Customising navbar in Xamarin.forms - xaml

I want to replace the navbar of a Xamarin.forms application with a custom navbar which includes a image in the centre rather than the page title. Is there any documentation or tutorial for the same?

Try this code it should work
[assembly: ExportRenderer(typeof(NavigationPage), typeof(CustomMapRenderer))]
namespace XamarinFormsMaps.Droid
{
public class CustomMapRenderer : NavigationPageRenderer
{
protected override void OnElementChanged(ElementChangedEventArgs<NavigationPage> e)
{
base.OnElementChanged(e);
var bar = (Android.Support.V7.Widget.Toolbar)typeof(NavigationPageRenderer)
.GetField("_toolbar", BindingFlags.NonPublic | BindingFlags.Instance)
.GetValue(this);
bar.SetLogo(Resource.Drawable.icon);
}
}
}

Related

Analogous to the abstract Adorner (wpf) class in Avalonia UI?

If in WPF a decorative element is implemented using the abstract class Adorner, then how to achieve the implementation of this object in Avalonia UI?
//code wpf
public class ControlAdorner: Adorner
{
public ControlAdorner(UIElement adornedElement) : base(adornedElement)
{
}
protected override void OnRender(DrawingContext drawingContext)
{
Rect adornedElementRect = new Rect(this.AdornedElement.DesiredSize);
... some code ...
}
}
There is AdornerLayer class with attached property AdornedElement.
I haven't tested code below, but it should work.
var adornerElement = yourElement;
var adornerLayer = AdornerLayer.GetAdornerLayer(adornerElement);
if (adornerLayer != null)
{
var adornedElement = new Border();
adornerLayer.Children.Add(adornedElement);
AdornerLayer.SetAdornedElement(adornedElement, adornerElement);
}

Scrollable Layout in Vaadin Flow

In Vaadin Flow, there exists no Component that is essentially a Scrollable Layout.
In Vaadin 8, this was done by the Panel.
Is there a way to achieve a scrollable Component in Vaadin Flow?
Edit: I have now published an add-on here that provides the class VerticalScrollLayout, and also the class HorizontalScrollLayout. If there are suggestions for improvements, feel free to contact me or comment here.
Yes it is possible, although there is no existing Component that does it automatically.
The way to go is placing a VerticalLayout (for a vertical scroll bar) inside another component, and setting the display property of that VerticalLayout from flex to block. (credits to Diego Sanz Villafruela in the vaadin forum)
I have made my own VerticalScrollLayout class that does it all for you, so that using it in a view is as easy as using a simple VerticalLayout
public class VerticalScrollLayout extends VerticalLayout {
private VerticalLayout content;
public VerticalScrollLayout(){
preparePanel();
}
public VerticalScrollLayout(Component... children){
preparePanel();
this.add(children);
}
private void preparePanel() {
setWidth("100%");
setHeight("100%");
getStyle().set("overflow", "auto");
content = new VerticalLayout();
content.getStyle().set("display", "block");
content.setWidth("100%");
content.setPadding(false);
super.add(content);
}
public VerticalLayout getContent(){
return content;
}
#Override
public void add(Component... components){
content.add(components);
}
#Override
public void remove(Component... components){
content.remove(components);
}
#Override
public void removeAll(){
content.removeAll();
}
#Override
public void addComponentAsFirst(Component component) {
content.addComponentAtIndex(0, component);
}
}
There is now an official component for scrolling:
https://vaadin.com/docs/latest/components/scroller

Showing link inside custom hover (Eclipse plugin development)

I have a custom hover inside CDT editor (see the linked SO question) and now I want to show link inside my IAnnotationHover hover:
public class MyAwesomeHover implements IAnnotationHover {
#Override
public String getHoverInfo(ISourceViewer sw, int ln) {
return "<a href='www.stackoverflow.com'>so</a>"
}
}
Unfortunately the link is not shown - the hover window shows only simple text (i.e "so"). Other HTML elements I tried work OK (ul, li, p, font ...). Can anyone help me please?
As was mentioned in the comments, the RevisionHover was a good starting point. The magic is in implementing the IAnnotationHoverExtension and creation of a custom AbstractReusableInformationControlCreator. I am posting a code snippet with solution that worked for me.
public class MyHover implements IAnnotationHover, IAnnotationHoverExtension {
...
#Override
public IInformationControlCreator getHoverControlCreator() {
return new MyCreator();
}
...
#Override
public Object getHoverInfo(ISourceViewer sv, ILineRange lr, int vnl) {
return "<a href='www.stackoverflow.com'>so</a>";
}
...
private final class MyCreator extends AbstractReusableInformationControlCreator {
protected IInformationControl doCreateInformationControl(Shell parent) {
BrowserInformationControl control =
new BrowserInformationControl(
parent,
JFaceResources.DIALOG_FONT,
false);
control.addLocationListener(
new LocationAdapter() {
#Override
public void changing(LocationEvent ev) {
if (ev.location.startsWith("file:")) {
// !This opens the link!
openUrl(ev.location)
}
}
});
return control;
}
}
}

