ckeditor5-image-upload-base64
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The development environment of CKEditor 5 – the best browser-based rich text editor.
303 lines (263 loc) • 10.7 kB
JavaScript
/**
* @license Copyright (c) 2003-2020, CKSource - Frederico Knabben. All rights reserved.
* For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
*/
/**
* @module utils/dom/scroll
*/
import isRange from './isrange';
import Rect from './rect';
import isText from './istext';
const utils = {};
/**
* Makes any page `HTMLElement` or `Range` (`target`) visible inside the browser viewport.
* This helper will scroll all `target` ancestors and the web browser viewport to reveal the target to
* the user. If the `target` is already visible, nothing will happen.
*
* @param {HTMLElement|Range} options.target A target, which supposed to become visible to the user.
* @param {Number} [options.viewportOffset] An offset from the edge of the viewport (in pixels)
* the `target` will be moved by when the viewport is scrolled. It enhances the user experience
* by keeping the `target` some distance from the edge of the viewport and thus making it easier to
* read or edit by the user.
*/
export function scrollViewportToShowTarget( { target, viewportOffset = 0 } ) {
const targetWindow = getWindow( target );
let currentWindow = targetWindow;
let currentFrame = null;
// Iterate over all windows, starting from target's parent window up to window#top.
while ( currentWindow ) {
let firstAncestorToScroll;
// Let's scroll target's ancestors first to reveal it. Then, once the ancestor scrolls
// settled down, the algorithm can eventually scroll the viewport of the current window.
//
// Note: If the current window is target's **original** window (e.g. the first one),
// start scrolling the closest parent of the target. If not, scroll the closest parent
// of an iframe that resides in the current window.
if ( currentWindow == targetWindow ) {
firstAncestorToScroll = getParentElement( target );
} else {
firstAncestorToScroll = getParentElement( currentFrame );
}
// Scroll the target's ancestors first. Once done, scrolling the viewport is easy.
scrollAncestorsToShowRect( firstAncestorToScroll, () => {
// Note: If the target does not belong to the current window **directly**,
// i.e. it resides in an iframe belonging to the window, obtain the target's rect
// in the coordinates of the current window. By default, a Rect returns geometry
// relative to the current window's viewport. To make it work in a parent window,
// it must be shifted.
return getRectRelativeToWindow( target, currentWindow );
} );
// Obtain the rect of the target after it has been scrolled within its ancestors.
// It's time to scroll the viewport.
const targetRect = getRectRelativeToWindow( target, currentWindow );
scrollWindowToShowRect( currentWindow, targetRect, viewportOffset );
if ( currentWindow.parent != currentWindow ) {
// Keep the reference to the <iframe> element the "previous current window" was
// rendered within. It will be useful to re–calculate the rect of the target
// in the parent window's relative geometry. The target's rect must be shifted
// by it's iframe's position.
currentFrame = currentWindow.frameElement;
currentWindow = currentWindow.parent;
// If the current window has some parent but frameElement is inaccessible, then they have
// different domains/ports and, due to security reasons, accessing and scrolling
// the parent window won't be possible.
// See https://github.com/ckeditor/ckeditor5/issues/930.
if ( !currentFrame ) {
return;
}
} else {
currentWindow = null;
}
}
}
/**
* Makes any page `HTMLElement` or `Range` (target) visible within its scrollable ancestors,
* e.g. if they have `overflow: scroll` CSS style.
*
* @param {HTMLElement|Range} target A target, which supposed to become visible to the user.
*/
export function scrollAncestorsToShowTarget( target ) {
const targetParent = getParentElement( target );
scrollAncestorsToShowRect( targetParent, () => {
return new Rect( target );
} );
}
// TODO: Using a property value shorthand in the top of the file
// causes JSDoc to throw errors. See https://github.com/cksource/docs-builder/issues/75.
Object.assign( utils, {
scrollViewportToShowTarget,
scrollAncestorsToShowTarget
} );
// Makes a given rect visible within its parent window.
//
// Note: Avoid the situation where the caret is still in the viewport, but totally
// at the edge of it. In such situation, if it moved beyond the viewport in the next
// action e.g. after paste, the scrolling would move it to the viewportOffset level
// and it all would look like the caret visually moved up/down:
//
// 1.
// | foo[]
// | <--- N px of space below the caret
// +---------------------------------...
//
// 2. *paste*
// 3.
// |
// |
// +-foo-----------------------------...
// bar[] <--- caret below viewport, scrolling...
//
// 4. *scrolling*
// 5.
// |
// | foo
// | bar[] <--- caret precisely at the edge
// +---------------------------------...
//
// To prevent this, this method checks the rects moved by the viewportOffset to cover
// the upper/lower edge of the viewport. It makes sure if the action repeats, there's
// no twitching – it's a purely visual improvement:
//
// 5. (after fix)
// |
// | foo
// | bar[]
// | <--- N px of space below the caret
// +---------------------------------...
//
// @private
// @param {Window} window A window which is scrolled to reveal the rect.
// @param {module:utils/dom/rect~Rect} rect A rect which is to be revealed.
