GridNode

Iterates over a given macro in the input file named by the attribute repeat-over, generating a copy of all children widgets as a group. Configures each such group according to the input macros and then positions the set of widgets in a grid pattern. The group’s starting X and Y positions are set such that each group is a number of pixels away from the edges of any other group according to the value of the attribute padding.

If the macro named by repeat-over is parsed and found to be a number, then the node will iterate a number of times specified by the macro. On each loop, the children widgets will be provided with the macros N, __index__, __col__, and __row__ to use to configure themselves. __index__ is a number that starts at zero and increments by one every iteration of the loop. N is similar, but starts at a value specified by the attribute start-at. __row__ and __col__ specify the current 0-indexed position within the grid where the group will be generated.

If, instead, repeat-over names a macro that is found to be a list of dictionaries, then the dictionaries will be treated as the macros to use to configure the children widgets. The loop will iterate over each of the specified mappings and will provide the children elements of the group with those macros (alongside any other macros in the data file). All the same macros mentioned above will also be included.

The number of columns and rows in the node’s grid pattern are determined by the number of iterations specified by repeat-over combined with the attribute aspect-ratio. Defaulting to 1.0, aspect-ratio is the ratio between the number of columns to the number of rows to use. So an aspect-ratio of 2.0 would be specifying that the node should attempt to have twice as many columns as rows. This is an idealized ratio and it may not be possible to exactly match the ratio as given with the number of elements a user provides.

You can also control the shape by specifying the minimum and maximum numbers of columns and rows. Using ‘min-cols’, ‘max-cols’, ‘min-rows’, and ‘max-rows’, you can restrict the automatic shaping done based off of ‘aspect-ratio’. If there is a conflict between the number of iterations, the aspect-ratio, and the minimum/maximum values, then the ‘horizontal’ attribute will be used to determine which restrictions to weight heavier. If ‘horizontal’ is True, then size will break any horizontal constraints (adding additional columns). If ‘horizontal’ is False, then the vertical constraints will be broken (adding additional rows).

• Special Attributes

Name	Type	Description
children	List	A list of widgets to use as a template to copy in a grid pattern
repeat-over	String	The name of a macro that will be provided within the input data file
variable	String	The name under which to provide the value of the loop index, ‘N’ by default
start-at	Number	An offset value to the loop index to provide children widgets
padding	Number	The number of pixels between each widget group
aspect-ratio	Double	A ratio indicating the relative number of columns to the number of rows in the grid
background	Color	A fill color behind the entirety of each template copy
border-color	Color	The color of the group’s border surrounding each template copy
border-width	Number	The thickness of the group’s border in pixels
horizontal	Bool	Fill direction of the layout. Macros will be mapped to widgets across columns first, then proceed to the next row, rather than the reverse. True by default
visibility	String	A pv that determines the visibility of the layout, visibility is turned off if the PV’s value is zero. This logic is inverted if the !Not tag is used instead of String
ignore-empty	Bool	Defines whether or not to adjust positioning of elements if a repeated instance is an empty group. Useful for dealing with Conditional nodes. default: False

• Example

LED_Grid: !Grid
    geometry: 160x170 x 0x0
    aspect-ratio: 1.5
    repeat-over: "LEDs"

    padding: 10

    children:
        - !LED
            <<: *alarm_led
            geometry: 20x20