I have multiple JTextAreas inside a JPanel. I am using a BoxLayout to make them align vertically and fill the width of the container.
It works, but they seem to expand to fill the entire height as well.
What I really want is simple - a text area that wraps text where I can control the width but allow the height to scale dynamically as more lines are added. The above method was just my best attempt at it. If there is a solution that uses a different layout manager, different text component, etc, that works.
minimal verifiable example below:
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setPreferredSize(new Dimension(300, 300));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel textAreas = new JPanel();
textAreas.setLayout(new BoxLayout(textAreas, BoxLayout.Y_AXIS));
JTextArea area1 = new JTextArea();
area1.append("this is a string");
area1.setLineWrap(true);
area1.setWrapStyleWord(true);
textAreas.add(area1);
JTextArea area2 = new JTextArea("and another that is much longer, so that it wraps to the next line");
area2.setLineWrap(true);
area2.setWrapStyleWord(true);
textAreas.add(area2);
JScrollPane scrollPane = new JScrollPane();
scrollPane.setViewportView(textAreas);
frame.add(scrollPane);
frame.pack();
frame.setVisible(true);
}
I have done research on this topic on my own, including looking at different layout managers (http://docs.oracle.com/javase/tutorial/uiswing/layout/visual.html), and checking other questions on the site, but I haven't had much luck.
TLDR: Can I make it so each element of a layout has a height that scales to its content but a fixed width? If so how?
What I really want is simple - a text area that wraps text where I can control the width but allow the height to scale dynamically as more lines are added.
The BoxLayout respects the maximum size so the text area grows to fill all the space available in the panel. You can override the getMaximumSize() method to return the preferred height by using something like:
JTextArea area1 = new JTextArea()
{
public Dimension getMaximumSize()
{
Dimension d = super.getMaximumSize();
d.height = getPreferredSize().height;
return d;
}
};
It works...
Not really. Make the frame wider and the text will unwrap. Then shrink the frame and the scrollbar will appear. That is the text will not wrap again
What you need to do is force the panel added to the scroll pane to be the same width as the viewport. This will allow wrapping to work properly.
You do this by implementing the Scrollable interface on the panel. Specifically you need to override the getScrollableTracksViewportWidth() method to return true.
Or an easier solution is to use the Scrollable Panel class which allows you to set properties of the panel to control this behaviour.
You can replace a JPanel with the ScrollablePanel:
//JPanel textAreas = new JPanel();
ScrollablePanel textAreas = new ScrollablePanel();
textAreas.setScrollableWidth( ScrollablePanel.ScrollableSizeHint.FIT );
Edit:
If there is a solution that uses a different layout manager
Without overriding the getMaximumSize() method of the text areas and when using the Scrollable Panel you should be able to use the following layout managers.
The GridBagLayout allows you to specify the "weightx" constraint. This will allow the component to fill all the available space in the panel.
Or if you don't like specifying all the constrains of the GridBagLayout you could use the Relative Layout which support vertical/horizontal layout of components at their preferred size.
You would just need to use the following to force the component to fill the horizontal space:
//textAreas.setLayout(new BoxLayout(textAreas, BoxLayout.Y_AXIS));
RelativeLayout rl = new RelativeLayout(RelativeLayout.Y_AXIS);
rl.setFill( true );
textAreas.setLayout(rl);
Related
I am having issues getting a vertical scrollbar on my jlist.
listInfo is a vector with data in it.
right panel is a panel on the EAST side of the frame.
If I add just the JList, it appears. If I add scrollpane, nothing happens.
data = new JList(listInfor);
data.setVisible(true);
data.setVisibleRowCount(5);
data.setPreferredSize(new Dimension(400,400));
data.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
JScrollPane scroll = new JScrollPane(data);
rightPanel.add(scroll);
For some reason, this isn't working.
Don't set the preferred size of the JList, this is preventing it from calculating the size of the list based on it's contents, which will mean that it will never exceed the preferred size you have supplied, meaning that it will never show any scroll bars.
Instead, use a combination of JList#setVisibleRowCount and Jlist#setPrototypeCellValue to adjust how the JList calculates it's preferred size.
IF you REALLY want more control, you should take a look at the Scrollable interface that JList implements, but even then, I'd be careful
Tested this
public static void main(String[] args) {
String[] ar = {"one", "two", "three"};
JList data = new JList(ar);
data.setVisible(true);
data.setVisibleRowCount(5);
data.setPreferredSize(new Dimension(400,400));
data.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
JScrollPane scroll = new JScrollPane(data);
JFrame frame = new JFrame("StackOverflow Test");
frame.add(scroll);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null); // to center
frame.setVisible(true);
}
and all it's okay
You should specify a layout manager for your rightPanel variable, if it hasn't any. Absence of a layout manager may give you unexpected results, as you don't set the bounds of your components manually.
Besides, as pointed out by MadProgrammer's answer, you shouldn't set preferred sizes on your components, if possible. There are other ways to determine appealing dimensions. For instance, with JList, using setVisibleRowCount.
