JOptionPane vs. JDialog - java

This is a crosspost to the thread in Javaranch (includes some images): http://www.coderanch.com/t/567472/GUI/java/Optimal-solution-creating-multiple-dialog
I'm trying to develop a simple swing desktop application where I imagine alot of different dialog's jumping around to fetch user input. Would need to present labels, textfields, passwordfields, combobxes, checkboxes etc in various dialog windows.
For example: creating the database firsthand, creating the first admin account, adding users, changing user accounts etc.
I have an understanding that JOptionPane is used to create simple quick & easy modal dialog's. I would really like to know why one would choose one over another in this case. Which one is more preferable to use: JOptionPane vs. JDialog
Also I could use some pointers how one should appropriately design and implement this.
Thank you.

Here's a statement I found on the Java website that says one key point about the difference between the two.
How to make Dialogs
A Dialog can be modal. When a modal Dialog is visible, it blocks user input to all other windows in the program. JOptionPane creates JDialogs that are modal. To create a non-modal Dialog, you must use the JDialog class directly.
So it sounds like you would use JOptionPane if you want a user to have to make a choice and close the box before returning to the main screen. If you use a JDialog box, then they can just click around it and get back to the main screen without making a choice. For example, say you wanted to make a user choose the number of results before clicking submit, you wouldn't want them to be able to click around that window and click submit. You would use JOptionPane to force them to select a value first before going back to submit.

Check out http://docs.oracle.com/javase/tutorial/uiswing/components/dialog.html it pretty much has everything you would need.
As i understand it, JOptionPane is great for what it can do, but you can't really change the functionality beyond that (not easily). JDialog is better to inherit from if you want to create your own custom Dialogs.

Related

Prevent JOption from blocking child JFrame

Is there a possibility to prevent a JOptionPane dialog from blocking the interaction with the rest of the program, especially child JFrames? In my GUI, I launch a JFrame and want a message dialog to pop up after the child is closed to remind the user of something, but they launch parallel and the reminder blocks the child frame from being used.
Like here:
popupObjMan newPopup1 = new popupObjMan(gatewayAbstract, gatewayAbstractID);
JOptionPane.showInternalMessageDialog(this, "REMINDER: DO REFRESH");
I've tried to set the popup always on top, but this doesn't quite do the job.
I have no problem with them launching parallel (I'd even prefer it), but I could not work my head around it yet.
I just started Java programming ,so sorry in case that'd be something obvious.
A JOptionPane normally need to be modal. It shows something important and waits till the user answers with whatever option you give him (e.g. ok-button, yes/no-buttons, ...)
But there are several ways to reach your target.
(a)
Normally a JOptionPane creates a modal window.
You need a modeless window which does not block other windows.
https://docs.oracle.com/javase/tutorial/uiswing/misc/modality.html
(b)
You can start different threads to work for your different windows. They can have windows which are shown whenever the responsible thread commands them to. This is a bit difficult and can lead to memory-troubles.
(c)
You can write your own message-panels (e.g. notificaton) which are shown when and how long you like.
Bigger projects use different of these ways to achieve their goals.
A JOptionPane is a component, just like a JPanel. As a component it can be added to any other panel.
The JOptionPane API provides static methods to create a show the JOptionPane on a modal JDialog by default. You can't change this behaviour.
However, you can manually add the JOptionPane to a non-modal JDialog that you create. This is extra work as you now need to handle the closing of the dialog and processing the clicked button.
If you really want to do this then read the JOptionPane API. There is a section on Direct Use which demonstrates the basic code needed to add the JOptionPane to a JDialog.

Multiple frames in jFrame?

I'm currently learning how to create a program with Java and jFrame. One problem I have is that I cant create new "forms" (how they are called in visualbasic) or windows. I'm using "Java-Editor", a usually very simple editor for things like that. Can anyone help me create a new form?
Thanks for your help in advance,
Till
From JFrame I assume that you are using Swing, and that you want multiple windows for your application. Your app should only use one JFrame object, if you need more windows (usually these are popup messages) then you can use dialogs. The class for this is JOptionPane.
Here is an example:
JOptionPane.showMessageDialog(null,"title","content",JOptionPane.INFORMATION_DIALOG);
As you can see you can control the title and the content displayed. Note that for the content parameter you can pass any JPanel object, so you dialog can display a lot of things.
The first parameter is the owner of the dialog, now I just set it to null, which means the dialog will have no owner. If you store a reference to your JFrame object then you can pass this for example and the dialog will always appear above your main window.
The last parameter is just for the general styling of the dialog. You can set it to other message types like ERROR MESSAGE too.
More info about displaying simple dialogs: https://docs.oracle.com/javase/7/docs/api/javax/swing/JOptionPane.html

