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/* 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
/**
* Allows a popup panel to host multiple subviews. The main view shown when the
* panel is opened may slide out to display a subview, which in turn may lead to
* other subviews in a cascade menu pattern.
*
* The <panel> element should contain a <panelmultiview> element. Views are
* declared using <panelview> elements that are usually children of the main
* <panelmultiview> element, although they don't need to be, as views can also
* be imported into the panel from other panels or popup sets.
*
* The panel should be opened asynchronously using the openPopup static method
* on the PanelMultiView object. This will display the view specified using the
* mainViewId attribute on the contained <panelmultiview> element.
*
* Specific subviews can slide in using the showSubView method, and backwards
* navigation can be done using the goBack method or through a button in the
* subview headers.
*
* The process of displaying the main view or a new subview requires multiple
* steps to be completed, hence at any given time the <panelview> element may
* be in different states:
*
* -- Open or closed
*
* All the <panelview> elements start "closed", meaning that they are not
* associated to a <panelmultiview> element and can be located anywhere in
* the document. When the openPopup or showSubView methods are called, the
* relevant view becomes "open" and the <panelview> element may be moved to
* ensure it is a descendant of the <panelmultiview> element.
*
* The "ViewShowing" event is fired at this point, when the view is not
* visible yet. The event is allowed to cancel the operation, in which case
* the view is closed immediately.
*
* Closing the view does not move the node back to its original position.
*
* -- Visible or invisible
*
* This indicates whether the view is visible in the document from a layout
* perspective, regardless of whether it is currently scrolled into view. In
* fact, all subviews are already visible before they start sliding in.
*
* Before scrolling into view, a view may become visible but be placed in a
* special off-screen area of the document where layout and measurements can
* take place asynchronously.
*
* When navigating forward, an open view may become invisible but stay open
* after sliding out of view. The last known size of these views is still
* taken into account for determining the overall panel size.
*
* When navigating backwards, an open subview will first become invisible and
* then will be closed.
*
* -- Active or inactive
*
* This indicates whether the view is fully scrolled into the visible area
* and ready to receive mouse and keyboard events. An active view is always
* visible, but a visible view may be inactive. For example, during a scroll
* transition, both views will be inactive.
*
* When a view becomes active, the ViewShown event is fired synchronously,
* and the showSubView and goBack methods can be called for navigation.
*
* For the main view of the panel, the ViewShown event is dispatched during
* the "popupshown" event, which means that other "popupshown" handlers may
* be called before the view is active. Thus, code that needs to perform
* further navigation automatically should either use the ViewShown event or
* wait for an event loop tick, like BrowserTestUtils.waitForEvent does.
*
* -- Navigating with the keyboard
*
* An open view may keep state related to keyboard navigation, even if it is
* invisible. When a view is closed, keyboard navigation state is cleared.
*
* This diagram shows how <panelview> nodes move during navigation:
*
* In this <panelmultiview> In other panels Action
* ┌───┬───┬───┐ ┌───┬───┐
* │(A)│ B │ C │ │ D │ E │ Open panel
* └───┴───┴───┘ └───┴───┘
* ┌───┬───┬───┐ ┌───┬───┐
* │{A}│(C)│ B │ │ D │ E │ Show subview C
* └───┴───┴───┘ └───┴───┘
* ┌───┬───┬───┬───┐ ┌───┐
* │{A}│{C}│(D)│ B │ │ E │ Show subview D
* └───┴───┴───┴───┘ └───┘
* │ ┌───┬───┬───┬───┐ ┌───┐
* │ │{A}│(C)│ D │ B │ │ E │ Go back
* │ └───┴───┴───┴───┘ └───┘
* │ │ │
* │ │ └── Currently visible view
* │ │ │
* └───┴───┴── Open views
*/
const lazy = {};
ChromeUtils.defineLazyGetter(lazy, "gBundle", function () {
return Services.strings.createBundle(
);
});
/**
* Safety timeout after which asynchronous events will be canceled if any of the
* registered blockers does not return.
*/
const BLOCKERS_TIMEOUT_MS = 10000;
const TRANSITION_PHASES = Object.freeze({
START: 1,
PREPARE: 2,
TRANSITION: 3,
});
const gNodeToObjectMap = new WeakMap();
const gWindowsWithUnloadHandler = new WeakSet();
/**
* Allows associating an object to a node lazily using a weak map.
*
* Classes deriving from this one may be easily converted to Custom Elements,
* although they would lose the ability of being associated lazily.
*/
var AssociatedToNode = class {
constructor(node) {
/**
* Node associated to this object.
*/
this.node = node;
/**
* This promise is resolved when the current set of blockers set by event
* handlers have all been processed.
*/
this._blockersPromise = Promise.resolve();
}
/**
* Retrieves the instance associated with the given node, constructing a new
* one if necessary. When the last reference to the node is released, the
* object instance will be garbage collected as well.
*/
static forNode(node) {
let associatedToNode = gNodeToObjectMap.get(node);
if (!associatedToNode) {
associatedToNode = new this(node);
gNodeToObjectMap.set(node, associatedToNode);
}
return associatedToNode;
}
get document() {
return this.node.ownerDocument;
}
get window() {
return this.node.ownerGlobal;
}
_getBoundsWithoutFlushing(element) {
return this.window.windowUtils.getBoundsWithoutFlushing(element);
}
/**
* Dispatches a custom event on this element.
*
* @param {string} eventName Name of the event to dispatch.
* @param {object} [detail] Event detail object. Optional.
* @param {boolean} cancelable If the event can be canceled.
* @returns {boolean} `true` if the event was canceled by an event handler, `false`
* otherwise.
