clipboard-monitor assistance

[Obegg]

So I noticed that we have

--clipboard-enable=<yes|no>

    (Windows and Wayland only)

    Enable native clipboard support (default: yes). This allows reading and writing to the clipboard property to get and set clipboard contents.
    
--clipboard-monitor=<yes|no>

    (Windows only)

    Enable clipboard monitoring so that the clipboard property can be observed for content changes (default: no). This only affects clipboard implementations which use polling to monitor clipboard updates. Other platforms currently ignore this option and always/never notify changes.

I've tried to use it (with AI help), couldn't get it to work as I wanted - which was to monitor the clipboard for any URLs and then paste them into mpv and then bring mpv to foreground
(I use Windows)
So with the help of AI here's the final lua script that does that:

local ffi = require('ffi')
local utils = require('mp.utils')
local msg = require('mp.msg')

-- FFI Definitions for Windows API functions
ffi.cdef [[
    typedef void* HWND;
    typedef unsigned long DWORD;
    typedef int BOOL;
    typedef void* LPARAM;
    typedef int (*WNDENUMPROC)(HWND, LPARAM);

    BOOL EnumWindows(WNDENUMPROC lpEnumFunc, LPARAM lParam);
    DWORD GetWindowThreadProcessId(HWND hWnd, DWORD* lpdwProcessId);
    BOOL IsWindowVisible(HWND hWnd);
    BOOL ShowWindow(HWND hWnd, int nCmdShow);
    BOOL SetForegroundWindow(HWND hWnd);
    void keybd_event(unsigned char bVk, unsigned char bScan, DWORD dwFlags, unsigned long dwExtraInfo);

    typedef void* HANDLE;
    typedef const char* LPCSTR;
    typedef unsigned int UINT;

    HANDLE GetClipboardData(UINT uFormat);
    BOOL OpenClipboard(void* hWndNewOwner);
    BOOL CloseClipboard();
    BOOL EmptyClipboard();
    HANDLE SetClipboardData(UINT uFormat, HANDLE hMem);
    const char* GlobalLock(HANDLE hMem);
    BOOL GlobalUnlock(HANDLE hMem);

    enum {
        CF_TEXT = 1
    };
]]

-- Constants
local user32 = ffi.load("user32")
local kernel32 = ffi.load("kernel32")
local SW_RESTORE = 9
local VK_MENU = 0x12 -- Alt key
local KEYEVENTF_EXTENDEDKEY = 0x0001
local KEYEVENTF_KEYUP = 0x0002

-- Bring MPV window to the foreground
local function bring_to_foreground()
    local pid = mp.get_property_native("pid")
    if not pid then
        return
    end

    local target_hwnd = nil
    user32.EnumWindows(ffi.cast("WNDENUMPROC", function(hwnd, _)
        local window_pid = ffi.new("DWORD[1]")
        user32.GetWindowThreadProcessId(hwnd, window_pid)
        if window_pid[0] == pid and user32.IsWindowVisible(hwnd) then
            target_hwnd = hwnd
            return 0 -- Stop
        end
        return 1 -- Continue
    end), nil)

    if target_hwnd then
        user32.ShowWindow(target_hwnd, SW_RESTORE)
        user32.keybd_event(VK_MENU, 0, KEYEVENTF_EXTENDEDKEY, 0)
        user32.keybd_event(VK_MENU, 0, KEYEVENTF_EXTENDEDKEY + KEYEVENTF_KEYUP, 0)
        user32.SetForegroundWindow(target_hwnd)
    end
end

-- Helper function to get clipboard content
local function get_clipboard_content()
    if not user32.OpenClipboard(nil) then
        return nil
    end

    local handle = user32.GetClipboardData(ffi.C.CF_TEXT)
    if handle == nil then
        user32.CloseClipboard()
        return nil
    end

    local data = ffi.string(kernel32.GlobalLock(handle))
    kernel32.GlobalUnlock(handle)
    user32.CloseClipboard()
    return data
end

-- Helper function to clear clipboard
local function clear_clipboard()
    if user32.OpenClipboard(nil) then
        user32.EmptyClipboard()
        user32.CloseClipboard()
    end
end

local function monitor_clipboard()
    print("Waiting for user to copy URL")
    clear_clipboard()
    local last_clipboard = ""

    -- Define the timer variable outside to control it later
    local clipboard_timer = nil

