| /* |
| * 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. |
| */ |
| |
| import type Geo from '../coord/geo/Geo'; |
| import type View from '../coord/View'; |
| import type ExtensionAPI from '../core/ExtensionAPI'; |
| import type { Payload } from '../util/types'; |
| |
| export interface RoamPaylod extends Payload { |
| dx: number |
| dy: number |
| zoom: number |
| originX: number |
| originY: number |
| } |
| |
| function getCenterCoord(view: View, point: number[]) { |
| // Use projected coord as center because it's linear. |
| return (view as Geo).pointToProjected |
| ? (view as Geo).pointToProjected(point) |
| : view.pointToData(point); |
| } |
| |
| export function updateCenterAndZoom( |
| view: View, |
| payload: RoamPaylod, |
| zoomLimit?: { |
| min?: number, |
| max?: number |
| }, |
| api?: ExtensionAPI |
| ) { |
| const previousZoom = view.getZoom(); |
| const center = view.getCenter(); |
| let zoom = payload.zoom; |
| |
| const point = (view as Geo).projectedToPoint |
| ? (view as Geo).projectedToPoint(center) |
| : view.dataToPoint(center); |
| |
| if (payload.dx != null && payload.dy != null) { |
| point[0] -= payload.dx; |
| point[1] -= payload.dy; |
| |
| view.setCenter(getCenterCoord(view, point), api); |
| } |
| if (zoom != null) { |
| if (zoomLimit) { |
| const zoomMin = zoomLimit.min || 0; |
| const zoomMax = zoomLimit.max || Infinity; |
| zoom = Math.max( |
| Math.min(previousZoom * zoom, zoomMax), |
| zoomMin |
| ) / previousZoom; |
| } |
| |
| // Zoom on given point(originX, originY) |
| view.scaleX *= zoom; |
| view.scaleY *= zoom; |
| const fixX = (payload.originX - view.x) * (zoom - 1); |
| const fixY = (payload.originY - view.y) * (zoom - 1); |
| |
| view.x -= fixX; |
| view.y -= fixY; |
| |
| view.updateTransform(); |
| // Get the new center |
| view.setCenter(getCenterCoord(view, point), api); |
| view.setZoom(zoom * previousZoom); |
| } |
| |
| return { |
| center: view.getCenter(), |
| zoom: view.getZoom() |
| }; |
| } |