throwing out touches in WPF - wpf

I'm trying to eliminate TouchDevices in a WPF for Surface so I can ignore non-finger touches because blobs seem to trigger events I don't want.
At first I had something simple like this
private void SurfaceWindow1_PreviewTouchDown(object sender, TouchEventArgs e)
{
if (!e.TouchDevice.GetIsFingerRecognized() && InteractiveSurface.PrimarySurfaceDevice.IsFingerRecognitionSupported == true)
{
e.Handled = true;
}
}
Which works well to stop touch interactions with things like inside ScatterViewItems and manipulations. however there must be something else that happens before PreviewTouchDown because I can use a blob to activate an SVI and bring it to the top although no other manipulations occur. I'm guessin TouchEnter on the SVI still shows up and brings it forward but handling TouchEnter on all the elements gives me the same thing so there's still something else going on.
I looked into Touch.FrameReported but I can't release the proper TouchCaptures before the SVIs hear about it
private void myTouchFrameHandler(object sender, TouchFrameEventArgs e)
{
foreach (TouchPoint _tp in e.GetTouchPoints(this)) {
if (!_tp.TouchDevice.GetIsFingerRecognized())
{
this.ReleaseAllTouchCaptures();
}
}
}
Any ideas?
Thanks

I stumbled upon the same problem and implemented an attached behavior for ScatterViewItems. This behavior disables the automatic IsTopmostOnActivation behavior and listens to PreviewTouchDown events to decide if an item is to be brought to top based on a test condition. It features an easy to use activation method
CustomTopmostBehavior.Activate();
which adds an application-wide style enabling the behavior for all ScatterViewItems.
The behavior can be customized by setting its TestCondition property which is by default:
CustomTopmostBehavior.TestCondition = (t) =>
{
return t.GetIsFingerRecognized();
};

Ok here's my dirty workaround to stop Touches from advancing when they're not recognized as fingers, and stopping SVIs from rising to the top when hovered over.
this.PreviewTouchDown += new EventHandler<System.Windows.Input.TouchEventArgs>(SurfaceWindow1_PreviewTouchDown);
SVI.TouchEnter += new EventHandler<TouchEventArgs>(SVI_TouchEnter);
SVI.TouchLeave +=new EventHandler<TouchEventArgs>(SVI_TouchLeave);
void SurfaceWindow1_PreviewTouchDown(object sender, System.Windows.Input.TouchEventArgs e)
{
if (!e.TouchDevice.GetIsFingerRecognized() && Microsoft.Surface.Presentation.Input.InteractiveSurface.PrimarySurfaceDevice.IsFingerRecognitionSupported) { e.Handled = true; }
else
{
//normal stuff
}
}
private void SVI_TouchEnter(object sender, TouchEventArgs e)
{
ScatterViewItem svi = sender as ScatterViewItem;
if (!e.TouchDevice.GetIsFingerRecognized() && Microsoft.Surface.Presentation.Input.InteractiveSurface.PrimarySurfaceDevice.IsFingerRecognitionSupported == true)
{
svi.IsTopmostOnActivation = false;
e.Handled = true;
}
else
{
foreach(ScatterViewItem svi in mainScatterView.Items.SourceCollection){
svi.IsTopmostOnActivation = false;
}
SVI.IsTopmostOnActivation = true;
}
}
private void SVI_TouchLeave(object sender, TouchEventArgs e)
{
ScatterViewItem svi = sender as ScatterViewItem;
svi.IsTopmostOnActivation = true;
}
I feel gross just coming up with such an unclever method. But since there's no tunneling TouchEnter, you would have to check all the visual tree objects that get a TouchEnter, which would even worse. Plus I just couldn't figure out how to use the protected method TouchDevice.Deactivate() anyway. But since the SVIs capture the touchDevice anyway and get restacked the only way I found to keep them in place is with the TopmostOnActivation Property, then catch the PreviewTouchDown on the Window and throw out non-fingers.
There's got to be a better way to get into the touch hierarchy, right?

