I have a form with a progress bar and a cancel button which is displayed as a process runs. The buttons "Cancel" property is set to true so pressing escape, cancels the process.
But, as the button is the only control on the form capable of taking the focus, should the user inadvertently press enter (or space bar) while the process is running it will be cancelled.
I have prevented the Space Bar from working by setting KeyPreview to true (on the form) then setting KeyAscii to 0 but this approach deson't seem to work for the enter key as the button click event fires first.
I've tried setting the button's TabStop property to "false" - no change.
In my opinion, the Enter key should activate the cancel button. Or are you requiring the user to reach out for the mouse? why?
I suggest adding just a confirmation dialog after the user cancels the operation, so if anyone accidentally presses the Enter key have the chance to resume saying 'no, I don't want to cancel'.
But as a user I would be annoyed if the Cancel button has the focus and I can't activate it pressing the Enter key on my keyboard.
My 2 cents
Add a default button with size 1x1, no caption, no border, etc. Make a handler for it that does nothing. The Escape key will still do a cancel as it does now.
Related
I did a SetFocus to a button in a dialog. The button gets the dashed outline. When the user presses the return key, the dialog get a IDOK message rather than a message from the button were I set the focus. The same thing happens under other circumstances.
Why is this happening? And how can I cause the return to act as a button press?
Plain c++ windows app, no MFC, no NET.
Feature, not a bug. The [Enter] key operates the button that's marked as the default button for a dialog. Either with the DEFPUSHBUTTON in the .rc file or the BS_DEFPUSHBUTTON style flag. Which is typically the "OK" button so getting IDOK back is expected. The [Escape] key is special that way too, typically the [Cancel] button. This is bound to ring a bell if you think back on how you used dialogs before.
You click a button that has the focus by pressing the space bar instead.
In another SO question I found KB article that might help you:
If a dialog box or one of its controls currently has the input focus,
then pressing the ENTER key causes Windows to send a WM_COMMAND
message with the idItem (wParam) parameter set to the ID of the
default command button. If the dialog box does not have a default
command button, then the idItem parameter is set to IDOK by default.
When an application receives the WM_COMMAND message with idItem set to
the ID of the default command button, the focus remains with the
control that had the focus before the ENTER key was pressed. Calling
GetFocus() at this point returns the handle of the control that had
the focus before the ENTER key was pressed. The application can check
this control handle and determine whether it belongs to any of the
edit controls in the dialog box. If it does, then the user was
entering data into one of the edit controls and after doing so,
pressed ENTER. At this point, the application can send the
WM_NEXTDLGCTL message to the dialog box to move the focus to the next
control.
According to MSDN,
Dialog Box Keyboard Interface
The system provides a special keyboard interface for dialog boxes that carries out special processing for several keys. The interface generates messages that correspond to certain buttons in the dialog box or changes the input focus from one control to another. Following are the keys used in this interface and their respective actions.
...
ENTER: Sends a WM_COMMAND message to the dialog box procedure. The wParam parameter is set to IDOK or control identifier of the default push button.
Since the system intercepts and processes ENTER key pressed directly through the dialog, you'll need to handle it in your dialog box procedure by calling GetFocus() to first see which control has the focus, and perform the appropriate action for that particular control.
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.
Im trying to create a password page similar to the one that opens up when you click Lock+wallpaper in the settings of the Windows Phone.
How ever I could not find a keyboard with the done and cancel, a done and cancel buttons along with the numeric keyboard is visible in the lock+wallpaper page when you toggle the password switch.
How do I get one similar to that? As as alternative I tried to create done and cancel buttons, but the problem is, the keyboard overlaps these buttons where as in the lock+wallpaper page, the keyboard stays and does not overlap the button.This should mean that the buttons are present along with the keyboard right?
Could anyone help me on this one?
There is no InputScope which add "done" or "cancel" buttons to the SIP.
Instead you should look to use the ApplicationBar and add buttons for each of these functions. FOr doen you could use an image of a tick or a save icon for "done" and a cross for "cancel".
Be careful not to add a Cancel button if you really don't need one as the hardware back button would suffice instead.
Is there a method such that a user can click on the form itself, and in doing so remove focus from whatever object (textbox, combobox, etc) currently has it? Basically, can focus be uniformly removed from everything at once?
Setting the focus to the form itself does not work.
I thought about doing the old "hide a placeholder button behind another object" trick, but I'm really not a fan of that.
Thanks!
In VB6 a PictureBox can get focus, even if it does not contain any control.
In your case you can put a PictureBox with TabStop false, BorderStyle set to 0, TabIndex set to 0 behind every other control but not containing any focusable control and stretch it to ScaleWidth by ScaleHeight at run-time.
You have to put the labels and any windowless control in this background PictureBox too.
This way when the user clicks "on the form" the focus will "go away". With "no focus" Tab key will focus first control (the one with TabIndex set to 1).
When a form is active, something generally HAS to have focus. It sounds like you're just wanting to not "show" that a particular control has focus.
If that's the case, it's going to depend on the controls. Some have properties that control whether or not the specific control "indicates" its focus in some way.
But the built in Windows controls will always show their focus state unless you subclass them
Given this problem. I'd probably put a button on the form , then move it offscreen when the form loads. Make sure it's not a tab stop, but then when you want to hide focus, set focus specifically to the button, make sure the button is STILL in the tab order, even though it's not a tab stop, so the user can press tab while on the button and end up somewhere logical.
Don't have VB handy, but could you simply remove TabStop?
for x = 1 to me.Controls.count
me.Controls(x).TabStop = 0
next
I have a picturebox and a control on a form.
Private Sub cmdButton_Click
PictureBox.setFocus
Exit sub
End sub
The control doesn't change its appearance, nor does the picturebox.
Of course you'll need to add an If-Then clause if you want the control to respond normally sometimes.
GUI: should a button represent the current state or the state to be achieved through clicking the button?
I've seen both and it sometimes misleads the user. what do you think?
The label on the button should reflect what the button does, i.e. it should describe the change the button makes.
For example, if you have a call logging system a button should say "Close Call" and the user can click it to close the call. The button should not have the label "Call is Open" and the user clicks to change the call status as that's very counter-intuitive, since the button is effectively doing the opposite to what it says on it.
In my opinion the label - and so the function - of a button should rarely, if ever, change. A button is supposed to be a like a physical button and they usually only do a single thing. (There are a few exceptions like play-pause on a media player where it's OK for the button label/icon to change, but at least this is copying a button from a real physical device.)
To carry on the example from above, I would say usually you would want two buttons, "Open Call" and "Close Call" and disable whichever one is not appropriate. Ideally you'd have a field elsewhere displaying the status of the call.
In summary, buttons are for doing things not for passing on information to the user.
The button should represent the action to be executed, not the state.
Some buttons are actions and are not ambiguous, like "Save", "Print" or "Enable user".
When a button represents a state that can be toggled, like Enable and Disable something, I do one of the following:
Change the button text, and make it always point to the state that will be achieved; (i.e. make the button point to actions, not states);
- Keep the button's text the same, but use one of those sticky buttons that will stay pressed, representing that the current state is "on" or "off". I prefer the former approach, though.
It should represent the action taken when clicking the button. States should always be presented by other means.
But I know what you mean. My car radio has buttons with text that shows the current state. It is really confusing.
This depends on the function which will be triggerd by the button click.
if the click changes the state of an entity i would suggest that the button represents the state the entity will enter after clicking the button
if the click triggers some kind of functionality the button should represent the function.
The appearance of the button is also a clue to its state. It should follow the standards of the environment if any exist (example, beveled edge / shadow appears on mouse click in Windows).