Three windows laid out on the primary display by nativeapi — the deno desktop counterpart of flutter_multiple_window_example. WindowManager.setWillShowHook catches each window just before it is shown, sizes and positions it against Display.workArea, and lets the show through with callOriginalShow.

The primary window takes the top row (60% of the work area, full width); the secondary and tertiary windows share the bottom row. Each window's button opens the next one; hiding a window and showing it again goes through the hooks again. Every window lists what the hooks saw.

A will-show hook replaces the platform's show: a window whose hook does not call WindowManager.callOriginalShow(windowId) never appears. The window deno desktop opens at startup is on screen before the hook is installed, so the primary window is opened anew.

npm install     # at the repository root: builds the nativeapi addon
cd examples/deno_multiple_window_example
deno task dev

Requires Deno 2.9+ (deno desktop). macOS is the platform this was checked on.