| java.lang.Object
 java.awt.Component
java.awt.List
| List | | public class List extends Component implements ItemSelectable(Code) | | The List component presents the user with a
scrolling list of text items. The list can be set up so that
the user can choose either one item or multiple items.
For example, the code . . .
List lst = new List(4, false);
lst.add("Mercury");
lst.add("Venus");
lst.add("Earth");
lst.add("JavaSoft");
lst.add("Mars");
lst.add("Jupiter");
lst.add("Saturn");
lst.add("Uranus");
lst.add("Neptune");
lst.add("Pluto");
cnt.add(lst);
where cnt is a container, produces the following
scrolling list:
Clicking on an item that isn't selected selects it. Clicking on
an item that is already selected deselects it. In the preceding
example, only one item from the scrolling list can be selected
at a time, since the second argument when creating the new scrolling
list is false. Selecting an item causes any other
selected item to be automatically deselected.
Beginning with Java 1.1, the Abstract Window Toolkit
sends the List object all mouse, keyboard, and focus events
that occur over it. (The old AWT event model is being maintained
only for backwards compatibility, and its use is discouraged.)
When an item is selected or deselected, AWT sends an instance
of ItemEvent to the list.
When the user double-clicks on an item in a scrolling list,
AWT sends an instance of ActionEvent to the
list following the item event. AWT also generates an action event
when the user presses the return key while an item in the
list is selected.
If an application wants to perform some action based on an item
in this list being selected or activated, it should implement
ItemListener or ActionListener
as appropriate and register the new listener to receive
events from this list.
For multiple-selection scrolling lists, it is considered a better
user interface to use an external gesture (such as clicking on a
button) to trigger the action.
version:
1.77, %G
author:
Sami Shaio
See Also: java.awt.event.ItemEvent
See Also: java.awt.event.ItemListener
See Also: java.awt.event.ActionEvent
See Also: java.awt.event.ActionListener
since:
JDK1.0 |
| Field Summary | |
| final static int | DEFAULT_VISIBLE_ROWS
The default number of visible rows is 4. | | transient ActionListener | actionListener
| | transient ItemListener | itemListener
| | Vector | items
A vector created to contain items which will become
part of the List Component. | | boolean | multipleMode
multipleMode is a variable that will
be set to true if a list component is to be set to
multiple selection mode, that is where the user can
select more than one item in a list at one time. | | int | rows
This field will represent the number of rows in the
List Component. | | int | selected
selected is an array that will contain
the indices of items that have been selected. | | int | visibleIndex
This variable contains the value that will be used
when trying to make a particular list item visible. |
| Constructor Summary | |
| public | List()
Creates a new scrolling list. | | public | List(int rows)
Creates a new scrolling list initialized with the specified
number of visible lines. | | public | List(int rows, boolean multipleMode)
Creates a new scrolling list initialized to display the specified
number of rows. |
| Method Summary | |
| public void | add(String item)
Adds the specified item to the end of scrolling list. | | public void | add(String item, int index)
Adds the specified item to the the scrolling list
at the position indicated by the index. | | public synchronized void | addActionListener(ActionListener l)
Adds the specified action listener to receive action events from
this list. | | public void | addItem(String item)
| | public synchronized void | addItem(String item, int index)
| | public synchronized void | addItemListener(ItemListener l)
Adds the specified item listener to receive item events from
this list. | | public void | addNotify()
Creates the peer for the list. | | public boolean | allowsMultipleSelections()
| | public synchronized void | clear()
| | String | constructComponentName()
Construct a name for this component. | | public int | countItems()
| | public void | delItem(int position)
| | public synchronized void | delItems(int start, int end)
| | public synchronized void | deselect(int index)
Deselects the item at the specified index. | | boolean | eventEnabled(AWTEvent e)
| | public synchronized ActionListener[] | getActionListeners()
Returns an array of all the action listeners
registered on this list. | | public String | getItem(int index)
Gets the item associated with the specified index. | | public int | getItemCount()
Gets the number of items in the list. | | public synchronized ItemListener[] | getItemListeners()
Returns an array of all the item listeners
registered on this list. | | public synchronized String[] | getItems()
Gets the items in the list. | | public Dimension | getMinimumSize(int rows)
Gets the minumum dimensions for a list with the specified
number of rows.
