalone C23, no wlroots deps)
2026-07-05 21:53:30 -04:00
parent dac0b4fa6f
commit 48a4aed0ec
5 changed files with 492 additions and 2 deletions
@@ -0,0 +1,115 @@
+================================================================================
+EVIDENCE: Task 5 — wlr_fractional_scale_manager_v1 propagation chain
+================================================================================
+
+Goal: Verify that scale-change notifications reach surfaces when any output
+      configuration changes (wlr-randr, hotplug, layout rejig, etc.).
+
+================================================================================
+PATH 1 (direct): outputmgrapplyortest() → updatemons()
+================================================================================
+
+  File:      src/peachwm.c
+  Function:  outputmgrapplyortest()       (line 2553)
+  Call site: line 2612 — updatemons(nullptr, nullptr);
+
+  Triggered by:
+    - outputmgrapply()  (line 2548 — from wlr_output_manager config apply)
+    - outputmgrtest()   (line 2615 — from wlr_output_manager test)
+
+  This path fires when a client (e.g. wlr-randr) sends a new output
+  configuration.  After committing the per-head state and sending the
+  success/failure response, updatemons() is called unconditionally.
+
+  CONFIRMED ✅ — updatemons(nullptr, nullptr) at line 2612.
+
+================================================================================
+PATH 2 (indirect): output_layout.change signal → updatemons()
+================================================================================
+
+  Listener declaration: line 364
+    static struct wl_listener layout_change = {.notify = updatemons};
+
+  Signal wiring: line 3691
+    wl_signal_add(&output_layout->events.change, &layout_change);
+
+  This path fires when the output layout changes via any other route
+  (e.g. hotplug, wlr_output_layout_add call inside updatemons itself).
+  It is the "belt" to the "suspenders" of Path 1.
+
+  Note: outputmgrapplyortest() calls wlr_output_layout_add() at line 2600,
+        which itself triggers output_layout.change — so Path 2 also fires
+        during Path 1.  updatemons() is idempotent (no ill effect from
+        running twice in a single event cycle).
+
+  CONFIRMED ✅ — layout_change.notify = updatemons at line 364,
+                 wired at line 3691.
+
+================================================================================
+SCALE RE-NOTIFICATION HOOK (inside updatemons)
+================================================================================
+
+  File:      src/peachwm.c
+  Function:  updatemons()                  (line 4101)
+  Hook:      lines 4168–4201
+
+  For each enabled monitor:
+
+    [clients loop, line 4170]
+    wl_list_for_each(c, &clients, link) {
+      if (c->mon != m)
+        continue;
+      client_update_scale(c);                          // ← task 4 hook
+      if (!client_is_x11(c) && c->surface.xdg) {
+        struct wlr_xdg_popup *popup;
+        wl_list_for_each(popup, &c->surface.xdg->popups, link)
+          wlr_fractional_scale_v1_notify_scale(
+              popup->base->surface, (double)m->wlr_output->scale);
+      }
+    }
+
+    [layers loop, line 4181]
+    for (int i = 0; i < 4; i++) {
+      LayerSurface *l;
+      wl_list_for_each(l, &m->layers[i], link) {
+        layersurface_update_scale(l);                  // ← task 4 hook
+        {
+          struct wlr_scene_node *popup_node;
+          wl_list_for_each(popup_node, &l->popups->children, link) {
+            if (popup_node->type != WLR_SCENE_NODE_BUFFER)
+              continue;
+            struct wlr_scene_buffer *sb =
+                wlr_scene_buffer_from_node(popup_node);
+            struct wlr_scene_surface *ss =
+                wlr_scene_surface_try_from_buffer(sb);
+            if (ss && ss->surface)
+              wlr_fractional_scale_v1_notify_scale(
+                  ss->surface, (double)m->wlr_output->scale);
+          }
+        }
+      }
+    }
+
+  This covers both regular xdg-toplevel clients and layer-shell surfaces
+  (bars, backgrounds, OSDs), including their XDG popups.
+
+  CONFIRMED ✅ — scale re-notification hook present and complete.
+
+================================================================================
+VERDICT: PROPAGATION CHAIN CONFIRMED ✅
+================================================================================
+
+  outputmgrapplyortest() → updatemons()   [direct:   line 2612]
+  layout_change signal  → updatemons()   [indirect: lines 364, 3691]
+  updatemons()          → client_update_scale(), layersurface_update_scale(),
+                          wlr_fractional_scale_v1_notify_scale()  [lines 4168–4201]
+
+  No code changes required.  The chain is complete.  Scale-change notifications
+  will reach every surface (clients + layers + popups) whenever output
+  configuration changes through ANY path.
+
+  Test: wlr-randr --output DP-1 --scale 2   # triggers Path 1 via config apply
+        # which calls updatemons, which re-notifies every surface on that output.
+        # Also triggers Path 2 via wlr_output_layout_add calling events.change.
+
+================================================================================