Builtin Elements

Common properties

These properties are valid on all visible items

  • x and y (length): the position of the element relative to its parent

  • z (float): Allows to specify a different order to stack the items with its siblings. (default: 0)

  • width and height (length): The size of the element. When set, this overrides the default size.

  • max-width and max-height (length): The maximum size of an element when used in a layout.

  • min-width and min-height (length): The minimum size of an element when used in a layout.

  • preferred-width and preferred-height (length): The preferred size of an element when used in a layout.

  • col, row, colspan, rowspan (int): See GridLayout.

  • horizontal-stretch and vertical-stretch (float): Specify how much relative space these elements are stretching in a layout. When 0, this means that the elements will not be stretched unless all elements are 0. Builtin widgets have a value of either 0 or 1

  • opacity (float): A value between 0 and 1 (or a percentage) that is used to draw the element and its children with transparency. 0 is fully transparent (invisible), and 1 is fully opaque. (default: 1)

  • visible (bool): When set to false, the element and all his children will not be drawn and not react to mouse input (default: true)

  • cache-rendering-hint (bool): When set to true, this provides a hint to the renderer to cache the contents of the element and all the children into an intermediate cached layer. For complex sub-trees that rarely change this may speed up the rendering, at the expense of increased memory consumption. Not all rendering backends support this, so this is merely a hint. (default: false)

  • dialog-button-role (enum DialogButtonRole): Specify that this is a button in a Dialog.

Accessibility

Use the following accessible- properties to make your items interact well with software like screen readers, braille terminals and other software to make your application accessible.

  • accessible-role (enum AccessibleRole): The accessibility role of the element. This property is mandatory to be able to use any other accessible properties. It should be set to a constant value. The default value is none for most elements, but is text for the Text element.

  • accessible-label (string): The label for an interactive element. The default value is empty for most elements, or is the value of the text property for Text elements.

  • accessible-description (string): The description for the current element.

  • accessible-checkable (bool): Whether the element is can be checked or not.

  • accessible-checked (bool): Whether the element is checked or not. This maps to the “checked” state of checkboxes, radio buttons, and other widgets.

  • accessible-has-focus (bool): Set to true when the current element currently has the focus.

  • accessible-value (string): The current value of the item.

  • accessible-value-maximum (float): The maximum value of the item. This is used for example by spin boxes.

  • accessible-value-minimum (float): The minimum value of the item.

  • accessible-value-step (float) The smallest increment or decrement by which the current value can change. This corresponds to the step by which a handle on a slider can be dragged.

Drop Shadows

To achieve the graphical effect of a visually elevated shape that shows a shadow effect underneath the frame of an element, it is possible to set the following drop-shadow properties:

  • drop-shadow-offset-x and drop-shadow-offset-y (length): The horizontal and vertical distance of the shadow from the element’s frame. A negative value places the shadow left / above of the element.

  • drop-shadow-color (color): The base color of the shadow to use. Typically that color is the starting color of a gradient that fades into transparency.

  • drop-shadow-blur (length): The radius of the shadow that also describes the level of blur applied to the shadow. Negative values are ignored and zero means no blur (default).

The drop-shadow effect is supported for Rectangle elements.

Window

Window is the root of what is on the screen

The Window geometry will be restricted by its layout constraints: setting the width will result in a fixed width, and the window manager will respect the min-width and max-width so the window can’t be resized bigger or smaller. The initial width can be controlled with the preferred-width property. The same applies for the height.

Properties

  • title (string): The window title that is shown in the title bar.

  • icon (image): The window icon shown in the title bar or the task bar on window managers supporting it.

  • no-frame (bool): Whether the window should be borderless/frameless or not.

  • background (color): The background color of the Window. (default value: depends on the style)

  • default-font-family (string): The font family to use as default in text elements inside this window, that don’t have their family set.

  • default-font-size (length): The font size to use as default in text elements inside this window, that don’t have their size set.

  • default-font-weight (int): The font weight to use as default in text elements inside this window, that don’t have their weight set. The values range from 100 (lightest) to 900 (thickest). 400 is the normal weight.

Rectangle

By default, the rectangle is just an empty item that shows nothing. By setting a color or a border it is then possible to draw a simple rectangle on the screen

When not part of a layout, its width or height defaults to 100% of the parent element when not specified.

