Abstract base class for scrollbars. Abstract base class for scrollbars, typically used to navigate through content that extends beyond the visible area of a control. Scrollbars are [Range]-based controls. Overrides the step used when clicking increment and decrement buttons or when using arrow keys when the [ScrollBar] is focused. Emitted when the scrollbar is being scrolled. Icon used as a button to scroll the [ScrollBar] left/up. Supports custom step using the [member ScrollBar.custom_step] property. Displayed when the mouse cursor hovers over the decrement button. Displayed when the decrement button is being pressed. Icon used as a button to scroll the [ScrollBar] right/down. Supports custom step using the [member ScrollBar.custom_step] property. Displayed when the mouse cursor hovers over the increment button. Displayed when the increment button is being pressed. Used as texture for the grabber, the draggable element representing current scroll. Used when the mouse hovers over the grabber. Used when the grabber is being dragged. Used as background of this [ScrollBar]. Used as background when the [ScrollBar] has the GUI focus.