-
Caroline Chao authored
Change-Id: I98b48b6dd50d1a693fb947509a9f6b05c893df83 Reviewed-by:Gabriel de Dietrich <gabriel.dedietrich@digia.com>
eceefe1e
/******************************************************************************** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).** Contact: http://www.qt-project.org/legal**** This file is part of the Qt Quick Controls module of the Qt Toolkit.**** $QT_BEGIN_LICENSE:BSD$** You may use this file under the terms of the BSD license as follows:**** "Redistribution and use in source and binary forms, with or without** modification, are permitted provided that the following conditions are** met:** * Redistributions of source code must retain the above copyright** notice, this list of conditions and the following disclaimer.** * Redistributions in binary form must reproduce the above copyright** notice, this list of conditions and the following disclaimer in** the documentation and/or other materials provided with the** distribution.** * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names** of its contributors may be used to endorse or promote products derived** from this software without specific prior written permission.****** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."**** $QT_END_LICENSE$******************************************************************************/import QtQuick 2.0import QtQuick.Controls 1.0import QtQuick.Controls.Private 1.0import "Private/PageStack.js" as JSArray/*! \qmltype PageStack \inherits Item \ingroup views \inqmlmodule QtQuick.Controls 1.0 \brief Provides a stack-based navigation model. PageStack implements a stack-based navigation model for an application. A stack-based navigation model means that "pages" (discrete views of information) are pushed onto a stack as the user navigates deeper into the application page hierarchy. Similarily, the user can return back to previous pages at a later point, which from a stack point of view means popping pages from the top of the stack and re-activating them (make them visible on screen). Pages can - but do not have to - use \l{Page} as the root item. \l{Page} defines a contract for how the page and the page stack works together. Namely the page can be notified when it becomes active or inactive through the \l{Page::status} {Page.status} property. Status will be \c PageStatus.Activating when a page is transitioning into being the current page on screen, and \c PageStatus.Active once the transition stops. When it leaves the screen, it will be \c PageStatus.Deactivating, and then \c PageStatus.Inactive. When the page is inactive, it will be hidden.7172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140
\section1 Using PageStack in an Application
Using the PageStack in the application is typically a simple matter of adding
the PageStack as a child to e.g the applications top-level
\l{http://doc.qt.nokia.com/latest/qml-item.html} {Item}. The stack is usually
anchored to the edges of the window, except at the top or bottom where it might
be anchored to a status bar, or some other similar UI component.
The stack can then be used by invoking its navigation methods. The first page
to show in the PageStack is commonly loaded assigning it to \l initialPage.
\section1 Basic Navigation
There are three primary navigation operations in PageStack: push(), pop() and
replace (you replace by specifying argument \c replace to push()).
These correspond to classic stack operations where "push" adds a page to the
top of a stack, "pop" removes the top page from the stack, and "replace" is like a
pop followed by a push in that it replaces the topmost page on the stack with
a new page (but the applied transtition might be different). The topmost page
in the stack corresponds to the one that is \l{PageStack::currentPage} {current},
i.e. the one that is visible on
screen. That means that "push" is the logical equivalent of navigating forward or
deeper into the application, "pop" is the equivalent of navigation back and
"replace" is the equivalent of replacing the current page with a different page.
Sometimes it is necessary to go back more than a single step in the stack, e.g.
to return to a "main" page or some kind of section page in the application.
For this use case, pop() can be provided with a page to pop to. This is called
an "unwind" operation as the stack gets unwound to the specified page. If the
page is not found then the stack unwinds until there is only a single page in
the stack, which becomes the current page. To explicitly unwind to the bottom
of the stack it is recommended to use \l{pop()} {pop(null)}, though technically any
non-existent page will do.
Given the stack [A, B, C]:
\list
\li \l{push()}{push(D)} => [A, B, C, D] - "push" transition animation between C and D
\li pop() => [A, B] - "pop" transition animation between C and B
\li \l{push()}{push(D, replace)} => [A, B, D] - "replace" transition between C and D
\li \l{pop()}{pop(A)} => [A] - "pop" transition between C and A
\endlist
Note that when the stack is empty, a push() will not perform a
transition animation because there is nothing to transition from (which will
typically happend during application start-up). A pop() on a stack with
depth 1 or 0 is a no-operation. If removing all pages from the stack is
needed, a separate function clear() is available.