*/
dispatchCustomEvent(eventName, detail, cancelable = false) {
const event = new this.window.CustomEvent(eventName, {
detail,
bubbles: true,
cancelable,
});
this.node.dispatchEvent(event);
return event.defaultPrevented;
}
/**
* Dispatches a custom event on this element and waits for any blocking
* promises registered using the "addBlocker" function on the details object.
* If this function is called again, the event is only dispatched after all
* the previously registered blockers have returned.
*
* The event can be canceled either by resolving any blocking promise to the
* boolean value "false" or by calling preventDefault on the event. Rejections
* and exceptions will be reported and will cancel the event.
*
* Blocking should be used sporadically because it slows down the interface.
* Also, non-reentrancy is not strictly guaranteed because a safety timeout of
* BLOCKERS_TIMEOUT_MS is implemented, after which the event will be canceled.
* This helps to prevent deadlocks if any of the event handlers does not
* resolve a blocker promise.
*
* @note Since there is no use case for dispatching different asynchronous
* events in parallel for the same element, this function will also wait
* for previous blockers when the event name is different.
*
* @param eventName
* Name of the custom event to dispatch.
*
* @resolves True if the event was canceled by a handler, false otherwise.
*/
async dispatchAsyncEvent(eventName) {
// Wait for all the previous blockers before dispatching the event.
const blockersPromise = this._blockersPromise.catch(() => {});
return (this._blockersPromise = blockersPromise.then(async () => {
const blockers = new Set();
let cancel = this.dispatchCustomEvent(
eventName,
{
addBlocker(promise) {
// Any exception in the blocker will cancel the operation.
blockers.add(
promise.catch(ex => {
console.error(ex);
return true;
})
);
},
},
true
);
if (blockers.size) {
const timeoutPromise = new Promise((resolve, reject) => {
this.window.setTimeout(reject, BLOCKERS_TIMEOUT_MS);
});
try {
const results = await Promise.race([
Promise.all(blockers),
timeoutPromise,
]);
cancel = cancel || results.some(result => result === false);
} catch (ex) {
console.error(
new Error(`One of the blockers for ${eventName} timed out.`)
);
return true;
}
}
return cancel;
}));
}
};
/**
* This is associated to <panelmultiview> elements.
*/
export class PanelMultiView extends AssociatedToNode {
/**
* Tries to open the specified <panel> and displays the main view specified
* with the "mainViewId" attribute on the <panelmultiview> node it contains.
*
* If the panel does not contain a <panelmultiview>, it is opened directly.
* This allows consumers like page actions to accept different panel types.
*
* @see The non-static openPopup method for details.
*/
static async openPopup(panelNode, ...args) {
const panelMultiViewNode = panelNode.querySelector("panelmultiview");
if (panelMultiViewNode) {
return this.forNode(panelMultiViewNode).openPopup(...args);
}
panelNode.openPopup(...args);
return true;
}
/**
* Closes the specified <panel> which contains a <panelmultiview> node.
*
* If the panel does not contain a <panelmultiview>, it is closed directly.
* This allows consumers like page actions to accept different panel types.
*
* @see The non-static hidePopup method for details.
*/
static hidePopup(panelNode) {
const panelMultiViewNode = panelNode.querySelector("panelmultiview");
if (panelMultiViewNode) {
this.forNode(panelMultiViewNode).hidePopup();
} else {
panelNode.hidePopup();
}
}
/**
* Removes the specified <panel> from the document, ensuring that any
* <panelmultiview> node it contains is destroyed properly.
*
* If the viewCacheId attribute is present on the <panelmultiview> element,
* imported subviews will be moved out again to the element it specifies, so
* that the panel element can be removed safely.
*
* If the panel does not contain a <panelmultiview>, it is removed directly.
* This allows consumers like page actions to accept different panel types.
*/
static removePopup(panelNode) {
try {
const panelMultiViewNode = panelNode.querySelector("panelmultiview");
if (panelMultiViewNode) {
const panelMultiView = this.forNode(panelMultiViewNode);
panelMultiView._moveOutKids();
panelMultiView.disconnect();
}
} finally {
// Make sure to remove the panel element even if disconnecting fails.
panelNode.remove();
}
}
/**
* Ensures that when the specified window is closed all the <panelmultiview>
* node it contains are destroyed properly.
*/
static ensureUnloadHandlerRegistered(window) {
if (gWindowsWithUnloadHandler.has(window)) {
return;
}
window.addEventListener(
"unload",
() => {
for (const panelMultiViewNode of window.document.querySelectorAll(
"panelmultiview"
)) {
this.forNode(panelMultiViewNode).disconnect();
}
},
{ once: true }
);
gWindowsWithUnloadHandler.add(window);
}
get _panel() {
return this.node.parentNode;
}
set _transitioning(val) {
if (val) {
this.node.setAttribute("transitioning", "true");
} else {
this.node.removeAttribute("transitioning");
}
}
constructor(node) {
super(node);
this._openPopupPromise = Promise.resolve(false);
this._openPopupCancelCallback = () => {};
}
connect() {
this.connected = true;
PanelMultiView.ensureUnloadHandlerRegistered(this.window);
const viewContainer = (this._viewContainer =
this.document.createXULElement("box"));
viewContainer.classList.add("panel-viewcontainer");
const viewStack = (this._viewStack = this.document.createXULElement("box"));
viewStack.classList.add("panel-viewstack");
viewContainer.append(viewStack);
const offscreenViewContainer = this.document.createXULElement("box");
offscreenViewContainer.classList.add("panel-viewcontainer", "offscreen");
const offscreenViewStack = (this._offscreenViewStack =
this.document.createXULElement("box"));
offscreenViewStack.classList.add("panel-viewstack");
offscreenViewContainer.append(offscreenViewStack);
this.node.prepend(offscreenViewContainer);
this.node.prepend(viewContainer);
this.openViews = [];
this._panel.addEventListener("popupshowing", this);
this._panel.addEventListener("popuphidden", this);
this._panel.addEventListener("popupshown", this);
// Proxy these public properties and methods, as used elsewhere by various
// parts of the browser, to this instance.
