gecko-dev/browser/components/customizableui/PanelMultiView.jsm

1555 строки
58 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/. */
/**
* 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 asyncronously.
*
* 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
*/
"use strict";
var EXPORTED_SYMBOLS = [
"PanelMultiView",
"PanelView",
];
ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
ChromeUtils.import("resource://gre/modules/Services.jsm");
ChromeUtils.defineModuleGetter(this, "AppConstants",
"resource://gre/modules/AppConstants.jsm");
ChromeUtils.defineModuleGetter(this, "CustomizableUI",
"resource:///modules/CustomizableUI.jsm");
XPCOMUtils.defineLazyGetter(this, "gBundle", function() {
return Services.strings.createBundle(
"chrome://browser/locale/browser.properties");
});
/**
* 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,
});
let gNodeToObjectMap = new WeakMap();
let gWindowsWithUnloadHandler = new WeakSet();
let gMultiLineElementsMap = new WeakMap();
/**
* 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;
}
/**
* nsIDOMWindowUtils for the window of this node.
*/
get _dwu() {
if (this.__dwu)
return this.__dwu;
return this.__dwu = this.window.QueryInterface(Ci.nsIInterfaceRequestor)
.getInterface(Ci.nsIDOMWindowUtils);
}
/**
* 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.
* @return {Boolean} `true` if the event was canceled by an event handler, `false`
* otherwise.
*/
dispatchCustomEvent(eventName, detail, cancelable = false) {
let 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.
let blockersPromise = this._blockersPromise.catch(() => {});
return this._blockersPromise = blockersPromise.then(async () => {
let blockers = new Set();
let cancel = this.dispatchCustomEvent(eventName, {
addBlocker(promise) {
// Any exception in the blocker will cancel the operation.
blockers.add(promise.catch(ex => {
Cu.reportError(ex);
return true;
}));
},
}, true);
if (blockers.size) {
let timeoutPromise = new Promise((resolve, reject) => {
this.window.setTimeout(reject, BLOCKERS_TIMEOUT_MS);
});
try {
let results = await Promise.race([Promise.all(blockers),
timeoutPromise]);
cancel = cancel || results.some(result => result === false);
} catch (ex) {
Cu.reportError(new Error(
`One of the blockers for ${eventName} timed out.`));
return true;
}
}
return cancel;
});
}
};
/**
* This is associated to <panelmultiview> elements.
*/
var PanelMultiView = class 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) {
let 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) {
let 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 {
let panelMultiViewNode = panelNode.querySelector("panelmultiview");
if (panelMultiViewNode) {
let 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 (let 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");
}
}
get _screenManager() {
if (this.__screenManager)
return this.__screenManager;
return this.__screenManager = Cc["@mozilla.org/gfx/screenmanager;1"]
.getService(Ci.nsIScreenManager);
}
constructor(node) {
super(node);
this._openPopupPromise = Promise.resolve(false);
this._openPopupCancelCallback = () => {};
}
connect() {
this.connected = true;
PanelMultiView.ensureUnloadHandlerRegistered(this.window);
let viewContainer = this._viewContainer =
this.document.createElement("box");
viewContainer.classList.add("panel-viewcontainer");
let viewStack = this._viewStack = this.document.createElement("box");
viewStack.classList.add("panel-viewstack");
viewContainer.append(viewStack);
let offscreenViewContainer = this.document.createElement("box");
offscreenViewContainer.classList.add("panel-viewcontainer", "offscreen");
let offscreenViewStack = this._offscreenViewStack =
this.document.createElement("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("popuppositioned", this);
this._panel.addEventListener("popuphidden", this);
this._panel.addEventListener("popupshown", this);
let cs = this.window.getComputedStyle(this.document.documentElement);
// Set CSS-determined attributes now to prevent a layout flush when we do
// it when transitioning between panels.
this._dir = cs.direction;
// 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("popuppositioned", this);
this._panel.removeEventListener("popupshown", this);
this._panel.removeEventListener("popuphidden", this);
this.window.removeEventListener("keydown", this);
this.node = this._openPopupPromise = this._openPopupCancelCallback =
this._viewContainer = this._viewStack = this.__dwu =
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 args
* 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(...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;
let 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.
