I have created a JFrame - now I want to add the 4 JPanel in that frame at a particular location. How can set the location of panels in the frame?
Use (possibly nested1) layouts for the logic. See Laying Out Components Within a Container for details. They can:
Include default spacing in the constructor (often)
Calculate how big the GUI needs to be in order to display the components (in whatever PLAF, on whatever system the app. is deployed).
Extra spacing can be organized by adding an EmtpyBorder to child components.
See the nested layout example
Placing components in a container is quite a complicated subject in Swing. Instead of defining the exact places for your components, you would normally use a layout manager that arranges them in a certain way.
Here is the tutorial you should read to get a (visual) clue about the different layout managers: A Visual Guide to Layout Managers
However, the standard layout managers of Swing can be cumbersome for more complex layouts. Either, you could use nested layouts to get the desired result, or you could use a very powerful third-party library: JGoodies Forms. The downside is of course that you have to learn yet another library. Therefore, I would only recommend it for a bigger project.
For me it is good way to set GridbagLayout for the container of the frame. There are several visual swing GUI editors available to do this easily. You can use NetBeans GUI editor or GWT Designer (https://developers.google.com/web-toolkit/tools/gwtdesigner/) for complex GUI designing tasks
If its 4 locations, you can use BorderLayout,by default its the CENTRE, but it also have EAST, WEST , NORTH, SOUTH locations for the placement of the components. You can also use setLocation to put the panels in the appropriate locations, if a layout isn't used.
Its even better to use GroupLayout developed my NetBeans team in 2005, use Windows Builder Pro, now provided by google for free.
set the layout of the Frame to be null via setLayout(null)
create 4 JPanel and set their location using setLocation method
add these panels using JFrame's add method
Related
Having read over the internet about JPanel for a while I feel I still need clarification after reading it. My questions:
What is JPanel mostly used for?
Which layout manager is most flexible to use?
How do you position components at certain areas using layout managers?
I find it really difficult to position components at certain areas within the container using a layout manager.
What layout manager do you recommend I use or do you have to use a mixture of different ones?
My first question is what is JPanel mostly used for.
You already know that. You add components to the panel.
My second question is which layout manager is most flexible to use
The more flexible that layout manager, the more complicated the layout manager is to use. So the trick is design your GUI logically and then use multiple panels with different layout manager to achieve your desire effect.
Each layout manager has its own strengths and weaknesses.
I find it really difficult to position components at certain areas within the container using a layout manager.
That is old thinking. You should not be trying to position components specifically. You position components generally and let the layout manager adjust as the size of the frame is changed by the user.
Maybe you want components centered, or in a grid. There are different layout managers to achieve your task. We can't give specific advice. If you have a specific problem then as a specific question and post your code that shows what you have tried.
But first, read the Swing tutorial on Layout Manager and download the example code play with the code to understand how each works. You learn by trying.
What layout manager do you recommend I use or do you have to use a mixture of different ones.
It depends on the GUI. I'd typically use a combination of layout managers for anything but the most trivial user interfaces. On the other hand, some like to try and use a more complex layout for those same GUIs, using layouts like:
GridBagLayout - older, but quite versatile.
GroupLayout - newer, more powerful, and provides better ability to align elements that are not next to each other, but considered so difficult to hand write that most use a GUI designer that will produce code that will not be portable to the next GUI designer or IDE.
A third party layout manager like MigLayout or FormLayout
JPanel can be used:
As a container for other components
Base for a custom widget
Drawing area
MigLayout is hands down the most flexible layout manager.
There are many layout managers in Swing, but in my opinion
only three are up to the job:
MigLayout
GroupLayout
FormLayout
Since MigLayout is an (greatly) improved FormLayout, I usually
recommend the first two managers.
Using a mixture of various managers is a poor practice. It is a way
of overcoming the simplicity of basic layout managers. One should choose a good layout manager and not to tangle with multiple layout managers. Most layouts can be easily done with MigLayout and GroupLayout.
I would like to ask if SpringLayout can do anything like absolute position because I think absolute position have problem when I maximize the frame and what do I have to use if I need to set JMenu and JToolBar and JTextField and JTable all in one line in order?
I tried to use Borderlayout but it give me very big JTextField. I tried Gridlayout it give also big JTextField I need it big but not as big as it shows up.
can SpringLayout do all the job
No. It is neither designed, nor intended to do 'all the job'.
Java GUIs might have to work on a number of platforms, on different screen resolutions & using different PLAFs. As such they are not conducive to exact placement of components. To organize the components for a robust GUI, instead use layout managers, or combinations of them1, along with layout padding & borders for white space2.
For absolute positioning, don't use a layout manager at all.
However, that's not really recommended. Usually you should use a layout that would scale.