["goBack", "showSubView"].forEach(method => {
Object.defineProperty(this.node, method, {
enumerable: true,
value: (...args) => this[method](...args),
});
});
}
disconnect() {
// Guard against re-entrancy.
if (!this.node || !this.connected) {
return;
}
this._panel.removeEventListener("mousemove", this);
this._panel.removeEventListener("popupshowing", this);
this._panel.removeEventListener("popupshown", this);
this._panel.removeEventListener("popuphidden", this);
this.window.removeEventListener("keydown", this, true);
this.node =
this._openPopupPromise =
this._openPopupCancelCallback =
this._viewContainer =
this._viewStack =
this._transitionDetails =
null;
}
/**
* Tries to open the panel associated with this PanelMultiView, and displays
* the main view specified with the "mainViewId" attribute.
*
* The hidePopup method can be called while the operation is in progress to
* prevent the panel from being displayed. View events may also cancel the
* operation, so there is no guarantee that the panel will become visible.
*
* The "popuphidden" event will be fired either when the operation is canceled
* or when the popup is closed later. This event can be used for example to
* reset the "open" state of the anchor or tear down temporary panels.
*
* If this method is called again before the panel is shown, the result
* depends on the operation currently in progress. If the operation was not
* canceled, the panel is opened using the arguments from the previous call,
* and this call is ignored. If the operation was canceled, it will be
* retried again using the arguments from this call.
*
* It's not necessary for the <panelmultiview> binding to be connected when
* this method is called, but the containing panel must have its display
* turned on, for example it shouldn't have the "hidden" attribute.
*
* @param anchor
* The node to anchor the popup to.
* @param options
* Either options to use or a string position. This is forwarded to
* the openPopup method of the panel.
* @param args
* Additional arguments to be forwarded to the openPopup method of the
* panel.
*
* @resolves With true as soon as the request to display the panel has been
* sent, or with false if the operation was canceled. The state of
* the panel at this point is not guaranteed. It may be still
* showing, completely shown, or completely hidden.
* @rejects If an exception is thrown at any point in the process before the
* request to display the panel is sent.
*/
async openPopup(anchor, options, ...args) {
// Set up the function that allows hidePopup or a second call to showPopup
// to cancel the specific panel opening operation that we're starting below.
// This function must be synchronous, meaning we can't use Promise.race,
// because hidePopup wants to dispatch the "popuphidden" event synchronously
// even if the panel has not been opened yet.
let canCancel = true;
const cancelCallback = (this._openPopupCancelCallback = () => {
// If the cancel callback is called and the panel hasn't been prepared
// yet, cancel showing it. Setting canCancel to false will prevent the
// popup from opening. If the panel has opened by the time the cancel
// callback is called, canCancel will be false already, and we will not
// fire the "popuphidden" event.
if (canCancel && this.node) {
canCancel = false;
this.dispatchCustomEvent("popuphidden");
}
});
// Create a promise that is resolved with the result of the last call to
// this method, where errors indicate that the panel was not opened.
const openPopupPromise = this._openPopupPromise.catch(() => {
return false;
});
// Make the preparation done before showing the panel non-reentrant. The
// promise created here will be resolved only after the panel preparation is
// completed, even if a cancellation request is received in the meantime.
return (this._openPopupPromise = openPopupPromise.then(async wasShown => {
// The panel may have been destroyed in the meantime.
if (!this.node) {
return false;
}
// If the panel has been already opened there is nothing more to do. We
// check the actual state of the panel rather than setting some state in
// our handler of the "popuphidden" event because this has a lower chance
// of locking indefinitely if events aren't raised in the expected order.
if (wasShown && ["open", "showing"].includes(this._panel.state)) {
return true;
}
try {
if (!this.connected) {
this.connect();
}
// Allow any of the ViewShowing handlers to prevent showing the main view.
if (!(await this._showMainView())) {
cancelCallback();
}
} catch (ex) {
cancelCallback();
throw ex;
}
// If a cancellation request was received there is nothing more to do.
if (!canCancel || !this.node) {
return false;
}
// We have to set canCancel to false before opening the popup because the
// hidePopup method of PanelMultiView can be re-entered by event handlers.
// If the openPopup call fails, however, we still have to dispatch the
// "popuphidden" event even if canCancel was set to false.
try {
canCancel = false;
this._panel.openPopup(anchor, options, ...args);
// On Windows, if another popup is hiding while we call openPopup, the
// call won't fail but the popup won't open. In this case, we have to
// dispatch an artificial "popuphidden" event to reset our state.
if (this._panel.state == "closed" && this.openViews.length) {
this.dispatchCustomEvent("popuphidden");
return false;
}
if (
options &&
typeof options == "object" &&
options.triggerEvent &&
options.triggerEvent.type == "keypress" &&
this.openViews.length
) {
// This was opened via the keyboard, so focus the first item.
this.openViews[0].focusWhenActive = true;
}
return true;
} catch (ex) {
this.dispatchCustomEvent("popuphidden");
throw ex;
}
}));
}
/**
* Closes the panel associated with this PanelMultiView.
*
* If the openPopup method was called but the panel has not been displayed
* yet, the operation is canceled and the panel will not be displayed, but the
* "popuphidden" event is fired synchronously anyways.
*
* This means that by the time this method returns all the operations handled
* by the "popuphidden" event are completed, for example resetting the "open"
* state of the anchor, and the panel is already invisible.