Calling push() returns the page that was pushed onto the stack.
Calling pop() returns the page that was popped off the stack. When pop() is
called in an unwind operation the top-most page (the first page that was
popped, which will also be the one transitioning out) is returned.
\section1 Deep Linking
Deep linking means launching an application into a particular state. For example
a Newspaper application could be launched into showing a particular article,
bypassing the front page (and possible a section page) that would normally have
to be navigated through to get to the article in question. In terms of page
stacks deep linking means the ability to modify the state of the stack so that
you e.g. push a set of pages to the top of the stack, or that you completely reset
the stack to a given state.
The API for deep linking in PageStack is the same as for basic navigation. If
you push an array instead of a single page then all the pages in that array will
be pushed onto the stack. The transition animation, however, will be conducted as
if only the last page in the array was pushed onto the stack. The normal semantics
of push() apply for deep linking, meaning that push() adds whatever you push onto
the stack. Note also that only the last item in the array will actually be loaded
(in case of a \l{http://doc.qt.nokia.com/latest/qml-url.html}{URL} or
\l{http://doc.qt.nokia.com/latest/qml-component.html}{Component}).
The rest will be lazy loaded as needed when entering
the screen upon subsequent calls to pop (or when requesting the page by using \a get).
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This gives us the following result, given the stack [A, B, C]:
\list
\li \l{push()}{push([D, E, F])} => [A, B, C, D, E, F] - "push" transition animation between C and F
\li \l{push()}{push([D, E, F], replace)} => [A, B, D, E, F] - "replace" transition animation between C and F
\li clear(); \l{push()}{push([D, E, F])} => [D, E, F] - no transition animation (since the stack was empty)
\endlist
\section1 Pushing pages
A page you push onto the PageStack can be either a \l Page, a \l{http://doc.qt.nokia.com/latest/qml-url.html}{URL}, a
string with a URL, an \l{http://doc.qt.nokia.com/latest/qml-item.html}{Item}, or a
\l{http://doc.qt.nokia.com/latest/qml-component.html}{Component}. To push it, you assign it
to a property "page" inside a property list, and send it as argument to \l{PageStack::push}{push}:
\code
pageStack.push({page: yourPage})
\endcode
The list can contain several properties that controls how the page should be pushed:
\list
\li \c page: This property is required, and holds the page you want to push.
\li \c properties: You can set a property list of QML properties that should be assigned
to the page upon push. These properties will be copied into the page at the
time the page is loaded, or about to become the current page (normally upon push).
\li \c immediate: Set this property to \c true to skip transition effects. When pushing
an array, you only need to set this property on the first element to make the
whole operation immediate.
\li \c replace: Set this property to replace the current page on the stack. When pushing
an array, you only need to set this property on the first element to replace
as many elements on the stack as inside the array.
\li \c destroyOnPop: Set this property to be explicit to whether or not PageStack should
destroy the page when its popped off the stack. By default (if \a destroyOnPop is
not specified), PageStack will destroy pages pushed as components or URLs. Pages
not destroyed will be reparented back to the original parents they had before being
pushed onto the stack, and hidden. If you need to set this property, do it with
care, so that pages are not leaked.
\endlist
If the only argument needed is "page", you can also, as a short-hand
notation, do:
\code
pageStack.push(yourPage).
\endcode
You can push several pages in one go by using an array of property lists. This is
optimizing compared to pushing pages one by one, since PageStack then can load only the
last page in the list. The rest will be loaded as they are about to become
the current page (which happends when the stack is popped). The following example shows how
to push an array of pages:
\code
pageStack.push([{page: yourPage1}, {page: yourPage2}])
\endcode
If inline pages/items are pushed, the page gets re-parented into an internal
container in the PageStack. When the page is later popped off, it gets
re-parented back to its original owner. If, however, a page is pushed
as a component or a URL, the actual page will be created as a page from that component. This
happens automatically when the page is about to become the current page in the stack. Ownership
over the item will then normally be taken by the PageStack. It will as such automatically
destroy the page when it is later popped off. The component that declared the page, by
contrast, remains in the ownership of the application and is not destroyed by the page stack.