OK so I've dug deeper into the touch hierarchy.
First of all TouchEnter happens before all the TouchDowns occur, but there's no tunneling event for that. TouchFrameHandler occurs after all the events are done, so throw that out.
Then I realized Releasing Captures on UIElements doesn't really make a difference for my problem because the Touch is already Captured. So I need to eliminate the TouchDevice in TouchEnter on every element. There is a Deactivate method in TouchDevice but it's protected. If I can figure out how to Deactivate a TouchDevice I think that should do the trick. Does that sound reasonable? If so I have to figure out how to override a protected method.

Related

Integration Testing of WPF GUI: How do I identify that current work was finished

I want to run integration UI tests on my WPF application, and I'm not sure how to detect when the current test has finished so that I can proceed to the next one.
Simplifying, suppose I have a button on my window. When the button is clicked I disable it, I modify the model, and I re-enable the button. Once it detects that the model has changed, WPF changes the view on the screen.
Now I want to run a test that simulates clicking the button again and again. To click the button I’ll use automation, as described in this SO question. But how do I know when the work is finished and the display updated, so as to "click" the button again? Do I hook the botton’s IsEnabledChanged, or is there some global indication that the current cycle of processing has finished?
Edit: What was missing in my description is that I want the user to see the interim results on the screen. For example, if the test has 10 phases I want the user to see something like a Step Counter label with values 1 .. 10 appearing on the screen, and not just the number changing immediately from 1 to 10. See my answer below.
how do I know when the work is finished and the display updated, so as to "click" the button again?
According to your description, you said When the button is clicked I disable it, I modify the model, and I re-enable the button.
Therefore, I can only assume that when the model has changed, the Button will be re-enabled. So you could either attach a handler to the model's NotifyPropertyChanged event, or as you suggested, add a handler for the IsEnabledChanged event.
Here is how I managed to get it working. This might be trivial - I'm a novice with GUI. I'm just posting it here in the hope it'll help other novices like me :)
Anyhow, what I used is a two button solutions: Test and Step. Test starts the testing sequence, Step runs each step of the tests. The Step buttons interact with an Integration Tester By Steps helper.
The helper receives an Init with the Number Of Commands as parameter, (currently the helper generates random commands by itself, so it just needs to know how many commands to generate). The helpe provides a Step method to execute the next command, and a Needs More Steps property to indicate whether testing should continue.
The helper derives form INotifyPropertyChanged and has a Counter dependency property that is displayed on the main window.
The states of the Test and Step buttons are controlled by three helper methods: SetButtonsFor_OutsideTesting, SetButtonsFor_InsideTestingOutsideAnyStep and SetButtonsFor_InsideTestingInsideAStep.
First, I verified that everything is working manually, and then I added a timer and automated the process using the Stack Overflow suggestions on how to programmatically click a button in WPF and how to make a WPF Timer Like C# Timer.
Now, here's the Main Window's code:
private void Test_Click(object sender, RoutedEventArgs e)
{
SetButtonsFor_InsideTestingOutsideAnyStep();
RunTheTestBySteps();
}
public readonly IntegrationTesterBySteps _integrationTesterBySteps =
new IntegrationTesterBySteps();
void RunTheTestBySteps()
{
SetButtonsFor_InsideTestingOutsideAnyStep();
IntegrationTesterBySteps.Init(10);
StartTheTimer();
}
private void StartTheTimer()
{
DispatcherTimer = new DispatcherTimer();
DispatcherTimer.Tick += DispatcherTimer_Tick;
DispatcherTimer.Interval = new TimeSpan(0, 0, 1);
DispatcherTimer.Start();
}
private void StopTheTimer()
{
DispatcherTimer.Stop();
DispatcherTimer.Tick -= DispatcherTimer_Tick;
}
private DispatcherTimer DispatcherTimer { get; set; }
private void DispatcherTimer_Tick(object sender, EventArgs e)
{
if (!BtnStep.IsEnabled) return;
ClickTheStepButton();
CommandManager.InvalidateRequerySuggested();
}
private void BtnStep_Click(object sender, RoutedEventArgs e)
{
SetButtonsFor_InsideTestingInsideAStep();
IntegrationTesterBySteps.Step();
if (this.IntegrationTesterBySteps.NeedsMoreSteps)
SetButtonsFor_InsideTestingOutsideAnyStep();
else
{
SetButtonsFor_OutsideTesting();
StopTheTimer();
}
}
private void ClickTheStepButton()
{
var peer = new ButtonAutomationPeer(BtnStep);
var invokeProv = peer.GetPattern(PatternInterface.Invoke)
as IInvokeProvider;
if (invokeProv != null)
invokeProv.Invoke();
}
void SetButtonsFor_InsideTestingInsideAStep()
{
BtnTest.IsEnabled = false;
BtnStep.IsEnabled = false;
}
void SetButtonsFor_InsideTestingOutsideAnyStep()
{
BtnTest.IsEnabled = false;
BtnStep.IsEnabled = true;
}
void SetButtonsFor_OutsideTesting()
{
BtnTest.IsEnabled = true;
BtnStep.IsEnabled = false;
}