*/
hidePopup() {
if (!this.node || !this.connected) {
return;
}
// If we have already reached the _panel.openPopup call in the openPopup
// method, we can call hidePopup. Otherwise, we have to cancel the latest
// request to open the panel, which will have no effect if the request has
// been canceled already.
if (["open", "showing"].includes(this._panel.state)) {
this._panel.hidePopup();
} else {
this._openPopupCancelCallback();
}
// We close all the views synchronously, so that they are ready to be opened
// in other PanelMultiView instances. The "popuphidden" handler may also
// call this function, but the second time openViews will be empty.
this.closeAllViews();
}
/**
* Move any child subviews into the element defined by "viewCacheId" to make
* sure they will not be removed together with the <panelmultiview> element.
*/
_moveOutKids() {
const viewCacheId = this.node.getAttribute("viewCacheId");
if (!viewCacheId) {
return;
}
// Node.children and Node.children is live to DOM changes like the
// ones we're about to do, so iterate over a static copy:
const subviews = Array.from(this._viewStack.children);
const viewCache = this.document.getElementById(viewCacheId);
for (const subview of subviews) {
viewCache.appendChild(subview);
}
}
/**
* Slides in the specified view as a subview.
*
* @param viewIdOrNode
* DOM element or string ID of the <panelview> to display.
* @param anchor
* DOM element that triggered the subview, which will be highlighted
* and whose "label" attribute will be used for the title of the
* subview when a "title" attribute is not specified.
*/
showSubView(viewIdOrNode, anchor) {
this._showSubView(viewIdOrNode, anchor).catch(console.error);
}
async _showSubView(viewIdOrNode, anchor) {
const viewNode =
typeof viewIdOrNode == "string"
? this.document.getElementById(viewIdOrNode)
: viewIdOrNode;
if (!viewNode) {
console.error(new Error(`Subview ${viewIdOrNode} doesn't exist.`));
return;
}
if (!this.openViews.length) {
console.error(new Error(`Cannot show a subview in a closed panel.`));
return;
}
const prevPanelView = this.openViews[this.openViews.length - 1];
const nextPanelView = PanelView.forNode(viewNode);
if (this.openViews.includes(nextPanelView)) {
console.error(new Error(`Subview ${viewNode.id} is already open.`));
return;
}
// Do not re-enter the process if navigation is already in progress. Since
// there is only one active view at any given time, we can do this check
// safely, even considering that during the navigation process the actual
// view to which prevPanelView refers will change.
if (!prevPanelView.active) {
return;
}
// If prevPanelView._doingKeyboardActivation is true, it will be reset to
// false synchronously. Therefore, we must capture it before we use any
// "await" statements.
const doingKeyboardActivation = prevPanelView._doingKeyboardActivation;
// Marking the view that is about to scrolled out of the visible area as
// inactive will prevent re-entrancy and also disable keyboard navigation.
// From this point onwards, "await" statements can be used safely.
prevPanelView.active = false;
// Provide visual feedback while navigation is in progress, starting before
// the transition starts and ending when the previous view is invisible.
if (anchor) {
anchor.setAttribute("open", "true");
}
try {
// If the ViewShowing event cancels the operation we have to re-enable
// keyboard navigation, but this must be avoided if the panel was closed.
if (!(await this._openView(nextPanelView))) {
if (prevPanelView.isOpenIn(this)) {
// We don't raise a ViewShown event because nothing actually changed.
// Technically we should use a different state flag just because there
// is code that could check the "active" property to determine whether
// to wait for a ViewShown event later, but this only happens in
// regression tests and is less likely to be a technique used in
// production code, where use of ViewShown is less common.
prevPanelView.active = true;
}
return;
}
prevPanelView.captureKnownSize();
// The main view of a panel can be a subview in another one. Make sure to
// reset all the properties that may be set on a subview.
nextPanelView.mainview = false;
// The header may change based on how the subview was opened.
nextPanelView.headerText =
viewNode.getAttribute("title") ||
(anchor && anchor.getAttribute("label"));
// The constrained width of subviews may also vary between panels.
nextPanelView.minMaxWidth = prevPanelView.knownWidth;
if (anchor) {
viewNode.classList.add("PanelUI-subView");
}
await this._transitionViews(prevPanelView.node, viewNode, false, anchor);
} finally {
if (anchor) {
anchor.removeAttribute("open");
}
}
nextPanelView.focusWhenActive = doingKeyboardActivation;
this._activateView(nextPanelView);
}
/**
* Navigates backwards by sliding out the most recent subview.
*/
goBack() {
this._goBack().catch(console.error);
}
async _goBack() {
if (this.openViews.length < 2) {
// This may be called by keyboard navigation or external code when only
// the main view is open.
return;
}
const prevPanelView = this.openViews[this.openViews.length - 1];
const nextPanelView = this.openViews[this.openViews.length - 2];
// Like in the showSubView method, do not re-enter navigation while it is
// in progress, and make the view inactive immediately. From this point
// onwards, "await" statements can be used safely.
if (!prevPanelView.active) {
return;
}
prevPanelView.active = false;
prevPanelView.captureKnownSize();
await this._transitionViews(prevPanelView.node, nextPanelView.node, true);
this._closeLatestView();
this._activateView(nextPanelView);
}
/**
* Prepares the main view before showing the panel.
*/
async _showMainView() {
const nextPanelView = PanelView.forNode(
this.document.getElementById(this.node.getAttribute("mainViewId"))
);
// If the view is already open in another panel, close the panel first.
const oldPanelMultiViewNode = nextPanelView.node.panelMultiView;
if (oldPanelMultiViewNode) {
PanelMultiView.forNode(oldPanelMultiViewNode).hidePopup();
// Wait for a layout flush after hiding the popup, otherwise the view may
// not be displayed correctly for some time after the new panel is opened.
await this.window.promiseDocumentFlushed(() => {});
}
if (!(await this._openView(nextPanelView))) {
return false;
}
// The main view of a panel can be a subview in another one. Make sure to
// reset all the properties that may be set on a subview.
nextPanelView.mainview = true;
nextPanelView.headerText = "";
nextPanelView.minMaxWidth = 0;
// Ensure the view will be visible once the panel is opened.
nextPanelView.visible = true;
return true;
}
/**
* Opens the specified PanelView and dispatches the ViewShowing event, which
* can be used to populate the subview or cancel the operation.
