I want to write GUI code that is orthogonal. Lets say I have a circle class and a square class and they need to interact. Right now, to get the circle and square talking to each other - say the circle object sends a message to the square object, I would use something like square_obj.listen_for_circle(circle_obj) where listen_for_circle is a method that implements an addlistener.
This is a problem for me since now the two objects are linked - and removing one object from my code would break it. What I am looking to do is for the circle_obj to be able to broadcast a global message say 'CIRCLE_EVENT'. Additionally square_obj would be listening for global message broadcasts of type 'CIRCLE_EVENT', and upon hearing the event - does some action.(Ahhh, now the objects have no links to each other in the code base!)
Is this possible or even reasonable in MATLAB? (or maybe i'm just going crazy).
As always, advice much appreciated.
I'm not really sure why addlistener is problematic for you. It basically just adds an event listener that doesn't do anything if the event-origin object (the circle) is deleted.
Alternately you can use event.listener or handle.listener. They are undocumented but work well, and are widely used within the Matlab codebase (m-files). See explanation here: http://UndocumentedMatlab.com/blog/continuous-slider-callback/#Event_Listener
Related
I'm trying to transfer all graphical objects from one figure to another, by changing the object's 'parent'.
The problem begins when I try to execute the object's callbacks (in this case a pushbutton) after reparenting.
I suspect it has something to do with the object's callback handle, but I'm not quite sure how to solve this.
Any solutions?
Thanks!
What is the difference between those two methods? Why should i prefer one?
1)
GameObject.FindGameObjectWithTag("").GetComponent<Rocket>().active = true;
2)
GameObject.FindGameObjectWithTag("").GetComponent<Rocket>().SendMessage("setActive");
thanks!
Sending a message searches through all the components of the gameObject and invokes any function that has the same name as the message. Not a 100% sure but Im sure this uses reflection which is generally considered slow.
SetActive() or the active variable set the gameObject as active or not. If its not active it wont render in the scene and vice versa.
First of all it seems there are several inconsistencies with your code above:
1) Components (and MonoBehavior) don't have an active property (active belongs to GameObject), so the first line of code shouldn't compile. In addition the most recente version of unity don't have active anymore, it's substitued with activeSelf and activeInHierarchy.
And btw, both activeSelf and activeInHierarchy are read only, so you can't assing directly a value to them. For changing their value use SetActive method.
2)
The second line of code shouldn't work either (unless Unity does some magic behind the scenes) because SetActive methods belong to GameObject and not to your Rocket Component.
Now, I suppose your question was the difference between:
gameObject.SetActive(true);
and
gameObject.SendMessage("SetActive",true);
The result is the same, but in the second way Unity3D will use reflection to find the proper method to be called, if any. Reflection has an heavy impact on performance, so I suggest you to avoid it as much as possible.
Is there any way to monitor all signals emitted from a widget with GTK3? I know that the event signal is emitted before an event, but I'm not sure of the distinction between "event" and "signal" in GTK terminology - as this does not seem to capture all signals.
I know GDK has a function gdk_set_show_events but this mostly shows events which are sent to the window from the operating system. Is there a GTK3 equivalent?
There is not built in function AFAIK, but I'm sure you can hack something together yourself:
Use g_signal_lookup to get all signal ids for a gtype. Then use g_signal_add_emission_hook on each signal of your instance to register a hook to be called whenever that particular signal is emitted. Inside the hook function, you're provided with the signal id via *ihint, from which g_signal_query should provide you with all the information you need to print debug messages. (I didn't test it, but it should work)
Note that this will unfortunately not work for signals defined with G_SIGNAL_NO_HOOKS.
Use g_signal_lookup to get all signal ids
It's a little more complicated than described. In order to use g_signal_lookup, you first need a signal-name. If you want to monitor every signal independent of the object-type, you first need to list all signals of the specific instance-type. This can be arranged by g_signal_list_ids for exactly one single GType. To get really ALL signals emitted on the instance, you need to iterate over all parent-types of this instance. You can do this by using g_type_parent.
I have build some utility-functions by myself, that provide this functionality for the same debugging purpose the question was intended. You can connect an Emission-Hook for all signals of a GObject-instance with gemu_glib_util_connect_to_all_signals or connect an emission-Hook to a GtkWidget-instance and all its children with gemu_gtk_util_signal_connect_to_widget_children.
Simple question:
I've added some scales (sliders) to my window, and I want to call a method when you move the scale.
What is the signal name that I use for gtk_signal_connect?
ie I should be able to write something like:
gtk_signal_connect(GTK_OBJECT(my_scale), "scale_moved", (GtkSignalFunc)my_event, data);
or am I missing something here?
And more importantly - how do I find out in the future what the signal names are? for example - I googled 'gtk_signal_connect' but I didn't find a big list of different signals.
Similarly, I didn't find details about related signals in the GtkScale documentation. (Well, in this page, there is a single signal detail, but it relates to changing the displayed value format).
GtkScale inherits from GtkRange, and signals are inherited in GTK+. Therefore, you can connect to the value-changed signal exposed by GtkRange.
You're on the right track to find the signals exposed by a given GTK+ widget: besides the source code itself, the documentation is indeed the canonical resource, but you should also take the base classes into account in your search.
I have a gtk.Fixed. I move components inside it around using:
myFixed.move( myEventBox, new_x, new_y )
What event do I listen for to know when myEventBox has been rendered at its new position?
Do I connect to the fixed or the eventbox?
MORE INFO:
I need this information so I know when it is safe to queue a video under the eventbox... if I do it too soon (e.g. right after calling myFixed.move) I can see the glitch. Currently getting around this with a gobject.idle_add.
To be honest, I am not aware of any such event. The object should move immediately and redraw the screen, but I don't think any signal is emitted when that happens.
The PyGTK documentation is very comprehensive, and it will list all of the functions and events of every object in the library. In searching (through both the gtk.Container (for fixed) and gtk.Widget (for fixed and eventbox) signal lists, I can't find any such event. The closest thing is an "add" signal in gtk.Container, but I don't think that's what you're looking for.
If the object is not moving, please post your code, because there is probably a subtle error.
If the object is moving just fine and you just want the event/signal, you may have to simulate it yourself. Write the function you want to be called as soon as the object is moved in a function (def) inside "__ init __", and then call that function in code in the line right after "myFixed.move".