Did you know SD-WANs can improve network connectivity? Check out this webinar to learn how an SD-WAN simplified, one-click tool can help you migrate and manage data in the cloud.
Course Of The Month
Become a Premium Member and unlock a new, free course in leading technologies each month.
Solved
MVC with a twist.
Posted on 2006-11-09
Hi all,
Old programmer, getting there with Java, new to GUI.
I want to put together a GUI that handles interrelated models. The model is a Person object in a family tree. The view will initially just be a box with the person's details shown in it, linked with lines to parents, siblings and children. The controller will obviously bind these two together.
I want to allow the user to move from person to person, up to parents, left/right to siblings and down to children, probably with cursor keys.
My problem is this. The view can recognise the user operation, say 'select father'. It must then ask the model (a Person object) to identify which person is its father. But how can that mechanism then indicate which controller or view should be signalled to take focus?
Clearly I could create a Map that lets me find the controller responsible for the parent of the person but this feels like breaking the whole advantage of the MVC pattern. Is there a 'good' way of dealing with this?
Paul
Old programmer, getting there with Java, new to GUI.
I want to put together a GUI that handles interrelated models. The model is a Person object in a family tree. The view will initially just be a box with the person's details shown in it, linked with lines to parents, siblings and children. The controller will obviously bind these two together.
I want to allow the user to move from person to person, up to parents, left/right to siblings and down to children, probably with cursor keys.
My problem is this. The view can recognise the user operation, say 'select father'. It must then ask the model (a Person object) to identify which person is its father. But how can that mechanism then indicate which controller or view should be signalled to take focus?
Clearly I could create a Map that lets me find the controller responsible for the parent of the person but this feels like breaking the whole advantage of the MVC pattern. Is there a 'good' way of dealing with this?
Paul
[X]
Welcome to Experts Exchange
Add your voice to the tech community where 5M+ people just like you are talking about what matters.
- Help others & share knowledge
- Earn cash & points
- Learn & ask questions
-
2
-
2
4 Comments
View represents the front-end User Interface.
Controller represents the object which gets the values from user interface, calls appropriate classes and forwards a response back to the view.
Model represents the Object which holds the information in the front-end view and passes it over to the controller when controller is invoked
>>>But how can that mechanism then indicate which controller or view should be signalled to take focus?
You would have a single "controller" which would control the entire application.
You would have multiple "views", for parents , children, siblings, ect and you would have their corrosponding objects as Models.
I am not sure if you have followed the MVC architecture correctly.
Some refrences which might help:
http://www.enode.com/x/markup/tutorial/mvc.html
http://cristobal.baray.com/indiana/projects/mvc.html
Controller represents the object which gets the values from user interface, calls appropriate classes and forwards a response back to the view.
Model represents the Object which holds the information in the front-end view and passes it over to the controller when controller is invoked
>>>But how can that mechanism then indicate which controller or view should be signalled to take focus?
You would have a single "controller" which would control the entire application.
You would have multiple "views", for parents , children, siblings, ect and you would have their corrosponding objects as Models.
I am not sure if you have followed the MVC architecture correctly.
Some refrences which might help:
http://www.enode.com/x/markup/tutorial/mvc.html
http://cristobal.baray.com/indiana/projects/mvc.html
>>I am not sure if you have followed the MVC architecture correctly.
LOL :-)
Nice links! I'll browse through those later.
So the Model is the object, a Person object in my case. This has the responsibility of HOLDING the data.
The box with text in is the View. This has the rsponsibility of DISPLAYING the data.
Who controls user interaction, the view or the controller?
It the data is interrelated at both the model level and the view level (parent, child, sibling) and the controller distributes UI events to the view, how can the view indicate to the controller that focus should be changed or window should be scrolled for example?
Do you see my quandary? I fully agree that the model must be separated from the view, that would allow me to change the view seamlessly, but how can the view tell the controller to scroll the window if it is independent of the controller?
Paul
LOL :-)
Nice links! I'll browse through those later.
So the Model is the object, a Person object in my case. This has the responsibility of HOLDING the data.
The box with text in is the View. This has the rsponsibility of DISPLAYING the data.
Who controls user interaction, the view or the controller?
It the data is interrelated at both the model level and the view level (parent, child, sibling) and the controller distributes UI events to the view, how can the view indicate to the controller that focus should be changed or window should be scrolled for example?
Do you see my quandary? I fully agree that the model must be separated from the view, that would allow me to change the view seamlessly, but how can the view tell the controller to scroll the window if it is independent of the controller?
Paul
Perhaps I have been confused by some sample code I found. It assigns a controller for every person. Is this unusual or normal?
Paul
Paul
>>>Who controls user interaction, the view or the controller?
The Controller . Controller is the boss :)
>>>how can the view tell the controller to scroll the window if it is independent of the controller
Each view (in MVC) has a unique "mapping" to the controller...meaning , for instance lets say there are three views
Parentview, Childview, Siblingview. Now all these three views call the controller in three different UNIQUE ways , so the controller knows WHO is making the call(parent, child or sibling).
The Controller . Controller is the boss :)
>>>how can the view tell the controller to scroll the window if it is independent of the controller
Each view (in MVC) has a unique "mapping" to the controller...meaning , for instance lets say there are three views
Parentview, Childview, Siblingview. Now all these three views call the controller in three different UNIQUE ways , so the controller knows WHO is making the call(parent, child or sibling).
Featured Post
Question has a verified solution.
If you are experiencing a similar issue, please ask a related question
Java Flight Recorder and Java Mission Control together create a complete tool chain to continuously collect low level and detailed runtime information enabling after-the-fact incident analysis. Java Flight Recorder is a profiling and event collectio…
International Data Corporation (IDC) prognosticates that before the current the year gets over disbursing on IT framework products to be sent in cloud environs will be $37.1B.
Viewers will learn about if statements in Java and their use
The if statement:
The condition required to create an if statement:
Variations of if statements:
An example using if statements:
This video teaches viewers about errors in exception handling.
Suggested Courses
Earn Certification
HTML5 Specialist - Certification
Free withPremium
Course of the Month6 days, 5 hours left to enroll
627 members asked questions and received personalized solutions in the past 7 days.
Join the community of 500,000 technology professionals and ask your questions.