Parameters:
rows - number of rows in the list. | | public Dimension | getMinimumSize()
Determines the minimum size of this scrolling list. | | public Dimension | getPreferredSize(int rows)
Gets the preferred dimensions for a list with the specified
number of rows.
Parameters:
rows - number of rows in the list. | | public Dimension | getPreferredSize()
Gets the preferred size of this scrolling list. | | public int | getRows()
Get the number of visible lines in this list. | | public synchronized int | getSelectedIndex()
| | public synchronized int[] | getSelectedIndexes()
Gets the selected indexes on the list.
an array of the selected indexesof this scrolling list. | | public synchronized String | getSelectedItem()
Get the selected item on this scrolling list. | | public synchronized String[] | getSelectedItems()
Get the selected items on this scrolling list. | | public Object[] | getSelectedObjects()
Returns the selected items on the list in an array of Objects. | | public int | getVisibleIndex()
Gets the index of the item that was last made visible by
the method makeVisible. | | public boolean | isIndexSelected(int index)
Determines if the specified item in this scrolling list is
selected.
Parameters:
index - the item to be checked. | | public boolean | isMultipleMode()
Determines whether this list allows multiple selections. | | public boolean | isSelected(int index)
| | public synchronized void | makeVisible(int index)
Makes the item at the specified index visible. | | public Dimension | minimumSize(int rows)
| | public Dimension | minimumSize()
| | protected String | paramString()
Returns the parameter string representing the state of this
scrolling list. | | public Dimension | preferredSize(int rows)
| | public Dimension | preferredSize()
| | protected void | processActionEvent(ActionEvent e)
Processes action events occurring on this component
by dispatching them to any registered
ActionListener objects.
This method is not called unless action events are
enabled for this component. | | protected void | processEvent(AWTEvent e)
Processes events on this scrolling list. | | protected void | processItemEvent(ItemEvent e)
Processes item events occurring on this list by
dispatching them to any registered
ItemListener objects.
This method is not called unless item events are
enabled for this component. | | public synchronized void | remove(String item)
Removes the first occurrence of an item from the list. | | public void | remove(int position)
Remove the item at the specified position
from this scrolling list. | | public synchronized void | removeActionListener(ActionListener l)
Removes the specified action listener so that it no longer
receives action events from this list. | | public void | removeAll()
Removes all items from this list. | | public synchronized void | removeItemListener(ItemListener l)
Removes the specified item listener so that it no longer
receives item events from this list. | | public void | removeNotify()
Removes the peer for this list. | | public synchronized void | replaceItem(String newValue, int index)
Replaces the item at the specified index in the scrolling list
with the new string. | | public void | select(int index)
Selects the item at the specified index in the scrolling list. | | public void | setMultipleMode(boolean b)
Sets the flag that determines whether this list
allows multiple selections. | | public synchronized void | setMultipleSelections(boolean b)
|
| DEFAULT_VISIBLE_ROWS | | final static int DEFAULT_VISIBLE_ROWS(Code) | | The default number of visible rows is 4. A list with
zero rows is unusable and unsightly.
|
| items | | Vector items(Code) | | A vector created to contain items which will become
part of the List Component.
See Also: addItem()
See Also: getItem() |
| multipleMode | | boolean multipleMode(Code) | | multipleMode is a variable that will
be set to true if a list component is to be set to
multiple selection mode, that is where the user can
select more than one item in a list at one time.
multipleMode will be set to false if the
list component is set to single selection, that is where
the user can only select one item on the list at any
one time.
See Also: isMultipleMode()
See Also: setMultipleMode() |
| rows | | int rows(Code) | | This field will represent the number of rows in the
List Component. It is specified only once, and
that is when the list component is actually
created. It will never change.
