How can I make the button have the animation of blinking?
I want to add it while waiting to retrieve the location of the user, but I cannot see any example.
What I have done now is only changing the background then change it again after retrieving the location.
button.SetBackgroundColor(new Color(ContextCompat.GetColor(this.Context, Resource.Color.primaryColor)));
Normally I'd say use Xamarin's Animation class, but you're not asking for any gradual transitions. I would then use System.Threading.Timer:
private readonly Timer _blinkTimer;
Then in your constructor:
_blinkTimer= new Timer(BlinkTimerCallback);
Create the BlinkTimerCallback method:
private void BlinkTimerCallback(object state)
{
// This is sudo code - I don't know the proper syntax off the top of my head
if(button.BackgroundColor == red)
{
button.SetBackgroundColor(gray);
}
else
{
button.SetBackgroundColor(red);
}
}
Then you just switch the timer off or on based on state:
To switch it on:
_blinkTimer.Change(new TimeSpan(0, 0, 1), new TimeSpan(0, 0, 1));
To switch it off:
_blinkTimer.Change(Timeout.Infinite, Timeout.Infinite);
Related
I am trying to develop an app using Xamarin.Forms. At a certain point I am trying to have multiple switches that are grouped. This is to say that when one switch is toggled, every other switch needs to be untoggled and, at the same time, there needs to be at least one switch always toggled. This is to say that tapping on a switch that is already toggled should not change anything.T
Now my problem is that Xamarin.forms Toggled event for switches can be fired from the UI, but is also fired programmatically. I thought I had found a way around this problem, but still by doing:
-If the switch was turned on, turn off all others and do application stuff.
-else if a switch was turned off, check if there are any others that are on. If not, turn the switch back on. If yes, do nothing.
A sample code for two switches could be:
private void OnFirstToggled(object sender, EventArgs args)
{
if(FirstSwitch.isToggled)
{
//Application stuff.
SecondSwitch.isToggled = false;
}
else if (!SecondSwitch.isToggled)
{
FirstSwitch.isToggled = true;
}
}
private void OnSecondToggled(object sender, EventArgs args)
{
if(SecondSwitch.isToggled)
{
//Application stuff.
FirstSwitch.isToggled = false;
}
else if (!FirstSwitch.isToggled)
{
SecondSwitch.isToggled = true;
}
}
This solution results in an infinite loop when an already toggled switch is tapped. In fact, the isToggled property of the switch alternates between true and false infinitely. However when debugging the other event never seems to be fired (or at least my debugger does not see it). This is why I don't understand where the isToggled property is changed after that first tap.
I know this is probably a very simple issue, but I cannot seem to find the solution somewhere online. Can anyone see the problem or recommend a better, common way to implement this?
I write a simple solution to you to always keep one Switch open from a Switch group.
Let's first add three switch for test, make sure these Switch will fire the same event of Toggled:
<StackLayout>
<!-- Place new controls here -->
<Switch Toggled="Switch_Toggled" x:Name="FirstSwitch"/>
<Switch Toggled="Switch_Toggled" x:Name="SecondSwitch"/>
<Switch Toggled="Switch_Toggled" x:Name="ThirdSwitch"/>
</StackLayout>
In the code behind, I add those Switches into a list, and loop them in Switch_Toggled event to open/close the Switches:
public partial class MainPage : ContentPage
{
List<Switch> switchList;// To store all your Switches
bool isLooping; //To make sure the Switch_Toggled metod not fired a second time during one toogle event
public MainPage()
{
InitializeComponent();
switchList = new List<Switch>();
switchList.Add(FirstSwitch);
switchList.Add(SecondSwitch);
switchList.Add(ThirdSwitch);
isLooping = false;
}
private void Switch_Toggled(object sender, ToggledEventArgs e)
{
//To make sure the Switch_Toggled metod not fired a second time during one toogle event
if (isLooping == true)
{
return;
}
isLooping = true;
Switch clickSwitch = sender as Switch;
clickSwitch.IsToggled = true;
foreach (var tempSwitch in switchList)
{
if (tempSwitch != clickSwitch)
{
if (tempSwitch.IsToggled == true)
{
tempSwitch.IsToggled = false;
}
}
}
isLooping = false;
}
}
You can try this solution and feel free to ask me any question if you don't understand.
Your problem are the two else blocks. Take in account that you're toggling it on anyway.
I set up an alarm to show a corresponding Notification. The PendingIntent of the Notification is used to start the Gluon App main class. To show a View other than the homeView, I call switchView(otherView) in the postInit method. OtherView is shown, but without AppBar. While it's possible to make the AppBar appear, I wonder if this is the right approach.
#Override
public void postInit(Scene scene) {
// additional setUp logic
boolean showReadingView = (boolean) PlatformProvider.getPlatform().getLaunchIntentExtra("showReadingView", false);
if (showReadingView) {
switchView(READING_VIEW);
}
}
When triggering anything related to the JavaFX thread from another thread, we have to use Platform.runLater().
