roamHelper.js 2.18 KB
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements.  See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership.  The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License.  You may obtain a copy of the License at
*
*   http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied.  See the License for the
* specific language governing permissions and limitations
* under the License.
*/

/**
 * @param {module:echarts/coord/View} view
 * @param {Object} payload
 * @param {Object} [zoomLimit]
 */
export function updateCenterAndZoom(
    view, payload, zoomLimit
) {
    var previousZoom = view.getZoom();
    var center = view.getCenter();
    var zoom = payload.zoom;

    var point = view.dataToPoint(center);

    if (payload.dx != null && payload.dy != null) {
        point[0] -= payload.dx;
        point[1] -= payload.dy;

        var center = view.pointToData(point);
        view.setCenter(center);
    }
    if (zoom != null) {
        if (zoomLimit) {
            var zoomMin = zoomLimit.min || 0;
            var zoomMax = zoomLimit.max || Infinity;
            zoom = Math.max(
                Math.min(previousZoom * zoom, zoomMax),
                zoomMin
            ) / previousZoom;
        }

        // Zoom on given point(originX, originY)
        view.scale[0] *= zoom;
        view.scale[1] *= zoom;
        var position = view.position;
        var fixX = (payload.originX - position[0]) * (zoom - 1);
        var fixY = (payload.originY - position[1]) * (zoom - 1);

        position[0] -= fixX;
        position[1] -= fixY;

        view.updateTransform();
        // Get the new center
        var center = view.pointToData(point);
        view.setCenter(center);
        view.setZoom(zoom * previousZoom);
    }

    return {
        center: view.getCenter(),
        zoom: view.getZoom()
    };
}