*
* This also clears all the attributes and styles that may be left by a
* transition that was interrupted.
*
* @resolves With true if the view was opened, false otherwise.
*/
async _openView(panelView) {
if (panelView.node.parentNode != this._viewStack) {
this._viewStack.appendChild(panelView.node);
}
panelView.node.panelMultiView = this.node;
this.openViews.push(panelView);
const canceled = await panelView.dispatchAsyncEvent("ViewShowing");
// The panel can be hidden while we are processing the ViewShowing event.
// This results in all the views being closed synchronously, and at this
// point the ViewHiding event has already been dispatched for all of them.
if (!this.openViews.length) {
return false;
}
// Check if the event requested cancellation but the panel is still open.
if (canceled) {
// Handlers for ViewShowing can't know if a different handler requested
// cancellation, so this will dispatch a ViewHiding event to give a chance
// to clean up.
this._closeLatestView();
return false;
}
// Clean up all the attributes and styles related to transitions. We do this
// here rather than when the view is closed because we are likely to make
// other DOM modifications soon, which isn't the case when closing.
const { style } = panelView.node;
style.removeProperty("outline");
style.removeProperty("width");
return true;
}
/**
* Activates the specified view and raises the ViewShown event, unless the
* view was closed in the meantime.
*/
_activateView(panelView) {
if (panelView.isOpenIn(this)) {
panelView.active = true;
if (panelView.focusWhenActive) {
panelView.focusFirstNavigableElement(false, true);
panelView.focusWhenActive = false;
}
panelView.dispatchCustomEvent("ViewShown");
}
}
/**
* Closes the most recent PanelView and raises the ViewHiding event.
*
* @note The ViewHiding event is not cancelable and should probably be renamed
*/
_closeLatestView() {
const panelView = this.openViews.pop();
panelView.clearNavigation();
panelView.dispatchCustomEvent("ViewHiding");
panelView.node.panelMultiView = null;
// Views become invisible synchronously when they are closed, and they won't
// become visible again until they are opened. When this is called at the
// end of backwards navigation, the view is already invisible.
panelView.visible = false;
}
/**
* Closes all the views that are currently open.
*/
closeAllViews() {
// Raise ViewHiding events for open views in reverse order.
while (this.openViews.length) {
this._closeLatestView();
}
}
/**
* 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 displayed, but
* is about to be transitioned away. This
* must be already inactive at this point.
* @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.
*/
async _transitionViews(previousViewNode, viewNode, reverse) {
const { window } = this;
const nextPanelView = PanelView.forNode(viewNode);
const prevPanelView = PanelView.forNode(previousViewNode);
const details = (this._transitionDetails = {
phase: TRANSITION_PHASES.START,
});
// Set the viewContainer dimensions to make sure only the current view is
// visible.
const olderView = reverse ? nextPanelView : prevPanelView;
this._viewContainer.style.minHeight = olderView.knownHeight + "px";
this._viewContainer.style.height = prevPanelView.knownHeight + "px";
this._viewContainer.style.width = prevPanelView.knownWidth + "px";
// Lock the dimensions of the window that hosts the popup panel.
const rect = this._getBoundsWithoutFlushing(this._panel);
this._panel.style.width = rect.width + "px";
this._panel.style.height = rect.height + "px";
let viewRect;
if (reverse) {
// Use the cached size when going back to a previous view, but not when
// reopening a subview, because its contents may have changed.
viewRect = {
width: nextPanelView.knownWidth,
height: nextPanelView.knownHeight,
};
nextPanelView.visible = true;
} else if (viewNode.customRectGetter) {
// We use a customRectGetter for WebExtensions panels, because they need
// to query the size from an embedded browser. The presence of this
// getter also provides an indication that the view node shouldn't be
// moved around, otherwise the state of the browser would get disrupted.
const width = prevPanelView.knownWidth;
const height = prevPanelView.knownHeight;
viewRect = Object.assign({ height, width }, viewNode.customRectGetter());
nextPanelView.visible = true;
// Until the header is visible, it has 0 height.
// Wait for layout before measuring it
const header = viewNode.firstElementChild;
if (header && header.classList.contains("panel-header")) {
viewRect.height += await window.promiseDocumentFlushed(() => {
return this._getBoundsWithoutFlushing(header).height;
});
}
} else {
this._offscreenViewStack.style.minHeight = olderView.knownHeight + "px";
this._offscreenViewStack.appendChild(viewNode);
nextPanelView.visible = true;
viewRect = await window.promiseDocumentFlushed(() => {
return this._getBoundsWithoutFlushing(viewNode);
});
// Bail out if the panel was closed in the meantime.
if (!nextPanelView.isOpenIn(this)) {
return;
}
// Place back the view after all the other views that are already open in
// order for the transition to work as expected.
