private async Task <bool> RaisePageOnNavigatingFromAsync(MtPageDescription currentPage, MtPageDescription nextPage, NavigationMode mode)
{
var page = currentPage.GetPage(this);
var args = new MtNavigatingCancelEventArgs();
args.Content = page;
args.SourcePageType = currentPage.Type;
args.NavigationMode = mode;
args.Parameter = currentPage.Parameter;
await page.OnNavigatingFromCoreAsync(args);
if (!args.Cancel && nextPage != null)
{
var args2 = new MtNavigatingCancelEventArgs();
args2.SourcePageType = nextPage.Type;
args2.NavigationMode = mode;
args2.Parameter = nextPage.Parameter;
var copy = Navigating;
if (copy != null)
{
copy(this, args2);
args.Cancel = args2.Cancel;
}
}
return(args.Cancel);
}
private async Task <bool> NavigateAsync(MtPageDescription newPage)
{
try
{
IsNavigating = true;
var currentPage = CurrentPage;
if (currentPage != null)
{
if (await RaisePageOnNavigatingFromAsync(CurrentPage, newPage, NavigationMode.New))
{
return(false);
}
}
RemoveForwardStack();
await NavigateWithAnimationsAndCallbacksAsync(NavigationMode.New, currentPage, newPage, CurrentIndex + 1);
return(true);
}
finally
{
IsNavigating = false;
}
}
private void ReleasePageIfNecessary(MtPageDescription page)
{
if (page != null && (page.Page.NavigationCacheMode == NavigationCacheMode.Disabled || DisableCache))
{
page.ReleasePage();
}
}
private void RaisePageOnNavigatedTo(MtPageDescription description, NavigationMode mode)
{
var page = description.GetPage(this);
var args = new MtNavigationEventArgs();
args.Content = page;
args.SourcePageType = description.Type;
args.Parameter = description.Parameter;
args.NavigationMode = mode;
page.OnNavigatedToCore(args);
var copy = Navigated;
if (copy != null)
{
copy(this, args);
}
OnNavigated(this, args);
if (args.NavigationMode == NavigationMode.New)
{
OnPageCreated(this, page);
}
}
private void SwitchPagesIfSequential(PageInsertionMode insertionMode, MtPageDescription currentPage, MtPageDescription newPage)
{
if (insertionMode == PageInsertionMode.Sequential)
{
if (currentPage != null)
{
ContentGrid.Children.Remove(currentPage.GetPage(this).InternalPage);
}
ContentGrid.Children.Add(newPage.GetPage(this).InternalPage);
}
}
/// <summary>Removes a page from the page stack. </summary>
/// <param name="pageDescription">The page to remove. </param>
/// <returns><c>true</c> if the page has been found and was removed; otherwise, <c>false</c>. </returns>
/// <exception cref="ArgumentException">The current page cannot be removed from the stack. </exception>
public bool RemovePageFromStack(MtPageDescription pageDescription)
{
var index = _pages.IndexOf(pageDescription);
if (index >= 0)
{
RemovePageFromStackAt(index);
return(true);
}
return(false);
}
private void ChangeCurrentPageAndRaiseNavigationEvents(NavigationMode navigationMode, MtPageDescription currentPage,
MtPageDescription newPage, int nextPageIndex)
{
if (currentPage != null)
{
RaisePageOnNavigatedFrom(currentPage, navigationMode);
}
_pageStackManager.ChangeCurrentPage(newPage, nextPageIndex);
RaisePageOnNavigatedTo(newPage, navigationMode);
((CommandBase)GoBackCommand).RaiseCanExecuteChanged();
}
private void RaisePageOnNavigatedFrom(MtPageDescription description, NavigationMode mode)
{
var page = description.GetPage(this);
var args = new MtNavigationEventArgs();
args.Content = page;
args.SourcePageType = description.Type;
args.Parameter = description.Parameter;
args.NavigationMode = mode;
page.OnNavigatedFromCore(args);
}
private async Task <bool> RaisePageOnNavigatingFromAsync(MtPageDescription description, NavigationMode mode)
{
var page = description.GetPage(this);
var args = new MtNavigatingCancelEventArgs();
args.Content = page;
args.SourcePageType = description.Type;
args.NavigationMode = mode;
IsNavigating = true;
await page.OnNavigatingFromCoreAsync(args);
IsNavigating = false;
return(args.Cancel);
}