Properties

  • background (brush): The background brush of the Rectangle, typically a color. (default value: transparent)

  • border-width (length): The width of the border. (default value: 0)

  • border-color (brush): The color of the border. (default value: transparent)

  • border-radius (length): The size of the radius. (default value: 0)

  • clip (bool): By default, when an item is bigger or outside another item, it is still shown. But when this property is set to true, then the children element of this Rectangle are going to be clipped. (default: false)

Example

Example := Window {
    width: 270px;
    height: 100px;

    Rectangle {
        x: 10px;
        y: 10px;
        width: 50px;
        height: 50px;
        background: blue;
    }

    // Rectangle with a border
    Rectangle {
        x: 70px;
        y: 10px;
        width: 50px;
        height: 50px;
        background: green;
        border-width: 2px;
        border-color: red;
    }

    // Transparent Rectangle with a border and a radius
    Rectangle {
        x: 140px;
        y: 10px;
        width: 50px;
        height: 50px;
        border-width: 4px;
        border-color: black;
        border-radius: 10px;
    }

    // A radius of width/2 makes it a circle
    Rectangle {
        x: 210px;
        y: 10px;
        width: 50px;
        height: 50px;
        background: yellow;
        border-width: 2px;
        border-color: blue;
        border-radius: width/2;
    }
}

Image

An Image can be used to represent an image loaded from an image file.

Properties

  • source (image): The image to load. In order to reference image, one uses the @image-url("...") macro which loads the file relative to the directory containing the .slint file.

  • source-clip-x, source-clip-y, source-clip-width, source-clip-height (int): properties in source image coordinates that, when specified, can be used to render only a portion of the specified image.

  • image-fit (enum): Specifies how the source image shall be fit into the image element. Possible values are:

    • fill: Scales and stretches the image to fit the width and height of the element.

    • contain: The source image is scaled to fit into the image element’s dimension while preserving the aspect ratio.

    • cover: The source image is scaled to cover into the image element’s dimension while preserving the aspect ratio.

    When the Image element is part of a layout, the default value for image-fit is contain. Otherwise it is fill.

  • image-rendering (enum): Specifies how the source image will be scaled. Possible values are:

    • smooth: The image is scaled with a linear interpolation algorithm.

    • pixelated: The image is scaled with the nearest neighbor algorithm.

    The default value is smooth.

  • colorize (brush): When set, the image is used as an alpha mask and is drown in the given color (or with the gradient)

  • width, height (length): The width and height of the image as it appears on the screen.The default values are the sizes provided by the source image. If the Image is not in a layout and only one of the two sizes are specified, then the other defaults to the specified value scaled according to the aspect ratio of the source image.

Example

Example := Window {
    width: 100px;
    height: 100px;
    VerticalLayout {
        Image {
            source: @image-url("https://slint-ui.com/logo/slint-logo-full-light.svg");
            // image-fit default is `contain` when in layout, preserving aspect ratio
        }
        Image {
            source: @image-url("https://slint-ui.com/logo/slint-logo-full-light.svg");
            colorize: red;
        }
    }
}

Scaled while preserving the aspect ratio:

Example := Window {
    width: 100px;
    height: 150px;
    VerticalLayout {
        Image {
            source: @image-url("https://slint-ui.com/logo/slint-logo-full-light.svg");
            width: 100px;
            // implicit default, preserving aspect ratio:
            // height: self.width * natural_height / natural_width;
        }
    }
}

Text

The Text element is responsible for rendering text. Besides the text property, that specifies which text to render, it also allows configuring different visual aspects through the font-family, font-size, font-weight and color properties.

The Text element can break long text into multiple lines of text. A line feed character (\n) in the string of the text property will trigger a manual line break. For automatic line breaking you need to set the wrap property to a value other than no-wrap and it is important to specify a width and height for the Text element, in order to know where to break. It’s recommended to place the Text element in a layout and let it set the width and height based on the available screen space and the text itself.

Properties

  • text (string): The actual text.

  • font-family (string): The font name

  • font-size (length): The font size of the text

  • font-weight (int): The weight of the font. The values range from 100 (lightest) to 900 (thickest). 400 is the normal weight.