let 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(...args);
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() {
let viewCacheId = this.node.getAttribute("viewCacheId");
if (!viewCacheId) {
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(this._viewStack.childNodes);
let viewCache = this.document.getElementById(viewCacheId);
for (let 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(Cu.reportError);
}
async _showSubView(viewIdOrNode, anchor) {
let viewNode = typeof viewIdOrNode == "string" ?
this.document.getElementById(viewIdOrNode) : viewIdOrNode;
if (!viewNode) {
Cu.reportError(new Error(`Subview ${viewIdOrNode} doesn't exist.`));
return;
}
if (!this.openViews.length) {
Cu.reportError(new Error(`Cannot show a subview in a closed panel.`));
return;
}
let prevPanelView = this.openViews[this.openViews.length - 1];
let nextPanelView = PanelView.forNode(viewNode);
if (this.openViews.includes(nextPanelView)) {
Cu.reportError(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;
}
// 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");
}
}
this._activateView(nextPanelView);
}
/**
* Navigates backwards by sliding out the most recent subview.
*/
goBack() {
this._goBack().catch(Cu.reportError);
}
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;
}
let prevPanelView = this.openViews[this.openViews.length - 1];
let 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() {
let nextPanelView = PanelView.forNode(this.document.getElementById(
this.node.getAttribute("mainViewId")));
// If the view is already open in another panel, close the panel first.
let 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.
// This is filed as bug 1441015.
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;
nextPanelView.descriptionHeightWorkaround();
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);
let 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.
let { 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;
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
* to ViewHidden or ViewClosed instead, see bug 1438507.
*/
_closeLatestView() {
let 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;
let nextPanelView = PanelView.forNode(viewNode);
let prevPanelView = PanelView.forNode(previousViewNode);
let details = this._transitionDetails = {
phase: TRANSITION_PHASES.START,
};
// Set the viewContainer dimensions to make sure only the current view is
// visible.
let 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.
let rect = this._panel.popupBoxObject.getOuterScreenRect();
this._panel.setAttribute("width", rect.width);
this._panel.setAttribute("height", rect.height);
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.
let width = prevPanelView.knownWidth;
let 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
let header = viewNode.firstChild;
if (header && header.classList.contains("panel-header")) {
viewRect.height += await window.promiseDocumentFlushed(() => {
return this._dwu.getBoundsWithoutFlushing(header).height;
});
}
await nextPanelView.descriptionHeightWorkaround();
} else {
this._offscreenViewStack.style.minHeight = olderView.knownHeight + "px";
this._offscreenViewStack.appendChild(viewNode);
nextPanelView.visible = true;
// Now that the subview is visible, we can check the height of the
// description elements it contains.
await nextPanelView.descriptionHeightWorkaround();
viewRect = await window.promiseDocumentFlushed(() => {
return this._dwu.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.
let moveToLeft = (this._dir == "rtl" && !reverse) || (this._dir == "ltr" && reverse);
let deltaX = prevPanelView.knownWidth;
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 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.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";
// 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();
});
});
// 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();
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;
}
let {phase, resolve, listener, cancelListener} = this._transitionDetails;
this._transitionDetails = null;
if (phase >= TRANSITION_PHASES.START) {
this._panel.removeAttribute("width");
this._panel.removeAttribute("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();
}
}
_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":
// 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.
let currentView = this.openViews[this.openViews.length - 1];
currentView.keyNavigation(aEvent, this._dir);
break;
case "mousemove":
this.openViews.forEach(panelView => panelView.clearNavigation());
break;
case "popupshowing": {
this._viewContainer.setAttribute("panelopen", "true");
if (!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":
// 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.
let mainPanelView = this.openViews[0];
mainPanelView.descriptionHeightWorkaround(true).catch(Cu.reportError);
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);
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.
*/
var PanelView = class 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;
}
/**
* 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;
}
}
/**
* Constrains the width of this view using the "min-width" and "max-width"
* styles. Setting this to zero removes the constraints.
