File : dialogs/baseDialog/BackgroundMouseEL.js

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/*
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Copyright - 2017 2023 - wwwouaiebe - Contact: https://www.ouaie.be/
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This  program is free software;
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you can redistribute it and/or modify it under the terms of the
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GNU General Public License as published by the Free Software Foundation;
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either version 3 of the License, or any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
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*/
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/*
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Changes:
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    - v4.0.0:
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        - created from v3.6.0
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Doc reviewed 202208
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 */
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import theGeometry from '../../core/lib/Geometry.js';
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import theTravelNotesData from '../../data/TravelNotesData.js';
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import { ZERO, ONE } from '../../main/Constants.js';
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/* ------------------------------------------------------------------------------------------------------------------------- */
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/**
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mouse event listener for the background
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*/
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/* ------------------------------------------------------------------------------------------------------------------------- */
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class BackgroundMouseEL {
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    /**
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    constant for the left button
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    @type {Number}
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    */
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    static get LEFT_BUTTON ( ) { return ZERO; }
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    /**
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    A flag set to true when a pan is ongoing
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    @type {Boolean}
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    */
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    #panOngoing = false;
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    /**
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    The X screen coordinate of the beginning of the pan
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    @type {Number}
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    */
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    #startPanX = ZERO;
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    /**
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    The Y screen coordinate of the beginning of the pan
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    @type {Number}
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    */
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    #startPanY = ZERO;
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    /**
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    A leaflet LatLng object with the center of the map
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    @type {LeafletObject}
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    */
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    #mapCenter;
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    /**
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    Execute the pan when a mousemove or mouseup event occurs after a mousedown event
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    @param { Event } mouseEvent The mouse event to process
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    */
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    #processPan ( mouseEvent ) {
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        const latLngAtStart = theGeometry.screenCoordToLatLng ( this.#startPanX, this.#startPanY );
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        const latLngAtEnd = theGeometry.screenCoordToLatLng ( mouseEvent.screenX, mouseEvent.screenY );
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        theTravelNotesData.map.panTo (
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            [
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                this.#mapCenter.lat +
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                    latLngAtStart [ ZERO ] -
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                    latLngAtEnd [ ZERO ],
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                this.#mapCenter.lng +
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                    latLngAtStart [ ONE ] -
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                    latLngAtEnd [ ONE ]
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            ]
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        );
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    }
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    /**
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    The constructor
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    */
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    constructor ( ) {
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        Object.freeze ( this );
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    }
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    /**
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    Event listener method
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    @param {Event} mouseEvent The event to handle
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    */
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    handleEvent ( mouseEvent ) {
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        switch ( mouseEvent.type ) {
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        case 'mousedown' :
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            if (
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                mouseEvent.button === BackgroundMouseEL.LEFT_BUTTON
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                &&
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                mouseEvent.target === mouseEvent.currentTarget
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            ) {
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                this.#startPanX = mouseEvent.screenX;
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                this.#startPanY = mouseEvent.screenY;
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                this.#mapCenter = theTravelNotesData.map.getCenter ( );
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                this.#panOngoing = true;
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            }
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            break;
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        case 'mousemove' :
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            if ( mouseEvent.button === BackgroundMouseEL.LEFT_BUTTON && this.#panOngoing ) {
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                if ( document.selection ) {
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                    document.selection.empty ();
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                }
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                else {
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                    window.getSelection ().removeAllRanges ();
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                }
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                this.#processPan ( mouseEvent );
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            }
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            break;
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        case 'mouseup' :
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            if (
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                mouseEvent.button === BackgroundMouseEL.LEFT_BUTTON
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                &&
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                this.#panOngoing
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                &&
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                ( this.#startPanX !== mouseEvent.screenX || this.#startPanY !== mouseEvent.screenY )
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            ) {
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                this.#processPan ( mouseEvent );
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            }
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            this.#panOngoing = false;
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            break;
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        default :
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            break;
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        }
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    }
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}
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export default BackgroundMouseEL;
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/* --- End of file --------------------------------------------------------------------------------------------------------- */
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