fune/browser/components/customizableui/PanelMultiView.jsm
Paolo Amadini fd72a1cb37 Bug 1392340 - Height jumps when opening subviews of different lengths. r=Gijs
The height of the subview being opened was supposedly calculated using an off-screen container independent from the currently displayed views, but this didn't work as expected because of the incorrect box alignment. This is now fixed and the correct minimum and maximum heights are set on the container separately, also preventing the current view from flickering before the transition in case the subview was taller.

With this issue fixed, the height can now be recalculated each time the subview is opened, without the caching that caused incorrect results when the same view was reopened with different elements or text.

Jumping could also occur because of a border applied only during the transition, which could influence the subview height in the presence of wrapping text.

MozReview-Commit-ID: EWHs1hFKXT4

--HG--
extra : rebase_source : 5b0bc4e5d4d2d10d684c2c2bf94a9030aadd09bd
2017-11-28 16:53:42 +00:00

1185 lines
44 KiB
JavaScript

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";
this.EXPORTED_SYMBOLS = ["PanelMultiView"];
const {classes: Cc, interfaces: Ci, utils: Cu} = Components;
Cu.import("resource://gre/modules/XPCOMUtils.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "AppConstants",
"resource://gre/modules/AppConstants.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "BrowserUtils",
"resource://gre/modules/BrowserUtils.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "CustomizableUI",
"resource:///modules/CustomizableUI.jsm");
const TRANSITION_PHASES = Object.freeze({
START: 1,
PREPARE: 2,
TRANSITION: 3,
END: 4
});
/**
* Simple implementation of the sliding window pattern; panels are added to a
* linked list, in-order, and the currently shown panel is remembered using a
* marker. The marker shifts as navigation between panels is continued, where
* the panel at index 0 is always the starting point:
* ┌────┬────┬────┬────┐
* │▓▓▓▓│ │ │ │ Start
* └────┴────┴────┴────┘
* ┌────┬────┬────┬────┐
* │ │▓▓▓▓│ │ │ Forward
* └────┴────┴────┴────┘
* ┌────┬────┬────┬────┐
* │ │ │▓▓▓▓│ │ Forward
* └────┴────┴────┴────┘
* ┌────┬────┬────┬────┐
* │ │▓▓▓▓│ │ │ Back
* └────┴────┴────┴────┘
*/
class SlidingPanelViews extends Array {
constructor() {
super();
this._marker = 0;
}
/**
* Get the index that points to the currently selected view.
*
* @return {Number}
*/
get current() {
return this._marker;
}
/**
* Setter for the current index, which changes the order of elements and
* updates the internal marker for the currently selected view.
* We're manipulating the array directly to have it reflect the order of
* navigation, instead of continuously growing the array with the next selected
* view to keep memory usage within reasonable proportions. With this method,
* the data structure grows no larger than the number of panels inside the
* panelMultiView.
*
* @param {Number} index Index of the item to move to the current position.
* @return {Number} The new marker index.
*/
set current(index) {
if (index == this._marker) {
// Never change a winning team.
return index;
}
if (index == -1 || index > (this.length - 1)) {
throw new Error(`SlidingPanelViews :: index ${index} out of bounds`);
}
let view = this.splice(index, 1)[0];
if (this._marker > index) {
// Correct the current marker if the view-to-select was removed somewhere
// before it.
--this._marker;
}
// Then add the view-to-select right after the currently selected view.
this.splice(++this._marker, 0, view);
return this._marker;
}
/**
* Getter for the currently selected view node.
*
* @return {panelview}
*/
get currentView() {
return this[this._marker];
}
/**
* Setter for the currently selected view node.
*
* @param {panelview} view
* @return {Number} Index of the currently selected view.
*/
set currentView(view) {
if (!view)
return this.current;
// This will throw an error if the view could not be found.
return this.current = this.indexOf(view);
}
/**
* Getter for the previous view, which is always positioned one position after
* the current view.
*
* @return {panelview}
*/
get previousView() {
return this[this._marker + 1];
}
/**
* Going back is an explicit action on the data structure, moving the marker
* one step back.
*
* @return {Array} A list of two items: the newly selected view and the previous one.
*/
back() {
if (this._marker > 0)
--this._marker;
return [this.currentView, this.previousView];
}
/**
* Reset the data structure to its original construct, removing all references
* to view nodes.
*/
clear() {
this._marker = 0;
this.splice(0, this.length);
}
}
/**
* This is the implementation of the panelUI.xml XBL binding, moved to this
* module, to make it easier to fork the logic for the newer photon structure.
* Goals are:
* 1. to make it easier to programmatically extend the list of panels,
* 2. allow for navigation between panels multiple levels deep and
* 3. maintain the pre-photon structure with as little effort possible.
