Some time ago in Apache Flex project we have started to port MDL library into FlexJS framework. [1]
When I was working on Toast component I have faced an issue where removing "mdl-snackbar__action" button from HTML cause an error. It seems that snackbar.js [2] throws an error if snackbar action doesn't exists.
if (!this.actionElement_) {
throw new Error('There must be an action element for a snackbar.');
}
My question is - Why this element is required in case of Toast ? Toast component do not need it.
[1] https://cwiki.apache.org/confluence/display/FLEX/Table+Of+Components
[2] https://github.com/google/material-design-lite/blob/release/src/snackbar/snackbar.js
Thanks,
Piotr
I think it's because the snackbar and toast are implemented as a single component in the HTML/CSS. That way, an app can throw either type by either including or omitting the action-related parts of the data object that gets passed to the showSnackbar method.
It's just to cut down on the number of components in the library by making the one more flexible.
Related
In PrismForms we got the problem, that the NavigationStack is empty after navigating to a new page. That means after using the hardware back-button on the SecondPage, the app is closed. Although the back-arrow in the header on Android isnt shown. If looking closely you can see the back-arrow for a short moment after the page is switched. I guess thats before the NavigationStack gets cleared.
To the first page we navigate with the following command in OnInitialized() in our App.xaml.cs which derives from PrismApplication.
NavigationService.NavigateAsync("NavigationPage/StartPage");
(If only Navigating to „StartPage“ here, the Stack doesnt get cleared.)
That has do to with PageNavigationService.ProcessNavigationForNavigationPage(...) calling
bool clearNavStack = GetClearNavigationPageNavigationStack(currentPage); and PageNavigationService.ProcessNavigationForContentPage(...) not.
From the StartPage to the next we navigate with NavigateAsync("SecondPage")“. Here the described behaviour appears.
For navigation we use a class which wraps the Prism NavigationService. We hold him as a property and get him via Unity in our constructor:
this.PrismNavigation = prismNavigation ?? throw new ArgumentNullException(nameof(prismNavigation));
The methods „NavigateAsync“ and „GoBackAsync“, etc. we just pass through.
This way we want to seperate our ViewModel-Project from references to XamarinForms to later be able to use the same ViewModels for for example a WPF-GUI.
Why is the stack beeing cleared by our own NavigationService? If we register the original Prism NavigationService in App.xaml.cs instead, navigating back works as expected again. We found the point in the framework and could avoid the clearing with a drity hack, but that’s against the navigation-logic implemented in PrismForms, but we don’t understand how to do it the correct way.
Every help appreciated!
We edited a few things to get it working after finding some interesting information by Brian Lagunas in the forlast-post here:
https://github.com/PrismLibrary/Prism/issues/591
Although the topic was about something else, it led to improvements for overwriting the Navigation Service.
Remember that in your viewModels the Navigation Service must be named "navigationService" by convention. Also we switched from just holding the Prism Navigation Service as a parameter to deriving from it as suggested in the link above.
public class MyNavigationService : UnityPageNavigationService
I want to make error message like this on JavaFX. How can I do it?
Use an Alert:
Alert errorAlert = new Alert(AlertType.ERROR);
errorAlert.setHeaderText("Input not valid");
errorAlert.setContentText("The size of First Name must be between 2 and 25 characters");
errorAlert.showAndWait();
~~>Default Way
Alert class and some more are already in JavaFX library a full tutorial here
How to costumize an Alert?Here
^^Using ControlsFX library^^
There is a ready JavaFX library that make messages like in your icon.I am talking about ControlsFX library
~~>More Costumizable
It contains a Class named NotificationPane which you can modify in the way you want to display messages like JavaFX Alert and more complicated.
~~>For your situation
I would use Notifications class which display messages in the bootom,top,right,left and combination of them in the screen.
Example Code:
Notifications.create() .title("Title Text") .text("Hello World 0!") .showWarning();
Image:
Look here Edit this cause for some reason isn't displayed in stackoverflow
~~>How to costumize Notifications:
Customize ControlsFX Notifications
I was working on creating my custom "Button" class... Im not using CCMenuItems because I need some flexibility in my buttons.
My implementation is the following:
DMenuButton : CCSprite <CCTargetedTouchDelegate>
When created, the button receives a target and selector, and builds an NSInvocation. When touched, the invocation is called. I will use this buttons mainly to go from one layer to another.
The problem is that when going from a layer to the next, and then back to the previous, something strange occurs: either no sprites are loaded into the next view or an EXC_BAD_ACCESS error is thrown.
Can anyone help me with this?
Thanks!
PS: My theory is that it has to do with the NSInvocation and the "dealloc" method.
Am I doing something wrong?
I have a main application calling several ViewStack states, each with popup windows. If I don't open any popup windows, I can move between states fine. If I open a popup window then try to change the state using currentState=... I get the error:
TypeError: Error #1009: Cannot access a property or method of a null object reference.
at spark.components::Scroller/focusInHandler()[E:\dev\4.y\frameworks\projects\spark\src\spark\components\Scroller.as:2139]
at flash.display::Stage/set focus()
at mx.core::UIComponent/setFocus() [E:\dev\4.y\frameworks\projects\framework\src\mx\core\UIComponent.as:9905]
...