See Also: getRows() |
| selected | | int selected(Code) | | selected is an array that will contain
the indices of items that have been selected.
See Also: getSelectedIndexes()
See Also: getSelectedIndex() |
| visibleIndex | | int visibleIndex(Code) | | This variable contains the value that will be used
when trying to make a particular list item visible.
See Also: makeVisible() |
| List | | public List()(Code) | | Creates a new scrolling list.
By default, there are four visible lines and multiple selections are
not allowed.
|
| List | | public List(int rows)(Code) | | Creates a new scrolling list initialized with the specified
number of visible lines. By default, multiple selections are
not allowed.
Parameters:
rows - the number of items to show.
since:
JDK1.1 |
| List | | public List(int rows, boolean multipleMode)(Code) | | Creates a new scrolling list initialized to display the specified
number of rows. If the value of multipleMode is
true, then the user can select multiple items from
the list. If it is false, only one item at a time
can be selected.
Parameters:
rows - the number of items to show.
Parameters:
multipleMode - if true,then multiple selections are allowed;otherwise, only one item can be selected at a time. |
| add | | public void add(String item)(Code) | | Adds the specified item to the end of scrolling list.
Parameters:
item - the item to be added.
since:
JDK1.1 |
| add | | public void add(String item, int index)(Code) | | Adds the specified item to the the scrolling list
at the position indicated by the index. The index is
zero-based. If the value of the index is less than zero,
or if the value of the index is greater than or equal to
the number of items in the list, then the item is added
to the end of the list.
Parameters:
item - the item to be added.If this parameter is null then the item istreated as an empty string, "".
Parameters:
index - the position at which to add the item.
since:
JDK1.1 |
| addItem | | public synchronized void addItem(String item, int index)(Code) | | |
| addNotify | | public void addNotify()(Code) | | Creates the peer for the list. The peer allows us to modify the
list's appearance without changing its functionality.
|
| allowsMultipleSelections | | public boolean allowsMultipleSelections()(Code) | | |
| clear | | public synchronized void clear()(Code) | | |
| constructComponentName | | String constructComponentName()(Code) | | Construct a name for this component. Called by getName() when the
name is null.
|
| countItems | | public int countItems()(Code) | | |
| delItem | | public void delItem(int position)(Code) | | |
| delItems | | public synchronized void delItems(int start, int end)(Code) | | |
| getItem | | public String getItem(int index)(Code) | | Gets the item associated with the specified index.
an item that is associated withthe specified index.
Parameters:
index - the position of the item.
See Also: java.awt.List.getItemCount |
| getItemCount | | public int getItemCount()(Code) | | Gets the number of items in the list.
the number of items in the list.
See Also: java.awt.List.getItem
since:
JDK1.1 |
| getMinimumSize | | public Dimension getMinimumSize(int rows)(Code) | | Gets the minumum dimensions for a list with the specified
number of rows.
Parameters:
rows - number of rows in the list. the minimum dimensions for displaying this scrolling listgiven that the specified number of rows must be visible.
See Also: java.awt.Component.getMinimumSize
since:
JDK1.1 |
| getPreferredSize | | public Dimension getPreferredSize(int rows)(Code) | | Gets the preferred dimensions for a list with the specified
number of rows.
Parameters:
rows - number of rows in the list. the preferred dimensions for displaying this scrolling listgiven that the specified number of rows must be visible.
See Also: java.awt.Component.getPreferredSize
since:
JDK1.1 |
| getRows | | public int getRows()(Code) | | Get the number of visible lines in this list.
the number of visible lines in this scrolling list. |
| getSelectedObjects | | public Object[] getSelectedObjects()(Code) | | Returns the selected items on the list in an array of Objects.
See Also: ItemSelectable |
| getVisibleIndex | | public int getVisibleIndex()(Code) | | Gets the index of the item that was last made visible by
the method makeVisible.
the index of the item that was last made visible.
