yomichan/ext/js/display/display-resizer.js

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/*
* Copyright (C) 2021-2022 Yomichan Authors
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
class DisplayResizer {
constructor(display) {
this._display = display;
this._token = null;
this._handle = null;
this._touchIdentifier = null;
this._startSize = null;
this._startOffset = null;
this._eventListeners = new EventListenerCollection();
}
prepare() {
this._handle = document.querySelector('#frame-resizer-handle');
if (this._handle === null) { return; }
this._handle.addEventListener('mousedown', this._onFrameResizerMouseDown.bind(this), false);
this._handle.addEventListener('touchstart', this._onFrameResizerTouchStart.bind(this), false);
}
// Private
_onFrameResizerMouseDown(e) {
if (e.button !== 0) { return; }
// Don't do e.preventDefault() here; this allows mousemove events to be processed
// if the pointer moves out of the frame.
this._startFrameResize(e);
}
_onFrameResizerTouchStart(e) {
e.preventDefault();
this._startFrameResizeTouch(e);
}
_onFrameResizerMouseUp() {
this._stopFrameResize();
}
_onFrameResizerWindowBlur() {
this._stopFrameResize();
}
_onFrameResizerMouseMove(e) {
if ((e.buttons & 0x1) === 0x0) {
this._stopFrameResize();
} else {
if (this._startSize === null) { return; }
const {clientX: x, clientY: y} = e;
this._updateFrameSize(x, y);
}
}
_onFrameResizerTouchEnd(e) {
if (this._getTouch(e.changedTouches, this._touchIdentifier) === null) { return; }
this._stopFrameResize();
}
_onFrameResizerTouchCancel(e) {
if (this._getTouch(e.changedTouches, this._touchIdentifier) === null) { return; }
this._stopFrameResize();
}
_onFrameResizerTouchMove(e) {
if (this._startSize === null) { return; }
const primaryTouch = this._getTouch(e.changedTouches, this._touchIdentifier);
if (primaryTouch === null) { return; }
const {clientX: x, clientY: y} = primaryTouch;
this._updateFrameSize(x, y);
}
_startFrameResize(e) {
if (this._token !== null) { return; }
const {clientX: x, clientY: y} = e;
const token = {};
this._token = token;
this._startOffset = {x, y};
this._eventListeners.addEventListener(window, 'mouseup', this._onFrameResizerMouseUp.bind(this), false);
this._eventListeners.addEventListener(window, 'blur', this._onFrameResizerWindowBlur.bind(this), false);
this._eventListeners.addEventListener(window, 'mousemove', this._onFrameResizerMouseMove.bind(this), false);
const {documentElement} = document;
if (documentElement !== null) {
documentElement.dataset.isResizing = 'true';
}
this._initializeFrameResize(token);
}
_startFrameResizeTouch(e) {
if (this._token !== null) { return; }
const {clientX: x, clientY: y, identifier} = e.changedTouches[0];
const token = {};
this._token = token;
this._startOffset = {x, y};
this._touchIdentifier = identifier;
this._eventListeners.addEventListener(window, 'touchend', this._onFrameResizerTouchEnd.bind(this), false);
this._eventListeners.addEventListener(window, 'touchcancel', this._onFrameResizerTouchCancel.bind(this), false);
this._eventListeners.addEventListener(window, 'blur', this._onFrameResizerWindowBlur.bind(this), false);
this._eventListeners.addEventListener(window, 'touchmove', this._onFrameResizerTouchMove.bind(this), false);
const {documentElement} = document;
if (documentElement !== null) {
documentElement.dataset.isResizing = 'true';
}
this._initializeFrameResize(token);
}
async _initializeFrameResize(token) {
const {parentPopupId} = this._display;
if (parentPopupId === null) { return; }
const size = await this._display.invokeParentFrame('PopupFactory.getFrameSize', {id: parentPopupId});
if (this._token !== token) { return; }
this._startSize = size;
}
_stopFrameResize() {
if (this._token === null) { return; }
this._eventListeners.removeAllEventListeners();
this._startSize = null;
this._startOffset = null;
this._touchIdentifier = null;
this._token = null;
const {documentElement} = document;
if (documentElement !== null) {
delete documentElement.dataset.isResizing;
}
}
async _updateFrameSize(x, y) {
const {parentPopupId} = this._display;
if (parentPopupId === null) { return; }
const handleSize = this._handle.getBoundingClientRect();
let {width, height} = this._startSize;
width += x - this._startOffset.x;
height += y - this._startOffset.y;
width = Math.max(Math.max(0, handleSize.width), width);
height = Math.max(Math.max(0, handleSize.height), height);
await this._display.invokeParentFrame('PopupFactory.setFrameSize', {id: parentPopupId, width, height});
}
_getTouch(touchList, identifier) {
for (const touch of touchList) {
if (touch.identifier === identifier) {
return touch;
}
}
return null;
}
}