Yours is a clear case of this situation: the Android thread is calling some pending intent, and as a result, the app is started again.
This should be done:
#Override
public void postInit(Scene scene) {
// additional setUp logic
boolean showReadingView = (boolean) PlatformProvider.getPlatform().getLaunchIntentExtra("showReadingView", false);
if (showReadingView) {
Platform.runLater(() -> switchView(READING_VIEW));
}
}
Is there any solution to detect the visibility of an Unity3D game? especially do some specific thing while it's switched to the foreground/background?
MonoBehaviours support two useful hooks:
OnApplicationFocus will be called any time the player gains or loses focus.
OnApplicationPause will be called any time the application is paused or unpaused. Note that it will only be paused if "run in background" is false in player settings, and that most code execution will stop until the app regains focus.
With the above caveats in mind, I usually prefer to use OnApplicationFocus, but both can be useful depending on what exactly you're trying to do.
As far as handling those events, you could make sure that some object in every scene is listening for them. Either attach some sort of singleton object that persists between scenes, or keep an object per scene that handles them appropriately.
Unity's scripting reference provides this example. By attaching this script to an object in some scene, it will throw up a GUI message while the game has lost focus:
public class Example : MonoBehaviour {
public bool paused;
void OnGUI() {
if (paused) {
GUI.Label(new Rect(100, 100, 50, 30), "Game paused");
}
}
void OnApplicationFocus(bool focusStatus) {
paused = focusStatus;
}
}
OnApplicationPause should be what you need.
Example (pulled directly from Unity docs for readability):
using UnityEngine;
using System.Collections;
public class Example : MonoBehaviour {
public bool paused;
void OnGUI() {
if (paused)
GUI.Label(new Rect(100, 100, 50, 30), "Game paused");
}
void OnApplicationPause(bool pauseStatus) {
paused = pauseStatus;
}
}
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); }
}
I try to implement kind of a Videostream that relays on simple JPEG Files.
On my server, a JPEG is being created cyclically by an external Camera.
And I just want to include this Picture in my GWT Application.
My first idea to reload the Picture by a Timer was very simple but not so good: The client opens a connection for each reload-cycle, and the Picture flickers (at least in Firefox).
How could I solve these problems? I was thinking about something like "Web-Sockets", but I don't really know how to do.
I want to avoid a single connection for each reload. My idea was to have something like an open connection that just provides a new Picture as often as the Client asks for.
And how could I avoid the flickering when swapping the Picture?
Any ideas are welcome!
Regards, VanDahlen
A solution to avoid flickering is to have two images absolutely positioned in the same location. A timer would load one or other alternatively in each frame. Set a load handler to each image, so that it changes the z-index when the image is loaded and it restarts the timer.
Adding an extra parameter to the image url, makes the browser ask the server each time to bypass its cache.
If the time between frames is small, normally the browser will re-use the same connection if keep-alive is correctly configured in your server. It normally is enabled with a typical value of 5-15 seconds which you could increase, so if your .jpg images are updated with this periodicity, you don't have to worry and look for a better solution.
I propose a UI solution based on these ideas. But it will work as well if you use a websocket/comet mechanism giving you the last .jpg file in base64 format (just change the url by the value returned).
GWT code:
public void onModuleLoad() {
final Image i1 = new Image();
i1.setWidth("400px");
final Image i2 = new Image();
i2.setWidth("400px");
AbsolutePanel panel = new AbsolutePanel();
panel.add(i1, 0, 0);
panel.add(i2, 0, 0);
panel.setSize("600px", "400px");
RootPanel.get().add(panel);
// You could change this by base64 data if you use comet/websockets
String url = "my_image_url.jpg?";
final Timer loadNext = new Timer() {
boolean b;
int c;
public void run() {
// the counter parameter forces to load the next frame instead of using cache
if (b = !b) {
i1.setUrl(url + c++);
} else {
i2.setUrl(url + c++);
}
}
};
i1.addLoadHandler(new LoadHandler() {
public void onLoad(LoadEvent event) {
i1.getElement().getStyle().setZIndex(1);
i2.getElement().getStyle().setZIndex(0);
loadNext.schedule(1000);
}
});
i2.addLoadHandler(new LoadHandler() {
public void onLoad(LoadEvent event) {
i1.getElement().getStyle().setZIndex(0);
i2.getElement().getStyle().setZIndex(1);
loadNext.schedule(1000);
}
});
loadNext.schedule(1000);
}
If you want to use gwtquery, the code is obviously smaller:
// You could change this by base64 data if you use comet/websockets
final String url = "my_image_url.jpg?";
final GQuery images = $("<img/><img/>").appendTo(document);
images.css($$("position: fixed, top: 10px, left: 600px, width: 400px"));
final Timer timer = new Timer() {
int c;
public void run() {
images.eq(c%2).attr("src", url + c++);
}
};
images.bind("load", new Function(){
public void f() {
$(this).css($$("z-index: 1")).siblings("img").css($$("z-index: 0"));
timer.schedule(1000);
}
});
timer.schedule(1000);