test: 💍 add tab switch fix test

tests/apps/standalone/notebook/notebook_test.cpp

@@ -0,0 +1,147 @@
+// wxNotebook page-relayout Test - regression coverage for the WASM DOM-port
+// fix in wxwidgets/src/wasm/notebook.cpp (wxNotebook::WasmRelayoutSelectedPage).
+//
+// Bug (pcbjam#8): KiCad's APPEARANCE_CONTROLS::OnNotebookPageChanged calls
+// Fit() on the just-selected page from a wxEVT_NOTEBOOK_PAGE_CHANGED handler.
+// That collapses a wxScrolledWindow child's viewport to zero height; because
+// DoSetSize() only re-runs layout when the size actually changes, resizing the
+// page back was a no-op and the scrolled rows stayed clip-pathed away ("pages
+// came back blank" after switching tabs away and back).
+//
+// This app reproduces the same shape in pure wxWidgets: a wxNotebook whose
+// "Scrolled" page wraps a wxScrolledWindow full of labelled rows, plus a
+// PAGE_CHANGED handler that calls page->Fit() exactly like KiCad. With the fix,
+// OnDomEvent re-asserts the page geometry after SetSelection() so the rows stay
+// painted; without it, they collapse. The rows are wxStaticText so the DOM port
+// renders them as <span> elements the e2e spec can hit-test.
+
+#include "wx/wxprec.h"
+
+#ifndef WX_PRECOMP
+    #include "wx/wx.h"
+#endif
+
+#include "wx/notebook.h"
+#include "wx/scrolwin.h"
+
+#ifdef __EMSCRIPTEN__
+#include <emscripten/emscripten.h>
+#endif
+
+static const int kRowCount = 30;
+
+class NotebookApp : public wxApp
+{
+public:
+    virtual bool OnInit() override;
+};
+
+class NotebookFrame : public wxFrame
+{
+public:
+    NotebookFrame();
+
+private:
+    wxNotebook* m_notebook = nullptr;
+
+    wxWindow* CreatePlainPage();
+    wxWindow* CreateScrolledPage();
+
+    void Log(const wxString& msg);
+    void OnPageChanged(wxNotebookEvent& evt);
+};
+
+bool NotebookApp::OnInit()
+{
+    if ( !wxApp::OnInit() )
+        return false;
+
+    (new NotebookFrame())->Show(true);
+    return true;
+}
+
+wxIMPLEMENT_APP(NotebookApp);
+
+NotebookFrame::NotebookFrame()
+    : wxFrame(nullptr, wxID_ANY, "wxNotebook Page Relayout Test",
+              wxDefaultPosition, wxSize(420, 480))
+{
+    wxBoxSizer* sizer = new wxBoxSizer(wxVERTICAL);
+
+    m_notebook = new wxNotebook(this, wxID_ANY);
+    m_notebook->AddPage(CreatePlainPage(), "Plain", true);
+    m_notebook->AddPage(CreateScrolledPage(), "Scrolled", false);
+
+    sizer->Add(m_notebook, 1, wxEXPAND | wxALL, 6);
+    SetSizer(sizer);
+
+    // Reproduce KiCad's APPEARANCE_CONTROLS::OnNotebookPageChanged: call Fit()
+    // on the selected page from the PAGE_CHANGED handler. This is what collapses
+    // the scrolled child; the DOM-port fix repairs it after this handler runs.
+    m_notebook->Bind(wxEVT_NOTEBOOK_PAGE_CHANGED, &NotebookFrame::OnPageChanged, this);
+
+    Log("notebook test app started");
+}
+
+wxWindow* NotebookFrame::CreatePlainPage()
+{
+    wxPanel* panel = new wxPanel(m_notebook);
+    wxBoxSizer* sizer = new wxBoxSizer(wxVERTICAL);
+    sizer->Add(new wxStaticText(panel, wxID_ANY, "Plain page"), 0, wxALL, 10);
+    sizer->Add(new wxStaticText(panel, wxID_ANY,
+                                "Switch to the Scrolled page and back."),
+               0, wxLEFT | wxBOTTOM, 10);
+    panel->SetSizer(sizer);
+    return panel;
+}
+
+wxWindow* NotebookFrame::CreateScrolledPage()
+{
+    // panel -> wxScrolledWindow -> many rows. Mirrors KiCad's layer panel:
+    // the page is a wxPanel that hosts a scrolled list; Fit() on the panel is
+    // what drives the viewport to zero.
+    wxPanel* panel = new wxPanel(m_notebook);
+
+    wxScrolledWindow* scrolled =
+        new wxScrolledWindow(panel, wxID_ANY, wxDefaultPosition, wxDefaultSize,
+                             wxVSCROLL | wxBORDER_SIMPLE);
+    scrolled->SetScrollRate(0, 10);
+
+    wxBoxSizer* rows = new wxBoxSizer(wxVERTICAL);
+    for ( int i = 0; i < kRowCount; ++i )
+        rows->Add(new wxStaticText(scrolled, wxID_ANY,
+                                   wxString::Format("Row %d", i)),
+                  0, wxALL, 4);
+    scrolled->SetSizer(rows);
+    scrolled->FitInside();
+
+    wxBoxSizer* pageSizer = new wxBoxSizer(wxVERTICAL);
+    pageSizer->Add(scrolled, 1, wxEXPAND | wxALL, 4);
+    panel->SetSizer(pageSizer);
+    return panel;
+}
+
+void NotebookFrame::Log(const wxString& msg)
+{
+#ifdef __EMSCRIPTEN__
+    EM_ASM({
+        console.log('[NOTEBOOK_EVENT] ' + UTF8ToString($0));
+    }, (const char*)msg.utf8_str());
+#else
+    wxLogMessage("[NOTEBOOK_EVENT] %s", msg);
+#endif
+}
+
+void NotebookFrame::OnPageChanged(wxNotebookEvent& evt)
+{
+    const int sel = evt.GetSelection();
+    if ( sel != wxNOT_FOUND )
+    {
+        if ( wxWindow* const page = m_notebook->GetPage(sel) )
+            page->Fit();
+
+        Log(wxString::Format("switched to page %d (%s)",
+                             sel, m_notebook->GetPageText(sel)));
+    }
+    evt.Skip();
+}