I see others having the same problem, for example here:
http://forums.adobe.com/thread/1031531
http://forums.adobe.com/message/2767130
http://forums.adobe.com/message/3448443
http://forums.adobe.com/thread/655749?tstart=-1
http://forums.adobe.com/thread/801149
http://flex4examples.wordpress.com/2011/05/05/skinnabletextbase-focusmanager-runtime-error-popup/
http://bugs.adobe.com/jira/browse/SDK-32036?page=com.atlassian.jira.plugin.system.issuetabpanels%3Aall-tabpanel
But I haven't figured out how to implement the recommended solution. It sounds like I should just include:
import mx.managers.PopUpManager; PopUpManager;
inside my main application and it should work, but it doesn't work for me.
My application has each view state in a different file, each defined using <views:View>. Also, all of the popups are separate files defined as <s:TitleWindow>. Each file includes this line:
import mx.managers.PopUpManager;
I wonder if this means each file is using a different popup manager(?), when it's a singleton and only one should be used for the whole app (how to set that up?).
The code I use to call a popup is:
var _popupName:MyTitleWindowFileName = MyTitleWindowFileName(
PopUpManager.createPopUp(this, MyTitleWindowFileName, true));
_popupName.addEventListener(MyAppController.CLOSE_POPUP,onClosePopUp);
PopUpManager.centerPopUp(_popupName); // call popup
Note that when the main application (the one defined as <s:Application>) runs, the ViewStack states have not been loaded yet (since they get loaded when they are used the first time). Not sure if that has any cause/effect here.
I've tried to follow Adobe's example code in the "Passing data to and from a Spark pop-up window" section here:
http://help.adobe.com/en_US/flex/using/WS6c678f7b363d5da52e8f1ca1124a0430dcf-8000.html#WS6c678f7b363d5da52e8f1ca1124a0430dcf-7ffe
Any ideas much appreciated.
Based on your comments, it seems like the error occurs because the focus remains in the popup. I would expect the PopUpManager and FocusManager classes to handle this better.
One thing I can think of is that the FocusManager may be trying to handle this. But since the state changes, the item that originally had focus (in the view stack child, before the pop up was opened) may no longer be there when the view state changes. Just a hunch, w/out seeing your code.
Here's some things you can do to either work around the problem (or better) further debug it to understand what is happening:
Use FocusManager.setFocus() to move the focus back to an object in the view stack child before closing the pop up
Use FocusManager.getFocus() to debug and see where it thinks the focus is at various stages (before opening popup, before/after changing state, and before/after closing pop up).
It appears this is the situation I'm experiencing:
Adobe Air: scroller throws error when changes focus between different applications
It's an Adobe bug. Solution from Adobe is:
This bug is easily fixed by changing Scroller to do a null pointer check on focusManager before using it.
which is what the first link above attempts to do.
Another link: http://forums.adobe.com/message/3812805
I'm working on a Flex application that processes and displays small amounts of HTML, sometimes including images. I'm getting the HTML out of third-party RSS feeds. Sometimes, I see this in a pop-up window:
Error #2044: Unhandled IOErrorEvent:. text=Error #2035: URL Not Found.
The RSS URL is just fine, but there's apparently something in the downloaded HTML that's causing a problem. Since the application is meant to run as part of a non-interactive digital sign, anything that requires a click to continue is completely unacceptable. I don't care how useless or malformed a URL is; the app needs to ignore the problem without pestering the user.
Unfortunately, I'm having no luck trapping this event. I'm sprinkling calls like this liberally through the code:
[object].addEventListener(IOErrorEvent.IO_ERROR, handleIOError);
... where [object] is everything from the mx:Text object rendering the HTML to its mx:Canvas parent to the mx:Application top-level app, and handleIOError is a simple function that looks like this:
private function handleIOError(event:IOErrorEvent):void {
trace ("IO error occurred: " + event);
}
But so far, nothing; that bloody error keeps popping up in the Flash player. Does anybody have any insight as to where I'm going wrong?
Make sure you are putting the event on the right object. I haven't done a whole lot of remote loading in Flex, but in Flash, a hilarious and annoying quirk is that when you use the Loader class to load images, the object you need to put event handlers on is NOT the Loader itself, but a property of the loader called contentLoaderInfo.
Read the docs carefully on the objects you are using, a similar pitfall might be at play.
IOErrorEvent is not bubbled so you cant catch or control it if someone else is implementing it.
Please find out which third party component you are using and try to get source if its open source or read some documentation or ask support guys on how to turn off this alert.
For example, if I made RSS component for flex and on error if I displayed the alert, if you use my component, whatever you can do you cant turn off my error alert unless i have provided you a boolean switch to turn it off. So this is really a problem with who has written the code for this alert box. Whatever you do you will not be able to turn this thing off. Except reverse engineer, change the code and recompile it, but it should be legal.