JscrollPane doesn't enable ScrollBars whenever content gets to big - java

I have a JScrollPane processesScrollPane which has a JPanel processButtonPanel as component. Now in this component I add JButtons which come from an ArrayList I fill up while the programming is running.
I've set some settings of the JScrollPane, but the problem I'm having is that when there are more buttons in the JPanel then I can display, the JScrollPane isn't enabling its scrollbars.
Here some code snippets:
processesScrollPane = new JScrollPane();
processesScrollPane.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
processesScrollPane.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
processesScrollPane.setBounds(12, 42, 221, 380);
processPanel.add(processesScrollPane); //processPanel is the JPanel which holds the JScrollPane
processButtonPanel = new JPanel(); // here are the buttons added whenever they are made and placed in the buttonList
processesScrollPane.setViewportView(processButtonPanel);
processButtonPanel.setLayout(null);
processesScrollPane.setViewportView(processButtonPanel);
buttonList = new ArrayList<JButton>();
and the code where I'm making the buttons:
JButton b = new JButton("Process " + i);
b.setBounds(12, 5 + (30*i), 174, 25);
processButtonPanel.add(b);
processButtonPanel.repaint();
buttonList.add(b);
processesScrollPane.revalidate();
processesScrollPane.repaint();
(Yes I'm using no layout, but that's because I'm not going to scale the whole window etc)
Can anyone help me with the enabling of the scrollBars at the right time?

Related

How do I add JMenuBar to JTextArea?

I have a JTextArea, and I want to add a JMenuBar to it, but it doesn't seem to work.
ta = new JTextArea();
ta.setBackground(Color.RED);
// ta.setLayout(null); I tried with a null layout and
non-null
pane = new JScrollPane(ta);
pane.setBounds(Main.WIDTH - (Main.WIDTH - 20), Main.HEIGHT - (Main.HEIGHT - 20), Main.WIDTH - 60, Main.HEIGHT - 500);
bar = new JMenuBar();
bar.setBounds(0, 0, ta.getWidth(), 20); // This won't be there if
// there is a non-null layout.
ta.add(bar); // I also tried pane.add(bar); that didn't work either.
Is there any way to add JMenuBar to JTextArea?
Put the JTextArea into a JScrollPane -- always
Add the JScrollPane to the BorderLayout.CENTER position of a JPanel that uses BorderLayout
Add the JMenuBar to the BorderLayout.PAGE_START position of the same BorderLayout using JPanel
Done
e.g.,
JTextArea ta = new JTextArea(40, 20); // give columns and rows
JScrollPane scrollPane = new JScrollPane(ta);
JPanel borderLayoutPanel = new JPanel(new BorderLayout());
borderLayoutPanel.add(scrollPane, BorderLayout.CENTER);
JMenuBar menuBar = new JMenuBar();
// add menu's to the menu bar here
borderLayoutPanel.add(menuBar, BorderLayout.PAGE_START);
Side notes:
The code where you call, ta.getWidth() is likely returning a width value of 0, since it appears to be called before the JTextArea has been rendered.
You almost never want to add components directly to the JTextArea itself as that potentially interferes with the functioning of the text area.

