Below are two questions on the same component:
Which signal is triggered when the mouse passes over a Gio.MenuItem?
How to implement a tooltip for Gio.MenuItem?
Gio.MenuItem is a direct descendent from GObject.GObject (See https://lazka.github.io/pgi-docs/Gio-2.0/classes/MenuItem.html). It does not have any signals itself, and only receives a notify signal via its descent from GObject.
As Gio.MenuItem is not a widget, it does not receive any signals from the GUI. It only represents data (opaque data at that).
I suspect you want Gtk.MenuItem, which is the visual component.
EDIT It seems the widget you are after is Gtk.PopoverMenu. Just to be clear, Gio.MenuItem is not a visible item, which is why I replied as above. Gtk.PopoverMenu is a widget (widget = a visible item).
PopoverMenu is the visible widget, and you can see how it fits together with other widgets. It inherits from Popover, which inherits from Gtk.Bin, Gtk.Container and finally from Gtk.Widget.
So, you have all the signals from those widgets, but those are for the 'complete' Gtk.PopoverMenu, not for the individual items.
According to this definition, the individual items are Gtk.ModelButtons, so you might be able to access them that way.
The solution to get this was much further than I thought. I always suspected that the Devhelp's menu could not be built using GtkPopoverMenu because my OS uses gtk 3.14. The solution involves a totally new concept of running an application, proposed by Gtk.Application interface and the Gtk.Action features. These "new" concepts can be studied in the following places.
http://python-gtk-3-tutorial.readthedocs.io/en/latest/application.html?highlight=Gtk.Application
https://wiki.gnome.org/HowDoI/GtkApplication
https://github.com/Programmica/python-gtk3-tutorial/blob/master/_examples/application.py
Apparently tooltip features are not available for this menu type.
Related
I am learning hybris and I am stuck at widget creation. While creating a widget there is a tag , what does it do and why it's used?
Let's cover the basics first:
in the Backoffice, everything you see is a widget
widgets declare so-called "sockets". Widgets can send and receive events on sockets (the same idea as "signals and slots" from Qt, for example)
And now you may ask yourself:
How can I configure which widgets sends data do which other widget?
And that's where widget-connection comes in. With this tag, you can define that the data/event emitted by widget A on slot A1 is received by widget B on slot B2, for example.
Check out the "Backoffice Framework Architecture" page on help.hybris.com and all the sub-pages underneath it for the in-depth explanation for all Backoffice concepts
I am a newbie to xaml and windows app dev so sorry if this question might seem silly.
I created a textbox and in the designer I right clicked it and selected edit template=>edit a copy and put it into my custom dictionary.
In the control template for this textbox I saw visual states like disabled,focused and so on. And I modified them and run the mobile app and observed that my changes work like changing border color when textbox is focused.
But in order for this to work somebody has to call
VisualStateManager.GoToState("Focused")
when the textbox is focused so who is calling this because I don't see any visual transitions in the control template so how is this happening?
The code in the control itself is calling VisualStateManager.GoToState(...) .
When you start implementing your own custom controls, you might subscribe to events you have available and transition states based on your own logic. Here is an example of a custom control with its own two custom states.
https://github.com/xyzzer/WinRTXamlToolkit/blob/master/WinRTXamlToolkit/Controls/WatermarkTextBox/WatermarkTextBox.cs
XAML is a compiled language, and if you've looked extra close, what happens under the hood, is that the class behind your xaml has the same namespace as your xaml code.
This means (for no practical purpose) that compiling your program turns all of that XAML into C# code before then going over to MSIL and eventually execute as a binary program.
Much of the state changes that happen are event based, and TextBox, like all other user controls, will transmit a message and listen to messages. The Page that contains the TextBox will probably be the one that transmits a state change whenever one of it's children gets focus, and as a good control, the TextBox listens for this event and reacts to it.
I'm working in a legacy application using MFC.
We have a mechanism to enable/disable controls depending on some business logic.
This mechanism is implemented in the CView-derived class. The way it works is all the views in the application derived from a common CView-derived class (CBaseView) and on the PreTranslateMessage all controls of the view are enabled/disabled.