You can override this behavior if needed by explicitly setting "destroyOnPop" in the list
argument given to push.
If you specify the \c properties property to push, these properties will be copied into
the page at the time the page is loaded (in case of a component or URL), or instead when
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its about to become the current page (in case of an inline item). This normally happends when
the page is pushed. The following example shows how this can be done:
\code
pageStack.push({page: examplePage, properties: {fgcolor: "red", bgcolor: "blue"}});
\endcode
Note that if a page is declared in an item that is destroyed - even if a component
was used - then that page also gets destroyed.
This follows normal Qt parent-child destruction rules but sometimes comes as a surprise
for developers. In practice this means that if you declare a page B as a child of
page A and then do a replace from page A to page B, then page B will be destroyed when
page A was destroyed (as it was popped off the stack) and the application will effectively
be switching to a page that has been destroyed.
\section1 Lifecycle
The page lifecycle goes from instantiation to inactive, activating, active, deactivating,
inactive, and when no longer needed, destruction.
It can move any number of times between inactive and active. When a page is activated,
it's visible on the screen and is considered to be the current item. A page
in a page stack that is not visible is not activated, even if the page is currently the
top-most page in the stack. When the stack becomes visible the page that is top-most gets
activated. Likewise if the page stack is then hidden the top-most page would be deactivated.
Popping the page off the top of the stack at this point would not result in further
deactivation since the page is not active.
There is a \l{Page::status}{status} property that tracks the lifecycle. The value of status is
an enumeration with values \c PageStatus.Inactive, \c PageStatus.Activating, \c PageStatus.Active
and \c PageStatus.Deactivating. Combined with the normal \c Component.onComplete and
\c Component.onDestruction signals the entire lifecycle is thus:
\list
\li Created: Component.onCompleted()
\li Activating: onStatusChanged (status is PageStatus.Activating)
\li Acivated: onStatusChanged (status is PageStatus.Active)
\li Deactivating: onStatusChanged (status is PageStatus.Deactivating)
\li Deactivated: onStatusChanged (status is PageStatus.Inactive)
\li Destruction: Component.onDestruction()
\endlist
\section1 Finding Pages
Sometimes it is necessary to search for a page, e.g. in order to unwind the stack to
a page to which the application does not have a reference. This is facilitated using a
function find() in the page stack. The find() function takes a callback function as its
only argument. The callback gets invoked for each page in the stack (starting at the top).
If the callback returns true then it signals that a match has been found and the find()
function returns that page. If the callback fails to return true (i.e. no match is found)
then find() returns \c null.
The code below searches for a page in the stack that has a name "foo" and then unwinds to
that page. Note that since find() returns null if no page is found and since pop unwinds to
the bottom of the stack if null is given as the target page, the code works well even in the
case that no matching page was found.
\code
pageStack.pop(pageStack.find(function(page) {
return page.name == "foo";
}));
\endcode
You can also get to a page in the page stack using get(index). You should use
this function if your page depends on another page in the stack, as the function will
ensure that the page at the given index gets loaded before it is returned.
\code
previousPage = pageStack.get(myPage.index - 1));
\endcode
\section1 Transitions
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A transition is performed whenever a page is pushed or popped, and consists of
two pages: enterPage and exitPage. The pagestack itself will never move pages
around, but instead delegate the job to an external animation set by the style
or the application developer. How pages should visually enter and leave the stack
is therefore completely controlled from the outside.
When the transition starts, the pagestack will search for an animation that
matches the operation executed. There are three animations to choose
from: pushAnimation, popAnimation, and replaceAnimation. Each implements how
enterPage should animate in, and exitPage out. The animations are
collected inside a PageTransition object assigned to
\l {PageStack::pageTransition}{pageTransition}. By default, popAnimation and
replaceAnimation will be the same as PushAnimation, unless you set them
to something else.