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.
const moveToLeft =
(this.window.RTL_UI && !reverse) || (!this.window.RTL_UI && reverse);
const deltaX = prevPanelView.knownWidth;
const 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 that all the elements are in place for the start of the transition,
// give the layout code a chance to set the initial values.
await window.promiseDocumentFlushed(() => {});
// Bail out if the panel was closed in the meantime.
if (!nextPanelView.isOpenIn(this)) {
return;
}
// Now set the viewContainer dimensions to that of the new view, which
// kicks of the height animation.
this._viewContainer.style.height = viewRect.height + "px";
this._viewContainer.style.width = viewRect.width + "px";
this._panel.style.removeProperty("width");
this._panel.style.removeProperty("height");
// We're setting the width property to prevent flickering during the
// sliding animation with smaller views.
viewNode.style.width = viewRect.width + "px";
// Kick off the transition!
details.phase = TRANSITION_PHASES.TRANSITION;
// If we're going to show the main view, we can remove the
// min-height property on the view container.
if (viewNode.getAttribute("mainview")) {
this._viewContainer.style.removeProperty("min-height");
}
// Avoid transforming element if the user has prefers-reduced-motion set
if (
this.window.matchMedia("(prefers-reduced-motion: no-preference)").matches
) {
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();
})
);
});
}
// Bail out if the panel was closed during the transition.
if (!nextPanelView.isOpenIn(this)) {
return;
}
prevPanelView.visible = false;
// This will complete the operation by removing any transition properties.
nextPanelView.node.style.removeProperty("width");
deepestNode.style.removeProperty("outline");
this._cleanupTransitionPhase();
// Ensure the newly-visible view has been through a layout flush before we
// attempt to focus anything in it.
await this.window.promiseDocumentFlushed(() => {});
nextPanelView.focusSelectedElement();
}
/**
* 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.
*/
_cleanupTransitionPhase() {
if (!this._transitionDetails) {
return;
}
const { phase, resolve, listener, cancelListener } =
this._transitionDetails;
this._transitionDetails = null;
if (phase >= TRANSITION_PHASES.START) {
this._panel.style.removeProperty("width");
this._panel.style.removeProperty("height");
this._viewContainer.style.removeProperty("height");
this._viewContainer.style.removeProperty("width");
}
if (phase >= TRANSITION_PHASES.PREPARE) {
this._transitioning = false;
this._viewStack.style.removeProperty("margin-inline-start");
this._viewStack.style.removeProperty("transition");
}
if (phase >= TRANSITION_PHASES.TRANSITION) {
this._viewStack.style.removeProperty("transform");
if (listener) {
this._viewContainer.removeEventListener("transitionend", listener);
}
if (cancelListener) {
this._viewContainer.removeEventListener(
"transitioncancel",
cancelListener
);
}
if (resolve) {
resolve();
}
}
}
handleEvent(aEvent) {
// Only process actual popup events from the panel or events we generate
// ourselves, but not from menus being shown from within the panel.
if (
aEvent.type.startsWith("popup") &&
aEvent.target != this._panel &&
aEvent.target != this.node
) {
return;
}
switch (aEvent.type) {
case "keydown": {
// Since we start listening for the "keydown" event when the popup is
// already showing and stop listening when the panel is hidden, we
// always have at least one view open.
const currentView = this.openViews[this.openViews.length - 1];
currentView.keyNavigation(aEvent);
break;
}
case "mousemove":
this.openViews.forEach(panelView => panelView.clearNavigation());
break;
case "popupshowing": {
this._viewContainer.setAttribute("panelopen", "true");
if (!this.node.hasAttribute("disablekeynav")) {
// We add the keydown handler on the window so that it handles key
// presses when a panel appears but doesn't get focus, as happens
// when a button to open a panel is clicked with the mouse.
// However, this means the listener is on an ancestor of the panel,
// which means that handlers such as ToolbarKeyboardNavigator are
// deeper in the tree. Therefore, this must be a capturing listener
// so we get the event first.
this.window.addEventListener("keydown", this, true);
this._panel.addEventListener("mousemove", this);
}
break;
}
case "popupshown": {
// The main view is always open and visible when the panel is first
// shown, so we can check the height of the description elements it
// contains and notify consumers using the ViewShown event. In order to
// minimize flicker we need to allow synchronous reflows, and we still
// make sure the ViewShown event is dispatched synchronously.
const mainPanelView = this.openViews[0];
this._activateView(mainPanelView);
break;
}
case "popuphidden": {
// WebExtensions consumers can hide the popup from viewshowing, or
// mid-transition, which disrupts our state:
this._transitioning = false;
this._viewContainer.removeAttribute("panelopen");
this._cleanupTransitionPhase();
this.window.removeEventListener("keydown", this, true);
this._panel.removeEventListener("mousemove", this);
this.closeAllViews();
// Clear the main view size caches. The dimensions could be different
// when the popup is opened again, e.g. through touch mode sizing.
this._viewContainer.style.removeProperty("min-height");
this._viewStack.style.removeProperty("max-height");
this._viewContainer.style.removeProperty("width");
this._viewContainer.style.removeProperty("height");
this.dispatchCustomEvent("PanelMultiViewHidden");
break;
}
}
}
}
/**
* This is associated to <panelview> elements.
*/
export class PanelView extends AssociatedToNode {
constructor(node) {
super(node);
/**
* Indicates whether the view is active. When this is false, consumers can
* wait for the ViewShown event to know when the view becomes active.
*/
this.active = false;
/**
* Specifies whether the view should be focused when active. When this
* is true, the first navigable element in the view will be focused
* when the view becomes active. This should be set to true when the view
* is activated from the keyboard. It will be set to false once the view
* is active.
*/
this.focusWhenActive = false;
}
/**
* Indicates whether the view is open in the specified PanelMultiView object.
*/
isOpenIn(panelMultiView) {
return this.node.panelMultiView == panelMultiView.node;
}
/**
* The "mainview" attribute is set before the panel is opened when this view
* is displayed as the main view, and is removed before the <panelview> is
* displayed as a subview. The same view element can be displayed as a main
* view and as a subview at different times.
*/
set mainview(value) {
if (value) {
this.node.setAttribute("mainview", true);
} else {
this.node.removeAttribute("mainview");
}
}
/**
* Determines whether the view is visible. Setting this to false also resets
* the "active" property.
