My Prompts

Taskbar Sliders

Volume, brightness and blue-light sliders that sit right on the Windows 11 taskbar. Each knob is an icon that changes as you slide it.

1. Copy the prompt with the button below.
2. Open Claude Code on a Windows 11 computer and paste it in.
3. Approve what it asks.

The sliders were built and tested on one Windows 11 computer with two external monitors. The prompt has not been run on other computers, and laptop screen support is untested, so your results may differ. Read a prompt before you run it, because Claude Code will install and run this tool on your computer.

Build and install a small always-running tool for Windows 11: three sliders that sit directly on the Windows taskbar, just left of the tray icons. From left to right they control system volume, screen brightness and blue light. There are no text labels. Each slider's moving knob is a small icon that changes as the value changes. Do all of it yourself, including installing it and testing it.

GROUND RULES
- Write it in Python 3 with tkinter and ctypes only. Add no pip packages. Do not build an unsigned .exe, because Windows Smart App Control can block it.
- If Python with tkinter is missing, stop and ask me to install it from https://www.python.org/downloads/windows/ and then continue.
- No admin rights and no machine-wide changes. Do not change HKLM or any system setting.
- Install to %LOCALAPPDATA%\ScreenSliders\screen_sliders.pyw, with settings.json next to it.
- Start it with Windows through a value named ScreenSliders under HKCU\Software\Microsoft\Windows\CurrentVersion\Run, running pythonw.exe with the full script path.
- Allow only one running copy, using a named mutex.

THE WINDOW
- Use a borderless Tk window (overrideredirect) holding one Canvas that draws everything. Make the process per-monitor DPI aware.
- Get the real top-level handle with GetAncestor(winfo_id, GA_ROOT) and add WS_EX_TOOLWINDOW and WS_EX_NOACTIVATE, so it has no taskbar button, no Alt-Tab entry and does not steal focus.
- Every 400 ms: find Shell_TrayWnd and its child TrayNotifyWnd. Set the window's right edge 10 px left of the tray and centre it vertically on the taskbar. Call SetWindowPos with HWND_TOPMOST and SWP_NOACTIVATE. This must repeat, because the taskbar raises itself over other windows when clicked.
- Hide the window with ShowWindow while a full-screen app is in front: the foreground window covers the taskbar's full width and reaches from the top of the screen to the bottom of the taskbar, and its class is not Progman, WorkerW, Shell_TrayWnd or Shell_SecondaryTrayWnd. Show it again without activating it.
- About every 5 seconds, sample the screen colour 6 px left of the window with GetPixel, use it as the background so the bar blends in, and choose dark or light text and track colours by its luminance.

LAYOUT (pixels at 96 DPI; multiply everything by taskbar DPI / 96)
- Window: 490 wide, 40 high.
- Tracks are 99 long, 4 thick, with round caps. Volume runs x=14 to 113, brightness x=171 to 270, blue light x=328 to 427.
- Percentage text is Segoe UI 12 px, left aligned, at x=128, x=285 and x=442.
- A small grey × at x=476, Segoe UI 13 px, closes the app.
- Each track is grey, with the part left of the knob filled in the slider's colour.
- Before drawing each knob icon, draw a disc of radius 12 in the background colour, so the track does not run through the icon.

CONTROLS
- Pressing within 10 px of a track's ends jumps the knob there, and dragging moves it. Keep tracking while the button is held.
- Mouse wheel over a slider moves it by 2. Wheel up always moves the knob to the right.
- Save settings on mouse release and after wheel moves.
- The × saves, sets the screen colour back to normal and exits.

SLIDER 1: VOLUME (colour #2e9e6b, 0 to 100%)
- Control the default playback device's master volume through Core Audio, calling the COM vtables directly with ctypes. CoCreateInstance CLSID BCDE0395-E52F-467C-8E3D-C4579291692E, IID A95664D2-9614-4F35-A746-DE8DB63617E6. Call GetDefaultAudioEndpoint (vtable slot 4) with eRender=0 and eConsole=0, then Activate (slot 3) with IID 5CDF2C82-841E-4546-9722-0CF74078229A.
- On that interface use slot 7 SetMasterVolumeLevelScalar, slot 9 GetMasterVolumeLevelScalar, slot 14 SetMute and slot 15 GetMute. Get the device fresh for each call so it follows a change of speakers.
- Any change above 0 also turns mute off, like the Windows slider.
- About every 800 ms, unless this slider is being dragged, read the volume and mute state and redraw if they changed, so it follows the keyboard keys and the Windows volume panel.
- Icon: a filled speaker, with sound-wave arcs to its right, each 100 degrees wide and centred on the speaker's right edge. Radii are 5, 8, 11 and 14, 2 px thick. Show ceil(level x 4) arcs, so none at 0 and four at full.
- If the volume is 0 for any reason, or it is muted, replace the arcs with a small X. Dragging to 0 with the mouse must show the X too.