Modal Messagebox from background thread

I've noticed that there seems to be inconsistent behavior as to when a MessageBox is modal.
First up, launching a MessageBox from the UI thread. This results in a modal MessageBox, as expected :
void MainThreadClick(object sender, RoutedEventArgs e)
{
MessageBox.Show("Hello!");
}
Next up, launching from a background thread. This results in a Modeless MessageBox, I assume because it's not on the UI thread?
void WorkerThreadClick(object sender, RoutedEventArgs e)
{
ThreadPool.QueueUserWorkItem((x) =>
{
MessageBox.Show("Hello!");
});
}
Next, launching from a background thread, but dispatched to the UI thread, results in it being modal again :
void WorkerThreadClick(object sender, RoutedEventArgs e)
{
ThreadPool.QueueUserWorkItem((x) =>
{
Application.Current.Dispatcher.Invoke(() =>
{
MessageBox.Show("Hello!");
});
});
}
And finally, this is the strange one, similar to above, but using the FileSystemWatcher thread results in a Modeless dialog. Why is this? ... it's being Invoked on the UI thread, so why isn't it Modal like the previous example?
public MainWindow()
{
InitializeComponent();
m_watcher = new FileSystemWatcher()
{
Path = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments),
NotifyFilter = NotifyFilters.LastWrite,
IncludeSubdirectories = true,
Filter = "*.*"
};
m_watcher.Changed += OnFileSystemResourceChanged;
m_watcher.EnableRaisingEvents = true;
}
void OnFileSystemResourceChanged(object _sender, FileSystemEventArgs _args)
{
Application.Current.Dispatcher.Invoke(() =>
{
MessageBox.Show("Hello!");
});
}
Whilst I can solve the last problem using the MessagBox.Show() method that takes a Window owner as a parameter, I want to understand what's going on.
Why is the behavior different in the last 2 examples?
This question has indeed stumped me for some time. On doing some analysis I found that in the last case (FileSystemWatcher) the owner changed(I have not yet figured who has taken over the ownership).
I also found that there is a minor but important difference.
In the scenario number 2
void WorkerThreadClick(object sender, RoutedEventArgs e)
{
ThreadPool.QueueUserWorkItem((x) =>
{
MessageBox.Show("Hello!");
});
}
Even though the behaviour is Modeless when ever I close my MainWindow my application is also shut down.
In the FileSystemWatcher scenario the behaviour is again Modeless but when I close my MainWindow the application is not shut down unless I close the MessageBox(so I know that someone has taken over the ownership. Who has taken it I don't know yet).
EDIT
I changed the Shutdown mode in the last scenario
void OnFileSystemResourceChanged(object sender, FileSystemEventArgs args)
{
Application.Current.Dispatcher.Invoke(() =>
{
Application.Current.ShutdownMode=ShutdownMode.OnMainWindowClose;
MessageBox.Show("Test");
});
}
Even then when I close the MainWindow my Application is not closed unless the MessageBox is closed. I tried finding the owner but then I get null reference exceptions.