A simple fade transition could be implemented as:
\qml
PageStack {
pageTransition: PageTransition {
function cleanupAnimation(properties)
{
properties.exitPage.opacity = 1
}
property Component pushAnimation: PageAnimation {
PropertyAnimation {
target: enterPage
property: "opacity"
from: 0
to: 1
}
PropertyAnimation {
target: exitPage
property: "opacity"
from: 1
to: 0
}
}
}
}
\endqml
PushAnimation needs to inherit from PageAnimation, which is a ParallelAnimation that
contains the properties \c enterPage and \c exitPage. You set the target of your
inner animations to those pages. Since the same page instance can be pushed several
times to a pagestack, and since pages also can override transitions, your PageTransition
always need to override
\l {PageTransition::cleanupAnimation(properties)}{PageTransition.cleanupAnimation(properties)}.
Implement this function to reset any properties animated on the exitPage so that later
transitions can expect the pages to be in a default state.
A more complex example could look like the following. Here, the pages slides in lying on the side before
they are rotated up in an upright position:
\qml
PageStack {
pageTransition: PageTransition {
function cleanupAnimation(properties)
{
properties.exitPage.x = 0
properties.exitPage.rotation = 0
}
property Component pushAnimation: PageAnimation {
SequentialAnimation {
ScriptAction {
script: enterPage.rotation = 90
}
PropertyAnimation {
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target: enterPage
property: "x"
from: enterPage.width
to: 0
}
PropertyAnimation {
target: enterPage
property: "rotation"
from: 90
to: 0
}
}
PropertyAnimation {
target: exitPage
property: "x"
from: 0
to: -exitPage.width
}
}
}
}
\endqml
A single Page can also override the transition to use when itself is pushed or popped. This can
be done by just assigning another PageTransition object to \l{Page::pageTransition}{Page.pageTransition}.
\section2 Advanced usage
After PageStack finds the correct transition to use (it first checks
\l{Page::pageTransition}{Page.pageTransition}, then \l {PageStack::pageTransition}{pageTransition})
it calls \l {PageTransition::getAnimation(properties)}{PageTransition.getAnimation(properties)}.
The base implementation of this function just looks for a property named \c properties.name inside
itself (root), which is how it finds \c {property Component pushAnimation} in the examples above.
\code
function getAnimation(properties)
{
return root[properties.name]
}
\endcode
You can override this function for your transition if you need extra logic to decide which
animation to run. You could for example introspect the pages, and return different animations
depending on the their internal state. PageStack will expect you to return a Component that
contains a PageAnimation, or a PageAnimation directly. The former is easier, as PageStack will
then create the animation and later destroy it when it's done, while avoiding any sideeffects
caused by the animation being alive long after it ran. Returning a PageAnimation directly
can be useful if you need to write some sort of animation caching for performance reasons.
As an optimization, you can also return \c null to signal that you just want to show/hide the pages
immediately without creating or running any animations.
\c properties contains the same properties that will be assigned to the PageAnimation object by
PageStack. In fact, you can add more properties to this object during the call
if you need to initialize additional properties of your custom PageAnimation when the returned
component is instanciated.
The following example shows how you can decide run-time which animation to use:
\qml
PageTransition {
function getAnimation(properties)
{
return (properties.enterPage.index % 2) ? horizontalAnimation : verticalAnimation
}
function cleanupAnimation(properties)
{
properties.exitPage.x = 0
properties.exitPage.y = 0
}
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property Component horizontalAnimation: PageAnimation {
PropertyAnimation {
target: enterPage
property: "x"
from: target.width
to: 0
duration: 300
}
PropertyAnimation {
target: exitPage
property: "x"
from: 0
to: target.width
duration: 300
}
}
property Component verticalAnimation: PageAnimation {
PropertyAnimation {
target: enterPage
property: "y"
from: target.height
to: 0
duration: 300
}
PropertyAnimation {
target: exitPage
property: "y"
from: 0
to: target.height
duration: 300
}
}
}
\endqml
*/
Item {
id: root
/*! \qmlproperty int PageStack::depth
\readonly
The number of pages currently pushed onto the stack.
*/
readonly property alias depth: root.__depth
/*! \qmlproperty Item PageStack::currentPage
\readonly
The currently top-most page in the stack.