*
* @type {PanelMultiView}
*/
this.PanelMultiView = class {
get document() {
return this.node.ownerDocument;
}
get window() {
return this.node.ownerGlobal;
}
get _panel() {
return this.node.parentNode;
}
get showingSubView() {
return this._showingSubView;
}
get _mainViewId() {
return this.node.getAttribute("mainViewId");
}
set _mainViewId(val) {
this.node.setAttribute("mainViewId", val);
return val;
}
get _mainView() {
return this._mainViewId ? this.document.getElementById(this._mainViewId) : null;
}
get _transitioning() {
return this.__transitioning;
}
set _transitioning(val) {
this.__transitioning = val;
if (val) {
this.node.setAttribute("transitioning", "true");
} else {
this.node.removeAttribute("transitioning");
}
}
/**
* @return {Boolean} |true| when the 'ephemeral' attribute is set, which means
* that this instance should be ready to be thrown away at
* any time.
*/
get _ephemeral() {
return this.node.hasAttribute("ephemeral");
}
get panelViews() {
if (this._panelViews)
return this._panelViews;
this._panelViews = new SlidingPanelViews();
this._panelViews.push(...this.node.getElementsByTagName("panelview"));
return this._panelViews;
}
get _dwu() {
if (this.__dwu)
return this.__dwu;
return this.__dwu = this.window.QueryInterface(Ci.nsIInterfaceRequestor)
.getInterface(Ci.nsIDOMWindowUtils);
}
get _screenManager() {
if (this.__screenManager)
return this.__screenManager;
return this.__screenManager = Cc["@mozilla.org/gfx/screenmanager;1"]
.getService(Ci.nsIScreenManager);
}
/**
* @return {panelview} the currently visible subview OR the subview that is
* about to be shown whilst a 'ViewShowing' event is being
* dispatched.
*/
get current() {
return this._viewShowing || this._currentSubView;
}
get _currentSubView() {
return this.panelViews.currentView;
}
set _currentSubView(panel) {
this.panelViews.currentView = panel;
}
/**
* @return {Promise} showSubView() returns a promise, which is kept here for
* random access.
*/
get currentShowPromise() {
return this._currentShowPromise || Promise.resolve();
}
get _keyNavigationMap() {
if (!this.__keyNavigationMap)
this.__keyNavigationMap = new Map();
return this.__keyNavigationMap;
}
get _multiLineElementsMap() {
if (!this.__multiLineElementsMap)
this.__multiLineElementsMap = new WeakMap();
return this.__multiLineElementsMap;
}
constructor(xulNode, testMode = false) {
this.node = xulNode;
// If `testMode` is `true`, the consumer is only interested in accessing the
// methods of this instance. (E.g. in unit tests.)
if (testMode)
return;
this._currentSubView = this._subViewObserver = null;
this._mainViewHeight = 0;
this.__transitioning = this._ignoreMutations = this._showingSubView = false;
const {document, window} = this;
this._viewContainer =
document.getAnonymousElementByAttribute(this.node, "anonid", "viewContainer");
this._viewStack =
document.getAnonymousElementByAttribute(this.node, "anonid", "viewStack");
this._offscreenViewStack =
document.getAnonymousElementByAttribute(this.node, "anonid", "offscreenViewStack");
XPCOMUtils.defineLazyGetter(this, "_panelViewCache", () => {
let viewCacheId = this.node.getAttribute("viewCacheId");
return viewCacheId ? document.getElementById(viewCacheId) : null;
});
this._panel.addEventListener("popupshowing", this);
this._panel.addEventListener("popuppositioned", this);
this._panel.addEventListener("popuphidden", this);
this._panel.addEventListener("popupshown", this);
let cs = window.getComputedStyle(document.documentElement);
// Set CSS-determined attributes now to prevent a layout flush when we do
// it when transitioning between panels.
this._dir = cs.direction;
this.setMainView(this.panelViews.currentView);
this.showMainView();
this._showingSubView = false;
// Proxy these public properties and methods, as used elsewhere by various
// parts of the browser, to this instance.
["_mainView", "ignoreMutations", "showingSubView",
"_panelViews"].forEach(property => {
Object.defineProperty(this.node, property, {
enumerable: true,
get: () => this[property],
set: (val) => this[property] = val
});
});
["goBack", "descriptionHeightWorkaround", "setMainView", "showMainView",
"showSubView"].forEach(method => {
Object.defineProperty(this.node, method, {
enumerable: true,
value: (...args) => this[method](...args)
});
});
["current", "currentShowPromise"].forEach(property => {
Object.defineProperty(this.node, property, {
enumerable: true,
get: () => this[property]
});
});
}
destructor() {
// Guard against re-entrancy.
if (!this.node)
return;
this._cleanupTransitionPhase();
if (this._ephemeral)
this.hideAllViewsExcept(null);
let mainView = this._mainView;
if (mainView) {
if (this._panelViewCache)
this._panelViewCache.appendChild(mainView);
mainView.removeAttribute("mainview");
}
this._moveOutKids(this._viewStack);
this.panelViews.clear();
this._panel.removeEventListener("mousemove", this);
this._panel.removeEventListener("popupshowing", this);
this._panel.removeEventListener("popuppositioned", this);
this._panel.removeEventListener("popupshown", this);
this._panel.removeEventListener("popuphidden", this);
this.window.removeEventListener("keydown", this);
this.node = this._viewContainer = this._viewStack = this.__dwu =
this._panelViewCache = this._transitionDetails = null;
}
/**
* Remove any child subviews into the panelViewCache, to ensure
* they remain usable even if this panelmultiview instance is removed
* from the DOM.
