public class TextArea extends TextComponent
A TextArea
object is a multi-line region that displays text. It can be set to allow editing or to be read-only.
The following image shows the appearance of a text area:
This text area could be created by the following line of code:
new TextArea("Hello", 5, 40);
Modifier and Type | Class and Description |
---|---|
protected class |
TextArea.AccessibleAWTTextArea This class implements accessibility support for the |
TextComponent.AccessibleAWTTextComponent
Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy
public static final int SCROLLBARS_BOTH
Create and display both vertical and horizontal scrollbars.
public static final int SCROLLBARS_VERTICAL_ONLY
Create and display vertical scrollbar only.
public static final int SCROLLBARS_HORIZONTAL_ONLY
Create and display horizontal scrollbar only.
public static final int SCROLLBARS_NONE
Do not create or display any scrollbars for the text area.
public TextArea() throws HeadlessException
Constructs a new text area with the empty string as text. This text area is created with scrollbar visibility equal to SCROLLBARS_BOTH
, so both vertical and horizontal scrollbars will be visible for this text area.
HeadlessException
- if GraphicsEnvironment.isHeadless
returns trueGraphicsEnvironment.isHeadless()
public TextArea(String text) throws HeadlessException
Constructs a new text area with the specified text. This text area is created with scrollbar visibility equal to SCROLLBARS_BOTH
, so both vertical and horizontal scrollbars will be visible for this text area.
text
- the text to be displayed; if text
is null
, the empty string ""
will be displayedHeadlessException
- if GraphicsEnvironment.isHeadless
returns trueGraphicsEnvironment.isHeadless()
public TextArea(int rows, int columns) throws HeadlessException
Constructs a new text area with the specified number of rows and columns and the empty string as text. A column is an approximate average character width that is platform-dependent. The text area is created with scrollbar visibility equal to SCROLLBARS_BOTH
, so both vertical and horizontal scrollbars will be visible for this text area.
rows
- the number of rowscolumns
- the number of columnsHeadlessException
- if GraphicsEnvironment.isHeadless
returns trueGraphicsEnvironment.isHeadless()
public TextArea(String text, int rows, int columns) throws HeadlessException
Constructs a new text area with the specified text, and with the specified number of rows and columns. A column is an approximate average character width that is platform-dependent. The text area is created with scrollbar visibility equal to SCROLLBARS_BOTH
, so both vertical and horizontal scrollbars will be visible for this text area.
text
- the text to be displayed; if text
is null
, the empty string ""
will be displayedrows
- the number of rowscolumns
- the number of columnsHeadlessException
- if GraphicsEnvironment.isHeadless
returns trueGraphicsEnvironment.isHeadless()
public TextArea(String text, int rows, int columns, int scrollbars) throws HeadlessException
Constructs a new text area with the specified text, and with the rows, columns, and scroll bar visibility as specified. All TextArea
constructors defer to this one.
The TextArea
class defines several constants that can be supplied as values for the scrollbars
argument:
SCROLLBARS_BOTH
, SCROLLBARS_VERTICAL_ONLY
, SCROLLBARS_HORIZONTAL_ONLY
, SCROLLBARS_NONE
. scrollbars
argument is invalid and will result in this text area being created with scrollbar visibility equal to the default value of SCROLLBARS_BOTH
.text
- the text to be displayed; if text
is null
, the empty string ""
will be displayedrows
- the number of rows; if rows
is less than 0
, rows
is set to 0
columns
- the number of columns; if columns
is less than 0
, columns
is set to 0
scrollbars
- a constant that determines what scrollbars are created to view the text areaHeadlessException
- if GraphicsEnvironment.isHeadless
returns trueGraphicsEnvironment.isHeadless()
public void addNotify()
Creates the TextArea
's peer. The peer allows us to modify the appearance of the TextArea
without changing any of its functionality.
addNotify
in class TextComponent
TextComponent.removeNotify()
public void insert(String str, int pos)
Inserts the specified text at the specified position in this text area.
