I'd like to ask whether or not it is possible to make master page to appear from right side (opposite of it's default behaviour) in xamarin.forms (and preferably with XAML) and if it's possible,would you show me how?
By default it is not possible.
You can try Right Master Detail Page
public RightSideMasterPage ()
{
InitializeComponent ();
// You must set IsFullScreen in this case,
// otherwise you need to set HeightRequest,
// just like the QuickInnerMenu sample
this.IsFullScreen = true;
// You must set WidthRequest in this case
this.WidthRequest = 250;
this.MenuOrientations = MenuOrientation.RightToLeft;
// You must set BackgroundColor,
// and you cannot put another layout with background color cover the whole View
// otherwise, it cannot be dragged on Android
this.BackgroundColor = Color.White;
// This is shadow view color, you can set a transparent color
this.BackgroundViewColor = Color.FromHex ("#CE766C");
}
Related
The essence of the problem is that I want to write my own version of the AppBar that would include content as another Compose function. After looking at the source code of the current CollapsingTopAppBar implementation, I saw the following lines:
#Composable
private fun TwoRowsTopAppBar(
...
scrollBehavior: TopAppBarScrollBehavior?
) {
...
val pinnedHeightPx: Float = 64.dp
val maxHeightPx: Float = 152.dp
LocalDensity.current.run {
pinnedHeightPx = pinnedHeight.toPx()
maxHeightPx = maxHeight.toPx()
}
// Sets the app bar's height offset limit to hide just the bottom title area and keep top title
// visible when collapsed.
SideEffect {
if (scrollBehavior?.state?.heightOffsetLimit != pinnedHeightPx - maxHeightPx) {
scrollBehavior?.state?.heightOffsetLimit = pinnedHeightPx - maxHeightPx
}
}
...
Surface(...) {
Column {
TopAppBarLayout(
...
heightPx = pinnedHeightPx
...
)
TopAppBarLayout(
...
heightPx = maxHeightPx - pinnedHeightPx + (scrollBehavior?.state?.heightOffset
?: 0f),
...
)
}
}
}
As I understand it, scrollBehavior is used to handle the collapse and expansion behavior. In the current implementation, just constant values are put in heightOffsetLimit. And since I need my appbar implementation to be able to contain content of any size, I need to somehow know the size of this content in advance and put this value in heightOffsetLimit.
I have already written the code for my AppBar, so that it also contains content. But since I can't pass the height value of the content to scrollBehavior, the AppBar doesn't collapse to the end.
you need to calculate the height that the appbar will have before drawing it into the screen. I have followed this issue and solved my problem with the last solution. hope it helps:
Get height of element Jetpack Compose
use the content you can put (ex. an image or a huge text) as the MainContent
use your appbar as the DependentContent and use the size given in lambda to give the height to your appbar
finally set placeMainContent false as I believe you don't need to draw the image (or any other composable) directly in a box
and you will good to go
I have an Image in a grid where I display some custom content by setting the Image's source to a WritableBitmap and updating the bitmap. What I want to do is to implement a "detach" button that will put my Image on a separate window allowing the user to move it to a different screen, resize it etc. independent of my main app window. If the new window is closed, I would like to bring it back to its original spot. While the Image is on the new window, I want to continuously update it with new content via updating source bitmap (as it would have been before it was detached).
I initially thought I would be able to create a new window and "move" my Image control there by first removing it from its original parent then adding it as a child to a layout in the new window. I used the code below:
CoreApplicationView^ newCoreView = CoreApplication::CreateNewView();
int mainViewId = Windows::UI::ViewManagement::ApplicationView::GetApplicationViewIdForWindow(
CoreApplication::MainView->CoreWindow);
uint indexOfObjectToDetach = -1;
bool found = originalGrid->Children->IndexOf(imageToMove, &indexOfObjectToDetach);
if(found)
{
myGrid->Children->RemoveAt(indexOfObjectToDetach);
}
DispatchedHandler^ dispatchHandler = ref new DispatchedHandler([this, mainViewId]()
{
newView_ = Windows::UI::ViewManagement::ApplicationView::GetForCurrentView();
Windows::UI::Xaml::Controls::StackPanel^ newWindowGrid = ref new Windows::UI::Xaml::Controls::StackPanel();
Window::Current->Content = newWindowGrid;
Window::Current->Activate();
newWindowGrid->Children->Append(imageToMove); // Add to new parent
});
create_task(newCoreView->Dispatcher->RunAsync(Windows::UI::Core::CoreDispatcherPriority::Normal, dispatchHandler)).then([this, mainViewId]()
{
auto a = newView_->Id;
create_task(ApplicationViewSwitcher::TryShowAsStandaloneAsync(a, ViewSizePreference::Default, mainViewId, ViewSizePreference::Default));
});
However in the line where I add the Image to its new parent, I get an Interface was marshalled for a different thread error. Upon more reading, this is due to the fact that each new window is in its own thread and I'm moving an object to another thread.
I am new to UWP and I am not sure how to approach implementing this UI behavior. How do I access/transfer my state in one view to another ?
The problem is indeed the fact that each application view in UWP has its own thread and its own UI dispatcher. When you create a control, it is tied to the UI thread it was created on, hence you cannot place it onto another application view.
The solution is to create the new Image next to the StackPanel within the new view's UI thread. I don't really use C++, but in C# I would implement it as follows:
await newCoreView.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
StackPanel panel = new StackPanel();
Image image = new Image();
panel.Children.Add( panel );
image.Source = ...; //your source
Window.Current.Content = frame;
Window.Current.Activate();
newViewId = ApplicationView.GetForCurrentView().Id;
});
To further clarify - you can safely "transfer" normal data types into other view, the problem is mainly with the UI-tied types like controls, pages, etc.