* @param viewNodeContainer the container from which to remove subviews
*/
_moveOutKids(viewNodeContainer) {
if (!this._panelViewCache)
return;
// Node.children and Node.childNodes is live to DOM changes like the
// ones we're about to do, so iterate over a static copy:
let subviews = Array.from(viewNodeContainer.childNodes);
for (let subview of subviews) {
// XBL lists the 'children' XBL element explicitly. :-(
if (subview.nodeName != "children")
this._panelViewCache.appendChild(subview);
}
}
_placeSubView(viewNode) {
this._viewStack.appendChild(viewNode);
if (!this.panelViews.includes(viewNode))
this.panelViews.push(viewNode);
}
goBack(target) {
let [current, previous] = this.panelViews.back();
return this.showSubView(current, target, previous);
}
/**
* Checks whether it is possible to navigate backwards currently. Returns
* false if this is the panelmultiview's mainview, true otherwise.
*
* @param {panelview} view View to check, defaults to the currently active view.
* @return {Boolean}
*/
_canGoBack(view = this._currentSubView) {
return view.id != this._mainViewId;
}
setMainView(aNewMainView) {
if (!aNewMainView)
return;
if (this._mainView) {
this._mainView.removeAttribute("mainview");
}
this._mainViewId = aNewMainView.id;
aNewMainView.setAttribute("mainview", "true");
// If the new main view is not yet in the zeroth position, make sure it's
// inserted there.
if (aNewMainView.parentNode != this._viewStack &&
this._viewStack.firstChild != aNewMainView) {
this._viewStack.insertBefore(aNewMainView, this._viewStack.firstChild);
}
}
showMainView() {
if (!this._mainViewId)
return Promise.resolve();
return this.showSubView(this._mainView);
}
/**
* Ensures that all the panelviews, that are currently part of this instance,
* are hidden, except one specifically.
*
* @param {panelview} [theOne] The panelview DOM node to ensure is visible.
* Optional.
*/
hideAllViewsExcept(theOne = null) {
for (let panelview of this._panelViews) {
// When the panelview was already reparented, don't interfere any more.
if (panelview == theOne || !this.node || panelview.panelMultiView != this.node)
continue;
if (panelview.hasAttribute("current"))
this._dispatchViewEvent(panelview, "ViewHiding");
panelview.removeAttribute("current");
}
this._viewShowing = null;
if (!this.node || !theOne)
return;
this._currentSubView = theOne;
if (!theOne.hasAttribute("current")) {
theOne.setAttribute("current", true);
this.descriptionHeightWorkaround(theOne);
this._dispatchViewEvent(theOne, "ViewShown");
}
this._showingSubView = theOne.id != this._mainViewId;
}
showSubView(aViewId, aAnchor, aPreviousView) {
this._currentShowPromise = (async () => {
// Support passing in the node directly.
let viewNode = typeof aViewId == "string" ? this.node.querySelector("#" + aViewId) : aViewId;
if (!viewNode) {
viewNode = this.document.getElementById(aViewId);
if (viewNode) {
this._placeSubView(viewNode);
} else {
throw new Error(`Subview ${aViewId} doesn't exist!`);
}
} else if (viewNode.parentNode == this._panelViewCache) {
this._placeSubView(viewNode);
}
let reverse = !!aPreviousView;
let previousViewNode = aPreviousView || this._currentSubView;
// If the panelview to show is the same as the previous one, the 'ViewShowing'
// event has already been dispatched. Don't do it twice.
let showingSameView = viewNode == previousViewNode;
let playTransition = (!!previousViewNode && !showingSameView && this._panel.state == "open");
let isMainView = viewNode.id == this._mainViewId;
let dwu = this._dwu;
let previousRect = previousViewNode.__lastKnownBoundingRect =
dwu.getBoundsWithoutFlushing(previousViewNode);
// Cache the measures that have the same caching lifetime as the width
// or height of the main view, i.e. whilst the panel is shown and/ or
// visible.
if (!this._mainViewWidth) {
this._mainViewWidth = previousRect.width;
let top = dwu.getBoundsWithoutFlushing(previousViewNode.firstChild || previousViewNode).top;
let bottom = dwu.getBoundsWithoutFlushing(previousViewNode.lastChild || previousViewNode).bottom;
this._viewVerticalPadding = previousRect.height - (bottom - top);
}
if (!this._mainViewHeight) {
this._mainViewHeight = previousRect.height;
this._viewContainer.style.minHeight = this._mainViewHeight + "px";
}
this._viewShowing = viewNode;
// Because the 'mainview' attribute may be out-of-sync, due to view node
// reparenting in combination with ephemeral PanelMultiView instances,
// this is the best place to correct it (just before showing).