*/
set visible(value) {
if (value) {
this.node.setAttribute("visible", true);
} else {
this.node.removeAttribute("visible");
this.active = false;
this.focusWhenActive = false;
}
}
/**
* Constrains the width of this view using the "min-width" and "max-width"
* styles. Setting this to zero removes the constraints.
*/
set minMaxWidth(value) {
const style = this.node.style;
if (value) {
style.minWidth = style.maxWidth = value + "px";
} else {
style.removeProperty("min-width");
style.removeProperty("max-width");
}
}
/**
* Adds a header with the given title, or removes it if the title is empty.
*/
set headerText(value) {
// If the header already exists, update or remove it as requested.
let header = this.node.firstElementChild;
if (header && header.classList.contains("panel-header")) {
if (value) {
header.querySelector(".panel-header > h1 > span").textContent = value;
} else {
header.remove();
}
return;
}
// The header doesn't exist, only create it if needed.
if (!value) {
return;
}
header = this.document.createXULElement("box");
header.classList.add("panel-header");
const backButton = this.document.createXULElement("toolbarbutton");
backButton.className =
"subviewbutton subviewbutton-iconic subviewbutton-back";
backButton.setAttribute("closemenu", "none");
backButton.setAttribute("tabindex", "0");
backButton.setAttribute(
"aria-label",
lazy.gBundle.GetStringFromName("panel.back")
);
backButton.addEventListener("command", () => {
// The panelmultiview element may change if the view is reused.
this.node.panelMultiView.goBack();
backButton.blur();
});
const h1 = this.document.createElement("h1");
const span = this.document.createElement("span");
span.textContent = value;
h1.appendChild(span);
header.append(backButton, h1);
this.node.prepend(header);
}
/**
* Populates the "knownWidth" and "knownHeight" properties with the current
* dimensions of the view. These may be zero if the view is invisible.
*
* These values are relevant during transitions and are retained for backwards
* navigation if the view is still open but is invisible.
*/
captureKnownSize() {
const rect = this._getBoundsWithoutFlushing(this.node);
this.knownWidth = rect.width;
this.knownHeight = rect.height;
}
/**
* Determine whether an element can only be navigated to with tab/shift+tab,
* not the arrow keys.
*/
_isNavigableWithTabOnly(element) {
const tag = element.localName;
return (
tag == "menulist" ||
tag == "input" ||
tag == "textarea" ||
// Allow tab to reach embedded documents in extension panels.
tag == "browser"
);
}
/**
* Make a TreeWalker for keyboard navigation.
*
* @param {boolean} arrowKey If `true`, elements only navigable with tab are
* excluded.
*/
_makeNavigableTreeWalker(arrowKey) {
const filter = node => {
if (node.disabled) {
return NodeFilter.FILTER_REJECT;
}
const bounds = this._getBoundsWithoutFlushing(node);
if (bounds.width == 0 || bounds.height == 0) {
return NodeFilter.FILTER_REJECT;
}
if (
node.tagName == "button" ||
node.tagName == "toolbarbutton" ||
node.classList.contains("text-link") ||
(!arrowKey && this._isNavigableWithTabOnly(node))
) {
// Set the tabindex attribute to make sure the node is focusable.
if (!node.hasAttribute("tabindex")) {
node.setAttribute("tabindex", "-1");
}
return NodeFilter.FILTER_ACCEPT;
}
return NodeFilter.FILTER_SKIP;
};
return this.document.createTreeWalker(
this.node,
NodeFilter.SHOW_ELEMENT,
filter
);
}
/**
* Get a TreeWalker which finds elements navigable with tab/shift+tab.
*/
get _tabNavigableWalker() {
if (!this.__tabNavigableWalker) {
this.__tabNavigableWalker = this._makeNavigableTreeWalker(false);
}
return this.__tabNavigableWalker;
}
/**
* Get a TreeWalker which finds elements navigable with up/down arrow keys.
*/
get _arrowNavigableWalker() {
if (!this.__arrowNavigableWalker) {
this.__arrowNavigableWalker = this._makeNavigableTreeWalker(true);
}
return this.__arrowNavigableWalker;
}
/**
* Element that is currently selected with the keyboard, or null if no element
* is selected. Since the reference is held weakly, it can become null or
* undefined at any time.
*/
get selectedElement() {
return this._selectedElement && this._selectedElement.get();
}
set selectedElement(value) {
if (!value) {
delete this._selectedElement;
} else {
this._selectedElement = Cu.getWeakReference(value);
}
}
/**
* Focuses and moves keyboard selection to the first navigable element.
* This is a no-op if there are no navigable elements.
*
* @param {boolean} homeKey - `true` if this is for the home key.
* @param {boolean} skipBack - `true` if the Back button should be skipped.
*/
focusFirstNavigableElement(homeKey = false, skipBack = false) {
// The home key is conceptually similar to the up/down arrow keys.
const walker = homeKey
? this._arrowNavigableWalker
: this._tabNavigableWalker;
walker.currentNode = walker.root;
this.selectedElement = walker.firstChild();
if (
skipBack &&
walker.currentNode &&
walker.currentNode.classList.contains("subviewbutton-back") &&
walker.nextNode()
) {
this.selectedElement = walker.currentNode;
}
this.focusSelectedElement(/* byKey */ true);
}
/**
* Focuses and moves keyboard selection to the last navigable element.
* This is a no-op if there are no navigable elements.
*
* @param {boolean} endKey - `true` if this is for the end key.
*/
focusLastNavigableElement(endKey = false) {
// The end key is conceptually similar to the up/down arrow keys.
const walker = endKey
? this._arrowNavigableWalker
: this._tabNavigableWalker;
walker.currentNode = walker.root;
this.selectedElement = walker.lastChild();
this.focusSelectedElement(/* byKey */ true);
}
/**
* Based on going up or down, select the previous or next focusable element.