Using Rg Plugins Popup with Xamarin Forms

I am very new to Xamarin Forms development and I need a popup dialog. I found exactly what I am looking for in https://github.com/rotorgames/Rg.Plugins.Popup, but I cannot for the life of me figure out how to use it. Could someone point me to a working example or provide some direction on use? The README.md on the site is not helping me much.
I want the the popup dialog to appear when a info button is clicked in the top navigation bar. All the popup needs is 1-2 buttons (and labels) for setting user settings.
This is for Xamarin.Forms: iOS and Android.
In simple steps:
Install the plugin in all the projects
Add the PopUp in your
Xaml
Use the methods they provide on the documentacion for Show/Hide the PopUp:
Task PushAsync(PopupPage page, bool animate = true)
Task PopAllAsync(bool animate = true)
They also provide a demo, check it:
https://github.com/rotorgames/Rg.Plugins.Popup/tree/master/src/Demo
Add a reference to the library, i.e. from nuget, to all projects.
Within your Android project, add this Rg.Plugins.Popup.Popup.Init(this, savedInstanceState); inside the MainActivity.cs OnCreate method, before Xamarin Forms Inits.
And the same for the iOS project, inside AppDelegate.cs FinishedLaunching method()
//Android
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
Rg.Plugins.Popup.Popup.Init(this, savedInstanceState); /*Must add before the other Xamarin Inits*/
Xamarin.Essentials.Platform.Init(this, savedInstanceState);
Xamarin.Forms.Forms.Init(this, savedInstanceState);
}
//iOS
public override bool FinishedLaunching(UIApplication app, NSDictionary options)
{
Rg.Plugins.Popup.Popup.Init(); /* place at the top*/
....
}
Add a new ContentPage (.xaml) to your Views directory.
<?xml version="1.0" encoding="utf-8" ?>
<pages:PopupPage
xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:pages="clr-namespace:Rg.Plugins.Popup.Pages;assembly=Rg.Plugins.Popup"
xmlns:animations="clr-namespace:Rg.Plugins.Popup.Animations; assembly=Rg.Plugins.Popup"
x:Class="MyProjectName.Views.MyContentPageName">
<pages:PopupPage.Animation>
<animations:ScaleAnimation
PositionIn="Center"
PositionOut="Center"
ScaleIn="1.2"
ScaleOut="0.8"
DurationIn="400"
DurationOut="300"
EasingIn="SinOut"
EasingOut="SinIn"
HasBackgroundAnimation="True"/>
</pages:PopupPage.Animation>
<StackLayout HorizontalAlignment="FillAndExpand" VerticalAlignment="FillAndExpand">
<!-- place your layout content here ....fx a close popup button -->
<Button Clicked="CloseBtn_Clicked" Text="Close" />
</StackLayout>
</pages:PopupPage>
In the ContentPage (PopupPage) code behind file, add using Rg.Plugins.Popup.Services; and inherit from the following
using Rg.Plugins.Popup.Services;
using System;
using System.Threading.Tasks;
using Xamarin.Forms;
[XamlCompilation(XamlCompilationOptions.Compile)]
public partial class MyContentPageName: Rg.Plugins.Popup.Pages.PopupPage
{
public MyContentPageName()
{
InitializeComponent();
}
public void OnAnimationStarted(bool isPopAnimation)
{
// optional code here
}
public void OnAnimationFinished(bool isPopAnimation)
{
// optional code here
}
protected override bool OnBackButtonPressed()
{
// Return true if you don't want to close this popup page when a back button is pressed
return true;
}
// Invoked when background is clicked
protected override bool OnBackgroundClicked()
{
// Return false if you don't want to close this popup page when a background of the popup page is clicked
return false;
}
private async void CloseBtn_Clicked(object sender, EventArgs e)
{
await PopupNavigation.Instance.PopAsync(true);
}
}
From the .xaml.cs page, where you would like to open the popup, add this:
using System;
using Xamarin.Forms;
using Xamarin.Forms.Xaml;
using Rg.Plugins.Popup.Contracts;
using Rg.Plugins.Popup.Services;
public partial class MyOtherPage : ContentPage
{
private IPopupNavigation _popup { get; set; }
private MyContentPageName _modalPage;
public MyOtherPage()
{
_popup = PopupNavigation.Instance;
_modalPage = new MyContentPageName();
}
protected override void OnAppearing()
{
base.OnAppearing();
_popup.Popped += Popup_Popped;
}
protected override void OnDisappearing()
{
base.OnDisappearing();
_popup.Popped -= Popup_Popped;
}
private async void Tapped_OpenModal(object sender, EventArgs e)
{
await _popup.PushAsync(_modalPage);
}
/// <summary> Triggered when the MyContentPageName popup is closed "PopAsync()" </summary>
private async void Popup_Popped(object sender, Rg.Plugins.Popup.Events.PopupNavigationEventArgs e)
{
/* add your logic here, if necessary */
}
}
*Note: If your modal simply displays static content, there is no need for a _popped event delegate within the OnAppearing()/OnDisappearing().

How to add the OnShareTargetActivated() method manually in a windows 8 C# blank application?

I have created a Windows8 blank xaml application.And now i want to make this application as a Share Target.I have followed the instructions at below link and able to make it as a Target app.
http://msdn.microsoft.com/en-us/library/windows/apps/xaml/Hh973053
But where do i add the following method (OnShareTargetActivated) in my blank xaml application ?When i manually add this method in mainpage.xaml.cs , it shows the errors"
"Project.MainPage.OnShareTargetActivated(Windows.ApplicationModel.Activation.ShareTargetActivatedEventArgs)' is a new virtual member in sealed class "
"Project.MainPage.OnShareTargetActivated(Windows.ApplicationModel.Activation.ShareTargetActivatedEventArgs)': no suitable method found to override "
protected override async void OnShareTargetActivated(ShareTargetActivatedEventArgs args)
{
// Code to handle activation goes here.
}
It goes in the class that inherits from Windows.UI.Xaml.Application. Typically App.cs.
E.g.
sealed partial class App : Application
{
public App()
{
this.InitializeComponent();
}
//...
protected override void OnShareTargetActivated(ShareTargetActivatedEventArgs args)
{
var rootFrame = new Frame();
rootFrame.Navigate(typeof(MainPage), args.ShareOperation);
Window.Current.Content = rootFrame;
Window.Current.Activate();
}
}