gojs/extensionsJSM/NonRealtimeDraggingTool.js

Interactive diagrams, charts, and graphs, such as trees, flowcharts, orgcharts, UML, BPMN, or business diagrams

/*
*  Copyright (C) 1998-2020 by Northwoods Software Corporation. All Rights Reserved.
*/
/*
* This is an extension and not part of the main GoJS library.
* Note that the API for this class may change with any version, even point releases.
* If you intend to use an extension in production, you should copy the code to your own source directory.
* Extensions can be found in the GoJS kit under the extensions or extensionsTS folders.
* See the Extensions intro page (https://gojs.net/latest/intro/extensions.html) for more information.
*/
import * as go from '../release/go-module.js';
/**
 * The NonRealtimeDraggingTool class lets the user drag an image instead of actually moving any selected nodes,
 * until the mouse-up event.
 *
 * If you want to experiment with this extension, try the <a href="../../extensionsTS/NonRealtimeDragging.html">Non Realtime Dragging</a> sample.
 * @category Tool Extension
 */
export class NonRealtimeDraggingTool extends go.DraggingTool {
    constructor() {
        super(...arguments);
        this._imagePart = null; // a Part holding a translucent image of what would be dragged
        this._ghostDraggedParts = null; // a Map of the _imagePart and its dragging information
        this._originalDraggedParts = null; // the saved normal value of DraggingTool.draggedParts
    }
    /**
     * Call the base method, and then make an image of the returned collection,
     * show it using a Picture, and hold the Picture in a temporary Part, as _imagePart.
     * @param {Iterable.<Part>} parts A {@link Set} or {@link List} of {@link Part}s.
     * @return {Map.<Part,DraggingInfo>}
     */
    computeEffectiveCollection(coll) {
        const map = super.computeEffectiveCollection(coll, this.dragOptions);
        if (this.isActive && this._imagePart === null) {
            const bounds = this.diagram.computePartsBounds(map.toKeySet());
            const offset = this.diagram.lastInput.documentPoint.copy().subtract(bounds.position);
            const $ = go.GraphObject.make;
            this._imagePart =
                $(go.Part, { layerName: 'Tool', opacity: 0.5, locationSpot: new go.Spot(0, 0, offset.x, offset.y) }, $(go.Picture, { element: this.diagram.makeImage({ parts: map.toKeySet() }) }));
        }
        return map;
    }
    /**
     * When activated, replace the {@link #draggedParts} with the ghost dragged parts, which
     * consists of just one Part, the image, added to the Diagram at the current mouse point.
     */
    doActivate() {
        super.doActivate();
        if (this._imagePart !== null) {
            this._imagePart.location = this.diagram.lastInput.documentPoint;
            this.diagram.add(this._imagePart);
            this._originalDraggedParts = this.draggedParts;
            this._ghostDraggedParts = super.computeEffectiveCollection(new go.List().add(this._imagePart), this.dragOptions);
            this.draggedParts = this._ghostDraggedParts;
        }
    }
    /**
     * When deactivated, make sure any image is removed from the Diagram and all references are cleared out.
     */
    doDeactivate() {
        if (this._imagePart !== null) {
            this.diagram.remove(this._imagePart);
        }
        this._imagePart = null;
        this._ghostDraggedParts = null;
        this._originalDraggedParts = null;
        super.doDeactivate();
    }
    /**
     * Do the normal mouse-up behavior, but only after restoring {@link #draggedParts}.
     */
    doMouseUp() {
        if (this._originalDraggedParts !== null) {
            this.draggedParts = this._originalDraggedParts;
        }
        super.doMouseUp();
    }
    /**
     * If the user changes to "copying" mode by holding down the Control key,
     * return to the regular behavior and remove the image.
     */
    doKeyDown() {
        if (this._imagePart !== null && this._originalDraggedParts !== null &&
            (this.diagram.lastInput.control || this.diagram.lastInput.meta) && this.mayCopy()) {
            this.draggedParts = this._originalDraggedParts;
            this.diagram.remove(this._imagePart);
        }
        super.doKeyDown();
    }
    /**
     * If the user changes back to "moving" mode,
     * show the image again and go back to dragging the ghost dragged parts.
     */
    doKeyUp() {
        if (this._imagePart !== null && this._ghostDraggedParts !== null && this.mayMove()) {
            this._imagePart.location = this.diagram.lastInput.documentPoint;
            this.diagram.add(this._imagePart);
            this.draggedParts = this._ghostDraggedParts;
        }
        super.doKeyUp();
    }
}