/// <summary>Navigates forward to a new instance of the given page type. </summary>
/// <param name="pageType">The page type. </param>
/// <param name="parameter">The page parameter. </param>
/// <returns>Returns true if the navigation process has not been cancelled. </returns>
public async Task <bool> NavigateAsync(Type pageType, object parameter)
{
var currentPage = CurrentPage;
if (currentPage != null && await RaisePageOnNavigatingFromAsync(CurrentPage, NavigationMode.New))
{
return(false);
}
RemoveForwardStack();
var newPage = new MtPageDescription(pageType, parameter);
await NavigateWithAnimationsAndCallbacksAsync(NavigationMode.New, currentPage, newPage, _currentIndex + 1);
return(true);
}
private void ChangeCurrentPageAndRaiseNavigationEvents(NavigationMode navigationMode, MtPageDescription currentPage,
MtPageDescription newPage, int nextPageIndex)
{
if (currentPage != null)
{
RaisePageOnNavigatedFrom(currentPage, navigationMode);
}
if (navigationMode == NavigationMode.New)
{
_pages.Add(newPage);
}
CurrentIndex = nextPageIndex;
RaisePageOnNavigatedTo(newPage, navigationMode);
((CommandBase)GoBackCommand).RaiseCanExecuteChanged();
}
/// <summary>Navigates to the given page and copies the page.</summary>
/// <param name="page">The page.</param>
/// <returns>True if page is now on top of the stack, false when navigation from the current page failed.</returns>
public async Task <bool> CopyToTopAndNavigateAsync(MtPageDescription page)
{
if (CurrentPage == page)
{
return(true);
}
if (_pageStackManager.Pages.Contains(page))
{
if (await NavigateAsync(page, NavigationMode.Forward))
{
return(true);
}
}
return(false);
}
private Task <bool> NavigateAsync(MtPageDescription newPage, NavigationMode navigationMode)
{
return(RunNavigationWithCheckAsync(async() =>
{
var currentPage = CurrentPage;
if (currentPage != null)
{
if (await RaisePageOnNavigatingFromAsync(CurrentPage, newPage, navigationMode))
{
return false;
}
}
_pageStackManager.ClearForwardStack();
await NavigateWithAnimationsAndCallbacksAsync(navigationMode, currentPage, newPage, _pageStackManager.CurrentIndex + 1);
return true;
}));
}
private async Task NavigateWithAnimationsAndCallbacksAsync(NavigationMode navigationMode,
MtPageDescription currentPage, MtPageDescription nextPage, int nextPageIndex)
{
var pageAnimation = ActualPageAnimation;
var insertionMode = pageAnimation != null ? pageAnimation.PageInsertionMode : PageInsertionMode.Sequential;
ContentGrid.IsHitTestVisible = false;
AddNewPageToGridIfNotSequential(insertionMode, nextPage);
await AnimateNavigatedFromIfCurrentPageNotNull(pageAnimation, navigationMode, insertionMode, currentPage, nextPage);
SwitchPagesIfSequential(insertionMode, currentPage, nextPage);
ChangeCurrentPageAndRaiseNavigationEvents(navigationMode, currentPage, nextPage, nextPageIndex);
await AnimateNavigatedToAndRemoveCurrentPageAsync(pageAnimation, navigationMode, insertionMode, currentPage, nextPage);
ContentGrid.IsHitTestVisible = true;
ReleasePageIfNecessary(currentPage);
}
/// <summary>Navigates to the given page and removes the page from the previous position in the page stack.</summary>
/// <param name="page">The page.</param>
/// <returns>True if page is now on top of the stack, false when navigation from the current page failed.</returns>
public async Task <bool> MoveToTopAndNavigateAsync(MtPageDescription page)
{
if (CurrentPage == page)
{
return(true);
}
var index = _pages.IndexOf(page);
if (index != -1)
{
_pages.RemoveAt(index);
_currentIndex--;
if (await NavigateAsync(page))
{
return(true);
}
_pages.Insert(index, page);
}
return(false);
}
private async Task<bool> RaisePageOnNavigatingFromAsync(MtPageDescription description, NavigationMode mode)
{
var page = description.GetPage(this);
var args = new MtNavigatingCancelEventArgs();
args.Content = page;
args.SourcePageType = description.Type;
args.NavigationMode = mode;
