slint/internal/compiler/widgets/common/slider-base.slint

// Copyright © SixtyFPS GmbH <info@slint.dev>
// SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-1.1 OR LicenseRef-Slint-commercial

export component SliderBase {
    in property <bool> enabled <=> touch-area.enabled;
    in property <float> minimum;
    in property <float> maximum: 100;
    in property <Orientation> orientation;
    in property <length> ref-width;
    out property <bool> pressed <=> touch-area.enabled;
    out property <bool> has-hover <=> touch-area.has-hover;
    out property <bool> vertical: root.orientation == Orientation.vertical;
    out property <bool> has-focus <=> focus-scope.has-focus;
    in-out property <float> value;

    callback changed(/* value */ float);

    forward-focus: focus-scope;
    
    touch-area := TouchArea {
        property <float> pressed-value;

        width: 100%;
        height: 100%;

        pointer-event(event) => {
            if (event.button == PointerEventButton.left && event.kind == PointerEventKind.down) {
                self.pressed-value = root.value;
            }
        }

        moved => {
            if (!vertical && self.enabled && self.pressed) {
                root.value = max(root.minimum, min(root.maximum,
                    self.pressed-value + (touch-area.mouse-x - touch-area.pressed-x) * (root.maximum - root.minimum) / (root.width - root.ref-width)));
                root.changed(root.value);
            }
            if (vertical && self.enabled && self.pressed) {
                root.value = max(root.minimum, min(root.maximum,
                    self.pressed-value + (touch-area.mouse-y - touch-area.pressed-y) * (root.maximum - root.minimum) / (root.height - root.ref-width)));
                root.changed(root.value);
            }
        }
    }

    focus-scope := FocusScope {
        x: 0;
        y: 0;
        width: 0;
        height: 0;
        enabled: root.enabled;

        key-pressed(event) => {
            if (!self.enabled) {
                return reject;
            } 
            if (!vertical && self.enabled && event.text == Key.RightArrow) {
                root.value = Math.min(root.value + 1, root.maximum);
                accept
            } else if (!vertical && self.enabled && event.text == Key.LeftArrow) {
                root.value = Math.max(root.value - 1, root.minimum);
                accept
            } else if (vertical && self.enabled && event.text == Key.DownArrow) {
                root.value = Math.min(root.value + 1, root.maximum);
                accept
            } else if (vertical && self.enabled && event.text == Key.UpArrow) {
                root.value = Math.max(root.value - 1, root.minimum);
                accept
            } else {
                reject
            }
        }
    }
}