DropDownList

Table of contents

DropdownList normal

Regular state

DropdownList expanded

Expanded state

An element that allows to select an item from a list of options. We can set the possible values for the drop-down list by assigning them to the "items" property. The selected item is determined by the "current" property, which defaults to 0

Create from source

func NewDropDownList(session Session, params Params) DropDownList

Create new drop down list object and returns its interface

Create from resource

DropDownList {
    id = dropDownList,
    current = 0,
    items = [
        "item 1",
        "item 2"
    ],
}

Interface description

Inherit methods, properties and events from View

Properties

"current"

Current selected item

Constant: Current

Types: int, string

Values

int string Description
-1 "-1" No item has been selected
>= 0 >= "0" Index of selected item

"disabled-items"

An array of disabled(non selectable) items indices

Constant: DisabledItems

Types: []int, string, []string, []any containing elements of string or int

Internal type is []int, other types converted to it during assignment

Rules of conversion

[]int - Array of indices

string - Single index value or multiple index values separated by comma(,)

[]string - Array of indices in text format

[]any - Array of strings or integer values

Examples

DropDownList {
    items = [
        "Value 1",
        "Value 2",
        "Value 3",
        "Value 4",
        "Value 5",
    ],
    disabled-items = "0, 3",
}

dropdown := rui.NewDropDownList(session, rui.Params{
    rui.Items: []string{
        "Value 1",
        "Value 2",
        "Value 3",
        "Value 4",
        "Value 5",
    },
    rui.DisabledItems: []int{
        0, 3,
    },
})

"items"

Array of data elements

Constant: Items

Types: []string, string, []fmt.Stringer, []Color, []SizeUnit, []AngleUnit, []any containing elements of string, fmt.Stringer, bool, rune, float32, float64, int, int8 … int64, uint, uint8 … uint64

Internal type is []string, other types converted to it during assignment

Conversion rules

string - contain single item

[]string - an array of items

[]fmt.Stringer - an array of objects convertible to string

[]Color - An array of color values which will be converted to a string array

[]SizeUnit - an array of size unit values which will be converted to a string array

[]any - this array must contain only types which were listed in Types section

Examples

DropDownList {
    items = [
        "Value 1",
        "Value 2",
    ],
}

DropDownList {
    items = [
        1px,
        1em,
    ],
}

DropDownList {
    items = [
        #FF000000,
        #FFFFFFFF,
    ],
}

dropdown := rui.NewDropDownList(session, rui.Params{
    rui.Items: []string{
        "Value 1",
        "Value 2",
    },
})

dropdown := rui.NewDropDownList(session, rui.Params{
    rui.Items: []rui.SizeUnit{
        rui.Px(1),
        rui.Em(1),
    },
})

dropdown := rui.NewDropDownList(session, rui.Params{
    rui.Items: []rui.Color{
        rui.Black,
        rui.White,
    },
})

"item-separators"

An array of indices of DropDownList items after which a separator should be added

Constant: ItemSeparators

Types: []int, string, []string, []any containing elements of string or int

Internal type is []int, other types converted to it during assignment

Rules of conversion

[]int - Array of indices

string - Single index value or multiple index values separated by comma(,)

[]string - Array of indices in text format

[]any - Array of strings or integer values

Examples

DropDownList {
    items = [
        "Value 1",
        "Value 2",
        "Value 3",
        "Value 4",
        "Value 5",
    ],
    item-separators = "1, 3",
}

dropdown := rui.NewDropDownList(session, rui.Params{
    rui.Items: []string{
        "Value 1",
        "Value 2",
        "Value 3",
        "Value 4",
        "Value 5",
    },
    rui.ItemSeparators: []int{
        1, 3,
    },
})

Events

Occur when a list item becomes selected

Constant: DropDownEvent

General listener format:

func(list rui.DropDownList, index int)

where:

  • list - Interface of a drop down list which generated this event
  • index - Index of a newly selected item

Allowed listener formats:

func(list rui.DropDownList)

func(index int)

func()

func DropDownListByID(rootView View, id string, ids ...string) DropDownList

Returns the child DropDownList, path to which is specified using the arguments id, ids. Example: view := DropDownListByID(rootView, "id1", "id2", "id3"), view := DropDownListByID(rootView, "id1/id2/id3"). These two function calls are equivalent. If a View with this path is not found or View is not DropDownList, the function will return nil.

func GetDropDownDisabledItems(view View, subviewID ...string) []int

Return the list of DropDownList disabled item indexes. If the second argument (subviewID) is not specified or is an empty string then a value from the first argument (view) is returned.

func GetDropDownItems(view View, subviewID ...string) []string

Return the DropDownList items list. If the second argument (subviewID) is not specified or is an empty string then a value from the first argument (view) is returned.

func GetDropDownItemSeparators(view View, subviewID ...string) []int

Returns an array of indices of DropDownList items after which a separator should be added. If the second argument (subviewID) is not specified or it is "" then a value from the first argument (view) is returned.

func GetDropDownListeners(view View, subviewID ...string) []func(DropDownList, int, int)

Returns the "drop-down-event" listener list. If there are no listeners then the empty list is returned. If the second argument (subviewID) is not specified or is an empty string then a value from the first argument (view) is returned.

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