if (isMainView)
viewNode.setAttribute("mainview", true);
else
viewNode.removeAttribute("mainview");
// Make sure that new panels always have a title set.
if (aAnchor) {
if (!viewNode.hasAttribute("title"))
viewNode.setAttribute("title", aAnchor.getAttribute("label"));
viewNode.classList.add("PanelUI-subView");
}
if (!isMainView && this._mainViewWidth)
viewNode.style.maxWidth = viewNode.style.minWidth = this._mainViewWidth + "px";
if (!showingSameView || !viewNode.hasAttribute("current")) {
// Emit the ViewShowing event so that the widget definition has a chance
// to lazily populate the subview with things or perhaps even cancel this
// whole operation.
let detail = {
blockers: new Set(),
addBlocker(promise) {
this.blockers.add(promise);
}
};
let cancel = this._dispatchViewEvent(viewNode, "ViewShowing", aAnchor, detail);
if (detail.blockers.size) {
try {
let results = await Promise.all(detail.blockers);
cancel = cancel || results.some(val => val === false);
} catch (e) {
Cu.reportError(e);
cancel = true;
}
}
if (cancel) {
this._viewShowing = null;
return;
}
}
// Now we have to transition the panel. If we've got an older transition
// still running, make sure to clean it up.
await this._cleanupTransitionPhase();
if (playTransition) {
await this._transitionViews(previousViewNode, viewNode, reverse, previousRect, aAnchor);
this._updateKeyboardFocus(viewNode);
} else {
this.hideAllViewsExcept(viewNode);
}
})().catch(e => Cu.reportError(e));
return this._currentShowPromise;
}
/**
* Apply a transition to 'slide' from the currently active view to the next
* one.
* Sliding the next subview in means that the previous panelview stays where it
* is and the active panelview slides in from the left in LTR mode, right in
* RTL mode.
*
* @param {panelview} previousViewNode Node that is currently shown as active,
* but is about to be transitioned away.
* @param {panelview} viewNode Node that will becode the active view,
* after the transition has finished.
* @param {Boolean} reverse Whether we're navigation back to a
* previous view or forward to a next view.
* @param {Object} previousRect Rect object, with the same structure as
* a DOMRect, of the `previousViewNode`.
* @param {Element} anchor the anchor for which we're opening
* a new panelview, if any
*/
async _transitionViews(previousViewNode, viewNode, reverse, previousRect, anchor) {
// There's absolutely no need to show off our epic animation skillz when
// the panel's not even open.
if (this._panel.state != "open") {
return;
}
const {window, document} = this;
if (this._autoResizeWorkaroundTimer)
window.clearTimeout(this._autoResizeWorkaroundTimer);
let details = this._transitionDetails = {
phase: TRANSITION_PHASES.START,
previousViewNode, viewNode, reverse, anchor
};
if (anchor)
anchor.setAttribute("open", "true");
// Since we're going to show two subview at the same time, don't abuse the
// 'current' attribute, since it's needed for other state-keeping, but use
// a separate 'in-transition' attribute instead.
previousViewNode.setAttribute("in-transition", true);
// Set the viewContainer dimensions to make sure only the current view is
// visible.
this._viewContainer.style.height = Math.max(previousRect.height, this._mainViewHeight) + "px";
this._viewContainer.style.width = previousRect.width + "px";
// Lock the dimensions of the window that hosts the popup panel.
let rect = this._panel.popupBoxObject.getOuterScreenRect();
this._panel.setAttribute("width", rect.width);
this._panel.setAttribute("height", rect.height);
let viewRect;
if (reverse && viewNode.__lastKnownBoundingRect) {
// Use the cached size when going back to a previous view, but not when
// reopening a subview, because its contents may have changed.
viewRect = viewNode.__lastKnownBoundingRect;
viewNode.setAttribute("in-transition", true);
} else if (viewNode.customRectGetter) {
// Can't use Object.assign directly with a DOM Rect object because its properties
// aren't enumerable.
let {height, width} = previousRect;
viewRect = Object.assign({height, width}, viewNode.customRectGetter());
let {header} = viewNode;
if (header) {
viewRect.height += this._dwu.getBoundsWithoutFlushing(header).height;
}
viewNode.setAttribute("in-transition", true);
} else {
let oldSibling = viewNode.nextSibling || null;
this._offscreenViewStack.style.minHeight =
this._viewContainer.style.height;
this._offscreenViewStack.appendChild(viewNode);
viewNode.setAttribute("in-transition", true);
// Now that the subview is visible, we can check the height of the
// description elements it contains.