See Also: java.awt.List.makeVisible |
| isIndexSelected | | public boolean isIndexSelected(int index)(Code) | | Determines if the specified item in this scrolling list is
selected.
Parameters:
index - the item to be checked. true if the specified item has beenselected; false otherwise.
See Also: java.awt.List.select
See Also: java.awt.List.deselect
since:
JDK1.1 |
| isMultipleMode | | public boolean isMultipleMode()(Code) | | Determines whether this list allows multiple selections.
true if this list allows multipleselections; otherwise, false.
See Also: java.awt.List.setMultipleMode
since:
JDK1.1 |
| isSelected | | public boolean isSelected(int index)(Code) | | |
| makeVisible | | public synchronized void makeVisible(int index)(Code) | | Makes the item at the specified index visible.
Parameters:
index - the position of the item.
See Also: java.awt.List.getVisibleIndex |
| paramString | | protected String paramString()(Code) | | Returns the parameter string representing the state of this
scrolling list. This string is useful for debugging.
the parameter string of this scrolling list. |
| remove | | public synchronized void remove(String item)(Code) | | Removes the first occurrence of an item from the list.
Parameters:
item - the item to remove from the list.
exception:
IllegalArgumentException - if the item doesn't exist in the list.
since:
JDK1.1 |
| remove | | public void remove(int position)(Code) | | Remove the item at the specified position
from this scrolling list.
Parameters:
position - the index of the item to delete.
See Also: java.awt.List.add(Stringint)
since:
JDK1.1
exception:
ArrayIndexOutOfBoundsException - if the position is less than 0 orgreater than getItemCount()-1 |
| removeNotify | | public void removeNotify()(Code) | | Removes the peer for this list. The peer allows us to modify the
list's appearance without changing its functionality.
|
| replaceItem | | public synchronized void replaceItem(String newValue, int index)(Code) | | Replaces the item at the specified index in the scrolling list
with the new string.
Parameters:
newValue - a new string to replace an existing item.
Parameters:
index - the position of the item to replace. |
| setMultipleMode | | public void setMultipleMode(boolean b)(Code) | | Sets the flag that determines whether this list
allows multiple selections.
Parameters:
b - if true then multiple selectionsare allowed; otherwise, only one item fromthe list can be selected at once.
See Also: java.awt.List.isMultipleMode
since:
JDK1.1 |
| setMultipleSelections | | public synchronized void setMultipleSelections(boolean b)(Code) | | |
| Methods inherited from java.awt.Component | public boolean action(Event evt, Object what)(Code)(Java Doc)
public synchronized void add(PopupMenu popup)(Code)(Java Doc)
public synchronized void addComponentListener(ComponentListener l)(Code)(Java Doc)
public synchronized void addFocusListener(FocusListener l)(Code)(Java Doc)
public synchronized void addKeyListener(KeyListener l)(Code)(Java Doc)
public synchronized void addMouseListener(MouseListener l)(Code)(Java Doc)
public synchronized void addMouseMotionListener(MouseMotionListener l)(Code)(Java Doc)
public void addNotify()(Code)(Java Doc)
boolean areInputMethodsEnabled()(Code)(Java Doc)
public Rectangle bounds()(Code)(Java Doc)
final void checkEnableNewEventsOnly(Object listener)(Code)(Java Doc)
public int checkImage(Image image, ImageObserver observer)(Code)(Java Doc)
public int checkImage(Image image, int width, int height, ImageObserver observer)(Code)(Java Doc)
