Improved Tiling Control
in a
Stacking Window Environment

by David Yockey

Modern stacking window managers generally provide a degree of window tiling functionality, where the tiling is usually controlled in one of two ways: by window dragging or selection among keyboard shortcuts. Both are effective, but each has its problems.

In the first case, the active window is tiled by using a pointing device to drag it to a particular edge or edge portion of the screen, at which point the window is automatically sized and positioned into the corresponding tile location. This control is simple, but is rather slow and is limited in the number of tile locations that can effectively addressed.

In the second case, the active window is tiled to a particular location by use of a corresponding one of a number of keyboard shortcuts, the shortcuts being either predefined by the environment or configured by the user. This control is fast and allows for a large number of tiling locations, but remembering all of the keyboard shortcuts can be problematic. Also, where necessary, user configuration of a collection of shortcuts can be frustrating.

An improved approach to control would aim to provide adequate speed for most users and permit numerous tiling locations while avoiding the need for a multitude of actuators. The proposed solution described here uses a pointer position to determine coarse tile location and a single tiling actuator to actuate coarse tiling. The same tiling actuator is further used to toggle between a number of fine tile sizes, thus limiting the number of controls required to two. For convenience, the proposed solution is referred to herein as demitile control or demitiling.


Demitile control enables coarse tiling by dividing the display into a number of areas within which the pointer can be positioned to indicate a particular tiling. The number of divisions should provide areas large enough to allow for easy positioning of the pointer within a selected area. On a 1920x1080 display, division into a 3x3 grid of equal-size areas is a workable arrangement. More divisions to provide additional coarse tiling options may be workable given a larger display or a pointing device allowing sufficiently precise control.

Desktop exclusion areas where windows are normally prevented from being automatically positioned, such as areas occupied by panels or taskbars, should also be considered in establishing the coarse tiling grid and consequent window tiling. Two possibilities for addressing the presence of exclusion areas are contemplated: division of display working area and constraint of overlapping tiles.

In the first case, the exclusion areas are effectively subtracted from the total display area to provide a working area. The coarse tiling grid is then determined and windows then tiled as if the display were only the size of the working area. In this case, a window tiled to one half of the effective display covers half of the working area, and a centered window is centered within the working area but not necessarily centered within the display as a whole.

In the second case, the exclusion areas are ignored in determining the coarse tiling grid. In this case, a tiled window that overlaps an exclusion area is reduced in size along the appropriate dimensions to avoid the overlap. A window tiled to one half of the display that would overlap an exclusion area to the side of the display is thus reduced in width to avoid the overlap, potentially resulting in windows tiled to halves of the display having different widths. However, a centered window overlapping no exclusion area would still be centered within the overall display.

In either case, a pointer location that happens to be within an exclusion area should be considered to be within the closest adjacent grid area to avoid conveying the impression of there being dead zones within the grid.


With the pointer positioned in a given area of a display divided in a 3x3 grid as discussed above, activating the tiling actuator will cause the active window to be tiled as indicated in the following table.

Tile to Upper-Left Quarter Tile to Upper Half Tile to Upper-Right Quarter
Tile to Left Half Tile to Center Tile to Right Half
Tile to Lower-Left Quarter Tile to Lower Half Tile to Lower-Right Quarter
Display Divisions for Coarse Tiling Control

Consequently, coarse tiling provides the same tiling options as many stacking window managers, i.e. tiling to quarters, left/right halves, and top/bottom halves of the display. It also provides a "Tile to Center" option that results in a centered active window of half display width. While the resulting centered window fails to tile with other coarse tiled windows, it does tile with demitiling's fine tiled windows.


Fine tiling can be performed once a window has been coarse tiled. Demitiling control allows for fine tiling by repeated activation of the tiling actuator. The repeated actuation toggles the tile through a sequence of widths based on the tile location.

The number of widths in a sequence being determined based on the number of coarse grid divisions so as to provide the greatest number of possible tiling arrangements. For the 3x3 coarse grid discussed above, fine tiling sequences are contemplated as follows:

Such fine tiling enables a greater variety of tiled window arrangements than window dragging with a minimum of additional controls. Examples of tiling arrangements thus enabled are illustrated in the following figure.

Tiled window arrangement examples


The most common pointing device used for demitiling on a desktop machine is likely to be a three-button/scroll-wheel mouse with the tiling actuator being a keyboard key or key combination assigned a shortcut for triggering actuator software. Where a 4+ button mouse is used, the keyboard key may be eliminated in favor of an extra button on the mouse, reducing demitiling to a point & click operation.

In the case of a laptop, the pointing device would most likely be a touchpad, and the tiling actuator again a keyboard shortcut. However, a touchpad offers additional actuator options. Depending on the configurability of the touchpad, a tap on a designated touchpad area or a designated multi-finger tap might be preferred over use of a keyboard key.

Using a pointing device and a keyboard key, selection of the key such that it can be pressed with the hand opposite that operating the pointing device is advisable. By so doing, the user need not unhand the pointing device to operate the selected key or vice versa.

Other pointing devices and/or tiling actuators may be more appropriate depending on the user and/or application, particularly in addressing accessibility issues.


Demitile control as described provides for quick tiling, a rich variety of tiling arrangements, and a minimum of control complexity. As an improvement within the domain of stacking window managers, demitiling is not meant to displace existing tiling window managers which are preferred by power users and demonstrably superior for many use cases. It can, however, enhance the usefulness of tiling within desktop environments preferred by the majority of computer users.


The following video demonstrates an implementation of the improved tiling control described above. A three-button/scroll-wheel mouse and a keyboard shortcut assigned to the Menu key are used as the controls, the display resolution is 1920x1080. The software used in the video, entitled demitile (, is a proof-of-concept application implemented as a Bash script that implements the 3x3 grid coarse tiling, toggled fine tiling, and working area handling of exclusion areas described above. While useful as is, such control would ideally be implemented in a compiled language to improve performance, and/or integrated directly into a stacking window manager.