  • color (brush): The color of the text (default value: depends on the style)

  • horizontal-alignment (enum TextHorizontalAlignment): The horizontal alignment of the text.

  • vertical-alignment (enum TextVerticalAlignment): The vertical alignment of the text.

  • wrap (enum TextWrap): The way the text wraps (default: no-wrap).

  • overflow (enum TextOverflow): What happens when the text overflows (default: clip).

  • letter-spacing (length): The letter spacing allows changing the spacing between the glyphs. A positive value increases the spacing and a negative value decreases the distance. The default value is 0.

Example

This example shows the text “Hello World” in red, using the default font:

Example := Window {
    width: 270px;
    height: 100px;

    Text {
        text: "Hello World";
        color: red;
    }
}

This example breaks a longer paragraph of text into multiple lines, by setting a wrap policy and assigning a limited width and enough height for the text to flow down:

Example := Window {
    width: 270px;
    height: 300px;

    Text {
        text: "This paragraph breaks into multiple lines of text";
        wrap: word-wrap;
        width: 150px;
        height: 100%;
    }
}

Path

The Path element allows rendering a generic shape, composed of different geometric commands. A path shape can be filled and outlined.

When not part of a layout, its width or height defaults to 100% of the parent element when not specified.

A path can be defined in two different ways:

  • Using SVG path commands as a string

  • Using path command elements in .slint markup.

The coordinates used in the geometric commands are within the imaginary coordinate system of the path. When rendering on the screen, the shape is drawn relative to the x and y properties. If the width and height properties are non-zero, then the entire shape is fit into these bounds - by scaling accordingly.

Common Path Properties

  • fill (brush): The color for filling the shape of the path.

  • fill-rule (enum FillRule): The fill rule to use for the path. (default value: nonzero)

  • stroke (brush): The color for drawing the outline of the path.

  • stroke-width (length): The width of the outline.

  • width (length): If non-zero, the path will be scaled to fit into the specified width.

  • height (length): If non-zero, the path will be scaled to fit into the specified height.

  • viewbox-x/viewbox-y/viewbox-width/viewbox-height (float) These four properties allow defining the position and size of the viewport of the path in path coordinates.

    If the viewbox-width or viewbox-height is less or equal than zero, the viewbox properties are ignored and instead the bounding rectangle of all path elements is used to define the view port.

  • clip (bool): By default, when a path has a view box defined and the elements render outside of it, they are still rendered. When this property is set to true, then rendering will be clipped at the boundaries of the view box. This property must be a literal true or false (default: false)

Path Using SVG commands

SVG is a popular file format for defining scalable graphics, which are often composed of paths. In SVG paths are composed using commands, which in turn are written in a string. In .slint the path commands are provided to the commands property. The following example renders a shape consists of an arc and a rectangle, composed of line-to, move-to and arc commands:

Example := Path {
    width: 100px;
    height: 100px;
    commands: "M 0 0 L 0 100 A 1 1 0 0 0 100 100 L 100 0 Z";
    stroke: red;
    stroke-width: 1px;
}

The commands are provided in a property:

  • commands (*string): A string providing the commands according to the SVG path specification.

Path Using SVG Path Elements

The shape of the path can also be described using elements that resemble the SVG path commands but use the .slint markup syntax. The earlier example using SVG commands can also be written like that:

Example := Path {
    width: 100px;
    height: 100px;
    stroke: blue;
    stroke-width: 1px;

    MoveTo {
        x: 0;
        y: 0;
    }
    LineTo {
        x: 0;
        y: 100;
    }
    ArcTo {
        radius-x: 1;
        radius-y: 1;
        x: 100;
        y: 100;
    }
    LineTo {
        x: 100;
        y: 0;
    }
    Close {
    }
}

Note how the coordinates of the path elements do not use units - they operate within the imaginary coordinate system of the scalable path.

MoveTo Sub-element for Path

The MoveTo sub-element closes the current sub-path, if present, and moves the current point to the location specified by the x and y properties. Subsequent elements such as LineTo will use this new position as their starting point, therefore this starts a new sub-path.

Properties
  • x (float): The x position of the new current point.

  • y (float): The y position of the new current point.

