python - gui design question -

-

i use tkinter, question general.

this first time i'm designing gui. each of objects modeled class. don't understand how tie gui class hierarchy rest of class hierarchy.

for example, have creatures:

# before had gui in code class creature:   def current_position() # returns real-time x, y coords     # ...

i want display them circles move around on canvas. seemed reasonable me graphical representation of movement should provided method update_display in class creature. however, means class creature has know details gui. in addition, class app(tkinter.tk) redraw method need know list of existing creature instances in order call update_display methods. that's way dependency.

what's right approach?

the accepted pattern called model/view/controller. have controller object both knows creatures (your "model") , gui (your "view"). controller responsible connecting two. example, view have "draw_creature" method accepts creature input. controller iterate on creatures, passing one-by-one view. or, each creature has "draw" method accepts view parameter, , view asks each creature draw itself, passing reference view.

with pattern in place have multiple views creatures don't have updated know them. likewise, change how store , manage creatures , view doesn't need know that.


Comments

Post a Comment

Popular posts from this blog

java - SNMP4J General Variable Binding Error -

-
i trying use snmp4j snmp bulkget. when ever use snmp4j make call returned responseevent error says "general variable binding error" , data returned equal null. to debug: print out, console, exact oid , version number using in snmp4j. use printed out data snmpwalk on command line. valid results. know sending snmp4j correct pdu correct oid, version number, max repititions, etc. i have used snmp4j , code wrote succesffuly monitor other devices years. don't know different time. leaving me stumped. why "general variable binding error?" causes error? ideas debug? can reproduced? if so, first action should using wireshark or microsoft network monitor capture network packets. my guess agent gives generr response, not surprising, http://www.ietf.org/rfc/rfc1157.txt
Read more

windows - Python Service Installation - "Could not find PythonClass entry" -

-
i working on building python service. inducing error, not sure inducing it. ps c:\...> python .\file.py debug debugging service myservice - press ctrl+c stop. error 0xc00000f4 - not find service's pythonclass entry in registry error 1814 - specified resource name cannot found in image file. error 0xc0000080 - not locate module name in python class string (ie, no '.') this error coming pythonservicemessages.mc in pythonwin32. it turns out error result caused exception being thrown , python script dying off.
Read more

Determine if a XmlNode is empty or null in C#? -

-
the following code takes xmlnode data type , populates dataset object xmlnode content. write dataset's content file. public void populatedataset(xmlnode node) { xmlnodereader reader = new xmlnodereader(node); dataset ds = new dataset(); ds.readxml(reader); system.guid guid = system.guid.newguid(); string name = string.format("{0}{1}_{2}.xml", utility.xmloutputpath, utility.xmloutputfilename, guid.tostring()); //need write "node empty" file if xmlnode object empty of null ds.writexml(name, xmlwritemode.ignoreschema); } the problem encountered 1 scenario not write content file. how determine if xmlnode object null or empty? you can check if node parameter null or has innertext or innerxml properties null or empty, when enter method before creating xmlnodereader .
Read more