protected AWTEvent coalesceEvents(AWTEvent existingEvent, AWTEvent newEvent)(Code)(Java Doc)
String constructComponentName()(Code)(Java Doc)
public boolean contains(int x, int y)(Code)(Java Doc)
public boolean contains(Point p)(Code)(Java Doc)
public Image createImage(ImageProducer producer)(Code)(Java Doc)
public Image createImage(int width, int height)(Code)(Java Doc)
ComponentXWindow createXWindow()(Code)(Java Doc)
public void deliverEvent(Event e)(Code)(Java Doc)
public void disable()(Code)(Java Doc)
final protected void disableEvents(long eventsToDisable)(Code)(Java Doc)
final public void dispatchEvent(AWTEvent e)(Code)(Java Doc)
void dispatchEventImpl(AWTEvent e)(Code)(Java Doc)
public void doLayout()(Code)(Java Doc)
public void enable()(Code)(Java Doc)
public void enable(boolean b)(Code)(Java Doc)
final protected synchronized void enableEvents(long eventsToEnable)(Code)(Java Doc)
boolean eventEnabled(AWTEvent e)(Code)(Java Doc)
Component findFocusDelegate(Container container)(Code)(Java Doc)
public float getAlignmentX()(Code)(Java Doc)
public float getAlignmentY()(Code)(Java Doc)
public Color getBackground()(Code)(Java Doc)
public Rectangle getBounds()(Code)(Java Doc)
public ColorModel getColorModel()(Code)(Java Doc)
public Component getComponentAt(int x, int y)(Code)(Java Doc)
public Component getComponentAt(Point p)(Code)(Java Doc)
public Cursor getCursor()(Code)(Java Doc)
Component getFocusDelegate()(Code)(Java Doc)
public Font getFont()(Code)(Java Doc)
Component getFontAndColorDelegate()(Code)(Java Doc)
public FontMetrics getFontMetrics(Font font)(Code)(Java Doc)
public Color getForeground()(Code)(Java Doc)
public Graphics getGraphics()(Code)(Java Doc)
InputContext getInputContext()(Code)(Java Doc)
public Locale getLocale()(Code)(Java Doc)
public Point getLocation()(Code)(Java Doc)
public Point getLocationOnScreen()(Code)(Java Doc)
public Dimension getMaximumSize()(Code)(Java Doc)
public Dimension getMinimumSize()(Code)(Java Doc)
public String getName()(Code)(Java Doc)
Container getNativeContainer()(Code)(Java Doc)
public Container getParent()(Code)(Java Doc)
public Dimension getPreferredSize()(Code)(Java Doc)
public Dimension getSize()(Code)(Java Doc)
public Toolkit getToolkit()(Code)(Java Doc)
final public Object getTreeLock()(Code)(Java Doc)
public boolean gotFocus(Event evt, Object what)(Code)(Java Doc)
public boolean handleEvent(Event evt)(Code)(Java Doc)
public void hide()(Code)(Java Doc)
public boolean imageUpdate(Image img, int flags, int x, int y, int w, int h)(Code)(Java Doc)
public boolean inside(int x, int y)(Code)(Java Doc)
public void invalidate()(Code)(Java Doc)
static void invokeAndWait(Runnable runnable)(Code)(Java Doc)
public boolean isDisplayable()(Code)(Java Doc)
public boolean isEnabled()(Code)(Java Doc)
public boolean isFocusTraversable()(Code)(Java Doc)
public boolean isLightweight()(Code)(Java Doc)
boolean isLightweightWhenDisplayable()(Code)(Java Doc)
public boolean isOpaque()(Code)(Java Doc)
public boolean isShowing()(Code)(Java Doc)
public boolean isValid()(Code)(Java Doc)
public boolean isVisible()(Code)(Java Doc)
public boolean keyDown(Event evt, int key)(Code)(Java Doc)
public boolean keyUp(Event evt, int key)(Code)(Java Doc)
public void layout()(Code)(Java Doc)
void lightweightPrint(Graphics g)(Code)(Java Doc)
public void list()(Code)(Java Doc)
public void list(PrintStream out)(Code)(Java Doc)
public void list(PrintStream out, int indent)(Code)(Java Doc)
public void list(PrintWriter out)(Code)(Java Doc)
public void list(PrintWriter out, int indent)(Code)(Java Doc)
public Component locate(int x, int y)(Code)(Java Doc)
