It seems for me that best place for validation of user input is in focus-out-event handler of entry type widgets (but this is only my thinking). I try to return TRUE from focus-out-event with idea that this will avoid to transfer focus to next control and keep focus on current widget, but this is not OK (not work as needed).
Which is proper way to suppress of transfering focus to next control in case when validation don't pass and where to put validation code on such widgets (gtkEntry, gtkSpinButton, etc) to be usable with signals invoked with both - mouse and keyboard actions?
That is hardly a good idea... Focus is (should be) always owned by the user. That is, the users should be able to move the focus wherever they see fit. If you try to direct the focus, or prevent moving it, based on any logic you can imagine, you will likely frustrate them.
It will surely frustrate me! Say for example that I wrote a wrong data in a box, and then I say, "hey, that's wrong! I want to select that data over there, copy it and paste it here". But I cannot do that because the program will not let me leave the box where I am now without writing an acceptable data. I have to delete the wrong data and enter something... just not good.
The best way to validate the user entry is when you actually do something with it. Either when you save it or when you make it effective. Then you can even make a pop-up saying that there is an error, and when it is close, move the focus to the first error.
If you feel that the user can benefit from an early warning that he is doing wrong, you can use colors (paint the box yellow/red if there is an error), or add a small error icon next to the box. That is waaaay less disruptive than moving the focus around.
Related
I want to use an editor to display a log from a program, I just need a very basic text field:
With a vertical scrollbar
With a contextual menu for copy/paste
Prevent the user from changing the text
In order to activate the copy/paste menu, I use the class racket:text% from framework rather than the basic one.
How to prevent the user from changing the text?
I read the documentation, as far as I understand the closest thing I found is lock method:
https://docs.racket-lang.org/gui/editor___.html?q=lock#%28meth._%28%28%28lib._mred%2Fmain..rkt%29._editor~3c~25~3e%29._lock%29%29
But it is not convenient, as it also prevent my program to write the data.
I also find get-read-write? but cannot find set-read-write.
Use the lock method, and just unlock the editor around any modifications that you want to do. You may find it useful to write a call-with-unlock helper function or with-unlock macro.
If you do your updates from the eventspace's handler thread (and you probably should; use queue-callback if they originate from another thread), then as long as you re-lock the editor at the end of an update, the user will never be able to interact with the unlocked editor.
I'm trying to do the following. I have a TextField (or any other control) and I want to determine focus loss according to user’s input validation.
I’ve read this article https://docs.oracle.com/javase/tutorial/uiswing/misc/focus.html#inputVerification but it seems that JavaFX does not handle focus as Swing does.
What I’m trying to achieve is: “A component's input verifier is consulted whenever the component is about to lose the focus. If the component's value is not acceptable, the input verifier can take appropriate action, such as refusing to yield the focus on the component or replacing the user's input with the last valid value and then allowing the focus to transfer to the next component.”
When a user is focused on a textfield (or any other control) I want to validate user’s input in 3 scenarios:
1) Enter key was pressed (I would listen to the KeyEvent, validate input and, if appropriate, ask to focus on the next control, but I don’t know how to do the latter).
2) TAB key was pressed (I need to intercept the focus change event).
3)Focus is lost (for example by clicking on another control or outside the Stage or even by pressing TAB key)
I need to validate user’s input and decide whether I let focus loss or no. In a way, I need to intercept the focus change event.
I can’t simply listen to de textField.focusedProperty because that only tells me that I’m loosing focus, but I can’t (or at least I don´t know how) stop it from happening.
I tried to get information about focus subsystem in JavaFX but couldn’t find any.
I’d like to know when the engine handles focus events and act according to:
a) The control that is loosing focus (and its content)
b) The possible next control in the focus sequence.
c) If the focus remains in the same Stage o if its send to another Stage or application.
I hope I’ve been clear enough with my explanation and please forgive my English if there are any mistakes.
Thank you very much in advance.
I have a database that I work on using Access 2013, though I must maintain compatibility with Access 2010; I am using Windows 7.
I have an input form that is set to Pop Up = Yes, and Modal = No. When opening this input form directly from the Navigation Pane, it functions perfectly normally.
I have a macro in a search form that calls up this input form with the specified record using the "OpenForm" action. When opening the input form with this macro, the form's background is totally garbled (it pulls the background image from whatever was behind it when called, as though it were transparent), and all labels are unreadable.
That said, if I run the macro again by trying to open a different record, the form then appears correctly until it is closed. Also, if I change the "Window Mode" in the "OpenForm" action to "Dialog" rather than "Normal," it appears correctly.
Neither of these are valid solutions, though -- it should work on the first time, and I do not want the form to be modal. All my code seems okay (insomuch as I am not receiving error messages), so I don't understand why it would be doing this... any guidance is very much appreciated.
I have discovered what is causing this problem, though I don't understand why.
The macro I am using came from a sample database, and has some commands I am not fully familiar with. One such command is "Requery."
I experimented with removing various parts of the macro with the window mode as "Normal" for the "OpenForm" command. As soon as I tried removing "Requery" (and nothing else) the window opened in "Normal" mode with no distortion whatsoever.
In short, having "Requery" in the macro was what was causing this error to occur. It seems like an innocuous enough action (all it does is refresh data, from what I understand, as described here: https://msdn.microsoft.com/en-us/library/bb177360(v=office.12).aspx), but since I don't see why its inclusion was necessary anyway (if anyone could shed some light on that, it would be appreciated), it looks like this is essentially solved.
I hope this may help someone else in the future!
I am trying to bring my secondary form to the Foreground, however when I do
MyForm.Show; // It may be hidden, therefore show it first
SetForegroundWindow(MyForm.Handle);
my Main Form appears aswell. The only way I can prevent that is to do MainForm.Hide; but I got to avoid that.
The idea is to have my secondary form appear on top of another application, without my Main Form having to do so as well.
If you consider to make another application for this functionality, then you may also consider the following compromise: minimize the MainForm to the taskbar (rather than hiding it) to prevent it popping up when activating another form.
If so, then try this answer. It does add an extra icon to your taskbar for the secondary form, but I guess that'll be no problem since a different application would either. However, if the MainForm is nót minimized but obfuscated by other windows, activating the secondary form wíll also popup the MainForm, just like you are experiencing now.
And for the completeness of this answer's sake, but not by any means meant as advice: this answer describes a (somewhat experimental) construction to make fully independent windows. The little time I tested that solution, it seemed to work, but be prepared not counting any longer on the full/default functionality of the VCL.
Try settings the state of the form to fsAlwaysOnTop.
I'm trying to count the number of times that text is changed in a given RichEdit control. I considered using events like key down, but that gets messy when you consider keys that don't change the text (like arrows, page up, etc). And how do you make sure you get all of those keys?
It seems it would be simpler to register a callback for a onTextChanged event, if one exists. Is there any way to do something like that?
Well you need to listen to the EN_CHANGE message if your using C++. Note that you also have to call SetEventMask with ENM_CHANGE to receive these notifications unlike a normal edit control will sends these messages by default.