Doing something during a button is pressed in Windows Phone - windows

How can I do something (I want to increment a variable and display it on the screen) during someone pressed the button. Actually there is no event called OnPressed for a button in Windows Phone.

The Button has a Click event that you can handle and use to perform your logic.
In order to execute logic for the duration of the press, handle the ManipulationStarted and ManipulationEnded events.

In addition to the click event, you can use Tap event.

The problem is that your button will handle the event and prevent it from bubbling - if that wasn't the case you could use MouseLeftButtonDown/Up events to do this.
However there is a way to get around this and still get the event by using the more tedious UIElement.AddHandler method.
Ex:
myButton.AddHandler(UIElement.MouseLeftButtonDownEvent, new MouseButtonEventHandler(myMouseEventHandlerMethod), true);
The last bit ('true') is important since this overrides the event bubbling. 'myMouseEventHandlerMethod' is the method that you usually would use for handling a MouseLeftButtonDown event.
Handling 'Up' is the same thing. You probably also want to handle "Leave", or use CaptureMouse() when down triggers.

Related

Ignore OnClick before OnDblClick

I have a TDBgrid with an OnCellClick event that toggles a Boolean.
I want to be able to launch another Form with a OnDblClick but do not want the OnCellClick to change the Boolean.
Short of programatically calling the OnCellClick to revert the Boolean as part of the OnDblClick handling, is there any way to ignore the OnCellClick when double-clicking?
I do not want a Popup menu or Right-click as this is mostly going to be on touch screen devices.
Here's what TurboPower did in the VisualPlanIt components:
Remove the OnClick handler. Add a timer. Its interval length should be slightly longer than the duration of the double-click, i.e. a few tenths of a second. In the MouseDown event start the timer. In the timer's OnTimer handler disable the timer and perform the action that should occur in the regular OnClick event. If a second click occurs while the timer is active it must be a double-click.
This sequence separates the single from the double click. To me, however, it is a bit disturbing because a normal mouse click sees a reaction only after a short delay.
Or put your form opening on CTRL-Click.

Monitor Appointment Cancel Event

I am trying to run some code upon cancellation of an AppointmentItem, however two of the events that I tried to capture fire more than once (Application.Send, AppointmentItem.Write, BeforeDelete doesn't fire). This bring me to re-think my logic and find a suitable place to implement it. I couldn't find a reason why the two events are fired twice in my case as I am using inspector wrapper to register these events on a new inspector window and Un-registering them on inspector close event.
Please note that I want to monitor all possible scenario where an Appointment can be canceled/deleted.
Why do you even need any inspector events? Monitor the Application.ItemSend event, check if you get a MeetingItem object as an argument, check that the message class is "IPM.Schedule.Meeting.Resp.Neg" or Class = 55 (OlObjectClass.olMeetingResponseNegative).

wxPython Enter Button Event

I've seen plenty of information about this topic, but not the answer to this question exactly. I have the opposite problem of most. I want to prevent the Enter button from clicking a button when the button has focus. And to do this, I don't want to simply disable the button from accepting an Enter button press, but rather I want to conditionally capture the Enter button press in a callback method. Right now, I have bound the following event to all widgets in my python program:
parent.Bind(wx.EVT_CHAR, self.CharInputCallback)
The EVT_CHAR event is actually thrown when the enter button is pressed and I'm able to get the callback in my callback method. My problem is that the enter button's functionality of virtually clicking a button still goes through, despite purposely not skipping the event (which would forward on the event). Since this is happening, and I'm sure my callback method is not forwarding the event along (I've tested this by capturing characters going to a text box) I suspect that the enter button throws an additional event that I'm not capturing. I've tried binding and capturing the additional following events to prevent the "virtual click" from the enter button:
parent.Bind(wx.EVT_TEXT_ENTER, self.CharInputCallback)
parent.Bind(wx.EVT_KEY_UP, self.CharInputCallback)
parent.Bind(wx.EVT_KEY_DOWN, self.CharInputCallback)
Yet when I press enter, the button in focus is still clicked. To summarize, is there an additional event being thrown when I press the enter button? If so, which event in particular is "virtually clicking" the button? Most forums I've found have discussed how to recognize when the enter button is pressed, but I want to recognize it and disable it's default action when a button is in focus.
I tried binding all those events to different handlers and I also bound EVT_BUTTON. It appears that EVT_BUTTON always fires BEFORE the key and char events do. If you don't want your button to be clicked, then you'll probably have to either disable it, use a different widget (maybe one of the generic buttons) or create your own. I would also ask on the wxPython mailing list to see if they have any suggestions.
The only way to order the events in wxPython that I'm aware of is to use wx.CallAfter or wx.CallLater. I'm not sure how you'd use that in this context though.
The event that causes enter to click a button is the key up event. My code for my callback was messed up slightly. Capturing the key up event and not skipping it prevent the enter button from clicking a button in focus. On Windows 7 anyways.

