Spaces.json File

The Spaces.json file is used to define the spaces of OVE and describe the arrangement of clients within each space (these terms are explained in the Basic Concepts page).

Each client must have its geometry specified by four properties:

  • h: the height of the client in pixels
  • w: the width of the client in pixels
  • x: the x-coordinate of the top-left corner of the client (x-coordinate values begin at 0 and increase from left to right)
  • y: the y-coordinate of the top-left corner of the client (y-coordinate values begin at 0 increase downards)

The order in which the clients are defined determines the oveViewID of each, and thus the URL that should be opened in each browser window.

By default, OVE assumes that there is a one-to-one mapping between client pixels and screen pixels. The optional scale property can be used to specify an alternative mapping. It accepts either a single scaling factor, or separate scaling factors for the x and y axes, similar to the CSS scale() function.

The default Spaces.json file defines two spaces (LocalFour and LocalNine), corresponding to 2x2 and 3x3 arrangements of clients. Each client in these spaces has a resolution of 1440x808, so they have a total resolution of 2880x1616 and 4320x2424 respectively.

OVE must be relaunched after any changes are made to Spaces.json.


Additional spaces can be defined by adding descriptions to the Spaces.json file.

A number of example additions are provided below.

Single client

A space having a single client with a 4K resolution can be defined by adding:

"4K": [
    {"x": 0, "y": 0, "w": 3840, "h": 2160, "scale": 1}

The scale property is optional and can be omitted.

2x2 grid of screens

A 2x2 grid of clients, each with with Full HD (1080p) resolution can be defined by adding:

"HDFour": [
    {"x": 0, "y": 1080, "w": 1920, "h": 1080},
    {"x": 1920, "y": 1080, "w": 1920, "h": 1080},
    {"x": 0, "y": 0, "w": 1920, "h": 1080},
    {"x": 1920, "y": 0, "w": 1920, "h": 1080}

In the above arrangement, the first client would be positioned bottom-left, the second client would be positioned bottom-right, the third client would be positioned top-left, and the fourth client would be positioned top-right.

Non-contiguous arrangements and bezel correction

The specification of clients on the Spaces.json file need not always be contiguous and non-overlapping. The following is a perfectly valid configuration:

"HDFour-alternative": [
    {"x": 0, "y": 1090, "w": 1920, "h": 1080},
    {"x": 1930, "y": 1090, "w": 1920, "h": 1080},
    {"x": 0, "y": 0, "w": 1920, "h": 1080},
    {"x": 1930, "y": 0, "w": 1920, "h": 1080}

The above arrangement leaves room for a 10 pixel wide bezel between the each client in both horizontal and vertical directions and thereby creates a space of a 3850x2170 resolution (only 8,294,400 of the 8,354,500 pixels in this space are actually displayed by a client).

The Alignment App exists to help align the monitors by correcting the space configuration to compensate for the thickness of the bezels and any gaps that may exist between adjacent screens.