GTK+3 disable the close icon present in a window (c program) - c

I'm developing a GUI in Linux (Ubuntu 16.04 - WM: Gnome) using GTK+3 and the graphic library cairo.
After clicked on a push button (Plot), using the instruction of cairo I draw a red square on a new top window where I put a GtkDrawingArea.
In this window I also put a push button (Cancel) that clicked, hide the window. In this way, if I re-push "Plot", the red square reappear.
The issue is the "x" icon present in the top bar of the window.
If (no me) a user push this x, the window disapper and if he re-push the "Plot" an error is reported.
The question is: it is possible avoid this possible cause of error?
(remove this "x" from the top bar of the window or in some way disable its functionality).
I tryed to find alone a solution and the possibility found are:
1 - Remove from the window the property of "decorated".
The top bar disapper (so also the x) but is not possible move the window on the screen
2 - Using the function gtk_window_set_deletable(window, FALSE) (used before to show the window), but the x is always there and pushing it the window is destroyed.
If you think that can be useful, I can report the code.
I'm waiting your suggestion.

Edit:
Now we know what you want to achieve: display a separate window but avoid destroying it so you can display it again. You already have in the "Cancel" button of your secondary window the logic to hide it.
The cleanest solution is to just do the same: when the user tries to close the secondary window, hide it instead. This way the user is not frustrated of seeing something that apparently doesn't work as expected. Hidden or closed, it's different for you but it's the same for the user.
So you just need to connect to the delete-event of that secondary window, and hide it. There's even no need to create a specific callback for that, GTK+ provides it for you: you just need to connect the delete-event to gtk_widget_hide_on_delete. To display the window again, just call gtk_widget_show_all on it.
Original answer:
I realize the plot
"realize" is a term that has a defined meaning in GTK+. Don't use it out of context, and try to use an alternate term if you're not talking about widget realization.
What I would like is to remove this "x" from the top bar of the window
or in some way disable its functionality.
Do you understand this is ultra annoying for a user and defeats a unified user experience? Would you like to use applications that do random different things?
Anyway, one way of disabling the closing button is to connect to the delete-event and return TRUE there to stop the propagation of the event. The button will still be there but do nothing, so you will have to kill the app to exit it.
To make the button disappear, gtk_window_set_deletable will ask the Window Manager to do that, but we'd need some code to know what's wrong with your attempt.

Related

Maya drop down menu

I've got a pretty complex question for any Maya coders...
I want to utilize a drop down menu similar to that of the cmdScrollFieldExecuter's [script editor's] "Show Tooltip Help". It looks like a window that has been appended to the bottom of the inputted text with a feedback of all relative commands or strings.
Does anyone have experience with appending a similar textbox/ window/ menu to typed input, and if so, can you toss me in the right direction?
Note: I am not talking about "optionMenu".
Alternatively, is there a way to get cmdScrollFieldExecuter to reference a different array or set of strings?
A complete port of that won't be possible in vanilla Maya - You'd need to use python and QT because the built-in GUI objects (such as TextField) don't fire any events on keypresses so you won't be able to live-update as the user types.
You can almost fake the visual appearance with a window whose title bar is set to off. Use a formLayout to dock a TextScrollField inside it. You'll need to hack up some way of dismissing it since it won't have a close box -- you could put it on a timer or add an invisible button covering the whole thing which closed the window when clicked