SLIDER 2: BRIGHTNESS (colour #e0a100, 0 to 100%)
- One slider sets all monitors together. On external monitors use DDC/CI through Dxva2: GetPhysicalMonitorsFromHMONITOR and SetVCPFeature with VCP code 0x10, retrying up to 3 times.
- Monitors respond slowly, so send values from a helper thread that always sends only the newest value. The slider must never lag.
- On startup, read the current brightness with GetVCPFeatureAndVCPFeatureReply and show it. Do not change it on startup.
- For a laptop's built-in screen, or a monitor that does not answer DDC/CI, fall back to WMI (WmiMonitorBrightness to read and WmiMonitorBrightnessMethods to set) where available. If neither works on a screen, tell me which screen in your final report.
- Icon: a filled sun of radius 4 with evenly spaced rays around it, starting 6.5 from the centre. Ray count is 4 x ceil(level x 4), meaning 0, 4, 8, 12 or 16, so at 0% there are no rays and the sun is always symmetrical. Rays get longer with level, ending at 9 + 3 x level. Use 2 px thick rays up to 10 rays and 1 px above that.

SLIDER 3: BLUE LIGHT (colour #2f7de1)
- The number shows how much blue is REMOVED. Far left shows 0% and the screen is normal. Sliding right removes more blue and makes the screen warmer.
- Use SetDeviceGammaRamp on a DC from CreateDCW for each monitor device. With b = fraction of blue kept, for i from 0 to 255 and v = i x 257: red = v, green = v x (1 - (1 - b) x 0.3), blue = v x b.
- Windows refuses strong ramps. On first run, try blue kept at 40% and go up in steps of 2 until a ramp is accepted, save that as the floor in settings.json, and use it as the far-right limit. If the floor is 50, far right shows 50%.
- Save the setting and reapply it on startup. Also reapply it about every 5 seconds whenever blue is being removed, because Windows resets the ramp after sleep or a display change. Leave the ramp alone when the slider is at 0%.
- Icon: a light bulb. The glass is a circle of radius 6.5 centred 3 above the middle, with a tapered neck and two short lines for the base.
- Let level = position along the slider, 0 to 1. Blend the bulb's colour from pale #b9cde4 at level 0 to #2f7de1 at level 1, so it looks unlit on the left and fully on at the right.
- Add ceil(level x 9) rays fanning out from the top of the glass, spaced 27.5 degrees apart and centred straight up, from 8.5 to 10 + 2 x level from the glass centre, 2 px thick.

TESTING (do this with the real mouse before you say it is done)
1. Install it, start it, and confirm exactly one copy is running and the Run value is set.
2. Use SetCursorPos and mouse_event on the real sliders. Before clicking, use WindowFromPoint to confirm the slider is really what is under the pointer at each test point. Do not rely on counting windows or reading your own variables.
3. After each move, read the result back from the system: the monitors' brightness over DDC/CI, the gamma ramp with GetDeviceGammaRamp, and the volume and mute from Core Audio.
4. Test both ends of the blue slider, the mouse wheel on the volume and blue sliders, and changing the volume from outside the app to confirm the slider follows.
5. Drag volume to far left with the mouse and take a screenshot to confirm the X appears.
6. Click an empty part of the taskbar and confirm the sliders stay on top.
7. Take a zoomed screenshot of the bar and fix anything overlapping or clipped. Also draw each icon at levels 0, 0.1, 0.25, 0.5, 0.75 and 1 in a separate temporary window using the same drawing code, and check how they look.
8. Be careful with my settings. Record my volume, mute, brightness and blue values first, put them all back exactly afterwards, keep test volumes low so nothing gets loud, and raise brightness by no more than 20 points during tests.

WHEN DONE
Tell me plainly what passed, what failed and what you could not test. Mention these limits if they apply: some monitors do not support DDC/CI, HDR can stop the blue-light effect from working, and Windows Night Light can conflict with it. Tell me that the small × closes the sliders until the next restart.