I am new to JavaFX and have a problem with this code
pongAnimation = new Timeline(
new KeyFrame(new Duration(1.0), t -> {
checkForCollision();
})
);
pongAnimation.setCycleCount(Timeline.INDEFINITE);
Why does the Eventhandler
t -> { checkForCollision(); }
start after the Animantion has ended?
We don't have the code
pongAnimation.setOnFinished( t -> {
checkForCollision();)
In my Workbook, it says
When a KeyFrame has an action event handler, the code in that
handler—which in this case is once again a lambda expression—is
executed when the time for that KeyFrame is reached.
My question is when the KeyFrame has an action event handler, why does it start the event again?
Why does the Eventhandler start after the Animantion has ended?
Because you set the animation to repeat indefinitely by
pongAnimation.setCycleCount(Timeline.INDEFINITE);
If you want it to play only once do
pongAnimation.setCycleCount(1);
Related
From what I understand you need to track Activation and Deactivation of the Explorers. During activation, you need to add SelectionChange event handlers for the current explorer.
This seems to work perfectly for single clicks on AppointmentItems. But it crashes the Addin when double-clicking on an appointment series and selecting a single Appointment.
Here is the source:
On class level
private Outlook.Explorer currentExplorer = null;
private Outlook.AppointmentItem currentAppointmentItem = null;
within Startup:
currentExplorer = this.Application.ActiveExplorer();
((Outlook.ExplorerEvents_10_Event)currentExplorer).Activate +=
new Outlook.ExplorerEvents_10_ActivateEventHandler(
Explorer_Activate);
currentExplorer.Deactivate += new
Outlook.ExplorerEvents_10_DeactivateEventHandler(
Explorer_Deactivate);
The event handlers:
void Explorer_Activate()
{
currentExplorer.SelectionChange += new Outlook.ExplorerEvents_10_SelectionChangeEventHandler(Selection_Change);
}
void Explorer_Deactivate()
{
currentExplorer.SelectionChange -= new Outlook.ExplorerEvents_10_SelectionChangeEventHandler(Selection_Change); ;
}
private void Close_Explorer()
{
}
private void Selection_Change()
{
Outlook.MAPIFolder selectedFolder = currentExplorer.CurrentFolder;
if (currentExplorer.Selection.Count > 0)
{
Object selObject = currentExplorer.Selection[1];
if (selObject is Outlook.AppointmentItem)
{
currentAppointmentItem = (Outlook.AppointmentItem)selObject;
}
else
{
currentAppointmentItem = null;
}
}
}
What am I overlooking? Is the form of deregistering a problem?
Try to add try/catch blocks to the event handlers. The Outlook object model can give you unpredictable results sometimes. It is worth adding them and find where an exception is thrown.
currentExplorer.Selection.Count
Also, you may subscribe to the SelectionChange event in the NewExplorer event and don't switch between explorers when they are activated or deactivated. The event is fired whenever a new explorer window is opened, either as a result of user action or through program code.
The only thing which I added was a handler for NewInspector and InspectorClose events along with Marshal.ReleaseComObject(). The only thing which I can imagine that double clicking while debugging I got in some kind of race condition (because double clicking also triggers the Selection_Change event). But this is only a guess.
You do not need to add and remove event handlers as an explorer is activated / deactivated. Are you trying to support multiple explorers? In that case, create a wrapper class that hold the Explorer object as it member and uses its methods as event handlers.
I have a Xamarin form map on my screen and I'm using PropertyChanged event to retrieve geolocation information from my server and display the proper pins on screen.
While coding the solution I noticed the PropertyChanged event is triggered multiple times (up to 10 times) with a single zoom or drag action on the map. This causes unnecessary calls to server which I want to avoid.
Ideally I want to make only one call to server when the final PropertyChanged event is called but I cant's find an easy solution to implement this.
At this point I've added a refresh button to my page that becomes enabled when a PropertyChanged event happens and I disable it after user uses the button.
Obviously this fixed the too many calls to server but made the solution manual.
I was wondering if there is a more elegant way to make the server call but do it automatically.
Thanks in advance.
I just test the PropertyChanged event on iOS side and it just triggered one time with a single zoom or drag action on the map.
