Top of window truncated on panel auto resize with small window height

[per1234]

Describe the bug

If you have height of the IDE window set fairly small (as might be required with a small display/large interface scale/tiled windows), operations that automatically resize the panel (e.g., opening the panel or changing tabs) can cause the top of the window to truncate (resulting in the apparent disappearance of important UI elements such as the button bar).

To Reproduce

1. Open Serial Monitor
2. Resize the Arduino IDE window size until the bottom of the window is truncated to the point where the panel can not accommodate the height of the baud rate dropdown menu (Parts of the UI disappear when window is to small #662).
3. Open the baud rate menu in the Serial Monitor.

🐛 The elements at the top of the IDE window have been cut off to accommodate the forced resizing of the panel.
🐛 There is no scroll bar which would allow bringing that part of the window back into view, or indicate in a standard manner that the issue was caused by the window dimensions.

Expected behavior

The top of the window is never truncated.

If truncation is required, it occurs at the more intuitive bottom of the window.

Desktop

• OS: Windows 10
• Version: 2.0.0-rc3-snapshot.1d88263
  Date: 2022-01-24T16:22:30.529Z
  CLI Version: 0.20.2 [13783819]

Additional context

The demonstration above was the most simple procedure I found to reproduce it. However, there are several other conditions it can occur under. In these, simply opening Serial Monitor, clicking one of the panel tabs, or another common operation causes the top truncation.

This is essentially the same issue as #662. However, this variant is a worse user experience because it occurs at some unknown time after the window resizing, so they will not necessarily connect the window resizing action to the apparent loss of the user interface. The top of the window also contains the essential UI elements of the button bar and editor tabs, so its truncation has more of an impact than the loss of the status bar.

Originally reported at https://forum.arduino.cc/t/buttons-on-toolbar-disappear-after-upload-ide-2-0/948849

Related: #129

[per1234]

Closing as fixed by #1151