• Member Avatar for JamesCherrill
    JamesCherrill

    Replied To a Post in Keyboard GUI

    The integer values you need for the keys are those defined in the KeyEvent class. Otherwize looks OK so far.
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    JamesCherrill

    Replied To a Post in GA Elitism values strange

    Without actual code one can only make wild guesses, for example: When you copy the populations is that a shallow or a deep copy? Maybe its a shallow copy and …
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    JamesCherrill

    Replied To a Post in Array of object

    Java arrays start wil element [0], so element [1] is the second element. A new array of objects will initially have all its values as null. If you haven't initialised …
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    JamesCherrill

    Replied To a Post in Trying to avoid AWT classes in Swing GUI

    Agreed. BufferedImage was OK as it was, so there was no need to replace it. It's still the one to use.
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    JamesCherrill

    Replied To a Post in Array of object

    Your use of Arrays.toString is correct (no need to loop) it converts each element of the array to strings and lists them all. The problem is that the first element …
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    JamesCherrill

    Replied To a Post in Array of object

    "It doesn't work" tells us nothing. Would you take your car into the workshop and just say "there's something wrong with it" and expect the mechanic to fix it? Did …
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    JamesCherrill

    Replied To a Post in Keyboard GUI

    Yes, yes and yes
  • Member Avatar for JamesCherrill
    JamesCherrill

    Replied To a Post in Keyboard GUI

    A good example of why you shou;dn't start with the GUI details! Think about the heart of the program. When the user types a key you want to make changes …
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    JamesCherrill

    Replied To a Post in Arrays

    Maybe the code isn't of the highest professional standard, but honestly it's not particularly messy either. Good enough for an early-stage learner. So what EXACTLY do you need help with?
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    JamesCherrill

    Replied To a Post in Keyboard GUI

    Given that the buttons don't actually do anything, or have any data associated with them, I can't see any need for anything more than a vanilla JButton. Oh well, I …
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    JamesCherrill

    Replied To a Post in Keyboard GUI

    OK - I thought the idea was to be able to type on the screen? If it's not going to respond to touches then why use JButtons? Anyway - to …
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    JamesCherrill

    Replied To a Post in Keyboard GUI

    I would create a class, something like... class KeyButton extends JButton implements ActionListener { char normalChar, shiftedChar; int width; static int HEIGHT = 20, DEFAULT_WIDTH=20; public KeyButton( char normalChar, char …
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    JamesCherrill

    Replied To a Post in Keyboard GUI

    Thinking about this a bit more... it's a very interesting exercise. As soon as you think about the modifier key(s) it has great scope for good or bad design. It's …
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    JamesCherrill

    Replied To a Post in Keyboard GUI

    > so rather than GridBagLayout, do you think that GridLayout is a better idea? Apart from rows 2/3 the keys do not line up vertically, so the whole thing is …
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    JamesCherrill

    Replied To a Post in Keyboard GUI

    Looks reasonable to me - except I don't see why you have a panel (line 5) with only one thing in it - just add the text area directly. For …
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    JamesCherrill

    Replied To a Post in event handlers: anonymous inner class or not

    I just hate those if else if handlers. How about a reusaable parametised inner class class FontResizer implements ActionListener { int delta; FontResizer(int delta) { this.delta = delta; } public …
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    JamesCherrill

    Replied To a Post in event handlers: anonymous inner class or not

    Agreed, provided the reason for using for several components is that there is a lot of commonality between them (see example in previous post!). In beginners code we often see …
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    JamesCherrill

    Replied To a Post in JavaFX and Object Oriented

    I don't have alot of time at the moment, so here's a short version. The only thing that should be static in this app is your main method You just …
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    JamesCherrill

    Replied To a Post in event handlers: anonymous inner class or not

    The AIC approach gives you a separate handler for each event, which is typically what you want. You use a "normal" inner class when you want to pass parameters into …
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    JamesCherrill

    Replied To a Post in JavaFX and Object Oriented

    You are having problems because you are using an OO language as if it was purely procedural. The big clues are all those static members and classes whose names are …
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    JamesCherrill

    Replied To a Post in JFrame and JPanel

    Perfect!
  • Member Avatar for JamesCherrill
    JamesCherrill

    Replied To a Post in JFrame and JPanel

    Yes, you can put components directly into a JFrame (well, actually there are some panels that are part of every JFrame, and one of those is where your components are …
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    JamesCherrill

    Replied To a Post in How to attach output from the jbutton to jtext field?

    That ignores eveything from our last few posts. Go back and read them all again please.
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    JamesCherrill

    Replied To a Post in How to attach output from the jbutton to jtext field?

    No, Person isn't an interface, so you can't implement it. Person is just another class like String or JFrame, except you wrote it not Sun/Oracle. Provided its in the same …
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    JamesCherrill

    Replied To a Post in How to attach output from the jbutton to jtext field?

    No, it was the list that you had in your previous code. Adding items to a JList goes like this: JLists keep their data in a `ListModel` (that's defined as …
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    JamesCherrill

    Replied To a Post in Problem with deleting a record inside an SQLLite database in Android Studio

    It would help if you gave some better info than "it wont let me". If you have a compiler or runtime error message post the complete message plus the actual …
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    JamesCherrill

    Replied To a Post in How to attach output from the jbutton to jtext field?