Ext.js 4.x Dock-able window as tab

Has anyone seen an implementation or plugin for extjs where you can "pull off" or "dock" tabs/windows the way you can with a browser? Is it even possible?
Searching has not revealed much but I did come across a proposed solution in an older version:
http://www.sencha.com/forum/showthread.php?16842-Dockable-floatable-panels-in-ExtJS
#DmitryB
To clarify, in chrome if I have multiple tabs in the same window like so:
And I "drag" one of the tabs, it pops off into a new window:
I imagine you might accomplish this by moving the content of the tab panel into a window but not sure how to go about it.
In a nutshell:
- Make the tabs draggable, watch for the drag event and mark the
tab-strip as your "safe" zone
- When a tab is dragged and then "dropped" (as in, the drag event ends) you do a check:
> Is the tab within the safe area?
No: Create a new Ext.Window at the x/y of the mouse, copy the components/HTML
out of the original panel and insert them into the new window. Destroy the
original panel.
Yes: Do nothing.
Unfortunately, I am still quite jaded from learning D&D in ExtJS3, so I can't offer any help with this and real code pertaining to ExtJS 4, however the concept seems relatively straightforward to me. I would say you're going to probably want to do your best to NOT have this be flashy - unless you REALLY REALLY need to, I wouldn't worry about showing the panel's contents while you drag the tab - much less show the panel itself. Just let the tab element get dragged around the screen and copy when it's released outside of the safe zone.

How to put a close button in main window menu?

I'm looking to add a 'close' button to my main window's menu. An example can be found in the picture here: http://ifyoucodeittheywill.com/img/crimson-editor.png
(So, there's the normal close button in the window caption area, but, there's also a close button in the window's menu bar -- on the far right).
I'm using basic win32 API's, though an example using MFC would also be fine.
Does anyone know how to do this?
Thanks,
Andrew
These buttons usually come with MDI windows. However I'm pretty sure the depicted application uses either its own, or more probably some advanced third party toolkit. Because, to be honest, what the Windows API and MFC (which is just a classed wrapper around the windows API) give you for GUI programming is unbareably limited.
If you want to design neat UIs steer clear from MFC and better have a look at something like Qt, wxWidgets or the like.
A really simple way of doing this is to use a regular menu item, using AppendMenu, but use the following flags:
MF_BITMAP with a close button bitmap, or MF_OWNERDRAW or to draw it yourself
MF_HELP (aka WM_RIGHTJUSTIFY), a not-very-well documented flag, which will justify the item to the right.
Here's one reference to MF_HELP that I found on msdn - it's actually about using the Win32 API to right-justify a menu item, but using Visual Basic.
MF_HELP (defined in winuser.h) is something of a holdover from Win16 days, back then, the convention was to right-justify the Help menu item, so it would stand apart. It was 'renamed' - an additional #define added with the same value - to WM_RIGHTJUSTIFY around Win95.
Note that bitmap menu items aren't accessible (eg. to users that are relying on a screenreader to read out where they are on the screen); if taking this approach, then at least add a regular 'Close' menu item elsewhere in the menus (eg. under File), so that a user doesn't have to rely on this item, and can also close it through usual means. Also be sure to implement the Ctrl-F4 shortcut, which is what most applications that support multiple documents or tabs use to close the current item.
By all means do not try to create this behaviour yourself. This is functionality that you get "for free" if you are using the MDI architecture of MFC. The close button "next to the menu" as you call it closes the active MDI child window. If you are not using the MDI architecture then there is no point in trying to add a close button there. Can you explain if you are using the MDI architecture?

How can I disable the Start button (but not the Taskbar) on Windows 7?