See also this thread for more discussion.
i found note writing by java says
Note: This lesson covers writing layout code by hand, which can be
challenging. If you are not interested in learning all the details of
layout management, you might prefer to use the GroupLayout layout
manager combined with a builder tool to lay out your GUI. One such
builder tool is the NetBeans IDE. Otherwise, if you want to code by
hand and do not want to use GroupLayout, then GridBagLayout is
recommended as the next most flexible and powerful layout manager
I've made a java application in netbeans and am wondering how to have the size of the jframe half the width and height of the computer resolution and also having the components comply with this change. I tried putting code and it did make the frame half the height of the computer resolution but my components, such as buttons and textfields, stopped showing. How can I achieve this? Thanks.
(EDITED)
Set the JFrame's layout manager to GridLayout. In the properties window of the GridLayout itself (select in the navigator window) set columns to 1 and rows to 2. This should give you what you want and you won't have to get into the code.
This is the key code being called within the initComponents() method of your JFrame subclass (created by NetBeans) but it is important to understand where it is:
getContentPane().setLayout(new java.awt.GridLayout(2, 1));
I love Netbeans but you do have to understand the basics.
Good luck with your project. Swing is an awesome toolset that was way ahead of it's time.
As usual in this situation the key is using the right combination of layout managers for your containers. You're probably using NetBeans generated code (something I recommend you avoid until you are very comfortable with Swing coding), and it's probably having you use GroupLayout, a fine layout, but one that might not behave as well as you'd like on resizing components. I suggest that you go through the layout manager tutorial and try to nest JPanel containers and play with different layouts that re-size well such as GridLayout, GridBagLayout and BorderLayout to try to create the best layout that can re-size well.
I am trying to create a GUI for a program with an undefined number of rows but stay with two columns. Currently the only way I can get it to look how I want is using FlowLayout but the window of course needs to be smaller than desired. It needs to happen within one panel as well because it is being added to a tabbed pane.
What would be the best layout manager to solve the problem that is in the JDK? Or would just kind of brute forcing it with AbsoluteLayout be the best approach (as the user shouldn't really be resizing the window)?
I have attached the desired appearance.
Thanks for any help in advance.
Several layouts can do what you want. I'd suggest GridLayout (easy to use, but columns will be equal width) or GridBagLayout (harder to use, but you have lots of control). You could also use a BorderLayout and put all the fields in a sub-panel on the WEST and all the drop-downs in a sub-panel on the EAST. The difficulty with that is ensuring that the rows have the same height, since they won't be constrained by the layout itself.
The best thing to do would be to go through the Java tutorial on layouts and get up to speed on what the various layout managers can do.
Also, since you're using Swing, you could just use a JTable (as Gilbert Le Blanc suggests in his comment).
I am creating an application which has a scrollable and scalable (zoomable) view. Inside this view I want to place other components (most of them customized JPanels and JInternalFrames).
Things such as fonts and borders, and sub-elements such as buttons don't need to be scalable. Only dimensions and position of container components should be.
What do you think, what is a good way to implement scalable components?
EDIT: I'm talking about resizing the entire layout including all
components. Please think of something such as a visual UML editor with zoom functionality.
My alternatives are:
Create a custom layout manager;
Create custom resizeable sub-components;
Create a custom container which would take care of resizing its sub-components;
Do something else?
Possible problems:
Boilerplate code;
Necessity to provide access to additional custom properties of components;
Not straightforward (inconsistent) representation of components in code.
Something else?
This is why layout managers exist: they tell contained components where and how large they should be.
Since you're talking about a UML editor, are you using contained Swing components to represent the various objects in the diagram (eg, a component for a class)? If yes, then you've got a lot of work ahead of you (although it's not necessarily a bad approach). I'd recommend creating a constraints object that identifies the object's location on a "unit space," then multiplying by the current size.
I've done that by creating a custom layout manager. Every component (or rather component class) on the frame has a marker whether or not it shall be resized when the container is resized (e.g. tables are resized, buttons are not). Those which are not resized are moved when the container is resized.
This is used to make resizeable forms without any manual setup, i.e. forms are defined by just specifying x/y/length/width for each component (no further alignment info).
If I look at this problem as visual UML editor then I had to think about single "canvas" component drawing each element as graphical object with base aspect ration and zooming in/out. I can't see reason for list of components aligned within parent container.
I started a similar solution that works fine without touching the original layout.
It's as easy as this:
// Install scalable layout and CTRL+/CTRL- keys for scaling operations
ScalableLayoutUtils.installScalableLayoutAndKeys(new DefaultScalableLayoutRegistry(), frame, 0.1);
It's still under work but It will be soon available as part of the next "utils4swing" version.