In titanium it is possible to hide a view like so:
$.foo.hide()
or
$.foo.visible = false
However, in both cases the object still seems to take physical space. It is just invisible. In other words it is similar to the CSS property visibility: hidden.
I want it so that it disappears and take no physical space in terms of width or height, so it's similar to the CSS property display: none
How can I do this?
The best hacky solution I have is the following:
$.foo.width = 0;
$.foo.height = 0;
$.foo.left = 0;
$.foo.right = 0;
But that means when I want to make it visible again, I have to set all those properties back to their original values which is a pain and hard to maintain.
First of all, don't afraid of doing some hard coding ;)
Coming to your query, yes, this is true that hiding a view just hide it from UI, but physical-space is still there.
To do what you want, you will need to either remove view on hide & create it on show, or you can use absolute layout in some tricky way.
Other way could be to animate this view using transform property like this:
// on hide
$.foo.animate({
duration : 100,
transform : Ti.UI.create2DMatrix({scale:0})
}, function () {
$.foo.visible = false;
});
// on show
$.foo.visible = true; // we need to make it visible again before resetting its UI state since we hid it after completion of animation in above code
$.foo.animate({
duration : 100,
transform : Ti.UI.create2DMatrix() // passing empty matrix will reset the initial state of this view
});
OR
this could also work but never tried this:
// on hide
$.foo.transform = Ti.UI.create2DMatrix({scale:0});
$.foo.visible = false;
// on show
$.foo.visible = true;
$.foo.transform = Ti.UI.create2DMatrix();
On WP (Windows Runtime App in my case), if we set the app to be running on Light theme, while the transition is performed, we can still see a black background.
Is there any way to avoid that?
For example, in the animation below, you can see that the page animates but before it ends there is a black background still. I'd like to set that to white somehow, but I am not sure how...
(Image from http://jamescroft.co.uk/blog/windows-phone/utilizing-page-transition-animations-in-windows-phone-8-1-apps/#comment-907).
After thinking a little bit on what item could be parent of Page, I turned my attention towards Frame.
This could be solved by setting the BackgroundColor property of the Frame, when it is created, in the OnLaunchedmethod (App.xaml.cs):
protected override async void OnLaunched(LaunchActivatedEventArgs e)
{
Frame rootFrame = Window.Current.Content as Frame;
// Do not repeat app initialization when the Window already has content,
// just ensure that the window is active
if (rootFrame == null)
{
// Create a Frame to act as the navigation context and navigate to the first page
rootFrame = new Frame
{
CacheSize = 1,
Background = new SolidColorBrush(Colors.White)
};
if (e.PreviousExecutionState == ApplicationExecutionState.Terminated)
{
// TODO: Load state from previously suspended application
}
// Place the frame in the current Window
Window.Current.Content = rootFrame;
}
... //rest of OnLaunched method
}
Also you have to make sure to set the background of the Frame as well in the OnActivated method, since this will be launched in some cases where e.g. other apps launch URI to your app or Cortana launches the app, etc.
My application has a WinJS AppBar control at the bottom of the screen. I use .showOnlyCommands(buttonsToShowArray) to show and hide buttons on ListView itemSelectionChanged event.
The problem I have right now is that when every I call .showOnlyCommands, the buttons to be hidden (or you may say "replaced") are going to flash on the top of the screen.
I tried to use the Microsoft sample app, this doesn't happen. I tried to use .showCommands + .hideCommands method, it is the same behavior. Note that this didn't happen before the Release Preview version of Win8.
I have no idea what is going on. Any idea?
EDIT:
I did further investigation, the problem happens on hideCommands. Say I have 3 buttons displayed on the appbar. I call hideCommands to hide all 3 buttons. The icon of the 3 buttons would disappear on the appbar, then pile up at the top-left corner of the screen and then disappear. (i.e. there would be a flash of 3 piled up buttons at the corner of the screen).
You may be invoking showOnlyCommands when the AppBar is in the process of 'showing'. I've found that when calling these methods in the beforeshow or aftershow handler that this happens. This quote from Animating your UI sheds light on why:
Use fade in and fade out animations to show or hide transient UI or controls. One example is in an app bar in which new controls can appear due to user interaction.
The sample app shows/hides the buttons before the appbar is shown. You may be calling show on the app bar before calling showOnlyCommands.
A temporary hack for this problem is:
Set the button be invisible before calling showOnlyCommands or HideCommands.
Here is the code that I use for now:
/*
* #param {WinJS.UI.AppBar} appbar winControl
* #param {Array} array of appbar buttons to be shown
*/
function showOnlyCommands(appbarControl, buttonsToShow) {
var toShow = {};
for (var i = 0; i < buttonsToShow.length; i++) {
toShow[buttonsToShow[i].id] = true;
}
for (var i = 0; i < visibleButtonsList.length; i++) {
var id = visibleButtonsList[i].id;
if (!toShow[id]) {
// set the display property of the buttons to be hidden to "none"
var button = document.getElementById(id);
if (button) {
button.style.display = 'none';
}
}
}
// update the visible buttons list
visibleButtonsList = buttonsToShow;
// Note that we don't need to set the "display" property back for the buttons,
// because WinJS.UI.AppBar.showOnlyCommands would set it back internally
appbarControl.showOnlyCommands(buttonsToShow);
}