how to add a widget in shared preference - dart

I have built an application with intro sliders that appear after the user log in.
I want the intro sliders to appear only for the first user login and not every login user does.
How can I save all the widget in the SharedPreference?

There is no way to save a Widget in SharedPreferences.
You can try this simple logic.
#override
void initState() {
super.initState();
SharedPreferences.getInstance().then((prefs) {
bool isFirstTime = prefs.getBool("first_time") ?? true;
if (isFirstTime) {
// it is first time app opening you can show your intro part
// also call setState() from here to reflect changes in the build method.
prefs.setBool("first_time", false);
} else {
// it is regular opening of the app.
}
});
}

You can't save widgets in SharedPreferences. You can save Boolean value to show intro widgets or not .By default set the Boolean of the variable to true means you can show intro slides, then after showing slides successful then make that Boolean to false. such that from next time it won't appear.

Related

Flutter: How to prevent banner ad from showing if view is already disposed

I am currently experimenting with banner ads from the firebase_admob plugin. The process to show and dispose them is pretty straightforward, I do it in initState() and dispose().
The code to create and display the add looks like this:
_bannerAd = createBannerAd();
_bannerAd
..load().then((loaded) {
if (loaded) {
_bannerAd..show();
}
});
However, as I am calling show() asynchronously, it is possible that the view was already closed when the ad is being shown (i.e. by clicking back button really fast). In that case, the dispose() method will never be called and the ad will be "stuck" on the bottom of the screen.
How can I solve this problem? Am I using the banner ad wrong or is it possible to detect if the view was already changed? I tried using the "mounted" property of the state but it didn't seem to work.
Just check "this.mounted" property of state class before showing the add.
_bannerAd = createBannerAd();
_bannerAd
..load().then((loaded) {
if (loaded && this.mounted) {
_bannerAd..show();
}
});
From https://github.com/flutter/flutter/issues/21474#issuecomment-535188820, that's a little hack but it works for me.
You can add a little delay in your dispose method like this:
static void hideBannerAd() {
Future.delayed(Duration(milliseconds: 500), () {
if (_bannerAd != null) _bannerAd.dispose();
_bannerAd = null;
});
}
500 milliseconds is enough.

ICommand not always firing when tab selected

I have a simple ActionBar with 3 tabs attached. When a tab is clicked, the fragment is inflated and the view shows. The tab being click event is fired using an event. Initially, the first fragment is inflated, but the others respond and inflate if clicked.
If I change the event being fired to an ICommand, only the last fragment is inflated and then if I click on the first tab, that and the last are inflated. Never the second.
My code is this
ICommand TabClicked
{
get
{
return new RelayCommand(() =>
{
tab.TabSelected += (object sender, ActionBar.TabEventArgs e) => TabOnTabSelected(sender, e);
});
}
}
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
SetContentView(Resource.Layout.Main);
ActionBar.NavigationMode = ActionBarNavigationMode.Tabs;
fragments.Add(new TODFragment());
fragments.Add(new ConditionsFragment());
fragments.Add(new ResultsFragment());
AddTabToActionBar("Time", Resource.Drawable.crucifix_colour);
AddTabToActionBar("Conditions", Resource.Drawable.weather_colour);
AddTabToActionBar("Results", Resource.Drawable.tod_colour);
}
void AddTabToActionBar(string text, int iconResourceId)
{
tab = ActionBar.NewTab().SetTag(text).SetText(text).SetIcon(iconResourceId);
/* uncomment and comment out one of the two below to see the difference in operation */
tab.TabSelected += TabOnTabSelected;
//tab.SetCommand<ActionBar.TabEventArgs>("TabSelected", TabClicked);
ActionBar.AddTab(tab);
}
void TabOnTabSelected(object sender, ActionBar.TabEventArgs tabEventArgs)
{
var tabNo = sender as ActionBar.Tab;
var frag = fragments[tabNo.Position];
tabEventArgs.FragmentTransaction.Replace(Resource.Id.frameLayout1, frag);
}
Am I missing something fundamental here in the difference between ICommands and Events or is it something else?
I'm using Xam.Android and MVVMLight
I found the answer. When I create the partial class I define the UI objects like this (or something like this at least)
EditText myEditText;
EditText MyEditText = myEditText ?? (view.FindViewById<EditText>(Resources.Id.myEdit);
This is fine, but it does mean that once defined, it doesn't get redefined.
Not a problem if the UI is not really going to change, but every time an action tab is pressed, the fragment is refreshed. Only problem is the Id isn't changing as myEditText is not null.
The answer is add a method in the UI definition code that nulls the objects then in the main code, when the UI disappears, call the nulling method. Everything works then

