7 uses of REGIONS_VISIBLE

BlockController::getVisibleRegionNames in core/modules/block/src/Controller/BlockController.php
Returns the human-readable list of regions keyed by machine name.
BlockDeleteForm::getDeletionMessage in core/modules/block/src/Form/BlockDeleteForm.php
Gets the message to display to the user after deleting the entity.
BlockDeleteForm::getQuestion in core/modules/block/src/Form/BlockDeleteForm.php
BlockForm::form in core/modules/block/src/BlockForm.php
Gets the actual form array to be built.
BlockListBuilder::buildBlocksForm in core/modules/block/src/BlockListBuilder.php
Builds the main "Blocks" portion of the form.
block_theme_initialize in core/modules/block/block.module
Assigns an initial, default set of blocks for a theme.
system_default_region in core/modules/system/system.module
Gets the name of the default region for a given theme.

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