this.descriptionHeightWorkaround(viewNode);
viewRect = await BrowserUtils.promiseLayoutFlushed(this.document, "layout", () => {
return this._dwu.getBoundsWithoutFlushing(viewNode);
});
try {
this._viewStack.insertBefore(viewNode, oldSibling);
} catch (ex) {
this._viewStack.appendChild(viewNode);
}
this._offscreenViewStack.style.removeProperty("min-height");
}
this._transitioning = true;
details.phase = TRANSITION_PHASES.PREPARE;
// The 'magic' part: build up the amount of pixels to move right or left.
let moveToLeft = (this._dir == "rtl" && !reverse) || (this._dir == "ltr" && reverse);
let deltaX = previousRect.width;
let deepestNode = reverse ? previousViewNode : viewNode;
// With a transition when navigating backwards - user hits the 'back'
// button - we need to make sure that the views are positioned in a way
// that a translateX() unveils the previous view from the right direction.
if (reverse)
this._viewStack.style.marginInlineStart = "-" + deltaX + "px";
// Set the transition style and listen for its end to clean up and make sure
// the box sizing becomes dynamic again.
// Somehow, putting these properties in PanelUI.css doesn't work for newly
// shown nodes in a XUL parent node.
this._viewStack.style.transition = "transform var(--animation-easing-function)" +
" var(--panelui-subview-transition-duration)";
this._viewStack.style.willChange = "transform";
// Use an outline instead of a border so that the size is not affected.
deepestNode.style.outline = "1px solid var(--panel-separator-color)";
// Now set the viewContainer dimensions to that of the new view, which
// kicks of the height animation.
this._viewContainer.style.height = Math.max(viewRect.height, this._mainViewHeight) + "px";
this._viewContainer.style.width = viewRect.width + "px";
this._panel.removeAttribute("width");
this._panel.removeAttribute("height");
// We're setting the width property to prevent flickering during the
// sliding animation with smaller views.
viewNode.style.width = viewRect.width + "px";
await BrowserUtils.promiseLayoutFlushed(document, "layout", () => {});
// Kick off the transition!
details.phase = TRANSITION_PHASES.TRANSITION;
this._viewStack.style.transform = "translateX(" + (moveToLeft ? "" : "-") + deltaX + "px)";
await new Promise(resolve => {
details.resolve = resolve;
this._viewContainer.addEventListener("transitionend", details.listener = ev => {
// It's quite common that `height` on the view container doesn't need
// to transition, so we make sure to do all the work on the transform
// transition-end, because that is guaranteed to happen.
if (ev.target != this._viewStack || ev.propertyName != "transform")
return;
this._viewContainer.removeEventListener("transitionend", details.listener);
delete details.listener;
resolve();
});
this._viewContainer.addEventListener("transitioncancel", details.cancelListener = ev => {
if (ev.target != this._viewStack)
return;
this._viewContainer.removeEventListener("transitioncancel", details.cancelListener);
delete details.cancelListener;
resolve();
});
});
details.phase = TRANSITION_PHASES.END;
await this._cleanupTransitionPhase(details);
}
/**
* Attempt to clean up the attributes and properties set by `_transitionViews`
* above. Which attributes and properties depends on the phase the transition
* was left from - normally that'd be `TRANSITION_PHASES.END`.
*
* @param {Object} details Dictionary object containing details of the transition
* that should be cleaned up after. Defaults to the most
* recent details.
*/
async _cleanupTransitionPhase(details = this._transitionDetails) {
if (!details || !this.node)
return;
let {phase, previousViewNode, viewNode, reverse, resolve, listener, cancelListener, anchor} = details;
if (details == this._transitionDetails)
this._transitionDetails = null;
// Do the things we _always_ need to do whenever the transition ends or is
// interrupted.
this.hideAllViewsExcept(viewNode);
previousViewNode.removeAttribute("in-transition");
viewNode.removeAttribute("in-transition");
if (reverse)
this._resetKeyNavigation(previousViewNode);
if (anchor)
anchor.removeAttribute("open");
if (phase >= TRANSITION_PHASES.START) {
this._panel.removeAttribute("width");
this._panel.removeAttribute("height");
// Myeah, panel layout auto-resizing is a funky thing. We'll wait
// another few milliseconds to remove the width and height 'fixtures',
// to be sure we don't flicker annoyingly.