IsNavigating = true;
await page.OnNavigatingFromCoreAsync(args);
IsNavigating = false;
return args.Cancel;
}
private async Task AnimateNavigatedToAndRemoveCurrentPageAsync(IPageAnimation pageAnimation, NavigationMode navigationMode, PageInsertionMode insertionMode, MtPageDescription currentPage, MtPageDescription newPage)
{
if (currentPage != null)
{
if (insertionMode != PageInsertionMode.Sequential)
{
await AnimateNavigatedToAsync(pageAnimation, navigationMode,
currentPage.GetPage(this).ActualAnimationContext,
newPage.GetPage(this).ActualAnimationContext);
ContentGrid.Children.Remove(currentPage.GetPage(this).InternalPage);
}
else
{
await AnimateNavigatedToAsync(pageAnimation, navigationMode, null,
newPage.GetPage(this).ActualAnimationContext);
}
}
}
private void ChangeCurrentPageAndRaiseNavigationEvents(NavigationMode navigationMode, MtPageDescription currentPage,
MtPageDescription newPage, int nextPageIndex)
{
if (currentPage != null)
RaisePageOnNavigatedFrom(currentPage, navigationMode);
if (navigationMode == NavigationMode.New)
_pages.Add(newPage);
CurrentIndex = nextPageIndex;
RaisePageOnNavigatedTo(newPage, navigationMode);
((RelayCommand)GoBackCommand).RaiseCanExecuteChanged();
}
private void AddNewPageToGridIfNotSequential(PageInsertionMode insertionMode, MtPageDescription newPage)
{
if (insertionMode == PageInsertionMode.ConcurrentAbove)
ContentGrid.Children.Add(newPage.GetPage(this).InternalPage);
else if (insertionMode == PageInsertionMode.ConcurrentBelow)
ContentGrid.Children.Insert(0, newPage.GetPage(this).InternalPage);
}
private async Task NavigateWithAnimationsAndCallbacksAsync(NavigationMode navigationMode,
MtPageDescription currentPage, MtPageDescription nextPage, int nextPageIndex)
{
var pageAnimation = ActualPageAnimation;
var insertionMode = pageAnimation != null ? pageAnimation.PageInsertionMode : PageInsertionMode.Sequential;
ContentGrid.IsHitTestVisible = false;
AddNewPageToGridIfNotSequential(insertionMode, nextPage);
await AnimateNavigatedFromIfCurrentPageNotNull(pageAnimation, navigationMode, insertionMode, currentPage, nextPage);
SwitchPagesIfSequential(insertionMode, currentPage, nextPage);
ChangeCurrentPageAndRaiseNavigationEvents(navigationMode, currentPage, nextPage, nextPageIndex);
await AnimateNavigatedToAndRemoveCurrentPageAsync(pageAnimation, navigationMode, insertionMode, currentPage, nextPage);
ContentGrid.IsHitTestVisible = true;
ReleasePageIfNecessary(currentPage);
}
/// <summary>Navigates back to the given page. </summary>
/// <param name="pageDescription">The page to navigate to. </param>
/// <returns>True if the navigation could be performed. </returns>
public async Task<bool> GoBackToAsync(MtPageDescription pageDescription)
{
var index = _pages.IndexOf(pageDescription);
return await GoBackToAsync(index);
}
/// <summary>Navigates to the given page and removes the page from the previous position in the page stack.</summary>
/// <param name="page">The page.</param>
/// <returns>True if page is now on top of the stack, false when navigation from the current page failed.</returns>
public Task<bool> MoveToTopAndNavigateAsync(MtPageDescription page)
{
return _pageStackManager.MoveToTop(page, async p => await NavigateAsync(p, NavigationMode.Forward));
}
/// <summary>Navigates to the given page and removes the page from the previous position in the page stack.</summary>
/// <param name="page">The page.</param>
/// <returns>True if page is now on top of the stack, false when navigation from the current page failed.</returns>
public Task <bool> MoveToTopAndNavigateAsync(MtPageDescription page)
{
return(_pageStackManager.MoveToTop(page, async p => await NavigateAsync(p, NavigationMode.Forward)));
}
/// <summary>Navigates forward to a new instance of the given page type.</summary>
/// <param name="pageType">The page type. </param>
