1 // Copyright (C) 2018 The Android Open Source Project 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 import {TrackState} from '../common/state'; 16 import {globals} from './globals'; 17 18 /** 19 * This interface forces track implementations to have some static properties. 20 * Typescript does not have abstract static members, which is why this needs to 21 * be in a seperate interface. 22 */ 23 export interface TrackCreator { 24 // Store the kind explicitly as a string as opposed to using class.kind in 25 // case we ever minify our code. 26 readonly kind: string; 27 28 // We need the |create| method because the stored value in the registry is an 29 // abstract class, and we cannot call 'new' on an abstract class. 30 create(TrackState: TrackState): Track; 31 } 32 33 /** 34 * The abstract class that needs to be implemented by all tracks. 35 */ 36 export abstract class Track<Config = {}, Data = {}> { 37 constructor(protected trackState: TrackState) {} 38 abstract renderCanvas(ctx: CanvasRenderingContext2D): void; 39 40 get config(): Config { 41 return this.trackState.config as Config; 42 } 43 44 data(): Data|undefined { 45 return globals.trackDataStore.get(this.trackState.id) as Data; 46 } 47 48 getHeight(): number { 49 return 40; 50 } 51 52 onMouseMove(_position: {x: number, y: number}) {} 53 54 /** 55 * Returns whether the mouse click has selected something. 56 * Used to prevent further propagation if necessary. 57 */ 58 onMouseClick(_position: {x: number, y: number}): boolean { 59 return false; 60 } 61 62 onMouseOut() {} 63 } 64