C# checkedlistbox differentiate between ItemCheck via code and mouse click

I'm using C# VS2008, WinForm application
I have a checkedlistbox control on my form (win-form application)
In the code I check some items in checkedlistbox using the SetItemChecked(index, false) method and it raise the event ItemCheck.
I also allow the user to check items in that checkedlistbox and it also raise the event ItemCheck when the user check or uncheck an item.
How can I find in the ItemCheck event how this event occur (via code or via user keyboard/mouse input)?
Thanks.
I think that there is no a simple way to differentiate the situation using code.
The only thing that comes to mind is through the use of a global form variable:
public class Form1:Form
{
bool _isCodeClick = false;
.....
// Somewhere in your code
_isCodeClick = true;
checkedListBox1.SetItemChecked(index, true);
_isCodeClick = false;
.....
private void CheckedListBox1_ItemCheck(Object sender, ItemCheckEventArgs e)
{
if(_isCodeClick == true)
{
// Do processing for click by code
}
else
{
// Do processing for click by user
}
}
}
If you go for this solution remember to take additional steps to correctly trap exceptions that could bypass the reset of the global variable to the false state.
Probably using advanced manipulation of keyboard and mouse events you could reach a reasonable way to identify what has caused the ItemCheck event, but sometime some solutions are too complex and not worth it.
EDIT: Reviewing my answer I feel the need to add a little change to reduce the maintaining problems that this esponse implies.
The code that set the boolean variable and call the SetItemChecked should be encapsulated in a separate function like this
private void SetItemCheckedFromCode(int index, bool toSet)
{
try
{
_isCodeClick = true;
checkedListBox1.SetItemChecked(index, true);
}
finally
{
_isCodeClick = false;
}
}

Is there "LoadComplete" such an event in Windows Forms?

I want my windows form to be loaded first, render its children and all. After that load heavy data in it. This is why I am looking for any event which I could use just after form loading is complete.
Any thoughts on this?
I have never found a better solution than Activated; although that is raised every time the form receives focus - so you need to filter out all the times after the first:
bool _firstActivation = true;
void Form1_Activated(object sender, EventArgs e)
{
if (_firstActivation)
{
_firstActivation = false;
OnFirstActivation();
}
}
private void OnFirstActivation()
{
}
Perhaps you're looking for the Form.Shown event. If you're doing a lot of intensive work though, perhaps you should be using a background thread anyway to avoid locking up the UI.
Like MikeP said you want to handle the Form.Shown event just once. So just attach to the even and detach once done.
private void frmMain_Load(object sender, System.EventArgs e)
{
// Do stuff in form load.
Shown += FirstShown;
}
private void FirstShown(object sender, EventArgs eventArgs)
{
Refresh();
// Do something here
// Detach from this event.
Shown -= FirstShown;
}
I do that in a way that I fire a timer with duration of 1, and kill it in the event, and with that method, I know that message loop will be empty and form initialization will be complete when my event comes.
Event is set up from Form_OnLoad() method.

Identify that a Window is completely hidden

In order to create a screen shot, I am hiding a wpf window. The code looks like that.
Hide();
var fullScreenshot = _cropper.TakeFullScreenshot();
Show();
Sometimes the Application is not hidden when the screen shot is taken. How can I can I identify, that the window is completely hidden?
I don't know how the screenshot is taken but I suspect that the UI-Thread has not removed all the content and therefore the TakeFullScreenshot sees rests of your app.
I would try to wait until your app has done all necessary ui-work and then trigger the TakeFullScreenshot-operation.
Trigger the ScreenShot-Operation with the Dispatcher:
Hide();
Dispatcher.BeginInvoke(new Action(delegate {
fullScreenshot = _cropper.TakeFullScreenshot();
Show();
}), System.Windows.Threading.DispatcherPriority.ContextIdle, null);
Currently I am trying out this solution:
public void Foo()
{
IsVisibleChanged += WhenVisibiltyChangend_TakeScreenshot_and_OpenCreateTicketDialog;
Hide();
}}
void WhenVisibiltyChangend(object sender, DependencyPropertyChangedEventArgs e)
{
if ((bool)e.NewValue == false) {
var fullScreenshot = _cropper.TakeFullScreenshot();
Show();
}
}
I hope this is the correct answer, but I have to do some additional tests.

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