Intercepting and Disabling Global Mouse Events

I have a problem with my mouse. Every now and then it will double click when I only single click. I know this is a problem with the mouse, and I've contacted the manufacturer, still waiting for a reply. But in the meantime I was wondering if there was a way that I could find out when the left mouse button had been clicked twice within a very short period (probably 1-10 milliseconds) of time, and disable the second click.
I mostly know how to use hooks, so that's not the problem, my main question is how to stop an event from happening, if that's possible.
The information on how to prevent the mouse message from being processed is in the documentation of the "LowLevelMouseProc callback function" in MSDN:
http://msdn.microsoft.com/en-us/library/windows/desktop/ms644986(v=vs.85).aspx
Specifically, it says: "If the hook procedure processed the message, it may return a nonzero value to prevent the system from passing the message to the rest of the hook chain or the target window procedure." So, if you know about windows hooks, you know how to do it.
EDIT: Actually, now that I think more about it, you don't want to discard any event. You simply want to transform the doubleclick event into just another left-button-down event. I believe you can do it from within the hook handler, and it will work. Have you tried it?
In C#'s WinForms, you write an event handler involving the mouse receiving a MouseEventArgs object. Inside it, you can access certain info such as the number of times it was clicked, for example.
protected void RowClicked(object sender, MouseEventArgs evt)
{
// Trigger it when the mouse was clicked only once
if( evt.Button.Clicks == 1 ) {
// ... more things ...
}
return;
}
Other GUI libraries have other possibilities. That said, your problem has nothing to do with GUI libraries. You have to change the sensitivity of your mouse, in the configuration options of your operating system. For example, in the Windows' control panel, you can change how much time has to pass between a click and another one to be considered a doble-click. In lUbuntu, you can do the very same, in System menu >> Preferences >> Keyboard and Mouse.

Different layers in Corona/Lua

I've got a question about layering images/buttons with Corona/Lua. If I create one button on top of another one and then click it, both buttons' events are triggered. How do I prevent this?
Thanks, Elliot Bonneville
EDIT: Here's how I create the buttons:
button1 = display.newImage("button1.png")
button1:addEventListener("tap", Button1Call)
button2 = display.newImage("button2.png")
button2:addEventListener("tap", Button2Call)
Return true from the event handling function. Touch events keep propagating through the listeners until handled; it's explained here:
http://developer.anscamobile.com/content/events-and-listeners#Touch_Events
Note that the event listeners must be listening for the same event. In other words, both listeners must be set on either "touch" or "tap". Literally last night I was tripped up by this; I had a button listening to "touch" and another image on top listening to "tap" and was wondering why the button was still receiving events.
Use return true in the event handler where you handle the event to prevent further event propagation.
So, in your example, button2 will get the event first, since it's created last. If you handle the event in Button2Call andreturn true, Button1Call won't see the event at all. If you return false, or simply leave out the return statement altogether, Button1Call will get the event and can decide whether to handle it.

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