Window Rules (Advanced)

Regex Matching

Match using patterns instead of exact strings:

-- Match anything starting with "Picture-in-Picture"
samwm.windowrule(
    { title = "~^Picture-in-Picture" },
    { float = "true" }
)

Prefix	Meaning
`~^`	Regex: starts with
`~$`	Regex: ends with
`~*`	Regex: contains
`~=`	Case-insensitive match

Examples

-- Float all notification popups
samwm.windowrule(
    { title = "~*notification" },
    { float = "true" }
)

-- Tile any Picture-in-Picture window
samwm.windowrule(
    { title = "~^Picture-in-Picture" },
    { float = "false" }
)

Multiple Criteria

Combine criteria with AND logic — all must match:

-- Match Firefox with specific title
samwm.windowrule(
    { class = "Firefox", title = "~*Settings" },
    { float = "true" }
)

Action Stacking

Apply multiple actions in one rule:

-- Move to workspace 2, float, and set size
samwm.windowrule(
    { class = "Gimp" },
    {
        workspace = "2",
        float = "true",
        size = "1600x900",
        position = "center"
    }
)

Special Values

Position Values

{ position = "center" }      -- Center of screen
{ position = "cursor" }       -- At cursor position
{ position = "5,5" }         -- Pixel coordinates

Size Values

{ size = "800x600" }         -- Exact size
{ size = "50%" }             -- 50% of screen
{ size = "1280 720" }        -- Whitespace-separated

Dynamic Rules

Create rules programmatically:

-- Add rule from Lua
samwm.add_windowrule(
    { class = "my-app" },
    { float = "true" }
)

-- Remove rule
samwm.remove_windowrule({ class = "my-app" })

On-Demand Rules

Apply rules when windows open using event hooks:

samwm.on("window_open", function(window)
    if window.class == "mpv" then
        samwm.set_window_rule(window, { float = "true" })
    end
end)

Priority

Rules are checked in order. More specific rules should come after general ones:

-- General: all Firefox float
samwm.windowrule({ class = "Firefox" }, { float = "true" })

-- Specific: devtools tile
samwm.windowrule({ class = "Firefox", title = "~*Developer Tools" }, { float = "false" })