LineTo Sub-element for Path

The LineTo sub-element describes a line from the path’s current position to the location specified by the x and y properties.

Properties
  • x (float): The target x position of the line.

  • y (float): The target y position of the line.

ArcTo Sub-element for Path

The ArcTo sub-element describes the portion of an ellipse. The arc is drawn from the path’s current position to the location specified by the x and y properties. The remaining properties are modelled after the SVG specification and allow tuning visual features such as the direction or angle.

Properties
  • x (float): The target x position of the line.

  • y (float): The target y position of the line.

  • radius-x (float): The x-radius of the ellipse.

  • radius-y (float): The y-radius of the ellipse.

  • x-rotation (float): The x-axis of the ellipse will be rotated by the value of this properties, specified in as angle in degrees from 0 to 360.

  • large-arc (bool): Out of the two arcs of a closed ellipse, this flag selects that the larger arc is to be rendered. If the property is false, the shorter arc is rendered instead.

  • sweep (bool): If the property is true, the arc will be drawn as a clockwise turning arc; anti-clockwise otherwise.

CubicTo Sub-element for Path

The CubicTo sub-element describes a smooth Bézier from the path’s current position to the location specified by the x and y properties, using two control points specified by their respective properties.

Properties
  • x (float): The target x position of the curve.

  • y (float): The target y position of the curve.

  • control-1-x (float): The x coordinate of the curve’s first control point.

  • control-1-y (float): The y coordinate of the curve’s first control point.

  • control-2-x (float): The x coordinate of the curve’s second control point.

  • control-2-y (float): The y coordinate of the curve’s second control point.

QuadraticTo Sub-element for Path

The QuadraticTo sub-element describes a smooth Bézier from the path’s current position to the location specified by the x and y properties, using the control points specified by the control-x and control-y properties.

Properties
  • x (float): The target x position of the curve.

  • y (float): The target y position of the curve.

  • control-x (float): The x coordinate of the curve’s control point.

  • control-y (float): The y coordinate of the curve’s control point.

Close Sub-element for Path

The Close element closes the current sub-path and draws a straight line from the current position to the beginning of the path.

TouchArea

The TouchArea control what happens when the zone covered by it is touched or interacted with using the mouse.

When not part of a layout, its width or height default to 100% of the parent element if not specified.

Properties

  • pressed (bool): Set to true by the TouchArea when the mouse is pressed over it.

  • has-hover (bool): Set to true by the TouchArea when the mouse is over it.

  • mouse-x, mouse-y (length): Set by the TouchArea to the position of the mouse within it.

  • pressed-x, pressed-y (length): Set to true by the TouchArea to the position of the mouse at the moment it was last pressed.

  • mouse-cursor (enum MouseCursor): The mouse cursor type when the mouse is hovering the TouchArea.

Callbacks

  • clicked: Emitted when clicked (the mouse is pressed, then released on this element)

  • moved: The mouse has been moved. This will only be called if the mouse is also pressed.

  • pointer-event(PointerEvent): Received when a button was pressed or released.

Example

Example := Window {
    width: 200px;
    height: 100px;
    area := TouchArea {
        width: parent.width;
        height: parent.height;
        clicked => {
            rect2.background = #ff0;
        }
    }
    Rectangle {
        width: parent.width / 2;
        height: parent.height;
        background: area.pressed ? blue: red;
    }
    rect2 := Rectangle {
        x: parent.width / 2;
        width: parent.width / 2;
        height: parent.height;
    }
}

FocusScope

The FocusScope exposes callback to intercept the pressed key when it has focus.

The KeyEvent has a text property which is a character of the key entered. When a non-printable key is pressed, the character will be either a control character, or it will be mapped to a private unicode character. The mapping of these non-printable, special characters is available in the Keys namespace

Properties

  • has-focus (bool): Set to true when item is focused and receives keyboard events.

Methods

  • focus() Call this function to focus the text input and make it receive future keyboard events.