/// <param name="parameter">The page parameter. </param>
/// <returns>Returns true if the navigation process has not been cancelled. </returns>
public async Task <bool> NavigateAsync(Type pageType, object parameter)
{
var newPage = new MtPageDescription(pageType, parameter);
return(await NavigateAsync(newPage, NavigationMode.New));
}
/// <summary>Removes a page from the page stack. </summary>
/// <param name="pageDescription">The page to remove. </param>
/// <returns><c>true</c> if the page has been found and was removed; otherwise, <c>false</c>. </returns>
/// <exception cref="ArgumentException">The current page cannot be removed from the stack. </exception>
public bool RemovePageFromStack(MtPageDescription pageDescription)
{
return(_pageStackManager.RemovePageFromStack(pageDescription));
}
/// <summary>Navigates back to the given page. </summary>
/// <param name="pageDescription">The page to navigate to. </param>
/// <returns>True if the navigation could be performed. </returns>
public async Task <bool> GoBackToAsync(MtPageDescription pageDescription)
{
var index = _pageStackManager.GetPageIndex(pageDescription);
return(await GoBackToAsync(index));
}
/// <summary>Navigates to the given page and removes the page from the previous position in the page stack.</summary>
/// <param name="page">The page.</param>
/// <returns>True if page is now on top of the stack, false when navigation from the current page failed.</returns>
public async Task<bool> MoveToTopAndNavigateAsync(MtPageDescription page)
{
if (CurrentPage == page)
return true;
var index = _pages.IndexOf(page);
if (index != -1)
{
_pages.RemoveAt(index);
_currentIndex--;
if (await NavigateAsync(page))
return true;
_pages.Insert(index, page);
}
return false;
}
private async Task<bool> NavigateAsync(MtPageDescription newPage)
{
try
{
IsNavigating = true;
var currentPage = CurrentPage;
if (currentPage != null)
{
if (await RaisePageOnNavigatingFromAsync(CurrentPage, newPage, NavigationMode.New))
return false;
}
RemoveForwardStack();
await NavigateWithAnimationsAndCallbacksAsync(NavigationMode.New, currentPage, newPage, CurrentIndex + 1);
return true;
}
finally
{
IsNavigating = false;
}
}
private async Task<bool> RaisePageOnNavigatingFromAsync(MtPageDescription currentPage, MtPageDescription targetPage, NavigationMode mode)
{
var page = currentPage.GetPage(this);
var args = new MtNavigatingCancelEventArgs();
args.Content = page;
args.SourcePageType = currentPage.Type;
args.NavigationMode = mode;
args.Parameter = currentPage.Parameter;
await page.OnNavigatingFromCoreAsync(args);
if (!args.Cancel && targetPage != null)
{
var args2 = new MtNavigatingCancelEventArgs();
args2.SourcePageType = targetPage.Type;
args2.NavigationMode = mode;
args2.Parameter = targetPage.Parameter;
var copy = Navigating;
if (copy != null)
{
copy(this, args2);
args.Cancel = args2.Cancel;
}
}
return args.Cancel;
}
/// <exception cref="ArgumentException">The current page cannot be removed from the stack. </exception>
public bool RemovePageFromStack(MtPageDescription pageDescription)
{
var index = GetPageIndex(pageDescription);
if (index >= 0)
{
RemovePageFromStackAt(index);
return true;
}
return false;
}
/// <summary>Navigates forward to a new instance of the given page type. </summary>
/// <param name="pageType">The page type. </param>
/// <param name="parameter">The page parameter. </param>
/// <returns>Returns true if the navigation process has not been cancelled. </returns>
public async Task<bool> NavigateAsync(Type pageType, object parameter)
{
var newPage = new MtPageDescription(pageType, parameter);
return await NavigateAsync(newPage);
}
public void ChangeCurrentPage(MtPageDescription newPage, int nextPageIndex)
{
if (_pages.Count <= nextPageIndex)
_pages.Add(newPage);
CurrentIndex = nextPageIndex;
}
/// <summary>Removes a page from the page stack. </summary>