public Point location()(Code)(Java Doc)
public boolean lostFocus(Event evt, Object what)(Code)(Java Doc)
public Dimension minimumSize()(Code)(Java Doc)
public boolean mouseDown(Event evt, int x, int y)(Code)(Java Doc)
public boolean mouseDrag(Event evt, int x, int y)(Code)(Java Doc)
public boolean mouseEnter(Event evt, int x, int y)(Code)(Java Doc)
public boolean mouseExit(Event evt, int x, int y)(Code)(Java Doc)
public boolean mouseMove(Event evt, int x, int y)(Code)(Java Doc)
public boolean mouseUp(Event evt, int x, int y)(Code)(Java Doc)
public void move(int x, int y)(Code)(Java Doc)
public void nextFocus()(Code)(Java Doc)
public void paint(Graphics g)(Code)(Java Doc)
public void paintAll(Graphics g)(Code)(Java Doc)
protected String paramString()(Code)(Java Doc)
public boolean postEvent(Event e)(Code)(Java Doc)
public Dimension preferredSize()(Code)(Java Doc)
public boolean prepareImage(Image image, ImageObserver observer)(Code)(Java Doc)
public boolean prepareImage(Image image, int width, int height, ImageObserver observer)(Code)(Java Doc)
public void print(Graphics g)(Code)(Java Doc)
public void printAll(Graphics g)(Code)(Java Doc)
protected void processComponentEvent(ComponentEvent e)(Code)(Java Doc)
protected void processEvent(AWTEvent e)(Code)(Java Doc)
protected void processFocusEvent(FocusEvent e)(Code)(Java Doc)
protected void processKeyEvent(KeyEvent e)(Code)(Java Doc)
protected void processMouseEvent(MouseEvent e)(Code)(Java Doc)
protected void processMouseMotionEvent(MouseEvent e)(Code)(Java Doc)
public synchronized void remove(MenuComponent popup)(Code)(Java Doc)
public synchronized void removeComponentListener(ComponentListener l)(Code)(Java Doc)
public synchronized void removeFocusListener(FocusListener l)(Code)(Java Doc)
public synchronized void removeKeyListener(KeyListener l)(Code)(Java Doc)
public synchronized void removeMouseListener(MouseListener l)(Code)(Java Doc)
public synchronized void removeMouseMotionListener(MouseMotionListener l)(Code)(Java Doc)
public void removeNotify()(Code)(Java Doc)
public void repaint()(Code)(Java Doc)
public void repaint(long tm)(Code)(Java Doc)
public void repaint(int x, int y, int width, int height)(Code)(Java Doc)
public void repaint(long tm, int x, int y, int width, int height)(Code)(Java Doc)
public void requestFocus()(Code)(Java Doc)
public void reshape(int x, int y, int width, int height)(Code)(Java Doc)
public void resize(int width, int height)(Code)(Java Doc)
public void resize(Dimension d)(Code)(Java Doc)
public void setBackground(Color c)(Code)(Java Doc)
public void setBounds(int x, int y, int width, int height)(Code)(Java Doc)
public void setBounds(Rectangle r)(Code)(Java Doc)
public synchronized void setCursor(Cursor cursor)(Code)(Java Doc)
public void setEnabled(boolean b)(Code)(Java Doc)
public void setFont(Font f)(Code)(Java Doc)
public void setForeground(Color c)(Code)(Java Doc)
public void setLocale(Locale l)(Code)(Java Doc)
public void setLocation(int x, int y)(Code)(Java Doc)
public void setLocation(Point p)(Code)(Java Doc)
public void setName(String name)(Code)(Java Doc)
public void setSize(int width, int height)(Code)(Java Doc)
public void setSize(Dimension d)(Code)(Java Doc)
public void setVisible(boolean b)(Code)(Java Doc)
public void show()(Code)(Java Doc)
public void show(boolean b)(Code)(Java Doc)
public Dimension size()(Code)(Java Doc)
public String toString()(Code)(Java Doc)
public void transferFocus()(Code)(Java Doc)
public void update(Graphics g)(Code)(Java Doc)
public void validate()(Code)(Java Doc)
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