Callbacks

  • key-pressed(KeyEvent) -> EventResult: Emitted when a key is pressed, the argument is a KeyEvent struct

  • key-released(KeyEvent) -> EventResult: Emitted when a key is released, the argument is a KeyEvent struct

Example

Example := Window {
    width: 100px;
    height: 100px;
    forward-focus: my-key-handler;
    my-key-handler := FocusScope {
        key-pressed(event) => {
            debug(event.text);
            if (event.modifiers.control) {
                debug("control was pressed during this event");
            }
            if (event.text == Keys.Escape) {
                debug("Esc key was pressed")
            }
            accept
        }
    }
}

VerticalLayout / HorizontalLayout

These layouts place their children next to each other vertically or horizontally. The size of elements can either be fixed with the width or height property, or if they are not set they will be computed by the layout respecting the minimum and maximum sizes and the stretch factor.

Properties

  • spacing (length): The distance between the elements in the layout.

  • padding (length): the padding within the layout.

  • padding-left, padding-right, padding-top and padding-bottom (length): override the padding in specific sides.

  • alignment (FIXME enum): Can be one of stretch, center, start, end, space-between, space-around. Defaults to stretch. Matches the CSS flex.

Example

Foo := Window {
    width: 200px;
    height: 100px;
    HorizontalLayout {
        spacing: 5px;
        Rectangle { background: red; width: 10px; }
        Rectangle { background: blue; min-width: 10px; }
        Rectangle { background: yellow; horizontal-stretch: 1; }
        Rectangle { background: green; horizontal-stretch: 2; }
    }
}

GridLayout

GridLayout places the elements in a grid. GridLayout adds properties to each item: col, row, colspan, rowspan. You can control the position of elements with col and row. If col or row is not specified, they are automatically computed such that the item is next to the previous item, in the same row. Alternatively, the item can be put in a Row element.

Properties

  • spacing (length): The distance between the elements in the layout.

  • padding (length): the padding within the layout.

  • padding-left, padding-right, padding-top and padding-bottom (length): override the padding in specific sides.

Examples

This example uses the Row element

Foo := Window {
    width: 200px;
    height: 200px;
    GridLayout {
        spacing: 5px;
        Row {
            Rectangle { background: red; }
            Rectangle { background: blue; }
        }
        Row {
            Rectangle { background: yellow; }
            Rectangle { background: green; }
        }
    }
}

This example uses the col and row properties

Foo := Window {
    width: 200px;
    height: 150px;
    GridLayout {
        Rectangle { background: red; }
        Rectangle { background: blue; }
        Rectangle { background: yellow; row: 1; }
        Rectangle { background: green; }
        Rectangle { background: black; col: 2; row: 0; }
    }
}

PathLayout

FIXME: write docs

Flickable

The Flickable is a lower-level item that is the base for scrollable elements, such as the ScrollView widget. When the viewport-width or the viewport-height is greater than the parent width or parent height respectively the element becomes scrollable although the Flickable does not create a scrollbar. When unset, the viewport-width and viewport-height are calculated automatically based on the content. Excepted when using a for loop to populate the elements, that is tracked in issue #407. The maximum and preferred size of the Flickable are based on those of the viewport.

When not part of a layout, its width or height defaults to 100% of the parent element when not specified.

Properties

  • viewport-height, viewport-width (length): The total size of the scrollable element

  • viewport-x, viewport-y (length): The position of the scrollable element relative to the Flickable. This is usually a negative value.

  • interactive (bool): When true, the viewport can be scrolled by clicking on it and dragging it with the cursor. (default: true)

Example

Example := Window {
    width: 270px;
    height: 100px;

    Flickable {
        viewport-height: 300px;
        Text {
            y: 150px;
            text: "This is some text that you have to scroll to see";
        }
    }
}

TextInput

The TextInput is a lower-level item that shows text and allows entering text.

When not part of a layout, its width or height defaults to 100% of the parent element when not specified.

Properties

  • text (string): The actual text.

  • font-family (string): The font name

  • font-size (length): The font size of the text

  • font-weight (int): The weight of the font. The values range from 100 (lightest) to 900 (thickest). 400 is the normal weight.

  • color (brush): The color of the text (default value: depends on the style)

  • horizontal-alignment (enum TextHorizontalAlignment): The horizontal alignment of the text.

  • vertical-alignment (enum TextVerticalAlignment): The vertical alignment of the text.

  • has-focus (bool): Set to true when item is focused and receives keyboard events.