*/
set minMaxWidth(value) {
let 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.firstChild;
if (header && header.classList.contains("panel-header")) {
if (value) {
header.querySelector("label").setAttribute("value", value);
} else {
header.remove();
}
return;
}
// The header doesn't exist, only create it if needed.
if (!value) {
return;
}
header = this.document.createElement("box");
header.classList.add("panel-header");
let backButton = this.document.createElement("toolbarbutton");
backButton.className =
"subviewbutton subviewbutton-iconic subviewbutton-back";
backButton.setAttribute("closemenu", "none");
backButton.setAttribute("tabindex", "0");
backButton.setAttribute("aria-label",
gBundle.GetStringFromName("panel.back"));
backButton.addEventListener("command", () => {
// The panelmultiview element may change if the view is reused.
this.node.panelMultiView.goBack();
backButton.blur();
});
let label = this.document.createElement("label");
label.setAttribute("value", value);
header.append(backButton, label);
this.node.prepend(header);
}
/**
* Also make sure that the correct method is called on CustomizableWidget.
*/
dispatchCustomEvent(...args) {
CustomizableUI.ensureSubviewListeners(this.node);
return super.dispatchCustomEvent(...args);
}
/**
* 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() {
let rect = this._dwu.getBoundsWithoutFlushing(this.node);
this.knownWidth = rect.width;
this.knownHeight = rect.height;
}
/**
* 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.
*
* @param allowSyncReflows
* If set to true, the function takes a path that allows synchronous
* reflows, but minimizes flickering. This is used for the main view
* because we cannot use the workaround off-screen.
*/
async descriptionHeightWorkaround(allowSyncReflows = false) {
if (!this.node.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 = [];
let collectItems = () => {
// 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 this.node.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 = gMultiLineElementsMap.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 });
}
};
if (allowSyncReflows) {
collectItems();
} else {
await this.window.promiseDocumentFlushed(collectItems);
}
// 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.
let measureItems = () => {
for (let item of items) {
item.bounds = item.element.getBoundingClientRect();
}
};
if (allowSyncReflows) {
measureItems();
} else {
await this.window.promiseDocumentFlushed(measureItems);
}
// Now we can make all the necessary DOM changes at once.
for (let { element, bounds } of items) {
gMultiLineElementsMap.set(element, { bounds, textContent: element.textContent });
element.style.height = bounds.height + "px";
}
}
/**
* Retrieves the button elements that can be used for navigation using the
* keyboard, that is all enabled buttons including the back button if visible.
*
* @return {Array}
*/
getNavigableElements() {
let buttons = Array.from(this.node.querySelectorAll(".subviewbutton:not([disabled])"));
let dwu = this._dwu;
return buttons.filter(button => {
let bounds = dwu.getBoundsWithoutFlushing(button);
return bounds.width > 0 && bounds.height > 0;
});
}
/**
* 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.
*
* The element is usually, but not necessarily, in the "buttons" property
* which in turn is initialized from the getNavigableElements list.
*/
get selectedElement() {
return this._selectedElement && this._selectedElement.get();
}
set selectedElement(value) {
if (!value) {
delete this._selectedElement;
} else {
this._selectedElement = Cu.getWeakReference(value);
}
}
/**
* Based on going up or down, select the previous or next focusable button.
*
* @param {Boolean} isDown whether we're going down (true) or up (false).
*
* @return {DOMNode} the button we selected.
*/
moveSelection(isDown) {
let buttons = this.buttons;
let lastSelected = this.selectedElement;
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];
}
this.selectedElement = 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.
*
* 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
* @param {String} dir
* Direction for arrow navigation, either "ltr" or "rtl".
*/
keyNavigation(event, dir) {
if (!this.active) {
return;
}
let buttons = this.buttons;
if (!buttons || !buttons.length) {
buttons = this.buttons = this.getNavigableElements();
// 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":
case "Tab": {
stop();
let isDown = (keyCode == "ArrowDown") ||
(keyCode == "Tab" && !event.shiftKey);
let button = this.moveSelection(isDown);
button.focus();
break;
}
case "ArrowLeft":
case "ArrowRight": {
stop();
if ((dir == "ltr" && keyCode == "ArrowLeft") ||
(dir == "rtl" && 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.
let button = this.selectedElement;
if (!button || !button.classList.contains("subviewbutton-nav")) {
break;
}
// Fall-through...
}
case "Space":
case "Enter": {
let button = this.selectedElement;
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;
}
}
}
/**
* Focus the last selected element in the view, if any.
*/
focusSelectedElement() {
let selected = this.selectedElement;
if (selected) {
selected.focus();
}
}
/**
* Clear all traces of keyboard navigation happening right now.
*/
clearNavigation() {
delete this.buttons;
let selected = this.selectedElement;
if (selected) {
selected.blur();
this.selectedElement = null;
}
}
};