gistfile1.txt

Let me break down how `showInactive()` works on Windows and explain the rendering behavior:

1. For Windows, `showInactive()` is implemented in `native_window_views.cc`:

```478:487:shell/browser/native_window_views.cc
void NativeWindowViews::ShowInactive() {
  widget()->ShowInactive();

  NotifyWindowShow();

#if defined(USE_X11)
  if (global_menu_bar_)
    global_menu_bar_->OnWindowMapped();
#endif
}
```


The key is that it calls `widget()->ShowInactive()` which maps to the Win32 API call `ShowWindow(hwnd, SW_SHOWNOACTIVATE)`. This shows the window without giving it focus or bringing it to the foreground.

2. As for why rendering happens after calling `show()`, this is due to a chain of events:

When `show()` is called:

```460:476:shell/browser/native_window_views.cc
void NativeWindowViews::Show() {
  if (is_modal() && NativeWindow::parent() &&
      !widget()->native_widget_private()->IsVisible())
    static_cast<NativeWindowViews*>(parent())->IncrementChildModals();

  widget()->native_widget_private()->Show(GetRestoredState(), gfx::Rect());

  // explicitly focus the window
  widget()->Activate();

  NotifyWindowShow();

#if defined(USE_X11)
  if (global_menu_bar_)
    global_menu_bar_->OnWindowMapped();
#endif
}
```


This triggers three important things:
1. `widget()->native_widget_private()->Show()` - Makes the window visible
2. `widget()->Activate()` - Gives the window focus
3. `NotifyWindowShow()` - Sends notifications about visibility change

The key to rendering is in `BrowserWindow::OnWindowShow()`:

```485:488:shell/browser/api/electron_api_browser_window.cc
void BrowserWindow::OnWindowShow() {
  web_contents()->WasShown();
  BaseWindow::OnWindowShow();
}
```


The critical line is `web_contents()->WasShown()` which tells Chromium's content layer that the window is now visible. This triggers Chromium to:

1. Start the compositor
2. Allocate GPU resources
3. Begin actual rendering of web content

Before `show()` is called, Chromium keeps the renderer in a suspended state to conserve resources. This is why you don't see any rendering until after `show()`.

To implement similar behavior in another library, you would need to:

```cpp
// For showing without activation
void ShowWindowInactive(HWND hwnd) {
    ShowWindow(hwnd, SW_SHOWNOACTIVATE);
}

// For normal show with rendering
void ShowWindow(HWND hwnd) {
    ShowWindow(hwnd, SW_SHOW);
    SetForegroundWindow(hwnd);
    // Signal your rendering system to start
    StartRendering();
}
```

The key difference between `show()` and `showInactive()` on Windows is:
- `show()`: Uses `SW_SHOW` + `SetForegroundWindow()` 
- `showInactive()`: Uses `SW_SHOWNOACTIVATE` only

This is why `showInactive()` makes the window visible but doesn't steal focus or trigger the taskbar to flash.