*/
readonly property alias currentPage: root.__currentPage
/*! The first \l Page that should be shown when the PageStack is created.
\a initialPage can take same value as the first argument to \l{PageStack::push()}
{PageStack.push()}. Note that this is just a convenience for writing
\c{Component.onCompleted: pageStack.push(myInitialPage)}
Examples:
\list
\li initialPage: Qt.resolvedUrl("MyPage.qml")
\li initialPage: myItem
\li initialPage: {"page" : Qt.resolvedUrl("MyPage.qml"), "properties" : {"color" : "red"}}
\endlist
\sa push
*/
property var initialPage: null
/*! \readonly
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\a busy is \c true if a page transition is running, and \c false otherwise. */
readonly property bool busy: __currentTransition !== null
/*! The animations to use for page transitions.
For better understanding on how to apply custom page transitions, read \l{Transitions}.
\sa {Page::animations}{Page.transitions} */
property PageTransition pageTransition: PageSlideTransition {}
/*! Pushes a page onto the stack. The function takes a property list as argument, which
should contain one or more of the following properties:
\list
\li \c page: This property is required, and holds the page you want to push.
It can be a \l Page, a \l{http://doc.qt.nokia.com/latest/qml-url.html}{URL}, a string with a
URL, an \l{http://doc.qt.nokia.com/latest/qml-item.html}{Item}, a
\l{http://doc.qt.nokia.com/latest/qml-component.html}{Component}.
\li \c properties: You can set a property list of QML properties that should be assigned
to the page upon push. These properties will be copied into the page at the
time the page is loaded (in case of a component or URL), or else the first time it
becomes the current page (normally upon push).
\li \c immediate: Set this property to \c true to skip transition effects. When pushing
an array, you only need to set this property on the first element to make the
whole operation immediate.
\li \c replace: Set this property to replace the current page on the stack. When pushing
an array, you only need to set this property on the first element to replace
as many elements on the stack as inside the array.
\li \c destroyOnPop: Set this property to be explicit to whether or not PageStack should
destroy the page when its popped off the stack. By default (if \a destroyOnPop is
not specified), PageStack will destroy pages pushed as components or URLs. Pages
not destroyed will be reparented back to the original parents they had before being
pushed onto the stack, and hidden. If you need to set this property, do it with
care, so that pages are not leaked.
\endlist
You can also push an array of pages (property lists) if you need to push several pages
in one go. A transition will then only occur between the current page and the last
page in the list. The other pages will be deferred loaded until needed.
Examples:
\list
\li pageStack.push({page:aPage})
\li pageStack.push({page:aURL, immediate: true, replace: true})
\li pageStack.push({page:aRectangle, properties:{color:"red"}})
\li pageStack.push({page:aComponent, properties:{color:"red"}})
\li pageStack.push({page:aComponent.createObject(), destroyOnPop:true})
\li pageStack.push([{page:aPage, immediate:true}, {page:aURL}])
\endlist
Note: If the only argument needed is "page", you can also, as a short-hand
notation, do: \c{pageStack.push(aPage)}.
Returns the page that became current.
\sa initialPage
\sa {Pushing pages}
*/
function push(page) {
// Note: we support two different APIs in this function; The old meego API, and
// the new "property list" API. Hence the reason for hiding the fact that you
// can pass more arguments than shown in the signature:
if (__recursionGuard(true))
return
var properties = arguments[1]
var immediate = arguments[2]
var replace = arguments[3]
var arrayPushed = (page instanceof Array)
var firstPage = arrayPushed ? page[0] : page
immediate = (immediate || JSArray.pageStack.length === 0)
if (firstPage && firstPage.page && firstPage.hasOwnProperty("x") === false) {
// Property list API used:
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immediate = immediate || firstPage.immediate
replace = replace || firstPage.replace
}
// Create, and push, a new javascript object, called "element", onto the stack.