In order for the scroll to appear only as needed, you can specify the scroll bar policies on the JScrollPane constructor, or use its set methods to do so. Example:
jlist.setVisibleRowCount(5);
JScrollPane scroll = new JScrollPane(jlist);
scroll.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
scroll.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
Also, make sure the container of the scroll pane respects its preferred size, as the scroll pane respects the list's preferred size.
I have been working on a small project that is supposed to simulate a gambling game. Unfortunately, I ran into some odd issues while working with BoxLayout. To the best of my knowledge, LayoutManagers usually honor any component's preferred size. However, in the below code, BoxLayout does not.
Here is my code thus far:
import java.awt.*;
import javax.swing.*;
public class Main
{
public static void main(String[] args)
{
JFrame.setDefaultLookAndFeelDecorated(true);
JFrame frame = new JFrame("Suit-Up");
frame.setContentPane(makeGUI());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(900,450);
frame.setLocationRelativeTo(null);
frame.setResizable(false);
frame.setVisible(true);
}
public static JPanel makeGUI()
{
JPanel main = new JPanel();
main.setMinimumSize(new Dimension(900,450));
main.setBackground(Color.red);
JPanel infoPanel = new JPanel();
infoPanel.setLayout(new BoxLayout(infoPanel, BoxLayout.LINE_AXIS));
infoPanel.setPreferredSize(new Dimension(900,60));
infoPanel.setBackground(Color.green);
main.add(infoPanel);
JPanel infoText = new JPanel();
infoText.setLayout(new BoxLayout(infoText, BoxLayout.PAGE_AXIS));
infoPanel.add(infoText);
JPanel moneyText = new JPanel();
moneyText.setLayout(new BoxLayout(moneyText, BoxLayout.LINE_AXIS));
infoText.add(moneyText);
JPanel lastGameText = new JPanel();
lastGameText.setLayout(new BoxLayout(lastGameText, BoxLayout.LINE_AXIS));
infoText.add(lastGameText);
JButton playAgain = new JButton("Play Again ($20)");
playAgain.setPreferredSize(new Dimension(200,60));
infoPanel.add(playAgain);
JButton finish = new JButton("End Session");
finish.setPreferredSize(new Dimension(200,60));
infoPanel.add(finish);
JPanel cardPanel = new JPanel();
cardPanel.setLayout(new BoxLayout(cardPanel, BoxLayout.LINE_AXIS));
main.add(cardPanel);
return main;
}
}
Despite specifying preferred sizes for both JButtons, they do not change their sizes. I have tried setMaximumSize() and setMinimumSize() as well, but neither had any effect.
Am I overlooking something obvious, or is this a limitation of BoxLayout?
"To the best of my knowledge, LayoutManagers usually honor any component's preferred size" - That's actually not true. preferred/min/max size are just "hints" that layout managers MAY use to determine how best to layout there contents. Layout managers are allowed to simply ignore them if they want to.
From the JavaDocs
BoxLayout attempts to arrange components at their preferred widths
(for horizontal layout) or heights (for vertical layout). For a
horizontal layout, if not all the components are the same height,
BoxLayout attempts to make all the components as high as the highest
component. If that's not possible for a particular component, then
BoxLayout aligns that component vertically, according to the
component's Y alignment. By default, a component has a Y alignment of
0.5, which means that the vertical center of the component should have the same Y coordinate as the vertical centers of other components with
0.5 Y alignment.
Similarly, for a vertical layout, BoxLayout attempts to make all
components in the column as wide as the widest component. If that
fails, it aligns them horizontally according to their X alignments.
For PAGE_AXIS layout, horizontal alignment is done based on the
leading edge of the component. In other words, an X alignment value of
0.0 means the left edge of a component if the container's ComponentOrientation is left to right and it means the right edge of
the component otherwise.
I have this code below to create a page inside of a tab.
I want each layout in one row of the overall box layout but i want the elements to stay in their original size and not expand to fill the width of the overall window. does anyone know what lines of code i need to change or what is the best way of doing this?! The image attached shows what it looks like at the moment
public void createPage4() {
panel4 = new JPanel();
panel4.setLayout(new BoxLayout(panel4, BoxLayout.Y_AXIS));
navigatePanel = new JPanel();
navigatePanel.setLayout(new BoxLayout(navigatePanel, BoxLayout.X_AXIS));
previousButton.setText("Previous");
previousButton.setEnabled(false);
navigatePanel.add(previousButton);
navigatePanel.add(Box.createHorizontalStrut(10));
indexTextField.setHorizontalAlignment(JTextField.CENTER);
navigatePanel.add(indexTextField);
navigatePanel.add(Box.createHorizontalStrut(10));
ofLabel.setText("of");
navigatePanel.add(ofLabel);
navigatePanel.add(Box.createHorizontalStrut(10));
maxTextField.setHorizontalAlignment(JTextField.CENTER);
maxTextField.setEditable(false);
navigatePanel.add(maxTextField);
navigatePanel.add(Box.createHorizontalStrut(10));
nextButton.setText("Next");
nextButton.setEnabled(false);
navigatePanel.add(nextButton);
panel4.add(navigatePanel);
displayPanel = new JPanel();
displayPanel.setLayout(new GridLayout(5, 2, 4, 4));
firstNameLabel.setText("First Name:");
displayPanel.add(firstNameLabel);
displayPanel.add(firstNameTextField);
lastNameLabel.setText("Last Name:");
displayPanel.add(lastNameLabel);
displayPanel.add(lastNameTextField);
panel4.add(displayPanel);
}
image
BoxLayout accepting Min, Max and PreferredSize that came from JComponents
I want each layout in one row of the overall box layout but i want the elements to stay in their original size and not expand to fill the width of the overall window
I'd be to use proper LayoutManager, FlowLayout accepting only PreferredSize, and/or all JComponents layed by GridBagLayout without defininitions of GridBagConstraints stays unchanged on containers resize
doesn't make me sence (my view) for why reason (sure this is your job), but for better help sooner post an SSCCE
The easiest way is to add your panel4 to an other panel that uses GridBagLayout and then add that panel to the container. Then it will be centered and nothing will stretch on resize.