/// <param name="pageDescription">The page to remove. </param>
/// <returns><c>true</c> if the page has been found and was removed; otherwise, <c>false</c>. </returns>
/// <exception cref="ArgumentException">The current page cannot be removed from the stack. </exception>
public bool RemovePageFromStack(MtPageDescription pageDescription)
{
return _pageStackManager.RemovePageFromStack(pageDescription);
}
/// <summary>Navigates back to the given page. </summary>
/// <param name="pageDescription">The page to navigate to. </param>
/// <returns>True if the navigation could be performed. </returns>
public async Task<bool> GoBackToAsync(MtPageDescription pageDescription)
{
var index = _pageStackManager.GetPageIndex(pageDescription);
return await GoBackToAsync(index);
}
/// <summary>Navigates forward to a new instance of the given page type. </summary>
/// <param name="pageType">The page type. </param>
/// <param name="parameter">The page parameter. </param>
/// <returns>Returns true if the navigation process has not been cancelled. </returns>
public async Task<bool> NavigateAsync(Type pageType, object parameter)
{
var currentPage = CurrentPage;
if (currentPage != null && await RaisePageOnNavigatingFromAsync(CurrentPage, NavigationMode.New))
return false;
RemoveForwardStack();
var newPage = new MtPageDescription(pageType, parameter);
await NavigateWithAnimationsAndCallbacksAsync(NavigationMode.New, currentPage, newPage, CurrentIndex + 1);
return true;
}
private void ChangeCurrentPageAndRaiseNavigationEvents(NavigationMode navigationMode, MtPageDescription currentPage,
MtPageDescription newPage, int nextPageIndex)
{
if (currentPage != null)
RaisePageOnNavigatedFrom(currentPage, navigationMode);
_pageStackManager.ChangeCurrentPage(newPage, nextPageIndex);
RaisePageOnNavigatedTo(newPage, navigationMode);
((CommandBase)GoBackCommand).RaiseCanExecuteChanged();
}
private void ReleasePageIfNecessary(MtPageDescription page)
{
if (page != null && (page.Page.NavigationCacheMode == NavigationCacheMode.Disabled || DisableCache))
page.ReleasePage();
}
private void AddNewPageToGridIfNotSequential(PageInsertionMode insertionMode, MtPageDescription newPage)
{
var page = newPage.GetPage(this).InternalPage;
if (!ContentGrid.Children.Contains(page))
{
if (insertionMode == PageInsertionMode.ConcurrentAbove)
{
ContentGrid.Children.Add(page);
}
else if (insertionMode == PageInsertionMode.ConcurrentBelow)
{
ContentGrid.Children.Insert(0, page);
}
}
}
private async Task AnimateNavigatedFromIfCurrentPageNotNull(IPageAnimation pageAnimation, NavigationMode navigationMode,
PageInsertionMode insertionMode, MtPageDescription currentPage, MtPageDescription newPage)
{
if (currentPage != null)
{
if (insertionMode != PageInsertionMode.Sequential)
{
await AnimateNavigatingFromAsync(pageAnimation, navigationMode,
currentPage.GetPage(this).ActualAnimationContext,
insertionMode != PageInsertionMode.Sequential ? newPage.GetPage(this).ActualAnimationContext : null);
}
else
{
await AnimateNavigatingFromAsync(pageAnimation, navigationMode, currentPage.GetPage(this).ActualAnimationContext, null);
}
}
}
private Task<bool> NavigateAsync(MtPageDescription newPage, NavigationMode navigationMode)
{
return RunNavigationWithCheckAsync(async () =>
{
var currentPage = CurrentPage;
if (currentPage != null)
{
if (await RaisePageOnNavigatingFromAsync(CurrentPage, newPage, navigationMode))
return false;
}
_pageStackManager.ClearForwardStack();
await NavigateWithAnimationsAndCallbacksAsync(navigationMode, currentPage, newPage, _pageStackManager.CurrentIndex + 1);
return true;
});
}
private void SwitchPagesIfSequential(PageInsertionMode insertionMode, MtPageDescription currentPage, MtPageDescription newPage)
{
if (insertionMode == PageInsertionMode.Sequential)
{
if (currentPage != null)
ContentGrid.Children.Remove(currentPage.GetPage(this).InternalPage);