While if it really triggered multiple times, you can use a timer to call the server when the final PropertyChanged event is called, for example:
public partial class MapPage : ContentPage
{
Timer aTimer;
public MapPage()
{
InitializeComponent();
customMap.PropertyChanged += CustomMap_PropertyChanged;
}
private void CustomMap_PropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
{
if (aTimer != null)
{
aTimer.Enabled = false;
aTimer.Stop();
aTimer.Close();
}
aTimer = new Timer();
aTimer.Interval = 1000;
aTimer.Enabled = true;
aTimer.Elapsed += ATimer_Elapsed;
aTimer.Start();
}
private void ATimer_Elapsed(object sender, ElapsedEventArgs e)
{
aTimer.Stop();
//do web request
Console.WriteLine(sender);
Console.WriteLine("CustomMap_PropertyChanged");
}
}
In the above code, I set the Interval = 1 second, that means in 1 second, whatever how many times PropertyChanged triggered, only the last call will trigger the ATimer_Elapsed function.
The Interval can be set to any value depending on your requirement.
I would like to modify a Timeline while it is running, for example in response to a mouse-click I want to change the target value of the animation. I have tried several methods to do this including (in a mouse clicked handler) :
Pausing the animation by calling pause() on the Timeline, clearing the KeyFrames ObservableList, adding a new KeyFrame and calling play() on the Timeline.
Creating a new KeyFrame with a Cue-name, adding the new frame to the Observable list and calling jumpTo(cueName) on the Timeline.
Some example code is:
String cueName = String.valueOf(System.currentTimeMillis());
KeyValue kv = new KeyValue(myObject.rotateProperty(), -90 + 180.0 * Math.random(), new CustomInterpolator());
KeyFrame kf = new KeyFrame(Duration.seconds(10), cueName, kv);
startupTimeline.getKeyFrames().add(kf);
startupTimeline.jumpTo(cueName);
startupTimeline.play();
Neither of these appear to work, the animation just stops.
Should I be able to modify the KeyFrame list of an existing Timeline or do I need to create a new Timeline if I want to change an animation while it is executing?
To the best of my knowledge, a Timeline can't be changed in that manner once it has started playing. The issue is that you might change the total cycle duration, which would confuse all the interpolation computations.
You probably need an AnimationTimer for this. AnimationTimer has an abstract handle(long timestamp) method which takes a time stamp (in nano-seconds), and is invoked every time the scene graph is rendered. So you can do something like:
AnimationTimer animation = new AnimationTimer() {
private long startTime = -1;
#Override
public void handle(long timestamp) {
if (startTime == -1) {
startTime = timestamp ;
}
long totalElapsedNanoseconds = timestamp - startTime ;
// update UI based on elapsed time...
}
}
The handle() method is invoked on the JavaFX Application Thread, so it is safe to update the UI, and to reference any variables that are only changed on the same thread.
I have an activity that launches a confirmationActivity onclick(). I want that, while the confirmation activity is displayed, a new activity is launched so that when the confirmation activity ends, the new activity is displayed.
#Override
public void onTimerFinished(View view) {
//delayed confirmation
Intent intent = new Intent(getActivity().getBaseContext(), ConfirmationActivity.class);
intent.putExtra(ConfirmationActivity.EXTRA_ANIMATION_TYPE,
ConfirmationActivity.SUCCESS_ANIMATION);
intent.putExtra(ConfirmationActivity.EXTRA_MESSAGE,
"Run Saved!");
startActivity(intent);
Intent mainIntent = new Intent(getActivity(), WearUploadRunActivity.class);
startActivity(mainIntent);
mResults.finishIt();
end = true;
}
my code is like this atm. In this case, the confirmation activity is not displayed because the parent activity(mResults) is killed before it is displayed...
Can someone help me with this issue? I just want to activity A launch confirmationActivity and then when the confirmationactivity ends the activity B is displayed.
EDIT:
#Override
public void onTimerSelected(View v) {
if (animation == false) {
mDelayedView.start();
mDelayedView.setListener(this);
animation = true;
} else {
mDelayedView.reset();
animation = false;
}
}
You shouldn't start both activities as you are doing there. You should start your ConfirmationActivity and then, you can use the callbacks onTimerFinished() or onTimerSelected() of the ConfirmationActivity to trigger the start of the second activity.
I'm learning to develop windows phone application. I started with a browser based app by following this tutorial - http://blogs.msdn.com/b/jaimer/archive/2011/02/04/back-button-press-when-using-webbrowser-control-in-wp7.aspx. I'm experimenting with http://m.facebook.com I can correctly use back button to go to the previous page and all that stuff but I'm not able to implement exit on double tap of back button.
I have seen many browsers app which exit after double tapping the back button. for example - Flipkart - http://www.windowsphone.com/en-us/store/app/flipkart/84fc03ea-210d-4e3e-88e0-de502a2434c5
There is no double tab event for back button. How can we achieve this?
You can create a global long that represents the last time the user pressed the back button.
