Jsliders generate what type of event

UnsupportedLookAndFeelException; import javax. ChangeEvent; import javax. BOLD, 10 ; slider. MadProgrammer MadProgrammer k 21 21 gold badges silver badges bronze badges. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name.

Email Required, but never shown. The Overflow Blog. Does ES6 make JavaScript frameworks obsolete? Podcast Do polyglots have an edge when it comes to mastering programming Featured on Meta. Now live: A fully responsive profile. Slider change event Use Slider to control the color R G B value Move the slider by a fixed amount: the extent. Get the extent Set major tick marks every 25 units Set minor tick marks every 5 units Set to a spot between tick marks; the value moves to closest tick mark Set the value; the new value will be forced into the bar's range Set the extent Set all the values at once by using the model Make it vertical and move bottom-to-top Make it vertical and move top-to-bottom Make the horizontal slider move right-to-left Create a dynamic icon Hide the track Problem 7.

Problem 8. Problem 9. Problem Video Transcript Okay, So when an event is a subset of our example space. What is an event? Define an event. What distinguishes a wave from an oscillation? What type of processes occur in a Camot cycle? What is meant by the transition interval of an indicator? Alternatively, you can use evt. For a JCheckBox , the action command is, by default, the label of the checkbox. It is also possible to set a JTextField or JTextArea to be read-only so that the user can read the text that it contains but cannot edit the text.

Both classes are subclasses of an abstract class, JTextComponent , which defines their common properties. The instance method setText , which takes a parameter of type String , can be used to change the text that is displayed in an input component.

The contents of the component can be retrieved by calling its getText instance method, which returns a value of type String. If you want to stop the user from modifying the text, you can call setEditable false. Call the same method with a parameter of true to make the input component user-editable again. The user can only type into a text component when it has the input focus.

The user can give the input focus to a text component by clicking it with the mouse, but sometimes it is useful to give the input focus to a text field programmatically. You can do this by calling its requestFocus method.

For example, when I discover an error in the user's input, I usually call requestFocus on the text field that contains the error. This helps the user see where the error occurred and lets the user start typing the correction immediately.

By default, there is no space between the text in a text component and the edge of the component, which usually doesn't look very good.

You can use the setMargin method of the component to add some blank space between the edge of the component and the text. This method takes a parameter of type java. Insets which contains four integer instance variables that specify the margins on the top, left, bottom, and right edge of the component.

This is used to determine the preferred width of the text field. Because characters can be of different sizes and because the preferred width is not always respected, the actual number of characters visible in the text field might not be equal to columns. You don't have to specify the number of columns; for example, you might use the text field in a context where it will expand to fill whatever space is available.

In that case, you can use the default constructor JTextField , with no parameters. You can also use the following constructors, which specify the initial contents of the text field:.

The parameter rows specifies how many lines of text should be visible in the text area. This determines the preferred height of the text area, just as columns determines the preferred width. However, the text area can actually contain any number of lines; the text area can be scrolled to reveal lines that are not currently visible.

In that case, it is less useful to specify the number of lines and columns, since the TextArea will expand to fill all the space available in the center area of the container.

For example, the instance method append moreText , where moreText is of type String , adds the specified text at the end of the current content of the text area. And setLineWrap wrap , where wrap is of type boolean , tells what should happen when a line of text is too long to be displayed in the text area. If wrap is true, then any line that is too long will be "wrapped" onto the next line; if wrap is false, the line will simply extend outside the text area, and the user will have to scroll the text area horizontally to see the entire line.

The default value of wrap is false. Since it might be necessary to scroll a text area to see all the text that it contains, you might expect a text area to come with scroll bars.

Unfortunately, this does not happen automatically. This can be done as follows:. The scroll pane provides scroll bars that can be used to scroll the text in the text area. The scroll bars will appear only when needed, that is when the size of the text exceeds the size of the text area. Note that when you want to put the text area into a container, you should add the scroll pane, not the text area itself, to the container. Here is an applet that simply displays a text area, with a rather large font, in a scrollpane.

The source code of this short example is TextAreaDemo. You should check out how the scroll bars change as you type in additional lines of text:. If you want to respond to such events, you can register an ActionListener with the text field, using the text field's addActionListener method.

Since a JTextArea can contain multiple lines of text, pressing return in a text area does not generate an event; it simply begins a new line of text. JTextField has a subclass, JPasswordField , which is identical except that it does not reveal the text that it contains. The characters in a JPasswordField are all displayed as asterisks or some other fixed character. A password field is, obviously, designed to let the user enter a password without showing that password on the screen.

Text components are actually quite complex, and I have covered only their most basic properties here. I will return to the topic of text components in Subsection The JComboBox class provides a way to let the user select one option from a list of options. The options are presented as a kind of pop-up menu, and only the currently selected option is visible on the screen. When a JComboBox object is first constructed, it initially contains no items.

An item is added to the bottom of the list of options by calling the combo box's instance method, addItem str , where str is the string that will be displayed in the menu. You can call the getSelectedIndex method of a JComboBox to find out which item is currently selected. This method returns an integer that gives the position of the selected item in the list, where the items are numbered starting from zero.

Alternatively, you can call getSelectedItem to get the selected item itself. This method returns a value of type Object , since a JComboBox can actually hold other types of objects besides strings.

You can change the selection by calling the method setSelectedIndex n , where n is an integer giving the position of the item that you want to select. The most common way to use a JComboBox is to call its getSelectedIndex method when you have a need to know which item is currently selected.