This worked fine so far because all controls send at least WM_PAINT message when they need to be painted. So the system worked without the user having to move the mouse or anything. I recently added some drawing features and I had to use WS_EX_COMPOSITE to get ride of some flickering. With this flag activated my CView-derived class is not getting any called to PreTranslateMessage when creating the view....so the controls are not disabled until the user moves the mouse over the control.
I understand there is no way to send WM_PAINT using WS_EX_COMPOSITE but is there other message I can use to get the same behaviour???
Edited:
I am currently using the OnIdle approach but it has a big drawback, the windows doesn't become idle until after drawing all the controls...so when you enter the screen al controls are enabled and inmediately they are disabled...this makes a quite ugly effect!
More solutions???
Thanks in advance...
The logical place to enable/disable controls would be CView::OnUpdate, it is called by the framework after the view's document has been modified and from OnInitialUpdate(); you can also call this function if there is some change that would trigger re-evaluation of your business logic.
EDIT
After reading the question a bit more closely, what you could also do is to post a private message at the end of OnInitialUpdate and "catch" it in your PreTranslateMessage:
PostMessage(WM_APP, 0, 0);
Calling InvalidateRect followed by UpdateWindow against the window in question will mark the entire client area as dirty and force an immediate repaint. Remember that WM_PAINT is not really a message, in the queue in the usual sense, it is pushed out after all other messages have been processed for that window, which would include any invalidations of the area being drawn. No message is generated at all if there are no invalid segments of the active window display.
I have a core data document based cocoa app that is working well except for one slightly odd problem.
For some reason, if I make a change to any of my fields the menu/window don't seem to recognize it - ie. the red close button doesn't get the black 'dirty' indicator and the File/Save menu item isn't enabled. However, if I attempt to close the application (via command-Q), I do get the popup asking me if I want to save my changes.
It seems that the document's dirty flag is being set, but the window/menu items aren't reacting to it. I am curious as to where I might look to see why this might be the case. I suspect that it may have something to do with my window not knowing about my ManagedObjectContext...
The only slightly atypical behaviour is that my document's makeWindowControllers method has been overridden and I am adding my window controllers using a call to my document's [self addWindowController:xxx] method. My window controllers subclass from NSWindowController so I had to add my own instance variable to each window controller to hold the ManagedObjectContext, but I suspect that this isn't getting passed to the window/menu. Not sure what the normal pattern is here...
Anyway, any thoughts would be much appreciated. Thanks
From the description it sounds like your UI elements are not actually bound to the document itself. If so, then the UI elements are not observing the document and are not reacting to changes in the document. Check the bindings.
Thanks in part to TechZen, and also re-reading my own question (in particular, where I said "I suspect that it may have something to do with my window not knowing about my ManagedObjectContext") I started to look at the bindings for my WindowController subclass.
As it turned out, I hadn't bound the window outlet for the File's Owner to my actual NSWindow. As soon as I did that, the black dirty dot and the window's menus started behaving correctly.
I have a Glade GUI description file with a GtkTreeView in a GtkHBox in a window; and there's a handler for the row_activated signal. Now, Glade has automatically set the "events" property (inherited from GtkWidget) of that treeview to some value (GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK). And there are two strange things with this:
removing the pre-set value (so that the property is empty) doesn't seem to break the application (at least not with the old GTK 2.10 I have atm).
in fact, an annoying bug I has seen before (where the treeview items would not correctly react to expand or collapse clicks) is now gone!
I have yet to test this with a newer GTK version, but the question is already there: exactly what is the purpose for this events property? And why does Glade automatically and unnecessarily set it to some value? Does this have some side effects I'm not aware of?
It's a bug in glade, it always sets the event property of widgets it create. It has no notion of the default value of a property so it always sets it.
Doesn't this mask indicate the events you're willing to receive? In this case, you'll probably want to receive notification that the user has clicked or double-clicked an item in the GtkTreeView, and you'll want to register callbacks to handle these events.
me.yahoo.com/a/kUQ7zeQ: but even if I set the property to an empty string as mentioned, the row_activated handler is still called when I double-click on a row (or press Enter or Space). So the treeview still gets events...