/* Copyright 2017 Mozilla Foundation
*
* Licensed 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 { GrabToPan } from './grab_to_pan.js'
const CursorTool = {
SELECT: 0, // The default value.
HAND: 1,
ZOOM: 2,
}
/**
* @typedef {Object} PDFCursorToolsOptions
* @property {HTMLDivElement} container - The document container.
* @property {EventBus} eventBus - The application event bus.
* @property {number} [cursorToolOnLoad] - The cursor tool that will be enabled
* on load; the constants from {CursorTool} should be used. The default value
* is `CursorTool.SELECT`.
*/
class PDFCursorTools {
/**
* @param {PDFCursorToolsOptions} options
*/
constructor({ container, eventBus, cursorToolOnLoad = CursorTool.SELECT }) {
this.container = container
this.eventBus = eventBus
this.active = CursorTool.SELECT
this.activeBeforePresentationMode = null
this.handTool = new GrabToPan({
element: this.container,
})
this._addEventListeners()
// Defer the initial `switchTool` call, to give other viewer components
// time to initialize *and* register 'cursortoolchanged' event listeners.
Promise.resolve().then(() => {
this.switchTool(cursorToolOnLoad)
})
}
/**
* @type {number} One of the values in {CursorTool}.
*/
get activeTool() {
return this.active
}
/**
* NOTE: This method is ignored while Presentation Mode is active.
* @param {number} tool - The cursor mode that should be switched to,
* must be one of the values in {CursorTool}.
*/
switchTool(tool) {
if (this.activeBeforePresentationMode !== null) {
return // Cursor tools cannot be used in Presentation Mode.
}
if (tool === this.active) {
return // The requested tool is already active.
}
const disableActiveTool = () => {
switch (this.active) {
case CursorTool.SELECT:
break
case CursorTool.HAND:
this.handTool.deactivate()
break
case CursorTool.ZOOM:
/* falls through */
}
}
// Enable the new cursor tool.
switch (tool) {
case CursorTool.SELECT:
disableActiveTool()
break
case CursorTool.HAND:
disableActiveTool()
this.handTool.activate()
break
case CursorTool.ZOOM:
/* falls through */
default:
console.error(`switchTool: "${tool}" is an unsupported value.`)
return
}
// Update the active tool *after* it has been validated above,
// in order to prevent setting it to an invalid state.
this.active = tool
this._dispatchEvent()
}
/**
* @private
*/
_dispatchEvent() {
this.eventBus.dispatch('cursortoolchanged', {
source: this,
tool: this.active,
})
}
/**
* @private
*/
_addEventListeners() {
this.eventBus._on('switchcursortool', (evt) => {
this.switchTool(evt.tool)
})
this.eventBus._on('presentationmodechanged', (evt) => {
if (evt.switchInProgress) {
return
}
let previouslyActive
if (evt.active) {
previouslyActive = this.active
this.switchTool(CursorTool.SELECT)
this.activeBeforePresentationMode = previouslyActive
} else {
previouslyActive = this.activeBeforePresentationMode
this.activeBeforePresentationMode = null
this.switchTool(previouslyActive)
}
})
}
}
export { CursorTool, PDFCursorTools }