[XProf: trace viewer] Fix mouse wheel shortcuts and add input handler tests.

frontend/app/components/trace_viewer_v2/input_handler.cc

@@ -23,10 +23,10 @@ ImGuiKey TranslateKey(absl::string_view code) {
 
 void UpdateModifierKeys(const EmscriptenKeyboardEvent* event) {
   ImGuiIO& io = ImGui::GetIO();
-  io.AddKeyEvent(ImGuiKey_ModCtrl, event->ctrlKey);
-  io.AddKeyEvent(ImGuiKey_ModShift, event->shiftKey);
-  io.AddKeyEvent(ImGuiKey_ModAlt, event->altKey);
-  io.AddKeyEvent(ImGuiKey_ModSuper, event->metaKey);
+    io.AddKeyEvent(ImGuiKey_ModCtrl, event->ctrlKey);
+    io.AddKeyEvent(ImGuiKey_ModShift, event->shiftKey);
+    io.AddKeyEvent(ImGuiKey_ModAlt, event->altKey);
+    io.AddKeyEvent(ImGuiKey_ModSuper, event->metaKey);
 }
 
 }  // namespace
@@ -93,9 +93,9 @@ EM_BOOL HandleMouseUp(int, const EmscriptenMouseEvent* event, void*) {
 EM_BOOL HandleWheel(int, const EmscriptenWheelEvent* event, void*) {
   ImGuiIO& io = ImGui::GetIO();
 
-  io.AddKeyEvent(ImGuiKey_ModCtrl, event->mouse.ctrlKey);
-  io.AddKeyEvent(ImGuiKey_ModShift, event->mouse.shiftKey);
-  io.AddKeyEvent(ImGuiKey_ModSuper, event->mouse.metaKey);
+    io.AddKeyEvent(ImGuiKey_ModCtrl, event->mouse.ctrlKey);
+    io.AddKeyEvent(ImGuiKey_ModShift, event->mouse.shiftKey);
+    io.AddKeyEvent(ImGuiKey_ModSuper, event->mouse.metaKey);
 
   float wheel_x = static_cast<float>(event->deltaX);
   float wheel_y = static_cast<float>(event->deltaY);

frontend/app/components/trace_viewer_v2/input_handler_test.cc

@@ -0,0 +1,97 @@
+#include "frontend/app/components/trace_viewer_v2/input_handler.h"
+
+#include <emscripten/em_js.h>
+#include <emscripten/html5.h>
+
+#include "<gtest/gtest.h>"
+#include "imgui.h"
+
+namespace traceviewer {
+namespace {
+
+EM_JS(void, CreateTestCanvas, (), {
+  if (!document.getElementById('canvas')) {
+    const canvas = document.createElement('canvas');
+    canvas.id = 'canvas';
+    document.body.appendChild(canvas);
+  }
+});
+
+EM_JS(void, DispatchBrowserWheelEvent,
+      (double dx, double dy, bool ctrl, bool shift, bool meta), {
+        const el = document.getElementById('canvas');
+        const event = new WheelEvent('wheel', {
+          deltaX : dx,
+          deltaY : dy,
+          ctrlKey : ctrl,
+          shiftKey : shift,
+          metaKey : meta,
+          bubbles : true,
+          cancelable : true
+        });
+        el.dispatchEvent(event);
+      });
+
+class InputHandlerTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    // CreateTestCanvas();
+    ImGui::CreateContext();
+    ImGuiIO& io = ImGui::GetIO();
+    io.DisplaySize = ImVec2(1024, 768);
+    // Build font atlas to avoid assertion in NewFrame
+    unsigned char* pixels;
+    int width, height;
+    io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);
+  }
+
+  void TearDown() override { ImGui::DestroyContext(); }
+};
+
+TEST_F(InputHandlerTest, HandleWheelUpdatesModifiersAndDeltas) {
+  ImGuiIO& io = ImGui::GetIO();
+  EmscriptenWheelEvent event;
+  memset(&event, 0, sizeof(event));
+  event.mouse.ctrlKey = true;
+  event.mouse.shiftKey = false;
+  event.mouse.metaKey = true;
+  event.deltaX = 100.0;
+  event.deltaY = -200.0;
+
+  HandleWheel(0, &event, nullptr);
+
+  // Prepare for NewFrame to process queued events
+  io.DeltaTime = 1.0f / 60.0f;
+  ImGui::NewFrame();
+
+  EXPECT_TRUE(io.KeyCtrl);
+  EXPECT_FALSE(io.KeyShift);
+  EXPECT_TRUE(io.KeySuper);
+
+  // Expect negated and doubled values
+  EXPECT_FLOAT_EQ(io.MouseWheelH, 100.0f);
+  EXPECT_FLOAT_EQ(io.MouseWheel, -200.0f);
+}
+
+TEST_F(InputHandlerTest, HandleKeyDownUpdatesModifiers) {
+  ImGuiIO& io = ImGui::GetIO();
+  EmscriptenKeyboardEvent event;
+  memset(&event, 0, sizeof(event));
+  event.ctrlKey = false;
+  event.shiftKey = true;
+  event.altKey = false;
+  event.metaKey = true;
+
+  HandleKeyDown(0, &event, nullptr);
+
+  io.DeltaTime = 1.0f / 60.0f;
+  ImGui::NewFrame();
+
+  EXPECT_FALSE(io.KeyCtrl);
+  EXPECT_TRUE(io.KeyShift);
+  EXPECT_FALSE(io.KeyAlt);
+  EXPECT_TRUE(io.KeySuper);
+}
+
+}  // namespace
+}  // namespace traceviewer