// This element contains all the information necessary to construct the page, and
// will, after loaded, also contain the loaded page:
if (arrayPushed) {
if (page.length === 0)
return
var outElement = replace ? JSArray.pop() : JSArray.current()
for (var i=0; i<page.length; ++i)
JSArray.push({"pageComponent" : page[i], loaded: false, index: __depth, properties: properties});
} else {
outElement = replace ? JSArray.pop() : JSArray.current()
JSArray.push({"pageComponent" : page, loaded: false, index: __depth, properties: properties})
}
var currentElement = JSArray.current()
var transition = {
inElement: currentElement,
outElement: outElement,
transitionElement: currentElement,
immediate: immediate,
replace: replace,
push: true
}
__performPageTransition(transition)
__recursionGuard(false)
return __currentPage
}
/*! Pops one or more pages off the stack. The function takes a property list as argument
which can contain one or more of the following properties:
\list
\li \c page: If specified, all pages down to (but not including) \a page will be
popped off. if \a page is \c null, all pages down to (but not including) the
first page will be popped. If not specified, only the current page will be
popped.
\li \c immediate: Set this property to \c true to skip transition effects.
\endlist
Examples:
\list
\li pageStack.pop()
\li pageStack.pop({page:somePage, immediate: true})
\li pageStack.pop({immediate: true})
\li pageStack.pop(null)
\endlist
Note: If the only argument needed is "page", you can also, as a short-hand
notation, do: \c{pageStack.pop(aPage)}.
Returns the page that was popped off
\sa clear()
*/
function pop(page) {
if (__depth <= 1)
return null
if (page && page.hasOwnProperty("x") === false) {
// Property list API used:
var immediate = (page.immediate === true)
page = page.page
} else {
immediate = (arguments[1] === true)
}
if (page === __currentPage)
return
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if (__recursionGuard(true))
return
var outElement = JSArray.pop()
var transitionElement = outElement
var inElement = JSArray.current()
if (__depth > 1 && page !== undefined && page !== inElement.page) {
// Pop from the top until we find 'page', and return the corresponding
// element. Skip all non-loaded pages (except the first), since no one
// has any references to such pages anyway:
while (__depth > 1 && !JSArray.current().loaded)
JSArray.pop()
inElement = JSArray.current()
while (__depth > 1 && page !== inElement.page) {
JSArray.pop()
__cleanup(inElement)
while (__depth > 1 && !JSArray.current().loaded)
JSArray.pop()
inElement = JSArray.current()
}
}
var transition = {
inElement: inElement,
outElement: outElement,
transitionElement: transitionElement,
immediate: immediate,
replace: false,
push: false
}
__performPageTransition(transition)
__recursionGuard(false)
return outElement.page;
}
/*! Remove all pages from the stack. No animations will be applied. */
function clear() {
if (__recursionGuard(true))
return
if (__currentTransition)
__currentTransition.animation.complete()
__currentPage = null
var count = __depth
for (var i=0; i<count; ++i) {
var element = JSArray.pop()
if (element.page)
__cleanup(element);
}
__recursionGuard(false)
}
/*! Search for a specific page inside the stack. \a func will
be called for each page in the stack (with the page as argument)
until the function returns true. Return value will be the page found. E.g:
find(function(page, index) { return page.isTheOne })
Set \a onlySearchLoadedPages to \c true to not load pages that are
not loaded into memory */
function find(func, onlySearchLoadedPages) {
for (var i=__depth-1; i>=0; --i) {
var element = JSArray.pageStack[i];
if (onlySearchLoadedPages !== true)
__loadElement(element)
else if (!element.page)
continue
if (func(element.page))
return element.page
}
return null;
}
701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770
/*! Returns the page at position \a index in
the page stack. If \a dontLoad is true, the
page will not be forced to load (and \c null
will be returned if not yet loaded) */
function get(index, dontLoad)
{
if (index < 0 || index >= JSArray.pageStack.length)
return null
var element = JSArray.pageStack[index]
if (dontLoad !== true) {
__loadElement(element)
return element.page
} else if (element.page) {
return element.page
} else {
return null
}
}
/*! Immediately completes any ongoing transition.