  • letter-spacing (length): The letter spacing allows changing the spacing between the glyphs. A positive value increases the spacing and a negative value decreases the distance. The default value is 0.

  • single-line (bool): When set to true, no newlines are allowed (default value: true)

  • read-only (bool): When set to true, text editing via keyboard and mouse is disabled but selecting text is still enabled as well as editing text programatically (default value: false)

  • wrap (enum TextWrap): The way the text input wraps. Only makes sense when single-line is false. (default: no-wrap)

  • input-type (enum InputType): The way to allow special input viewing properties such as password fields (default value: text).

Methods

  • focus() Call this function to focus the text input and make it receive future keyboard events.

Callbacks

  • accepted(): Emitted when enter key is pressed

  • edited(): Emitted when the text has changed because the user modified it

  • cursor-position-changed(Point): The cursor was moved to the new (x, y) position

Example

Example := Window {
    width: 270px;
    height: 100px;

    TextInput {
        text: "Replace me with a name";
    }
}

Dialog

Dialog is like a window, but it has buttons that are automatically laid out.

A Dialog should have one main element for the content, that is not a button. And the window can have any number of StandardButton widgets or other button with the dialog-button-role property. The button will be layed out in an order that depends on the platform.

The kind property of the StandardButtons and the dialog-button-role properties needs to be set to a specific value, it cannot be a complex expression. There cannot be several StandardButton of the same kind.

A callback <kind>_clicked is automatically added for each StandardButton which does not have an explicit callback handler, so it can be handled from the native code. (e.g. if there is a button of kind cancel, a cancel_clicked callback will be added).

When viewed with the slint-viewer program, the ok, cancel, and close button will cause the dialog to close.

Properties

  • title (string): The window title that is shown in the title bar.

  • icon (image): The window icon shown in the title bar or the task bar on window managers supporting it.

Example

import { StandardButton, Button } from "std-widgets.slint";
Example := Dialog {
    Text {
      text: "This is a dialog box";
    }
    StandardButton { kind: ok; }
    StandardButton { kind: cancel; }
    Button {
      text: "More Info";
      dialog-button-role: action;
    }
}

Builtin Structures

Point

This structure represents a point with x and y coordinate

Fields

  • x (length)

  • y (length)

KeyEvent

This structure is generated and passed to the key press and release callbacks of the FocusScope element.

Fields

  • text (string): The string representation of the key

  • modifiers (KeyboardModifiers): The keyboard modifiers pressed during the event

KeyboardModifiers

This structure is generated as part of KeyEvent, to indicate which modifier keys are pressed during the generation of a key event.

Fields

  • control (bool): true if the control key is pressed. On macOS this corresponds to the command key.

  • alt (bool): true if alt key is pressed.

  • shift (bool): true if the shift key is pressed.

  • meta (bool): true if the windows key is pressed on Windows, or the control key on macOS.

PointerEvent

This structure is generated and passed to the pointer-event callback of the TouchArea element.

Fields

  • kind (enum PointerEventKind): The kind of the event: one of the following

    • down: The button was pressed.

    • up: The button was released.

    • cancel: Another element or window took hold of the grab. This applies to all pressed button and the button is not relevent.

  • button (enum PointerEventButton): The button that was pressed or released. left, right, middle, or none.

Namespaces

The following namespaces provide access to common constants such as special keys or named colors.

Keys

Use the constants in the Keys namespace to handle pressing of keys that don’t have a printable character. Check the value of KeyEvent’s text property against the constants below.

  • Backspace

  • Tab

  • Return

  • Escape

  • Backtab

  • Delete

  • UpArrow

  • DownArrow

  • LeftArrow

  • RightArrow

  • F1

  • F2

  • F3

  • F4

  • F5

  • F6

  • F7

  • F8

  • F9

  • F10

  • F11

  • F12

  • F13

  • F14

  • F15

  • F16

  • F17

  • F18

  • F19

  • F20

  • F21

  • F22

  • F23

  • F24

  • Insert

  • Home

  • End

  • PageUp

  • PageDown

  • ScrollLock

  • Pause

  • SysReq

  • Stop

  • Menu

Colors

Use the colors namespace to select colors by their name. For example you can use Colors.aquamarine or Colors.bisque. The entire list of names is very long. You can find a complete list in the CSS Specification.