JComponent partially hidden due to scrollpane in a BoxLayout

I want to add the possibility for my users to add a comment on a form. To display them, I created JPanel inside a simple JScrollPane. I set the layout of this JPanel to BoxLayout because I wish to add them all in only one column and it seemed to be the easiest way by calling BoxLayout.Y_AXIS in the constructor. I also tried GridLayout and GridBagLayout but it was not what I was looking for.
My problem is that when a JPanel has the BoxLayout layout, it's width automatically is the same as it's container, but my container is a JScrollPane and the caret hides the right side of my comment!
You can see the JTextField and a JButton on the bottom left, here's the code on the click event :
private void btnAjoutCommentaireActionPerformed(java.awt.event.ActionEvent evt) {
//I take the text from the JTextField and format it to html
String formattedComment = "<html><br><div style='width:280px;'>" +
txtArCommentaire.getText().replaceAll("\n", "<br>") +
"</div><br></html>";
JLabel label = new JLabel(formattedComment);
//I add a blue border
label.setBorder(new TitledBorder(new EtchedBorder(Color.lightGray, Color.blue), ConfigUser.getCu().toString()));
//this below doesn't work
label.setSize(280, 200);
//I tried adding a JPanel in between but it didn't really worked out
//JPanel panel = new JPanel();
//panel.setLayout(new GridLayout(1, 1));
//panel.setSize(297, 200);
//panel.add(label);
///pnlCommentaire is the JPanel inside the JScrollPane
pnlCommentaire.setLayout(new BoxLayout(pnlCommentaire, BoxLayout.Y_AXIS));
pnlCommentaire.add(label);
pnlCommentaire.revalidate();
pnlCommentaire.repaint();
}
As you can see I tried to adust the size in html using style='width:280px'and on the JLabel using label.setSize(280, 200); but none of them worked.
Do you have any idea on how I could resize this Jlabel?
EDIT :
I added a margin-right property to the div so that I can at least fully see the text in the JLabel but the right border is still hidden.
String formattedComment = "<html><br><div style='width:280px;margin-right:50px;'>" +
txtArCommentaire.getText().replaceAll("\n", "<br>") +
"</div><br></html>";

Java GUI development manually

I am trying to make a panel to have 4 items on top. these are a JLabel, JTextField, JLabel and JTextField.
In the center I need a JTextArea and to the left of it a JList that is scrollable.
On the bottom I need 3 buttons.
What would be the best layout manager for this and how should I go about it?
Would having just 3 columns be a good idea?
Heres what I have so far:
JPanel panel = new JPanel();
JTextField IDLabel = new JLabel("ID: ");
IDLabel.setBounds(10, 10, 80, 25);
panel.add(IDLabel);
JTextArea IDText = new JTextField(5);
IDText.setBounds(100, 10, 160, 25);
panel.add(IDText);
JLabel TitleLabel = new JLabel("Title: ");
TitleLabel.setBounds(10, 10, 80, 25);
panel.add(TitleLabel);
JTextField TitleText = new JTextField(10);
TitleText.setBounds(100, 10, 160, 25);
panel.add(TitleText);
JList list = new JList(new String[]{"test1", "test22"});
list.setFixedCellWidth(150);
list.setFixedCellHeight(50);
list.setFont(new Font("Serif",Font.BOLD,16));
list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
panel.add(list);
JTextArea BodyArea = new JTextArea();
BodyArea.setSize(200, 200);
BodyArea.setText("Test area");
panel.add(BodyArea);
You will mostly likely need to use a combination of layouts (AKA compound layouts), for example
North Panel
Create a JPanel and assign it a FlowLayout or GridBagLayout or GridLayout depending on what you want to achieve.
Add the JLabel, JTextField, JLabel, JTextField to it.
Center Panel
Create a JPanel with BorderLayout. Add the JTextArea to the CENTER position and the JList to the WEST position
South Panel
Craete a JPanel with a FlowLayout or GridBagLayout or GridLayout depending on what you want to achieve.
Add the buttons to it.
Putting it together
Create a JPanel with a BorderLayout, add the "north" panel to the NORTH position, the "center" panel to the CENTER position and the "south" panel to the SOUTH position
You could use a single container and a GridBagLayout, but that's a lot of work.
Take a look at Laying Out Components Within a Container for more details
Maybe start with a BorderLayout for the main layout. Then you can add components to the PAGE_START (NORTH), LINE_START (WEST) and CENTER and PAGE_END (SOUTH). Check out the section from the Swing tutorial on Using Layout Manager, for more information and examples.
Of course you would also use panels when you want to display multiple components in a single area. So your buttons would first be added to panels.
Also, follow standard naming conventions. Variable names should NOT start with an upper case character( ie. BodyArea, TitleText). You got variable like (panel, list) correct so be consistent.

