BlockHero::form in core/modules/layout/includes/block.hero.inc

Builds the block's configuration form.

ckeditor5_image_upload in core/modules/ckeditor5/ckeditor5.pages.inc

Menu callback; Saves images uploaded via copy/paste into the editor.

ckeditor_image_upload in core/modules/ckeditor/ckeditor.pages.inc

Menu callback; Saves images uploaded via copy/paste into the editor.

file_get_upload_validators in core/modules/file/file.pages.inc

Retrieves the upload validators for a file.

filter_format_editor_image_form in core/modules/filter/filter.pages.inc

Form callback: Display a form for inserting/editing an image.

image_field_widget_form in core/modules/image/image.field.inc

Implements hook_field_widget_form().

theme_file_upload_help in core/modules/file/file.theme.inc

Returns HTML for help text based on file upload validators.

user_validate_picture in core/modules/user/user.module

Validates an image uploaded by a user.