Window Manager Enhancements

What is it?

This roadmap takes the basic window manager to a Windows 11 quality experience, and is the single owner of window-management work that older desktop roadmaps also listed. It plans Fluent window chrome with a Mica title bar, minimize, maximize and restore with remembered state, snap layouts, a real desktop icon grid, global keyboard shortcuts, an Alt+Tab switcher with live thumbnails, drag and drop, and a compositor that repaints only what changed. None of its eight sections has shipped, but three already have partial groundwork in the code.

How does it work?

Today. wm.c keeps up to 32 windows, each with a client framebuffer, flags and a stacking order. What already exists toward this roadmap:

Chrome (partial, section 2). A 32 pixel title bar with a Mica-style tint computed from the wallpaper beneath it, the title in 14 pixel semibold, and 46 pixel close, maximize and minimize buttons with hover states and 10 pixel line glyphs; close turns red on hover. Colours are fixed WM_COLOR_* constants, the corner radius is 6 rather than the design's 8, there is no app icon or restore glyph, and shadows use their own values instead of the elevation tokens.
Minimize and maximize (section 1). The buttons are drawn and hit-tested, but their handlers only raise and focus the window.
Desktop icons (partial, section 4). Three fixed icons drawn in a right-edge column; see Desktop Icons.
Shortcuts (partial, section 5). Alt+F4 closes the focused window through an interrupt-safe queue; there is no hotkey table, Windows key, Alt+Tab or Win+D.
Compositor (partial, section 8). The compositor skips frames when nothing is dirty, presents only the drag rectangle while a window moves, and counts late frames against a 16.67 ms budget. It still repaints the full screen for every change.
Moving. Title bar dragging, clamped on screen. Edge resizing shows the cursor but does nothing.

Planned design.

Minimize, maximize, restore: minimized and maximized flags, a saved restore rectangle, title bar double-click, and state remembered per window title in the Registry.
Decorations: Mica through gfx_mica(), theme colours, radius 8, elevation shadows, a 16 pixel app icon, restore and pressed states, and the edge resize grab zone.
Snap layouts: a six-layout flyout after 500 ms hovering over maximize or on Win+Z, Win+arrow keyboard snapping, and edge-drag snapping with a preview.
Desktop icons: icons read from the Desktop folder on a 76 by 86 grid, with selection, launch and dragging.
Shortcuts: a kernel hotkey table checked before the focused window, with Win+D, Win+M, Win+Shift+M, Win+L, Win+number and Alt+F4.
Alt+Tab: a panel of live window thumbnails 158 pixels tall.
Drag and drop: a borderless ghost window following the pointer between windows.
Compositor performance: a dirty-rectangle union, an animation gate and a warning for late frames.

flowchart LR
    CB[caption buttons] --> ST[state: normal / min / max]
    ST --> SN[snap layouts]
    ST --> REG[Registry: per-title state]
    HK[hotkey table] --> ST
    HK --> AT[Alt+Tab thumbnails]
    ST --> DR[dirty-rect compositor]

What are its interfaces?

Interface	Status
`wm_create_window()`, `wm_destroy_window()`, `wm_move_window()`, `wm_raise_window()`, `wm_focus_window()`	Shipped (`wm.h`)
`wm_close_focused_window()` and the Alt+F4 check in `keyboard.c`	Shipped
`wm_get_frame_stats()`, `wm_get_drag_dirty_rect()`	Shipped
`wm_minimize()`, `wm_maximize()`, `wm_restore()`, `WM_FLAG_MINIMIZED`, `WM_FLAG_MAXIMIZED`	Planned, section 1
Snap layout flyout, hotkey table, Alt+Tab panel, drag-and-drop ghost	Planned, sections 3 to 7

How do I use it?

Drag windows by the title bar and close them with the close button or Alt+F4 (bash scripts/build.sh run). Window counting, focus, rectangles, Alt+F4 and frame statistics are covered by bash scripts/test.sh SUITE=desktop.

What is not implemented yet?

Minimize / Maximize / Restore, which also owns a teardown defect found while writing these pages: destroying a window mid-drag leaves the drag flag set, and the slot's controls are not released.
Window Decorations, including the edge resize drag that is still missing.
Snap Layouts and Desktop Icons.
Keyboard Shortcuts and Task Switching, whose hotkey table overlaps the one planned in Global Hotkey Dispatch Table (reconciliation filed there), and Alt+Tab Task Switcher.
Drag and Drop and Compositor Performance.
Window motion comes from the Animation Engine and colours from the Theme System.

How does it compare with Windows 11 and Linux?

Windows 11 has Mica title bars, remembered window state, the six-zone Snap Layouts flyout, Alt+Tab with thumbnails and OLE drag and drop, all composited on the GPU with damage tracking. GNOME's Mutter and KDE's KWin offer maximize and restore, edge tiling, Alt+Tab switchers and drag and drop, with snap layouts only as KWin tiling or extensions. The plan follows Windows 11 and adds a kernel-native drag ghost and a software dirty-rectangle compositor.