*
* @param {boolean} isDown - whether we're going down (true) or up (false).
* @param {boolean} arrowKey - `true` if this is for the up/down arrow keys.
*
* @returns {DOMNode} the element we selected.
*/
moveSelection(isDown, arrowKey = false) {
const walker = arrowKey
? this._arrowNavigableWalker
: this._tabNavigableWalker;
const oldSel = this.selectedElement;
let newSel;
if (oldSel) {
walker.currentNode = oldSel;
newSel = isDown ? walker.nextNode() : walker.previousNode();
}
// If we couldn't find something, select the first or last item:
if (!newSel) {
walker.currentNode = walker.root;
newSel = isDown ? walker.firstChild() : walker.lastChild();
}
this.selectedElement = newSel;
return newSel;
}
/**
* 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.
*
* Key navigation is only enabled while the view is active, meaning that this
* method will return early if it is invoked during a sliding transition.
*
* @param {KeyEvent} event
*/
/* eslint-disable-next-line complexity */
keyNavigation(event) {
if (!this.active) {
return;
}
let focus = this.document.activeElement;
// Make sure the focus is actually inside the panel. (It might not be if
// the panel was opened with the mouse.) If it isn't, we don't care
// about it for our purposes.
// We use Node.compareDocumentPosition because Node.contains doesn't
// behave as expected for anonymous content; e.g. the input inside a
// textbox.
if (
focus &&
!(
this.node.compareDocumentPosition(focus) &
Node.DOCUMENT_POSITION_CONTAINED_BY
)
) {
focus = null;
}
// Extension panels contain embedded documents. We can't manage
// keyboard navigation within those.
if (focus && focus.tagName == "browser") {
return;
}
const stop = () => {
event.stopPropagation();
event.preventDefault();
};
// If the focused element is only navigable with tab, it wants the arrow
// keys, etc. We shouldn't handle any keys except tab and shift+tab.
// We make a function for this for performance reasons: we only want to
// check this for keys we potentially care about, not *all* keys.
const tabOnly = () => {
// We use the real focus rather than this.selectedElement because focus
// might have been moved without keyboard navigation (e.g. mouse click)
// and this.selectedElement is only updated for keyboard navigation.
return focus && this._isNavigableWithTabOnly(focus);
};
// If a context menu is open, we must let it handle all keys.
// Normally, this just happens, but because we have a capturing window
// keydown listener, our listener takes precedence.
// Again, we only want to do this check on demand for performance.
const isContextMenuOpen = () => {
if (!focus) {
return false;
}
const contextNode = focus.closest("[context]");
if (!contextNode) {
return false;
}
const context = contextNode.getAttribute("context");
const popup = this.document.getElementById(context);
return popup && popup.state == "open";
};
const keyCode = event.code;
switch (keyCode) {
case "ArrowDown":
case "ArrowUp":
if (tabOnly()) {
break;
}
// Fall-through...
case "Tab": {
if (isContextMenuOpen()) {
break;
}
stop();
const isDown =
keyCode == "ArrowDown" || (keyCode == "Tab" && !event.shiftKey);
const button = this.moveSelection(isDown, keyCode != "Tab");
Services.focus.setFocus(button, Services.focus.FLAG_BYKEY);
break;
}
case "Home":
if (tabOnly() || isContextMenuOpen()) {
break;
}
stop();
this.focusFirstNavigableElement(true);
break;
case "End":
if (tabOnly() || isContextMenuOpen()) {
break;
}
stop();
this.focusLastNavigableElement(true);
break;
case "ArrowLeft":
case "ArrowRight": {
if (tabOnly() || isContextMenuOpen()) {
break;
}
stop();
if (
(!this.window.RTL_UI && keyCode == "ArrowLeft") ||
(this.window.RTL_UI && keyCode == "ArrowRight")
) {
this.node.panelMultiView.goBack();
break;
}
// If the current button is _not_ one that points to a subview, pressing
// the arrow key shouldn't do anything.
const button = this.selectedElement;
if (!button || !button.classList.contains("subviewbutton-nav")) {
break;
}
}
// Fall-through...
case "Space":
case "NumpadEnter":
case "Enter": {
if (tabOnly() || isContextMenuOpen()) {
break;
}
const button = this.selectedElement;
if (!button) {
break;
}
stop();
this._doingKeyboardActivation = true;
// Unfortunately, 'tabindex' doesn't execute the default action, so
// we explicitly do this here.
// We are sending a command event, a mousedown event and then a click
// event. This is done in order to mimic a "real" mouse click event.
// Normally, the command event executes the action, then the click event
// closes the menu. However, in some cases (e.g. the Library button),
// there is no command event handler and the mousedown event executes the
// action instead.
button.doCommand();
let dispEvent = new event.target.ownerGlobal.MouseEvent("mousedown", {
bubbles: true,
});
button.dispatchEvent(dispEvent);
dispEvent = new event.target.ownerGlobal.MouseEvent("click", {
bubbles: true,
});
button.dispatchEvent(dispEvent);
this._doingKeyboardActivation = false;
break;
}
}
}
/**
* Focus the last selected element in the view, if any.
*
* @param byKey {Boolean} whether focus was moved by the user pressing a key.
* Needed to ensure we show focus styles in the right cases.
*/
focusSelectedElement(byKey = false) {
const selected = this.selectedElement;
if (selected) {
const flag = byKey ? "FLAG_BYKEY" : "FLAG_BYELEMENTFOCUS";
Services.focus.setFocus(selected, Services.focus[flag]);
}
}
/**
* Clear all traces of keyboard navigation happening right now.
*/
clearNavigation() {
const selected = this.selectedElement;
if (selected) {
selected.blur();
this.selectedElement = null;
}
}
}