// @param {Number} viewportOffset See scrollViewportToShowTarget.
function scrollWindowToShowRect( window, rect, viewportOffset ) {
const targetShiftedDownRect = rect.clone().moveBy( 0, viewportOffset );
const targetShiftedUpRect = rect.clone().moveBy( 0, -viewportOffset );
const viewportRect = new Rect( window ).excludeScrollbarsAndBorders();
const rects = [ targetShiftedUpRect, targetShiftedDownRect ];
if ( !rects.every( rect => viewportRect.contains( rect ) ) ) {
let { scrollX, scrollY } = window;
if ( isAbove( targetShiftedUpRect, viewportRect ) ) {
scrollY -= viewportRect.top - rect.top + viewportOffset;
} else if ( isBelow( targetShiftedDownRect, viewportRect ) ) {
scrollY += rect.bottom - viewportRect.bottom + viewportOffset;
}
// TODO: Web browsers scroll natively to place the target in the middle
// of the viewport. It's not a very popular case, though.
if ( isLeftOf( rect, viewportRect ) ) {
scrollX -= viewportRect.left - rect.left + viewportOffset;
} else if ( isRightOf( rect, viewportRect ) ) {
scrollX += rect.right - viewportRect.right + viewportOffset;
}
window.scrollTo( scrollX, scrollY );
}
}
// Recursively scrolls element ancestors to visually reveal a rect.
//
// @private
// @param {HTMLElement} A parent The first ancestors to start scrolling.
// @param {Function} getRect A function which returns the Rect, which is to be revealed.
function scrollAncestorsToShowRect( parent, getRect ) {
const parentWindow = getWindow( parent );
let parentRect, targetRect;
while ( parent != parentWindow.document.body ) {
targetRect = getRect();
parentRect = new Rect( parent ).excludeScrollbarsAndBorders();
if ( !parentRect.contains( targetRect ) ) {
if ( isAbove( targetRect, parentRect ) ) {
parent.scrollTop -= parentRect.top - targetRect.top;
} else if ( isBelow( targetRect, parentRect ) ) {
parent.scrollTop += targetRect.bottom - parentRect.bottom;
}
if ( isLeftOf( targetRect, parentRect ) ) {
parent.scrollLeft -= parentRect.left - targetRect.left;
} else if ( isRightOf( targetRect, parentRect ) ) {
parent.scrollLeft += targetRect.right - parentRect.right;
}
}
parent = parent.parentNode;
}
}
// Determines if a given `Rect` extends beyond the bottom edge of the second `Rect`.
//
// @private
// @param {module:utils/dom/rect~Rect} firstRect
// @param {module:utils/dom/rect~Rect} secondRect
function isBelow( firstRect, secondRect ) {
return firstRect.bottom > secondRect.bottom;
}
// Determines if a given `Rect` extends beyond the top edge of the second `Rect`.
//
// @private
// @param {module:utils/dom/rect~Rect} firstRect
// @param {module:utils/dom/rect~Rect} secondRect
function isAbove( firstRect, secondRect ) {
return firstRect.top < secondRect.top;
}
// Determines if a given `Rect` extends beyond the left edge of the second `Rect`.
//
// @private
// @param {module:utils/dom/rect~Rect} firstRect
// @param {module:utils/dom/rect~Rect} secondRect
function isLeftOf( firstRect, secondRect ) {
return firstRect.left < secondRect.left;
}
// Determines if a given `Rect` extends beyond the right edge of the second `Rect`.
//
// @private
// @param {module:utils/dom/rect~Rect} firstRect
// @param {module:utils/dom/rect~Rect} secondRect
function isRightOf( firstRect, secondRect ) {
return firstRect.right > secondRect.right;
}
// Returns the closest window of an element or range.
//
// @private
// @param {HTMLElement|Range} firstRect
// @returns {Window}
function getWindow( elementOrRange ) {
if ( isRange( elementOrRange ) ) {
return elementOrRange.startContainer.ownerDocument.defaultView;
} else {
return elementOrRange.ownerDocument.defaultView;
}
}
// Returns the closest parent of an element or DOM range.
//
// @private
// @param {HTMLElement|Range} firstRect
// @returns {HTMLelement}
function getParentElement( elementOrRange ) {
if ( isRange( elementOrRange ) ) {
let parent = elementOrRange.commonAncestorContainer;
// If a Range is attached to the Text, use the closest element ancestor.
if ( isText( parent ) ) {
parent = parent.parentNode;
}
return parent;
} else {
return elementOrRange.parentNode;
}
}
// Returns the rect of an element or range residing in an iframe.
// The result rect is relative to the geometry of the passed window instance.
//
// @private
// @param {HTMLElement|Range} target Element or range which rect should be returned.
// @param {Window} relativeWindow A window the rect should be relative to.
// @returns {module:utils/dom/rect~Rect}
function getRectRelativeToWindow( target, relativeWindow ) {
const targetWindow = getWindow( target );
const rect = new Rect( target );
if ( targetWindow === relativeWindow ) {
return rect;
} else {
let currentWindow = targetWindow;
while ( currentWindow != relativeWindow ) {
const frame = currentWindow.frameElement;
const frameRect = new Rect( frame ).excludeScrollbarsAndBorders();
rect.moveBy( frameRect.left, frameRect.top );
currentWindow = currentWindow.parent;
}
}
return rect;
}