import { IIterator } from '../algorithm/iteration';
import { ISequence } from '../algorithm/sequence';
import { Layout, Widget } from './widget';
/**
 * A simple and convenient panel widget class.
 *
 * #### Notes
 * This class is suitable as a base class for implementing a variety of
 * convenience panel widgets, but can also be used directly with CSS to
 * arrange a collection of widgets.
 *
 * This class provides a convenience wrapper around a [[PanelLayout]].
 */
export declare class Panel extends Widget {
    /**
     * Construct a new panel.
     *
     * @param options - The options for initializing the panel.
     */
    constructor(options?: Panel.IOptions);
    /**
     * A read-only sequence of the widgets in the panel.
     *
     * #### Notes
     * This is a read-only property.
     */
    readonly widgets: ISequence<Widget>;
    /**
     * Add a widget to the end of the panel.
     *
     * @param widget - The widget to add to the panel.
     *
     * #### Notes
     * If the is already contained in the panel, it will be moved.
     */
    addWidget(widget: Widget): void;
    /**
     * Insert a widget at the specified index.
     *
     * @param index - The index at which to insert the widget.
     *
     * @param widget - The widget to insert into to the panel.
     *
     * #### Notes
     * If the widget is already contained in the panel, it will be moved.
     */
    insertWidget(index: number, widget: Widget): void;
}
/**
 * The namespace for the `Panel` class statics.
 */
export declare namespace Panel {
    /**
     * An options object for creating a panel.
     */
    interface IOptions {
        /**
         * The panel layout to use for the panel.
         *
         * The default is a new `PanelLayout`.
         */
        layout?: PanelLayout;
    }
}
/**
 * A concrete layout implementation suitable for many use cases.
 *
 * #### Notes
 * This class is suitable as a base class for implementing a variety of
 * layouts, but can also be used directly with standard CSS to layout a
 * collection of widgets.
 */
export declare class PanelLayout extends Layout {
    /**
     * Dispose of the resources held by the layout.
     *
     * #### Notes
     * This will clear and dispose all widgets in the layout.
     *
     * All reimplementations should call the superclass method.
     *
     * This method is called automatically when the parent is disposed.
     */
    dispose(): void;
    /**
     * A read-only sequence of the widgets in the layout.
     *
     * #### Notes
     * This is a read-only property.
     */
    readonly widgets: ISequence<Widget>;
    /**
     * Create an iterator over the widgets in the layout.
     *
     * @returns A new iterator over the widgets in the layout.
     */
    iter(): IIterator<Widget>;
    /**
     * Add a widget to the end of the layout.
     *
     * @param widget - The widget to add to the layout.
     *
     * #### Notes
     * If the widget is already contained in the layout, it will be moved.
     */
    addWidget(widget: Widget): void;
    /**
     * Insert a widget into the layout at the specified index.
     *
     * @param index - The index at which to insert the widget.
     *
     * @param widget - The widget to insert into the layout.
     *
     * #### Notes
     * The index will be clamped to the bounds of the widgets.
     *
     * If the widget is already added to the layout, it will be moved.
     */
    insertWidget(index: number, widget: Widget): void;
    /**
     * Remove a widget from the layout.
     *
     * @param widget - The widget to remove from the layout.
     *
     * #### Notes
     * A widget is automatically removed from the layout when its `parent`
     * is set to `null`. This method should only be invoked directly when
     * removing a widget from a layout which has yet to be installed on a
     * parent widget.
     *
     * This method does *not* modify the widget's `parent`.
     */
    removeWidget(widget: Widget): void;
    /**
     * Remove the widget at a given index from the layout.
     *
     * @param index - The index of the widget to remove.
     *
     * #### Notes
     * A widget is automatically removed from the layout when its `parent`
     * is set to `null`. This method should only be invoked directly when
     * removing a widget from a layout which has yet to be installed on a
     * parent widget.
     *
     * This method does *not* modify the widget's `parent`.
     */
    removeWidgetAt(index: number): void;
    /**
     * Perform layout initialization which requires the parent widget.
     */
    protected init(): void;
    /**
     * Attach a widget to the parent's DOM node.
     *
     * @param index - The current index of the widget in the layout.
     *
     * @param widget - The widget to attach to the parent.
     *
     * #### Notes
     * This method is called automatically by the panel layout at the
     * appropriate time. It should not be called directly by user code.
     *
     * The default implementation adds the widgets's node to the parent's
     * node at the proper location, and sends an `'after-attach'` message
     * to the widget if the parent is attached to the DOM.
     *
     * Subclasses may reimplement this method to control how the widget's
     * node is added to the parent's node, but the reimplementation must
     * send an `'after-attach'` message to the widget if the parent is
     * attached to the DOM.
     */
    protected attachWidget(index: number, widget: Widget): void;
    /**
     * Move a widget in the parent's DOM node.
     *
     * @param fromIndex - The previous index of the widget in the layout.
     *
     * @param toIndex - The current index of the widget in the layout.
     *
     * @param widget - The widget to move in the parent.
     *
     * #### Notes
     * This method is called automatically by the panel layout at the
     * appropriate time. It should not be called directly by user code.
     *
     * The default implementation moves the widget's node to the proper
     * location in the parent's node and sends both a `'before-detach'`
     * and an `'after-attach'` message to the widget if the parent is
     * attached to the DOM.
     *
     * Subclasses may reimplement this method to control how the widget's
     * node is moved in the parent's node, but the reimplementation must
     * send both a `'before-detach'` and an `'after-attach'` message to
     * the widget if the parent is attached to the DOM.
     */
    protected moveWidget(fromIndex: number, toIndex: number, widget: Widget): void;
    /**
     * Detach a widget from the parent's DOM node.
     *
     * @param index - The previous index of the widget in the layout.
     *
     * @param widget - The widget to detach from the parent.
     *
     * #### Notes
     * This method is called automatically by the panel layout at the
     * appropriate time. It should not be called directly by user code.
     *
     * The default implementation removes the widget's node from the
     * parent's node, and sends a `'before-detach'` message to the widget
     * if the parent is attached to the DOM.
     *
     * Subclasses may reimplement this method to control how the widget's
     * node is removed from the parent's node, but the reimplementation
     * must send a `'before-detach'` message to the widget if the parent
     * is attached to the DOM.
     */
    protected detachWidget(index: number, widget: Widget): void;
    private _widgets;
}