Align two panels next to eachother

I am currently trying to create a script editor. But the lineNumber JPanel is not top aligned next to the JTextArea. The lineNumber JPanel appears at the center on the right side of the JTextArea.
It looks like this:
This is the class which instantiates both of these components:
private ScriptEditor() {
((FlowLayout) this.getLayout()).setVgap(0);
((FlowLayout) this.getLayout()).setHgap(0);
//This is the lineNumber JPanel which has no LayoutManager set.
lineNumPanel = new LineNumberPanel();
//I tried setAlignmentY but it did not work
lineNumPanel.setAlignmentY(TOP_ALIGNMENT);
//The text area.
scriptArea = new JTextArea(22,15);
scriptArea.setFont(new Font(Font.SANS_SERIF, Font.PLAIN, 15));
scriptArea.setMargin(new Insets(3, 10, 3, 10));
//This JPanel contains the two components: lineNumber JPanel and the JTextArea
JPanel temp = new JPanel();
temp.add(lineNumPanel);
temp.add(scriptArea);
//Set the scrollPane
JScrollPane scrollPane = new JScrollPane(temp);
scrollPane.setPreferredSize(new Dimension(width, height));
//Add the scrollPane to this JPanel.
add(scrollPane);
}
JPanel temp = new JPanel();
By default a JPanel uses a FlowLayout. a FlowLayout vertically centers the components added to the panel. If you don't like this behaviour then try a different layout manager like a horizontal BoxLayout, which will allow you to align the component at the top/center/bottom depending on the components vertical alignment.
However, using a JPanel is not the best approach. Instead you should be adding the line number component to the row header of the scroll pane. See Text Component Line Number for an example of this approach.

Java swing layouts and/or labels not in order

I have got a window that should display the following:
JLablel "Have you used GUI before?" on the top, centered
two radioButtons "Yes" and "No" below it, somewhat in the center, a little bit towards the left
a JButton "NEXT" in the bottom-right corner
All three elements should have green font and darkGrey background.
The problem is that the window which is showing up, does not look like I would like it to.
And this is my code:
yesButton = new JRadioButton(yes);
//yesButton.setMnemonic(KeyEvent.VK_B); // doesn't work?
yesButton.setActionCommand(yes);
noButton = new JRadioButton(no);
// noButton.setMnemonic(KeyEvent.VK_C); // doesn't work?
noButton.setActionCommand(no);
ButtonGroup group = new ButtonGroup();
group.add(yesButton);
group.add(noButton);
nextButton = new JButton("NEXT");
nextButton.setActionCommand(next);
yesButton.addActionListener(this);
noButton.addActionListener(this);
nextButton.addActionListener(this);
JPanel radioPanel = new JPanel(new GridLayout(0, 1));
radioPanel.add(yesButton);
radioPanel.add(noButton);
add(radioPanel, BorderLayout.WEST);
// setBorder(BorderFactory.createEmptyBorder(20,20,20,20));
// radioPanel.setBorder(new EmptyBorder(250, 250, 20, 20));
// there is no difference between the above two, right?
String q = "Have you used GUI before?";
JPanel area = new JPanel(new BorderLayout());
area.setBackground(Color.darkGray);
JLabel textLabel2 = new JLabel("<html><div style=\"text-align: center;\">"
+ q + "</html>", SwingConstants.CENTER);
textLabel2.setForeground(Color.green);
Font font2 = new Font("SansSerif", Font.PLAIN, 30);
textLabel2.setFont(font2);
//textLabel2.setBorder(new EmptyBorder(0, 0, 250, 0)); //top, left, bottom, right
area.add(textLabel2, BorderLayout.NORTH);
area.add(nextButton, BorderLayout.EAST);
add(area, BorderLayout.CENTER);
I feel I'm nearly there, thanks for any help!
--EDIT--
A screenshot:
You need to use nested panels.
for the BorderLayout.NORTH you can add the JLabel directly. You will need to set the horizontal text alignment to center.
for the radio buttons you can create a JPanel with a FlowLayout and then add the buttons to the panel and add the panel to the CENTER.
for the button you add the button to a panel using a FlowLayout that is right aligned, then add the panel to the SOUTH.
There are other choices. You could also use a Vertical BoxLayout as the layout of the main panel and then add child panels to it.
You won't be able to get much control with just a BorderLayout. Try something else like MigLayout or one of the other many many layout managers Java has (GridBag, Box, etc).
In MigLayout it would look something like:
area.setLayout(new MigLayout("fill"));
area.add(textLabel2, "wrap");
area.add(radioPanel, "wrap");
area.add(nextButton, "tag right");

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