ListGrid put focus in the FilterEditor

I have a ListGrid defined like this:
ListGrid lgrid = new ListGrid();
ListGridField first = new ListGridField("first",first");
ListGridField second = new ListGridField("second ",second ");
lgrid.setFields(first, second);
lgrid.setShowFilterEditor(true);
¿How can i put the keyboard focus in the first filter editor field after i call show() in the layout?
Thxs in advance.
Depending on what your use case is (which would be useful to provide a more focused answer), the solution you posted might not be what you really need, because if you scroll on your ListGrid, it could trigger a new data fetch (if there are more records to show), and move the cursor to the filter editor as a result (if your user is editing some records at that point, the cursor moving to the filter row is not what she would want to happen!!).
In such a case, you probably just want to call grid.focusInFilterEditor("fieldToFocus") after the listGrid.show() statement or in the ClickHandler of some button you use to fetch the data, etc.
Anyway, you don't need the Timer either. This works:
listGrid.addDataArrivedHandler(new DataArrivedHandler() {
#Override
public void onDataArrived(DataArrivedEvent event) {
grid.focusInFilterEditor("fieldToFocus");
}
});
I got the solution, its focusInFilterEditor, this is an example to set the focus after the data arrived to the grid:
// Put the focus on the first listGrid field when is loaded
listGrid.addDataArrivedHandler(new DataArrivedHandler() {
#Override
public void onDataArrived(DataArrivedEvent event) {
Timer t = new Timer() {
public void run() {
if(listGrid.getFilterEditorCriteria() == null){
listGrid.focusInFilterEditor("fieldToFocus");
}
}
};
t.schedule(600);
}
});

Trackwheel Click Event Issue

I am dealing with KeywordFilterField which is populated with the list of the countries. Now the problem i am facing is that when i click the particular country it should move to the next screen as I have written the pushScreen code in the trackwheelClick event after checking that _keywordFilterField is focusable or not, but this is not the case. The Menu opens when trackwheelClick event is fired, at the center of the screen, rather than moving onto the next screen.Can anybody have the idea why Menu dialog opens on the trackwheelclick event instead of going to the next screen.
See what i have done on trackwheel click event:
protected boolean trackwheelClick(int status, int time) {
if (_keywordFilterField.isFocus()) {
int index = _keywordFilterField.getSelectedIndex();
ReadableList readableList = _keywordFilterField.getResultList();
Object selectedCountry = readableList.getAt(index);
String countryName=selectedCountry.toString();
urlutf8Encoder=new URLUTF8Encoder();
String newCountry=urlutf8Encoder.encode(countryName);
pushToSearchResult(newCountry,countryName);//To Next SCreen
return true;
}
return false;
}
But it looks like:
The trackwheelClick event returns a boolean that indicates whether the event is consumed. Once an event is consumed, it stops propagating to other UI elements. If you return true, the menu will stop appearing.

How to push new screen from global screen in blackberry?

Here I am display push notification in globalscreen in blackberry, I need to push screen by clicking OK button of the dialog. I want to start app by clicking the ok button.
Please help me.
Thanks in advance!
I'm not 100% sure I understand what you want, but if this doesn't work, just add a comment and I'll try to give you a better answer.
First, read this on pushing global screens
and this on performing actions after receiving global alerts
Your code, if I'm understanding correctly, should be similar to the second link's example.
Then, if you implement the DialogClosedListener, like in the second link, you might have something like this:
called from the background when you get notified:
Dialog myDialog = new Dialog(Dialog.D_OK_CANCEL, "Hello", Dialog.OK, null, 0);
myDialog.setDialogClosedListener(new MyListener());
UiApplication.getUiApplication().pushGlobalScreen(myDialog, 1, true);
implementation of your dialog listener:
private class MyListener implements DialogClosedListener {
public void dialogClosed(Dialog dialog, int choice) {
switch (choice) {
case Dialog.OK:
// ok clicked
UiApplication.getUiApplication().requestForeground();
break;
case Dialog.CANCEL:
// cancel clicked. or escape pressed
break;
default:
break;
}
}
}
And, then in your UiApplication class, you can respond to activation, which will happen if the user selects Ok from the Dialog:
public class MyApp extends UiApplication {
private boolean _nextScreenShowing = false;
public void activate() {
super.activate();
if (!_nextScreenShowing) {
pushScreen(new NextScreen());
_nextScreenShowing = true;
}
}
}
I show the _nextScreenShowing variable, just to make sure you think about whether pushing the next screen is appropriate. It probably won't be every time activate is called. You may need to keep track of that boolean flag by responding to the Application.deactivate() method, or maybe Screen.onExposed() or Screen.onObscured(). All that depends on how your app works.

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