Note that passing null
or inconsistent parameters is invalid and will result in unspecified behavior.
str
- the non-null
text to insertpos
- the position at which to insertTextComponent.setText(java.lang.String)
, replaceRange(java.lang.String, int, int)
, append(java.lang.String)
@Deprecated public void insertText(String str, int pos)
Deprecated. As of JDK version 1.1, replaced by insert(String, int)
.
public void append(String str)
Appends the given text to the text area's current text.
Note that passing null
or inconsistent parameters is invalid and will result in unspecified behavior.
str
- the non-null
text to appendinsert(java.lang.String, int)
@Deprecated public void appendText(String str)
Deprecated. As of JDK version 1.1, replaced by append(String)
.
public void replaceRange(String str, int start, int end)
Replaces text between the indicated start and end positions with the specified replacement text. The text at the end position will not be replaced. The text at the start position will be replaced (unless the start position is the same as the end position). The text position is zero-based. The inserted substring may be of a different length than the text it replaces.
Note that passing null
or inconsistent parameters is invalid and will result in unspecified behavior.
str
- the non-null
text to use as the replacementstart
- the start positionend
- the end positioninsert(java.lang.String, int)
@Deprecated public void replaceText(String str, int start, int end)
Deprecated. As of JDK version 1.1, replaced by replaceRange(String, int, int)
.
public int getRows()
Returns the number of rows in the text area.
setRows(int)
, getColumns()
public void setRows(int rows)
Sets the number of rows for this text area.
rows
- the number of rowsIllegalArgumentException
- if the value supplied for rows
is less than 0
getRows()
, setColumns(int)
public int getColumns()
Returns the number of columns in this text area.
setColumns(int)
, getRows()
public void setColumns(int columns)
Sets the number of columns for this text area.
columns
- the number of columnsIllegalArgumentException
- if the value supplied for columns
is less than 0
getColumns()
, setRows(int)
public int getScrollbarVisibility()
Returns an enumerated value that indicates which scroll bars the text area uses.
The TextArea
class defines four integer constants that are used to specify which scroll bars are available. TextArea
has one constructor that gives the application discretion over scroll bars.
SCROLLBARS_BOTH
, SCROLLBARS_VERTICAL_ONLY
, SCROLLBARS_HORIZONTAL_ONLY
, SCROLLBARS_NONE
, TextArea(java.lang.String, int, int, int)
public Dimension getPreferredSize(int rows, int columns)
Determines the preferred size of a text area with the specified number of rows and columns.
rows
- the number of rowscolumns
- the number of columnsComponent.getPreferredSize()
@Deprecated public Dimension preferredSize(int rows, int columns)
Deprecated. As of JDK version 1.1, replaced by getPreferredSize(int, int)
.
public Dimension getPreferredSize()
Determines the preferred size of this text area.
getPreferredSize
in class Component
Component.getPreferredSize()
@Deprecated public Dimension preferredSize()
Deprecated. As of JDK version 1.1, replaced by getPreferredSize()
.
preferredSize
in class Component
public Dimension getMinimumSize(int rows, int columns)
Determines the minimum size of a text area with the specified number of rows and columns.
rows
- the number of rowscolumns
- the number of columnsComponent.getMinimumSize()
@Deprecated public Dimension minimumSize(int rows, int columns)
Deprecated. As of JDK version 1.1, replaced by getMinimumSize(int, int)
.
public Dimension getMinimumSize()
Determines the minimum size of this text area.
getMinimumSize
in class Component
Component.getPreferredSize()
@Deprecated public Dimension minimumSize()
Deprecated. As of JDK version 1.1, replaced by getMinimumSize()
.
minimumSize
in class Component
protected String paramString()
Returns a string representing the state of this TextArea
. This method is intended to be used only for debugging purposes, and the content and format of the returned string may vary between implementations. The returned string may be empty but may not be null
.
paramString
in class TextComponent
public AccessibleContext getAccessibleContext()
Returns the AccessibleContext
associated with this TextArea
. For text areas, the AccessibleContext
takes the form of an AccessibleAWTTextArea
. A new AccessibleAWTTextArea
instance is created if necessary.
getAccessibleContext
in interface Accessible
getAccessibleContext
in class TextComponent
AccessibleAWTTextArea
that serves as the AccessibleContext
of this TextArea
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