// NB: HACK! Bug 1363756 is there to fix this.
this._autoResizeWorkaroundTimer = this.window.setTimeout(() => {
if (!this._viewContainer)
return;
this._viewContainer.style.removeProperty("height");
this._viewContainer.style.removeProperty("width");
}, 500);
}
if (phase >= TRANSITION_PHASES.PREPARE) {
this._transitioning = false;
if (reverse)
this._viewStack.style.removeProperty("margin-inline-start");
let deepestNode = reverse ? previousViewNode : viewNode;
deepestNode.style.removeProperty("outline");
this._viewStack.style.removeProperty("transition");
}
if (phase >= TRANSITION_PHASES.TRANSITION) {
this._viewStack.style.removeProperty("transform");
viewNode.style.removeProperty("width");
if (listener)
this._viewContainer.removeEventListener("transitionend", listener);
if (cancelListener)
this._viewContainer.removeEventListener("transitioncancel", cancelListener);
if (resolve)
resolve();
}
if (phase >= TRANSITION_PHASES.END) {
// We force 'display: none' on the previous view node to make sure that it
// doesn't cause an annoying flicker whilst resetting the styles above.
previousViewNode.style.display = "none";
await BrowserUtils.promiseLayoutFlushed(this.document, "layout", () => {});
previousViewNode.style.removeProperty("display");
}
}
/**
* Helper method to emit an event on a panelview, whilst also making sure that
* the correct method is called on CustomizableWidget instances.
*
* @param {panelview} viewNode Target of the event to dispatch.
* @param {String} eventName Name of the event to dispatch.
* @param {DOMNode} [anchor] Node where the panel is anchored to. Optional.
* @param {Object} [detail] Event detail object. Optional.
* @return {Boolean} `true` if the event was canceled by an event handler, `false`
* otherwise.
*/
_dispatchViewEvent(viewNode, eventName, anchor, detail) {
let cancel = false;
if (eventName != "PanelMultiViewHidden") {
// Don't need to do this for PanelMultiViewHidden event
CustomizableUI.ensureSubviewListeners(viewNode);
}
let evt = new this.window.CustomEvent(eventName, {
detail,
bubbles: true,
cancelable: eventName == "ViewShowing"
});
viewNode.dispatchEvent(evt);
if (!cancel)
cancel = evt.defaultPrevented;
return cancel;
}
_calculateMaxHeight() {
// While opening the panel, we have to limit the maximum height of any
// view based on the space that will be available. We cannot just use
// window.screen.availTop and availHeight because these may return an
// incorrect value when the window spans multiple screens.
let anchorBox = this._panel.anchorNode.boxObject;
let screen = this._screenManager.screenForRect(anchorBox.screenX,
anchorBox.screenY,
anchorBox.width,
anchorBox.height);
let availTop = {}, availHeight = {};
screen.GetAvailRect({}, availTop, {}, availHeight);
let cssAvailTop = availTop.value / screen.defaultCSSScaleFactor;
// The distance from the anchor to the available margin of the screen is
// based on whether the panel will open towards the top or the bottom.
let maxHeight;
if (this._panel.alignmentPosition.startsWith("before_")) {
maxHeight = anchorBox.screenY - cssAvailTop;
} else {
let anchorScreenBottom = anchorBox.screenY + anchorBox.height;
let cssAvailHeight = availHeight.value / screen.defaultCSSScaleFactor;
maxHeight = cssAvailTop + cssAvailHeight - anchorScreenBottom;
}
// To go from the maximum height of the panel to the maximum height of
// the view stack, we need to subtract the height of the arrow and the
// height of the opposite margin, but we cannot get their actual values
// because the panel is not visible yet. However, we know that this is
// currently 11px on Mac, 13px on Windows, and 13px on Linux. We also
// want an extra margin, both for visual reasons and to prevent glitches
// due to small rounding errors. So, we just use a value that makes
// sense for all platforms. If the arrow visuals change significantly,
// this value will be easy to adjust.
const EXTRA_MARGIN_PX = 20;
maxHeight -= EXTRA_MARGIN_PX;
return maxHeight;
}
handleEvent(aEvent) {
if (aEvent.type.startsWith("popup") && aEvent.target != this._panel) {
// Shouldn't act on e.g. context menus being shown from within the panel.
return;
}
switch (aEvent.type) {
case "keydown":
this._keyNavigation(aEvent);
break;
case "mousemove":
this._resetKeyNavigation();
break;
case "popupshowing": {
this.node.setAttribute("panelopen", "true");
if (this.panelViews && !this.node.hasAttribute("disablekeynav")) {
this.window.addEventListener("keydown", this);
this._panel.addEventListener("mousemove", this);
}
break;
}
case "popuppositioned": {
// When autoPosition is true, the popup window manager would attempt to re-position
// the panel as subviews are opened and it changes size. The resulting popoppositioned
// events triggers the binding's arrow position adjustment - and its reflow.
// This is not needed here, as we calculated and set maxHeight so it is known
// to fit the screen while open.