On Windows XP, it was possible to disable the Start button with the following code:
hTray = FindWindow (TEXT("Shell_TrayWnd"), NULL);
if (hTray)
{
hStartButton = FindWindowEx(hTray, NULL, TEXT("Button"), NULL);
if (hStartButton) ShowWindow(hStartButton, FALSE);
}
For a public-access computer configuration, I need to be able to do this on Windows 7. The Start button must be disabled (not just hidden), and the remainder of the Taskbar must still be visible and usable. Hiding the Taskbar along with the Start button is not an option. Running full-screen is not an option. Using "Start Killer" won't work because it doesn't actually disable the Start button, just hides it (users can still use hotkeys to pull up the Start menu).
I have already tried the method that uses FindWindowEx with 0xC017 as its third parameter and then tries to disable that window. It doesn't work. That method only works if the whole Taskbar is disabled first. What I need is a method that only disables the Start menu, just like the code I reproduced above does in XP.
Any help is greatly appreciated.
The "correct" version for Windows 7 is as shown below:
HWND hStartBtn = FindWindowEx(NULL, NULL, MAKEINTATOM(0xC017), TEXT("Start"));
if (hStartBtn != NULL)
{
ShowWindow(hStartBtn, FALSE);
}
However, this only disables the button, meaning you won't get the glow or other effects by hovering your mouse cursor over it. You can still click the button region on the taskbar to open the menu. Apparently, the click handler is now implemented in the taskbar window itself, not as part of the separate Start button. That's why you have to disable the entire taskbar first, and consequently why most of the solutions you've found online do precisely that.
However, it looks like the "Start Killer" application now has functions to disable the most common hotkeys that trigger the Start menu, namely Ctrl+Esc and the key. You'll find those options by launching the software, right-clicking on its icon in the taskbar, and selecting "Options" from the menu. You can also edit the Registry to disable the Windows key, as described in this knowledge base article. If you wanted to implement this same functionality yourself through code, the only solution would be a low-level keyboard hook that trapped the keypress events that are responsible and discarded them.
Undocumented hacks like this one are given to breaking with newer versions of Windows. I imagine that Raymond Chen would chuckle and say something like "I told you so". Hacking the Windows interface is a fool's errand. Or, as you say several times in the question, "is not an option".
IS there anything in particular about the start menu you need to disable? You may be able to do the same via policy settings or various other file permissions.
Use one of the available group policies listed here.
You did not mention why you want to disable the start button. If you think about what exactly it is that you don't want your users to do instead of telling us the solution you picked for it (i.e., "disable the start button"), you might come up with a much better solution.
For example, if you want to prevent users from changing certain settings, block that, not the start button!
Or if you don't want them to see all the installed apps, hide those apps instead of the start button!
Or...
(I hope you see my point here).

In forms application, is there any Alternative to MsgBox?

I like how MsgBox stops all further processing until it's clicked but I don't like how it pops that little msgbox in the middle of the screen. Is there a way to do something like a msgbox but keep it on my Form (which is always in view) so I can go ahead and click a button on the form instead of having to bring the little msgbox window on top of windows that may be covering it.
I use the msgbox to inform me that a certain situation has happened, which I manually fix and when I'm done I click the MsgBox to continue processing. It'd be nice to have this button right on the form.
which I then have bring to the front if there is a window covering it
That shouldn't happen, but can happen if you display the message box from a thread in your program. The window has the desktop as the parent and has no Z-order relationship with the windows in your user interface. And yes, can easily disappear behind the window of another app, including your own.
There's a MessageBoxOptions option that isn't exposed in Winforms, MB_TOPMOST, which ensures the window is top-most. You'd use it like this:
MessageBox.Show("text", "caption", MessageBoxButtons.OK,
MessageBoxIcon.Information, MessageBoxDefaultButton.Button1,
(MessageBoxOptions)0x40000); // use MB_TOPMOST
But by far the best thing to do is to display the message box on your UI thread. Use Control.Invoke() to do so. That way the other windows of your app are disabled, no way for the user to not notice the box.
Still one problem with this, the user won't expect the box to show up since it is shown asynchronously from anything she does. Which means the box can easily get dismissed by accident when the user just happened to press the Enter or Space key. Or clicked at just the wrong spot. Nothing much you can do about that.
Centering the box in your main window is technically possible, but fugly to do. Check this answer.
Do you mean that the form shall exchange its contents with a message plus an OK button?
This would be similar to the way a text mode interface typically works.
You can make it happen by adding a disabled panel or UserControl with message and button topmost on the form and enable it when you wish to alert the user. However, I am puzzled how to implement the blocking behavior similar to MessageBox.Show() and Dialog.Show().

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