ContentGrid.Children.Add(newPage.GetPage(this).InternalPage);
}
}
private async Task AnimateNavigatedFromIfCurrentPageNotNull(IPageAnimation pageAnimation, NavigationMode navigationMode,
PageInsertionMode insertionMode, MtPageDescription currentPage, MtPageDescription newPage)
{
if (currentPage != null)
{
if (insertionMode != PageInsertionMode.Sequential)
{
await AnimateNavigatingFromAsync(pageAnimation, navigationMode,
currentPage.GetPage(this).ActualAnimationContext,
insertionMode != PageInsertionMode.Sequential?newPage.GetPage(this).ActualAnimationContext : null);
}
else
{
await AnimateNavigatingFromAsync(pageAnimation, navigationMode, currentPage.GetPage(this).ActualAnimationContext, null);
}
}
}
internal void RaisePageOnNavigatedFrom(MtPageDescription description, NavigationMode mode)
{
var page = description.GetPage(this);
var args = new MtNavigationEventArgs();
args.Content = page;
args.SourcePageType = description.Type;
args.Parameter = description.Parameter;
args.NavigationMode = mode;
page.OnNavigatedFromCore(args);
}
private async Task AnimateNavigatedToAndRemoveCurrentPageAsync(IPageAnimation pageAnimation, NavigationMode navigationMode, PageInsertionMode insertionMode, MtPageDescription currentPage, MtPageDescription newPage)
{
if (currentPage != null)
{
if (insertionMode != PageInsertionMode.Sequential)
{
await AnimateNavigatedToAsync(pageAnimation, navigationMode,
currentPage.GetPage(this).ActualAnimationContext,
newPage.GetPage(this).ActualAnimationContext);
ContentGrid.Children.Remove(currentPage.GetPage(this).InternalPage);
}
else
{
await AnimateNavigatedToAsync(pageAnimation, navigationMode, null,
newPage.GetPage(this).ActualAnimationContext);
}
}
}
private void RaisePageOnNavigatedTo(MtPageDescription description, NavigationMode mode)
{
var page = description.GetPage(this);
var args = new MtNavigationEventArgs();
args.Content = page;
args.SourcePageType = description.Type;
args.Parameter = description.Parameter;
args.NavigationMode = mode;
page.OnNavigatedToCore(args);
var copy = Navigated;
if (copy != null)
copy(this, args);
OnNavigated(this, args);
if (args.NavigationMode == NavigationMode.New)
OnPageCreated(this, page);
}
/// <summary>Navigates to the given page and copies the page.</summary>
/// <param name="page">The page.</param>
/// <returns>True if page is now on top of the stack, false when navigation from the current page failed.</returns>
public async Task<bool> CopyToTopAndNavigateAsync(MtPageDescription page)
{
if (CurrentPage == page)
return true;
if (_pageStackManager.Pages.Contains(page))
{
if (await NavigateAsync(page, NavigationMode.Forward))
return true;
}
return false;
}
public async Task<bool> MoveToTop(MtPageDescription page, Func<MtPageDescription, Task<bool>> action)
{
if (CurrentPage == page)
return true;
var index = _pages.IndexOf(page);
if (index != -1)
{
_pages.RemoveAt(index);
_currentIndex--;
if (await action(page))
return true;
_pages.Insert(index, page);
}
return false;
}
/// <summary>Navigates back to the given page. </summary>
/// <param name="pageDescription">The page to navigate to. </param>
/// <returns>True if the navigation could be performed. </returns>
public async Task <bool> GoBackToAsync(MtPageDescription pageDescription)
{
var index = _pages.IndexOf(pageDescription);
return(await GoBackToAsync(index));
}
public int GetPageIndex(MtPageDescription pageDescription)
{
return _pages.IndexOf(pageDescription);
}
/// <summary>Determines whether the HamburgerItem represents the given page description.</summary>
/// <param name="item">The hamburger item.</param>
/// <param name="pageDescription">The page description.</param>
/// <returns>true or false.</returns>
protected virtual bool IsHamburgerItemForPage(HamburgerItem item, MtPageDescription pageDescription)
{
return(item is PageHamburgerItem && ((PageHamburgerItem)item).PageType == pageDescription.Type);
}