// autoPosition gets reset after each popuppositioned event, and when the
// popup closes, so we must set it back to false each time.
this._panel.autoPosition = false;
if (this._panel.state == "showing") {
let maxHeight = this._calculateMaxHeight();
this._viewStack.style.maxHeight = maxHeight + "px";
this._offscreenViewStack.style.maxHeight = maxHeight + "px";
}
break;
}
case "popupshown":
// Now that the main view is visible, we can check the height of the
// description elements it contains.
this.descriptionHeightWorkaround();
break;
case "popuphidden": {
// WebExtensions consumers can hide the popup from viewshowing, or
// mid-transition, which disrupts our state:
this._viewShowing = null;
this._transitioning = false;
this.node.removeAttribute("panelopen");
this.showMainView();
for (let panelView of this._viewStack.children) {
if (panelView.nodeName != "children") {
panelView.__lastKnownBoundingRect = null;
panelView.style.removeProperty("min-width");
panelView.style.removeProperty("max-width");
}
}
this.window.removeEventListener("keydown", this);
this._panel.removeEventListener("mousemove", this);
this._resetKeyNavigation();
// Clear the main view size caches. The dimensions could be different
// when the popup is opened again, e.g. through touch mode sizing.
this._mainViewHeight = 0;
this._mainViewWidth = 0;
this._viewContainer.style.removeProperty("min-height");
this._viewStack.style.removeProperty("max-height");
this._viewContainer.style.removeProperty("min-width");
this._viewContainer.style.removeProperty("max-width");
this._dispatchViewEvent(this.node, "PanelMultiViewHidden");
break;
}
}
}
/**
* Based on going up or down, select the previous or next focusable button
* in the current view.
*
* @param {Object} navMap the navigation keyboard map object for the view
* @param {Array} buttons an array of focusable buttons to select an item from.
* @param {Boolean} isDown whether we're going down (true) or up (false) in this view.
*
* @return {DOMNode} the button we selected.
*/
_updateSelectedKeyNav(navMap, buttons, isDown) {
let lastSelected = navMap.selected && navMap.selected.get();
let newButton = null;
let maxIdx = buttons.length - 1;
if (lastSelected) {
let buttonIndex = buttons.indexOf(lastSelected);
if (buttonIndex != -1) {
// Buttons may get selected whilst the panel is shown, so add an extra
// check here.
do {
buttonIndex = buttonIndex + (isDown ? 1 : -1);
} while (buttons[buttonIndex] && buttons[buttonIndex].disabled);
if (isDown && buttonIndex > maxIdx)
buttonIndex = 0;
else if (!isDown && buttonIndex < 0)
buttonIndex = maxIdx;
newButton = buttons[buttonIndex];
} else {
// The previously selected item is no longer selectable. Find the next item:
let allButtons = lastSelected.closest("panelview").getElementsByTagName("toolbarbutton");
let maxAllButtonIdx = allButtons.length - 1;
let allButtonIndex = allButtons.indexOf(lastSelected);
while (allButtonIndex >= 0 && allButtonIndex <= maxAllButtonIdx) {
allButtonIndex++;
// Check if the next button is in the list of focusable buttons.
buttonIndex = buttons.indexOf(allButtons[allButtonIndex]);
if (buttonIndex != -1) {
// If it is, just use that button if we were going down, or the previous one
// otherwise. If this was the first button, newButton will end up undefined,
// which is fine because we'll fall back to using the last button at the
// bottom of this method.
newButton = buttons[isDown ? buttonIndex : buttonIndex - 1];
break;
}
}
}
}
// If we couldn't find something, select the first or last item:
if (!newButton) {
newButton = buttons[isDown ? 0 : maxIdx];
}
navMap.selected = Cu.getWeakReference(newButton);
return newButton;
}
/**
* Allow for navigating subview buttons using the arrow keys and the Enter key.
* The Up and Down keys can be used to navigate the list up and down and the
* Enter, Right or Left - depending on the text direction - key can be used to
* simulate a click on the currently selected button.
* The Right or Left key - depending on the text direction - can be used to
* navigate to the previous view, functioning as a shortcut for the view's
* back button.
* Thus, in LTR mode:
* - The Right key functions the same as the Enter key, simulating a click
* - The Left key triggers a navigation back to the previous view.
*
* @param {KeyEvent} event
*/
_keyNavigation(event) {
if (this._transitioning)
return;
let view = this._currentSubView;
let navMap = this._keyNavigationMap.get(view);
if (!navMap) {
navMap = {};
this._keyNavigationMap.set(view, navMap);
}
let buttons = navMap.buttons;
if (!buttons || !buttons.length) {
buttons = navMap.buttons = this._getNavigableElements(view);
// Set the 'tabindex' attribute on the buttons to make sure they're focussable.
for (let button of buttons) {
if (!button.classList.contains("subviewbutton-back") &&
!button.hasAttribute("tabindex")) {
button.setAttribute("tabindex", 0);
}
}
}
if (!buttons.length)
return;
let stop = () => {
event.stopPropagation();
event.preventDefault();
};
let keyCode = event.code;
switch (keyCode) {
case "ArrowDown":
case "ArrowUp": {
stop();
let isDown = (keyCode == "ArrowDown");
let button = this._updateSelectedKeyNav(navMap, buttons, isDown);
button.focus();
break;
}
case "ArrowLeft":
case "ArrowRight": {
stop();
let dir = this._dir;
if ((dir == "ltr" && keyCode == "ArrowLeft") ||
(dir == "rtl" && keyCode == "ArrowRight")) {
if (this._canGoBack(view))
this.goBack(view.backButton);
break;
}
// If the current button is _not_ one that points to a subview, pressing
// the arrow key shouldn't do anything.
if (!navMap.selected || !navMap.selected.get() ||
!navMap.selected.get().classList.contains("subviewbutton-nav")) {
break;
}
// Fall-through...
