A hack that stops right-click menus moving in flight while the mouse is over them.

license

Copyright (c) 2014-2015 by Alexander Gavrilov

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

MenuStabilizer.cs

using System;
using UnityEngine;

using System.Collections.Generic;

namespace MenuStabilizer
{
    [KSPAddon(KSPAddon.Startup.Flight, false)]
    public class Loader : MonoBehaviour
    {
        public Loader()
        {
            Update();
        }

        public void Update()
        {
            var controller = UIPartActionController.Instance;
            if (!controller)
                return;

            var prefab = controller.windowPrefab;
            if (!prefab)
                return;

            // Pre-attach the stabilizer to the menu window template
            if (!prefab.GetComponent<WindowStabilizer>())
                prefab.gameObject.AddComponent<WindowStabilizer>();

            Destroy(this);
        }
    }

    // This is instantiated for every part menu window and locks it position when moused over
    public class WindowStabilizer : MonoBehaviour
    {
        private UIPartActionWindow window;
        private EZScreenPlacement window_pos;

        private int child_count = 0;
        private List<UIPartActionItem> items;
        private bool interactive = false;

        private bool frozen = false;
        private Vector3 frozen_pos;

        protected void Awake()
        {
            window = gameObject.GetComponent<UIPartActionWindow>();
            window_pos = gameObject.GetComponent<EZScreenPlacement>();
        }

        private void EnumerateItems()
        {
            child_count = transform.childCount;
            items = new List<UIPartActionItem>();

            for (int i = 0; i < child_count; i++)
            {
                var child = transform.GetChild(i).GetComponent<UIPartActionItem>();
                if (child != null)
                    items.Add(child);
            }
        }

        private bool IsInteractive(List<UIPartActionItem> items)
        {
            foreach (var item in items)
            {
                if (item is UIPartActionLabel || item is UIPartActionProgressBar)
                    continue;

                return true;
            }

            return false;
        }

        private Rect GetWindowRect()
        {
            var title_box = window.titleBar.collider as BoxCollider;
            Vector3 row_start = window.rowRootTransform.localPosition;

            float width = (title_box != null) ? title_box.size.x : row_start.x + 200;
            float height = -row_start.y + window.rowHeight * items.Count;

            return new Rect(window_pos.screenPos.x, window_pos.screenPos.y-height, width, height);
        }

        public void LateUpdate()
        {
            // Check if the window is valid or changed size
            if (!window.isValid)
            {
                frozen = false;
                items = null;
                return;
            }

            if (items == null || transform.childCount != child_count)
            {
                EnumerateItems();

                interactive = IsInteractive(items);
            }

            // Unfreeze all in map view or when manipulating the camera
            if (!interactive || MapView.MapIsEnabled ||
                Input.GetMouseButton(1) || Input.GetMouseButton(2) ||
                GameSettings.AXIS_MOUSEWHEEL.GetAxis() != 0f ||
                GameSettings.ZOOM_IN.GetKey() || GameSettings.ZOOM_OUT.GetKey() ||
                GameSettings.CAMERA_ORBIT_LEFT.GetKey() || GameSettings.CAMERA_ORBIT_RIGHT.GetKey() ||
                GameSettings.CAMERA_ORBIT_UP.GetKey() || GameSettings.CAMERA_ORBIT_DOWN.GetKey())
            {
                frozen = false;
                return;
            }

            // Restore last position if frozen
            if (frozen)
            {
                frozen_pos.z = window.zOffset;

                window_pos.screenPos = frozen_pos;
                window_pos.UpdateCamera();
            }

            // Save position if moused over
            frozen = GetWindowRect().Contains(Input.mousePosition);

            if (frozen)
                frozen_pos = window_pos.screenPos;
        }
    }
}

MenuStabilizer.dll