JPanel centeredPanel = new JPanel(new GridBagLayout());
centeredPanel.add(panel4); // add this panel to the container
You should also construct the textfields with a specified number of columns, like
indexTextField = new JTextField(20);
I have:
public class BaseStationFrame1 extends JFrame
{
JButton activateButton;
JButton deactivateButton;
BaseStation bs;
JTextField networkIdField;
JTextField portField;
public BaseStationFrame1(BaseStation _bs){
bs = _bs;
setTitle("Base Station");
setSize(600,500);
setLocation(100,200);
setVisible(true);
activateButton = new JButton("Activate");
deactivateButton = new JButton("Deactivate");
Container content = this.getContentPane();
content.setBackground(Color.white);
content.setLayout(new FlowLayout());
content.add(activateButton);
content.add(deactivateButton);
networkIdField = new JTextField("networkId : "+ bs.getNetworkId());
networkIdField.setEditable(false);
content.add(networkIdField);
portField = new JTextField("portId : "+ bs.getPort());
portField.setEditable(false);
content.add(portField);}
}
My problem is that i don't want the two TextFields to appear on the right of Activate and Deactivate buttons but below them. How can i fix that?
Specify your layout manager, like this:
content.setLayout(new GridLayout(2,2));
That would use the Grid Layout Manager to establish a grid with 2 columns and 2 rows, that your components would then be placed in.
The layout manager you are currently using, FlowLayout, only adds contents onto the end of the current row. it will wrap around once it reaches the constrained edge of the pane, though.
You should also check the other layout managers here
You could alternatively use GridBagLayout , but you will have to specify a GridBagConstraints object you then add alongside the individual elements, like so:
content.add(networkIdField, gridConstraints);
see more on that in the linked tutorial.
can I suggest that you use a Null Layout for the parent component?
setLayout(null);
then use a setBounds(xPos,yPos, Width, Height);
to position the components on the panel etc?
Doing this will prevent Java's UI Manager to manage the components to the Frame, Panel etc.
That seems to be the easiest and less painful way.
Regards
I have a JFrame which contains just one JPanel.
I have tried setting the Panel's size and packing the frame, but that has no effect.
If I set the JFrame's size, it will change the size so it includes the title bar and borders.
How do I set the "actual size" so it doesn't include the title bar and borders?
Example:
Thanks in advance, guys
You could set the contentPane's preferredSize and call pack on the JFrame, but in general it's usually best to let components size themselves based on their preferred sizes as determined by their layout managers.
This is an example of setting JPanel's size and packing the frame:
JFrame frame = new JFrame();
JPanel panel = new JPanel();
panel.setPreferredSize(new Dimension(200, 200));
frame.add(panel);
frame.pack();
frame.setVisible(true);
Did you try something like this?
If you set the preferred size of the JPanel then the JFrame's pack() method will respect it.
Use the .getInsets method on JFrame which gives you the dimensions of the sizes around the non-client area.
Then add it up to your wanted size, and set the size using setSize.
If you want to get Frame border then first use pack on your frame and after that get Frame Insets like in this code bellow:
frame.pack();
Insets insets = frame.getInsets();
int frameLeftBorder = insets.left;
int frameRightBorder = insets.right;
int frameTopBorder = insets.top;
int frameBottomBorder = insets.bottom;
Is better to use the pack method right after your setResizable(boolean) method, because resizable for some reason changes your frame borders, but if you dont use resize method then use pack method right on the start of frame constructor.
Setting the actual size of the usable space in JFrame could be done through setting the preferred size of the container in
createComponents(Container container) method. Done in this way, you skip setting the size of
the whole JFrame through setPreferredSize(new Dimension (width, length) in the run() method. So, the code will look like this:
#Override
public void run() {
JFrame frame = new JFrame();
// other code ...
this.createCompoents(frame.getContentPane());
}
private void createCompoents(Container container) {
// other code ...
container.setPreferredSize(new Dimension(width, length));
}