}
case "Space":
case "Enter": {
let button = navMap.selected && navMap.selected.get();
if (!button)
break;
stop();
// Unfortunately, 'tabindex' doesn't execute the default action, so
// we explicitly do this here.
// We are sending a command event and then a click event.
// This is done in order to mimic a "real" mouse click event.
// The command event executes the action, then the click event closes the menu.
button.doCommand();
let clickEvent = new event.target.ownerGlobal.MouseEvent("click", {"bubbles": true});
button.dispatchEvent(clickEvent);
break;
}
}
}
/**
* Clear all traces of keyboard navigation happening right now.
*
* @param {panelview} view View to reset the key navigation attributes of.
* If no view is passed, all navigation attributes for
* this panelmultiview are cleared.
*/
_resetKeyNavigation(view) {
let viewToBlur = view || this._currentSubView;
let navMap = this._keyNavigationMap.get(viewToBlur);
if (navMap && navMap.selected && navMap.selected.get()) {
navMap.selected.get().blur();
}
// We clear the entire key navigation map ONLY if *no* view was passed in.
// This happens e.g. when the popup is hidden completely, or the user moves
// their mouse.
// If a view is passed in, we just delete the map for that view. This happens
// when going back from a view (which resets the map for that view only)
if (view) {
this._keyNavigationMap.delete(view);
} else {
this._keyNavigationMap.clear();
}
}
/**
* Retrieve the button elements from a view node that can be used for navigation
* using the keyboard; enabled buttons and the back button, if visible.
*
* @param {nsIDOMNode} view
* @return {Array}
*/
_getNavigableElements(view) {
let buttons = Array.from(view.querySelectorAll(".subviewbutton:not([disabled])"));
if (this._canGoBack(view))
buttons.unshift(view.backButton);
let dwu = this._dwu;
return buttons.filter(button => {
let bounds = dwu.getBoundsWithoutFlushing(button);
return bounds.width > 0 && bounds.height > 0;
});
}
/**
* Focus the last selected element in the view, if any.
*
* @param {panelview} view the view in which to update keyboard focus.
*/
_updateKeyboardFocus(view) {
let navMap = this._keyNavigationMap.get(view);
if (navMap && navMap.selected && navMap.selected.get()) {
navMap.selected.get().focus();
}
}
/**
* If the main view or a subview contains wrapping elements, the attribute
* "descriptionheightworkaround" should be set on the view to force all the
* wrapping "description", "label" or "toolbarbutton" elements to a fixed
* height. If the attribute is set and the visibility, contents, or width
* of any of these elements changes, this function should be called to
* refresh the calculated heights.
*
* This may trigger a synchronous layout.
*
* @param viewNode
* Indicates the node to scan for descendant elements. This is the main
* view if omitted.
*/
descriptionHeightWorkaround(viewNode = this._mainView) {
if (!viewNode || !viewNode.hasAttribute("descriptionheightworkaround")) {
// This view does not require the workaround.
return;
}
// We batch DOM changes together in order to reduce synchronous layouts.
// First we reset any change we may have made previously. The first time
// this is called, and in the best case scenario, this has no effect.
let items = [];
// Non-hidden <label> or <description> elements that also aren't empty
// and also don't have a value attribute can be multiline (if their
// text content is long enough).
let isMultiline = ":not(:-moz-any([hidden],[value],:empty))";
let selector = [
"description" + isMultiline,
"label" + isMultiline,
"toolbarbutton[wrap]:not([hidden])",
].join(",");
for (let element of viewNode.querySelectorAll(selector)) {
// Ignore items in hidden containers.
if (element.closest("[hidden]")) {
continue;
}
// Take the label for toolbarbuttons; it only exists on those elements.
element = element.labelElement || element;
let bounds = element.getBoundingClientRect();
let previous = this._multiLineElementsMap.get(element);
// We don't need to (re-)apply the workaround for invisible elements or
// on elements we've seen before and haven't changed in the meantime.
if (!bounds.width || !bounds.height ||
(previous && element.textContent == previous.textContent &&
bounds.width == previous.bounds.width)) {
continue;
}
items.push({ element });
}
// Removing the 'height' property will only cause a layout flush in the next
// loop below if it was set.
for (let item of items) {
item.element.style.removeProperty("height");
}
// We now read the computed style to store the height of any element that
// may contain wrapping text.
for (let item of items) {
item.bounds = item.element.getBoundingClientRect();
}
// Now we can make all the necessary DOM changes at once.
for (let { element, bounds } of items) {
this._multiLineElementsMap.set(element, { bounds, textContent: element.textContent });
element.style.height = bounds.height + "px";
}
}
};