Getting information from a text field JFrame form in a different class

Okay so I'm making a Library admin program and I have created a special frame where the user would enter details about a new book. However my method for adding a new book is in a separate class (methods). My question is how can I get the information the user enters in the text fields? Do I have to use something like getters, or is there an easier way. Also keep in mind that I am using the GUI layout (thing) in netbeans, and that I have already actually made the form. (I know it's frowned upon but I'm pressed for time and this is how we were taught.) This is a school project by the way. Thanks.
Okay so I'm making a Library admin program and I have created a special frame where the user would enter details about a new book.
Usually, a detail window should be a dialog, and likely a modal dialog. I suggest that you display this information in a modal JDialog, not a JFrame. Do this and it will make extracting information from the detail window much easier.
However my method for adding a new book is in a separate class (methods). My question is how can I get the information the user enters in the text fields? Do I have to use something like getters, or is there an easier way.
This begs the question -- what's so hard about using getters? And in fact his is exactly what I suggest that you use! Please note that your question essentially boils down to, "how can I get information on the state of one class's object from within another class's object", and for this getter methods are almost mandatory.
Also keep in mind that I am using the GUI layout (thing) in netbeans, and that I have already actually made the form. (I know it's frowned upon but I'm pressed for time and this is how we were taught.) This is a school project by the way.
This is unrelated to your current problem and should have little effect on its solution other than if you've hard-coded your "form" as a JFrame, then scrap it and re-do it as a JPanel.
I suggest:
Create an addEditBook modal JDialog
Give it getter methods to allow outside classes to be able to query its textfields for their contents.
Display the dialog from the main program.
Since it is modal the main program's code flow will pause until the dialog has been dealt with.
In your OK and Cancel button, set the dialog's state (OK_STATE or CANCEL_STATE) and close the dialog. The easiest way to do this actually is to use a JOptionPane as your modal dialog since it has mechanism for just this sort of thing. This is easily accomplished if your addEditBook is geared to create a JPanel, one that you display in the JOptionPane.
Program flow will then resume in your main program from right after where you showed the dialog
query the dialog for the contents of its fields.
For examples of the JOptionPane solutions, including option panes that request information from multiple fields similar to your window above, please see:
How can I make a JFrame modal like a JOptionPane?
Multiple input in JOptionPane.showInputDialog
Edit
You state in comment:
Oh and I was wondering how can I make the field of a normal JOptionpane input dialogue come up with a word already in it like for editing it will show the information stored already?
Please see the example answers that I have listed above as you'll see that they're not examples of a "normal JOptionPane" but rather JOptionPanes that display a GUI that you create. And just the same as it's easy to query the state of this GUI after it is displayed, it's just as easy to set the state of the GUI via setter methods before it is displayed.
My question is how can I get the information the user enters in the
text fields? Do I have to use something like getters, or is there an
easier way
You need to add actionListeners for you buttons, which means you will be overriding a method called actionPerformed. You basically need to associate your actionListeners with your 'Ok' and 'Cancel' buttons. When the 'ok' button is pressed, you should get a callback in the associated actionPerformed method. Then you should try to fetch the values of your textfiled using the getText method. Collect all the fileds and set the bean you have created to store that data. Then you can call your business logic to save/modify the books info.

Retrieve Values from multiple JFrame to a single JFrame

I have 5 JFrames in my application and I want the values from all 5 JFrames to be sent to a single JFrame. And it is a process where I have to go one frame to another and the value entered previously should not be lost and must be visible at the end of the process.
Easy example is,
I key in my name in the first frame,
then I key in my Address in the second frame,
then my mobile number in the third frame
and so on till the last frame where I want my keyed in details in the previous forms to be in the final frame to display my data in JTextfields. Is this possible? Because if it is a single form, I know how to do it. But when it is multiple forms in this situation I am lost. Please help.
This has nothing to do with Swing or JFrames and all to do with the general issue of getting information from one object into another. Yes it's possible -- give the classes that you wish to extract information from "getter" methods, and then call them when you want the information. If you want to gather this information in an event-dependent fashion, then you will need to have one class listening for state changes brought on by events in the other classes. A PropertyChangeListener can work well for this.
Or if you use modal JDialog windows instead of JFrames, you will always be notified when the dialog has returned and is no longer visible, since the calling code's program flow resumes from right after where it told the dialog to become visible.
Next we can discuss whether having 5 separate JFrames is a good idea or not. I'm guessing you know my opinion on this, else I wouldn't have mentioned the subject.

OfficeBean won't display after moving containing Swing Panel from one Container to another

I'm developing a Java 6 applet which allows users to view OO (v.3.2) documents (read only), and if they choose, click a button which launches a new JDialog window, with the document displayed in it which allows the user to and mark and redact it as they wish. Once they are done, they can close the JDialog, which saves the document to a server and redisplay the updated document (read-only again) in the original applet window
I guessed that I could do this with a single instance of an OfficeBean, embedded in a Swing Panel. However, I cannot seem to successfully move my Panel (containing the OfficeBean) from the applet to the JDialog when the "Redact" button is clicked. All I get is a blank area in the JDialog where the document should be. I get no errors.
I have currently managed to get round this by creating new instances of the OfficeBean every time I need to display the document (once when the applet is loaded, again when the user chooses to redact and it is opened in a JDialog, and finally when they click "Save" in the dialog and the redacted result is displayed in the applet again.) However this means three trips to and from the server where the documents originate. That seems mad to me.
I'm in no way a Swing expert and may well be making a silly mistake. However, I've done a lot of fiddling around, debugging and googling and can't seem to get this to work. Can anyone help me in this? Am I trying to do something which is fundamentally impossible? I hope not.
One rule in Swing is that a component can only be displayed / attached to one part of the gui "tree" at a time. When you "move" your component to the dialog, are you first removing it from the applet?

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