Make studio python more like studio C++

- C++ Platform UX: Added a "Copy Camera" button to copy XML camera definitions to clipboard.
  - C++ Platform UX: Extracted `SetSpeedIndex` and `GetExpectedLabelWidth` into reusable platform helpers.
  - C++ Platform UX: Fixed combo box widths and removed auto-hide tab bar flag from dockspace.
  - C++ Studio App: Deduplicated label width and speed index logic by adopting platform helpers.
  - C++ Studio App: Updated the toolbar layout to use a 2-column table.
  - Python Bindings: Added pybind definitions for `set_camera_index`, `set_speed_index`, and `camera_to_string`.
  - Python Studio App: Aligned toolbar UI with C++ using a 2-column table and fixed immediate theme switching.
  - Python Studio App: Added a Help menu displaying the MuJoCo version and Stats toggle.
  - Python Events: Added `-`/`=` shortcuts for simulation speed and `Esc`/`[`/`]` shortcuts for camera selection.

PiperOrigin-RevId: 922097319
Change-Id: Iec74afe37bf5c7a1ebf1cab4141e47fff5fe9274

src/experimental/studio/app.cc

@@ -826,14 +826,7 @@ void App::SaveSettings() {
 }
 
 void App::SetSpeedIndex(int idx) {
-  if (idx == tmp_.speed_index || platform::kPercentRealTime.empty()) {
-    return;
-  }
-
-  tmp_.speed_index =
-      std::clamp<int>(idx, 0, platform::kPercentRealTime.size() - 1);
-  float speed = std::stof(platform::kPercentRealTime[tmp_.speed_index]);
-  step_control_.SetSpeed(speed);
+  platform::SetSpeedIndex(&step_control_, tmp_.speed_index, idx);
 }
 
 void App::MoveCamera(platform::CameraMotion motion, mjtNum reldx,
@@ -1022,7 +1015,7 @@ void App::BuildGui() {
 }
 
 void App::ModelOptionsGui() {
-  const float min_width = GetExpectedLabelWidth();
+  const float min_width = platform::GetExpectedLabelWidth();
   const ImGuiChildFlags child_flags =
       ImGuiChildFlags_AutoResizeY | ImGuiChildFlags_AlwaysAutoResize;
   const ImGuiTreeNodeFlags node_flags =
@@ -1064,7 +1057,7 @@ void App::DataInspectorGui() {
     return;
   }
 
-  const float min_width = GetExpectedLabelWidth();
+  const float min_width = platform::GetExpectedLabelWidth();
   const ImGuiChildFlags child_flags =
       ImGuiChildFlags_AutoResizeY | ImGuiChildFlags_AlwaysAutoResize;
   const ImGuiTreeNodeFlags node_flags =
@@ -1424,15 +1417,14 @@ void App::ToolBarGui() {
               ImVec2(ImGui::GetStyle().ItemSpacing.x * 2.0f,
                      ImGui::GetStyle().ItemSpacing.y));
 
-    const float label_width = GetExpectedLabelWidth();
-    const float copy_btn_width = ImGui::CalcTextSize(ICON_COPY_CAMERA).x +
-                                 ImGui::GetStyle().FramePadding.x * 2;
+    const float label_width = platform::GetExpectedLabelWidth();
+    const float copy_btn_width = ImGui::GetFrameHeight();
     const float theme_width =
         ImGui::CalcTextSize(platform::ICON_FA_CIRCLE_O).x +
         ImGui::GetStyle().FramePadding.x * 2;
     const float sp = ImGui::GetStyle().ItemSpacing.x;
-    const float right_width = label_width + sp + label_width + sp +
-                              label_width + sp + copy_btn_width + sp +
+    const float right_width = copy_btn_width + label_width + sp +
+                              label_width + sp + label_width + sp +
                               theme_width;
     const float separator_width = ImGui::GetFrameHeight() * .6f;
 
@@ -1467,26 +1459,15 @@ void App::ToolBarGui() {
 
     ImGui::TableNextColumn();
 
-    if (ImGui::Button(ICON_COPY_CAMERA, square_size)) {
-      std::string camera_string = platform::CameraToString(data(), &camera_);
-      platform::MaybeSaveToClipboard(camera_string);
-    }
-    ImGui::SetItemTooltip("%s", "Copy Camera");
-
-    ImGui::SameLine(0, 0);
-    ImGui::SetNextItemWidth(GetExpectedLabelWidth());
     platform::CameraSelectionGui(model(), data(), camera_, ui_.camera_idx);
 
     ImGui::SameLine();
-    ImGui::SetNextItemWidth(GetExpectedLabelWidth());
     platform::LabelSelectionGui(&vis_options_);
 
     ImGui::SameLine();
-    ImGui::SetNextItemWidth(GetExpectedLabelWidth());
     platform::FrameSelectionGui(&vis_options_);
 
     ImGui::SameLine();
-    ImGui::SetNextItemWidth(GetExpectedLabelWidth());
     if (platform::ThemeSelectGui(&ui_.theme, square_size)) {
       platform::SetupTheme(ui_.theme);
       ImGui::GetIO().WantSaveIniSettings = true;
@@ -1836,27 +1817,6 @@ void App::FileDialogGui() {
   }
 }
 
-float App::GetExpectedLabelWidth() {
-  // Find the longest label which we'll use to set the minimum toggle button
-  // width. This isn't perfect because we may have labels that are longer, but
-  // it's a good enough approximation.
-  if (tmp_.expected_label_width == 0) {
-    int longest = 0;
-    const char* longest_label = "";
-    for (int i = 0; i < mjNVISFLAG; ++i) {
-      int length = static_cast<int>(strlen(mjVISSTRING[i][0]));
-      if (length > longest) {
-        longest_label = mjVISSTRING[i][0];
-        longest = length;
-      }
-    }
-    // Pad the width a bit to account for how the labels will be displayed
-    // (e.g. as button labels or besides checkboxes).
-    tmp_.expected_label_width = ImGui::CalcTextSize(longest_label).x + 16;
-  }
-  return tmp_.expected_label_width;
-}
-
 App::UiState::Dict App::UiState::ToDict() const {
   return {
       {"theme", std::to_string(static_cast<int>(theme))},

src/experimental/studio/app.h

@@ -224,8 +224,6 @@ class App {
   void SpecExplorerGui();
   void SpecEditorGui();
 
-  float GetExpectedLabelWidth();
-
   mjSpec* spec() { return model_holder_->spec(); }
   mjModel* model() { return model_holder_->model(); }
   mjData* data() { return model_holder_->data(); }