Every time the back button is pressed, you can make your program subtract the number of elapsed ticks. If it has passed a short amount of ticks, you can make your program exit. If not, set the last tick variable once more.
You can get the current tick that represents the current time with System.DateTime.Ticks.
Simple code sample:
long LastExitAttemptTick = DateTime.Ticks;
private void BackButtonPressHandler(...)
{
long thisTick = DateTime.Ticks;
if (LastExitAttemptTick - thisTick < [specified amount])
throw new Exception("Exit Exception"); //You can use XNA, but this is a quick and dirty way of exiting
else
LastExitAttemptTick = DateTime.Ticks;
}
You can use a value of 10,000,000 ticks (1 second). MSDN says 10,000 ticks per millisecond, so 10,000 * 1000 = 10,000,000.
EDIT: Or as you said, you can also use DateTime.Now and use the seconds value instead. Either way works.
well this kind of logic could work for you
make a global variable
int Count=0
protected ovverride void OnBackKeyPress(CancelEventArgs e)
{
if(Count==0)
{
e.Canel=true;
Count++;
}
else if(Count==1)
{
Count=0;
//code for exiting
//may be App.Current.Terminate(); in wp8
//or in wp7
//if (NavigationService.CanGoBack)
//{
// while (NavigationService.RemoveBackEntry() != null)
// {
// NavigationService.RemoveBackEntry();
// }
//}
}
}
Hope this helps
To close the application on double click, you can use DispatcherTimer task to check whether a two clicks are within one second, if yes close the application else start timer and again check. The snippet for that as follows:
make a DispatcherTimer object as a class field like,
DispatcherTimer dt = new DispatcherTimer();
In your class's constructor specify the interval you want to check for double tap and also add event handler to perform some action when specified time has elapsed. You can do in a class's constructor,
dt.Interval = TimeSpan.FromSeconds(1.0);
dt.Tick += delegate(object s, EventArgs e)
{
dt.Stop();
};
Here what we're doing is we're specifying timespan of 1 second to check whether double tap occurs within that second. Tick event is for what we want to do when timer completes its 1 second. We're simply going to stop the timer.
Now navigate to back key event handler and here is my code to check double tap:
protected override void OnBackKeyPress(System.ComponentModel.CancelEventArgs e)
{
e.Cancel = true;
if (!dt.IsEnabled)
dt.Start();
else
new Microsoft.Xna.Framework.Game().Exit();
}
When for the first tap, timer is not started, it will go to if condition and will start the timer. If second tap occurs after 1 second, then the Tick event we wrote in constructor will fire and according to logic written there, the timer will stop.
Now assume the double tap occurs consequently within 1 second. For the 1st tap as usual it will start the timer, if immediately user presses back button again, then in its handler, it will check whether timer is running. As timer has not completed its 1 second interval, else condition will fired up and the application will close.
I used XNA library / shortcut to force close the application. To work with new Microsoft.Xna.Framework.Game().Exit(); method you should add a microsoft.xna.framework.game.dll in a reference.
Make TimeSpan interval as required.
Hope this helps. Thanks.
EDIT:
Sometimes XNA is not installed on windows 8. Here is a solution for that, so that you add above mentioned assembly reference in you project.
http://blogs.msdn.com/b/astebner/archive/2012/02/29/10274694.aspx
You have to download update which is around around 23MB.
To save time here's a Dropbox link to above assembly reference:
https://db.tt/RYTwv7cS
Yes there is no Double Tap event for back button. You have to write your own logic to exit application on Double Tap on device back key tap twice. Here is the solution this may be help you.
Create a Global variable and initialize with zero
Int TapCount =0;
Now Override OnBackKeyPress event with your own logic.
protected override void OnBackKeyPress(System.ComponentModel.CancelEventArgs e)
{
TapCount++;
if(TapCount==2)
{
if( windows phone 8 )
{
Application.Current.Terminate();
}
else
{
if (NavigationService.CanGoBack)
{
while (NavigationService.RemoveBackEntry() != null)
{
NavigationService.RemoveBackEntry();
}
}
}
}
else
e.Canel=true;
base.OnBackKeyPress(e);
}
It's very simple. I've implemented it like this:
First declare global variable:
int count;
Now initialize its value in OnNavigatedTo(NavigationEventArgs e) method:
count = 0;
Now at last add the below code to your cs file:
protected override void OnBackKeyPress(System.ComponentModel.CancelEventArgs e)
{
count++;
e.Cancel = true;
if(count == 2)
{ e.Cancel = false; base.OnBackKeyPress(e); }
}