/sa Animation.complete
*/
function completeTransition()
{
if (__recursionGuard(true))
return
if (__currentTransition)
__currentTransition.animation.complete()
__recursionGuard(false)
}
/********* DEPRECATED API *********/
/*! \internal
\deprecated Use Push() instead */
function replace(page, properties, immediate) {
push(page, properties, immediate, true)
}
/********* PRIVATE API *********/
width: parent ? parent.width : 0
height: parent ? parent.height : 0
/*! \internal The currently top-most page in the stack. */
property Item __currentPage: null
/*! \internal The number of pages currently pushed onto the stack. */
property int __depth: 0
/*! \internal Stores the transition info while a transition is ongoing */
property var __currentTransition: null
/*! \internal Stops the user from pushing pages while preparing a transition */
property bool __guard: false
/*! \internal */
Component.onCompleted: {
if (initialPage)
push(initialPage)
}
/*! \internal */
Component.onDestruction: {
if (__currentTransition)
__currentTransition.animation.complete()
__currentPage = null
}
/*! \internal */
function __recursionGuard(use)
{
771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840
if (use && __guard) {
console.warn("Warning: PageStack: You cannot push/pop recursively!")
console.trace()
return true
}
__guard = use
}
/*! \internal */
function __loadElement(element)
{
if (element.loaded) {
if (!element.page) {
element.page = invalidPageReplacement.createObject(root)
element.page.text = "\nError: The page has been deleted outside PageStack!"
}
return
}
if (!element.pageComponent) {
element.page = invalidPageReplacement.createObject(root)
element.page.text = "\nError: Invalid page (page was 'null'). "
+ "This might indicate that the page was deleted outside PageStack!"
return
}
var comp = __resolvePageComponent(element.pageComponent, element)
// Assign properties to Page:
if (!element.properties)
element.properties = {}
element.properties.__index = element.index
element.properties.__pageStack = root
if (comp.hasOwnProperty("createObject")) {
if (comp.status === Component.Error) {
element.page = invalidPageReplacement.createObject(root)
element.page.text = "\nError: Could not load: " + comp.errorString()
} else {
element.page = comp.createObject(root, element.properties)
// Destroy pages we create unless the user specified something else:
if (!element.hasOwnProperty("destroyOnPop"))
element.destroyOnPop = true
}
} else {
// comp is already an Item, so just reparent it into the pagestack:
element.page = comp
element.originalParent = parent
element.page.parent = root
for (var prop in element.properties) {
if (element.page.hasOwnProperty(prop))
element.page[prop] = element.properties[prop];
}
// Do not destroy pages we didn't create, unless the user specified something else:
if (!element.hasOwnProperty("destroyOnPop"))
element.destroyOnPop = false
}
delete element.properties.__index
delete element.properties.__pageStack
element.loaded = true
}
/*! \internal */
function __resolvePageComponent(unknownObjectType, element)
{
// We need this extra resolve function since we dont really
// know what kind of object the user pushed. So we try to
// figure it out by inspecting the object:
if (unknownObjectType.hasOwnProperty("createObject")) {
return unknownObjectType
841842843844845846847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878879880881882883884885886887888889890891892893894895896897898899900901902903904905906907908909910
} else if (typeof unknownObjectType == "string") {
return Qt.createComponent(unknownObjectType)
} else if (unknownObjectType.hasOwnProperty("x")) {
return unknownObjectType
} else if (unknownObjectType.hasOwnProperty("page")) {
// INVARIANT: user pushed a JS-object
element.properties = unknownObjectType.properties
if (!unknownObjectType.page)
unknownObjectType.page = invalidPageReplacement
if (unknownObjectType.hasOwnProperty("destroyOnPop"))
element.destroyOnPop = unknownObjectType.destroyOnPop
return __resolvePageComponent(unknownObjectType.page, element)
} else {
// We cannot determine the type, so assume its a URL:
return Qt.createComponent(unknownObjectType)
}
}
/*! \internal */
function __cleanup(element) {
// INVARIANT: element has been removed from JSArray. Destroy its
// page, or reparent it back to the parent it had before it was pushed:
var page = element.page
if (element.destroyOnPop) {
page.destroy()
} else {
// Mark the page as no longer part of the PageStack. It
// might reenter on pop if pushed several times:
page.visible = false
__setPageStatus(page, PageStatus.Inactive)
if (page.hasOwnProperty("__pageStack"))
page.__pageStack = null
if (page.hasOwnProperty("__index"))
page.__index = -1
if (element.originalParent)
page.parent = element.originalParent
}
}
/*! \internal */
function __setPageStatus(page, status) {
if (page.hasOwnProperty("__status"))
page.__status = status
}
/*! \internal */
function __performPageTransition(transition)
{
// Animate page in "outElement" out, and page in "inElement" in. Set a guard to protect
// the user from pushing new pages on signals that will fire while preparing for the transition
// (e.g Page.onCompleted, Page.onStatusChanged, Page.onIndexChanged etc). Otherwise, we will enter
// this function several times, which causes the pages to be half-way updated.