    Here's a very simple example. Experiment with somethimg like this: // container for info about one person class Person { String name; int age; public person(String name,int age) { this,name …
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    JamesCherrill

    Replied To a Post in Help with the pet store

    Well yes. That makes total sense when you are designing and maintaining the while hierarchy. That's why I think Java needed a visibility for members to subclasses only. IMHO the …
  • Member Avatar for JamesCherrill
    JamesCherrill

    Replied To a Post in How to attach output from the jbutton to jtext field?

    OK It looks like you should have a class that encapsulates a Parcel with all its data fields. That's how you implement a "storage/container" in Java. You can create an …
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    JamesCherrill

    Replied To a Post in How to attach output from the jbutton to jtext field?

    Sorry, I don't understand what you are trying to do. What is the purpose of your list of JTextFields? How do you imtend to use that?
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    JamesCherrill

    Replied To a Post in How to attach output from the jbutton to jtext field?

    Line 4 is OK, but line 2 looks dodgy `(count > 0) `is a boolean expression but I guess `jTextFieldParcelID` is not a Boolean, so they are never equal, so …
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    JamesCherrill

    Replied To a Post in How to attach output from the jbutton to jtext field?

    Yes, just convert the int to a String. Shortest way is string concatenation because that converts automatically, eg `""+count` ... but some people dislike that because it's a bit obscure, …
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    JamesCherrill

    Replied To a Post in How to attach output from the jbutton to jtext field?

    Use the JTextField's setText method to display the clicked count. You can do that as part of your jButtonScanActionPerformed method
  • Member Avatar for JamesCherrill
    JamesCherrill

    Replied To a Post in Help with the pet store

    "There is an error" is a useless answer. What error exactly, in what code exactly? Anyway... jwenting is right about private variables, but I totally disagree with him about how …
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    JamesCherrill

    Replied To a Post in Memento design pattern in Java

    Then why not code a test case that looks like that in your Caretaker, rather than the different sequence of events you have progrmmed in lines 40-49?
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    JamesCherrill

    Replied To a Post in Help with the pet store

    What do you mean "cannot use"? What exactly is your question?
  • Member Avatar for JamesCherrill
    JamesCherrill

    Replied To a Post in Memento design pattern in Java

    Create a Memento before each time you add or remove. Use the latest Memento to roll back the latest change. The WikiPedia article on memento design pattern has an example …
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    JamesCherrill

    Replied To a Post in Get name of month from integer

    When you have the month number as a String you can convert that to an Integer using the `Integer.parseInt `method (see API doc for details). Then you can use that …
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    JamesCherrill

    Replied To a Post in Properly using a Canvas [Java]

    Excellent! A while ago I did a test/demo program using the simple architecture above. It has hundreds of balls bouncing around and bouncing off each other, with full spherical bounce …
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    JamesCherrill

    Replied To a Post in Properly using a Canvas [Java]

    It looks like you are fighting the Java graphics system rather than working with it. Before getting into buffer strategies, just try the recommended (flicker free) mechanism... Override paintComponent for …
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    JamesCherrill

    Replied To a Post in Properly using a Canvas [Java]

    Swing components are double buffered by default, unlike the old AWT components that make you do it. If you place a canvas with some more complex buffering strategy inside a …
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    JamesCherrill

    Replied To a Post in Properly using a Canvas [Java]

    Useful in what ways?
  • Member Avatar for JamesCherrill
    JamesCherrill

    Replied To a Post in Properly using a Canvas [Java]

    Why? Canvas is an old AWT component that you would use in an old AWT Frame. Forget it, and use a JPanel.
  • Member Avatar for JamesCherrill
    JamesCherrill

    Replied To a Post in Fractions

    In that case please explain it to me, because I'm still confused. n isn't the result of anything, it's an arbitrary value passed in as a parameter. And what's wrong …
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    JamesCherrill

    Gave Reputation to David W in Dealing a deck of cards (w/ 4 players) without duplicates

    An other way to approach your problem is to 'huffle the deck' before dealing it out ... Take a look: /* 52Cards.c */ /* You can find file "readline.h" at: …
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    JamesCherrill

    Replied To a Post in Dealing a deck of cards (w/ 4 players) without duplicates

    Before going any further I urge you to look at David W's post again ... creating a full deck, shuffling it, and taking cards from it. His approach is going …
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    JamesCherrill

    Replied To a Post in Fractions

    That's a good question. All the definitions of mediant that I found in a quick google had no use or meaning for such a parameter. Are you sure that method …
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    JamesCherrill

    Replied To a Post in Crossing English Words- in java

    I posted some pseudocode earlier that gives you the logic for printing crossed words. Try to convert that into Java and see how far you can get. I'm on holiday …
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    JamesCherrill

    Replied To a Post in how to spot logic errors

    Hi Dennis Yes, you're right. char types in Java are numeric Unicode values, so it's valid to compare them with any other numeric type, but '0' is a char constant …
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    JamesCherrill

    Replied To a Post in Java, Constructor that MUST EXPLICITLY call super

    Whether you need a parameter isn't the point. This is the only way I know to do what you asked. Every constructor must start with a call to a superclass …

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