    -- Create the periodic timer
    clipboard_timer = mp.add_periodic_timer(1, function()
        print("Waiting")
        local new_clipboard = get_clipboard_content()
        if new_clipboard and new_clipboard ~= last_clipboard and new_clipboard:match("^https?://") then
            last_clipboard = new_clipboard

            -- Print the detected URL
            print("Detected URL: " .. new_clipboard)

            mp.commandv("loadfile", new_clipboard)
            bring_to_foreground()
            clear_clipboard()

            -- Stop the timer once the action is performed
            clipboard_timer:kill()
            print("URL loaded and timer stopped.")
        end
    end)
end

local idle_active = false

mp.observe_property("idle-active", "bool", function(_, is_idle)
    idle_active = is_idle
end)

mp.observe_property("path", "string", function(_, path)
    if idle_active and not path then
        monitor_clipboard()
    end
end)

mp.observe_property("eof-reached", "bool", function(_, eof_reached)
    if eof_reached then
        monitor_clipboard()
    end
end)

This script works.
But... now that we have property with clipboard I kinda need some help to shrink this long script to something more reasonable and efficient, are there any experts on the matter who can help me with that?

By the way I tried using PowerShell for some of those functions and it appears that it's a bad idea since it's slow + takes much more CPU usage

[guidocella]

mp.observe_property('clipboard/text', 'native', function (_, clipboard)
    if clipboard and clipboard:find('^http') and (mp.get_property_native('idle-active') or mp.get_property_native('eof-reached')) then
        mp.commandv('loadfile', clipboard)
    end
end)

[Sneakpeakcss]

mp.observe_property('clipboard/text', 'native', function (_, clipboard)
    if clipboard and clipboard:find('^http') and (mp.get_property_native('idle-active') or mp.get_property_native('eof-reached')) then
        mp.commandv('loadfile', clipboard)
    end
end)

This is interesting.

Is it expected that on Windows(10) observing clipboard does anything only when mpv is playing a video(can be paused can't[edit]) ?

On my side when its in idle or 'playing' an image, it requires hovering over the window to actually update. Docs don't mention anything about it in clipboard-monitor, but in the PR there was something about Wayland being only updated on window focus, nothing about Windows and hovering over it though. Should this be a potential bug report ?

[avih]

Is it expected that on Windows(10) observing clipboard does anything only when mpv is playing a video(can be paused) ?

Did you enable --clipboard-monitor ? - https://mpv.io/manual/master/#options-clipboard-monitor

If yes and it doesn't work, then please file a bug report. Thanks.

It might also be worth to document how different platforms behave. Currently it basically says "platforms can do whatever they want with regards to clipboard monitor".

[Sneakpeakcss]

Did you enable --clipboard-monitor ? - https://mpv.io/manual/master/#options-clipboard-monitor

It would be quite embarrassing if the answer was no.

I've opened the mentioned issue. Also corrected the working condition in the above comment, since it only works when video is playing.

[Obegg]

Wonderful, thank you @guidocella , I've tested it and it's working as expected.
Is there any other (easy) way to bring mpv to foreground?

Edit:
Well, there's issues with this approach, it appears mpv doesn't detect changes to the clipboard until mpv is in focus, this beats the whole point of monitoring the clipboard in the first place. (Yes, I have clipboard-monitor=yes in mpv.conf)
You can reproduce this by copying a non URL, open mpv, exit full screen, copy a URL from notepad, don't bring mpv to foreground = mpv will not play the copied URL.

[Sneakpeakcss]

Wonderful, thank you @guidocella , I've tested it and it's working as expected. Is there any other (easy) way to bring mpv to foreground?

Last time i've tried this i ended up toggling ontop property for the same effect, since focus properties are macOS only from what i remember. Ended up with this, but never used it because of the mentioned issues:

local function is_valid_url(url)
    return url:match('^%a[%a%d-_]+://') and (
           url:match("^https?://www.twitch.tv/(.*)videos?") or
           url:match("^https?://www.youtube.com/watch") or
           url:match("^https?://youtu.be/"))
end

local function clipboard_changed(_, clipboard)
    if clipboard then
        local trimmed_url = clipboard:match("^%s*(.-)%s*$")

        if is_valid_url(trimmed_url) then
            mp.msg.info("Appending to playlist: " .. trimmed_url)
            mp.commandv("loadfile", trimmed_url, "append-play")

            if not mp.get_property_bool("focused") then
                mp.set_property_native("ontop", true)
                mp.set_property_native("ontop", false)
            end
        end
    end
end
mp.observe_property("clipboard/text", "string", clipboard_changed)