if (__currentTransition)
__currentTransition.animation.complete()
__loadElement(transition.inElement)
transition.name = transition.replace ? "replaceAnimation" : (transition.push ? "pushAnimation" : "popAnimation")
var enterPage = transition.inElement.page
transition.enterPage = enterPage
// Since a page can be pushed several times, we need to update its properties:
enterPage.parent = root
if (enterPage.hasOwnProperty("__pageStack"))
enterPage.__pageStack = root
if (enterPage.hasOwnProperty("__index"))
enterPage.__index = transition.inElement.index
__currentPage = enterPage
if (!transition.outElement) {
// A transition consists of two pages, but we got just one. So just show the page:
911912913914915916917918919920921922923924925926927928929930931932933934935936937938939940941942943944945946947948949950951952953954955956957958959960961962963964965966967968969970971972973974975976977978979980
enterPage.visible = true
__setPageStatus(enterPage, PageStatus.Activating)
__setPageStatus(enterPage, PageStatus.Active)
return
}
var exitPage = transition.outElement.page
transition.exitPage = exitPage
if (enterPage === exitPage)
return
__searchForAnimationIn(transition.transitionElement.page, transition)
if (!transition.animation)
__searchForAnimationIn(root, transition)
if (!transition.animation) {
console.warn("Warning: PageStack: no", transition.name, "found!")
return
}
if (enterPage.anchors.fill || exitPage.anchors.fill)
console.warn("Warning: PageStack: cannot transition a page that is anchored!")
__currentTransition = transition
__setPageStatus(exitPage, PageStatus.Deactivating)
enterPage.visible = true
__setPageStatus(enterPage, PageStatus.Activating)
transition.animation.runningChanged.connect(animationFinished)
transition.animation.start()
// NB! For empty animations, "animationFinished" is already
// executed at this point, leaving __animation === null:
if (transition.immediate === true && transition.animation)
transition.animation.complete()
}
/*! \internal */
function __searchForAnimationIn(obj, transition)
{
var t = obj.pageTransition
if (t) {
transition.pageTransition = t
transition.properties = {
"name":transition.name,
"enterPage":transition.enterPage,
"exitPage":transition.exitPage,
"immediate":transition.immediate }
var anim = t.getAnimation(transition.properties)
if (anim.createObject) {
anim = anim.createObject(null, transition.properties)
anim.runningChanged.connect(function(){ if (anim.running === false) anim.destroy() })
}
transition.animation = anim
}
}
/*! \internal */
function animationFinished()
{
if (!__currentTransition || __currentTransition.animation.running)
return
__currentTransition.animation.runningChanged.disconnect(animationFinished)
__currentTransition.exitPage.visible = false
__setPageStatus(__currentTransition.exitPage, PageStatus.Inactive);
__setPageStatus(__currentTransition.enterPage, PageStatus.Active);
__currentTransition.properties.animation = __currentTransition.animation
__currentTransition.pageTransition.cleanupAnimation(__currentTransition.properties)
if (!__currentTransition.push || __currentTransition.replace)
__cleanup(__currentTransition.outElement)
981982983984985986987988989990991992993
__currentTransition = null
}
/*! \internal */
property Component invalidPageReplacement: Component {
Text {
width: parent.width
height: parent.height
wrapMode: Text.WrapAtWordBoundaryOrAnywhere
}
}
}