|
|||||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Object | +--org.gnu.glib.GObject | +--org.gnu.gtk.GtkObject | +--org.gnu.gtk.Widget | +--org.gnu.gtk.Container | +--org.gnu.gtk.TextView
java-gnome has an extremely powerful framework for multiline text editing. The
primary objects involved in the process are TextBuffer
, which represents
the text being edited, and TextView
, a widget which can display a
TextBuffer. Each buffer can be displayed by any number of views.
One of the important things to remember about text in java-gnome is that it's in the UTF-8 encoding. This means that one character can be encoded as multiple bytes. Character counts are usually referred to as offsets, while byte counts are called indexes. If you confuse these two, things will work fine with ASCII, but as soon as your buffer contains multibyte characters, bad things will happen.
Text in a buffer can be marked with tags. A tag is an attribute that can
be applied to some range of text. For example, a tag might be called "bold"
and make the text inside the tag bold. However, the tag concept is more
general than that; tags don't have to affect appearance. They can instead
affect the behavior of mouse and key presses, "lock" a range of text so the
user can't edit it, or countless other things. A tag is represented by a
TextTag
object. One TextTag can be applied to any number of text
ranges in any number of buffers.
Each tag is stored in a TextTagTable
. A tag table defines a set of
tags that can be used together. Each buffer has one tag table associated with
it; only tags from that tag table can be used with the buffer. A single tag
table can be shared between multiple buffers, however.
Tags can have names, which is convenient sometimes (for example, you can name your tag that makes things bold "bold"), but they can also be anonymous (which is convenient if you're creating tags on-the-fly).
Most text manipulation is accomplished with iterators, represented by a
TextIter
. An iterator represents a position between two characters in
the text buffer. Iterators are not valid indefinitely; whenever the buffer is
modified in a way that affects the number of characters in the buffer, all
outstanding iterators become invalid. (Note that deleting 5 characters and
then reinserting 5 still invalidates iterators, though you end up with the
same number of characters you pass through a state with a different number).
Because of this, iterators can't be used to preserve positions across
buffer modifications. To preserve a position, the TextMark
object is
ideal. You can think of a mark as an invisible cursor or insertion point; it
floats in the buffer, saving a position. If the text surrounding the mark is
deleted, the mark remains in the position the text once occupied; if text is
inserted at the mark, the mark ends up either to the left or to the right of
the new text, depending on its gravity. The standard text cursor in
left-to-right languages is a mark with right gravity, because it stays to the
right of inserted text.
Like tags, marks can be either named or anonymous. There are two marks
built-in to TextBuffer
; these are named "insert" and
"selection_bound" and refer to the insertion point and the boundary of the
selection which is not the insertion point, respectively. If no text is
selected, these two marks will be in the same position. You can manipulate
what is selected and where the cursor appears by moving these marks around.
Text buffers always contain at least one line, but may be empty (that is, buffers can contain zero characters). The last line in the text buffer never ends in a line separator (such as newline); the other lines in the buffer always end in a line separator. Line separators count as characters when computing character counts and character offsets. Note that some Unicode line separators are represented with multiple bytes in UTF-8, and the two-character sequence "\r\n" is also considered a line separator.
Constructor Summary | |
TextView()
Constructs a new TextView. |
|
TextView(int handle)
Construct a TextView from a handle to a native resource. |
|
TextView(TextBuffer buffer)
Creates a new TextView widget displaying the buffer buffer. |
Method Summary | |
void |
addChild(Widget child,
TextChildAnchor anchor)
Adds a child widget in the text buffer, at the given anchor. |
void |
addListener(TextViewListener listener)
Register an object to receive text view event notification. |
TextBuffer |
getBuffer()
Returns the buffer being used |
TextAttributes |
getDefaultAttributes()
Obtains a copy of the default text attributes. |
boolean |
getEditable()
Returns the default editability of the GtkTextView. |
java.lang.Class |
getEventListenerClass(java.lang.String signal)
|
GtkEventType |
getEventType(java.lang.String signal)
|
static Type |
getType()
Retrieve the runtime type used by the GLib library. |
boolean |
moveCursorOnScreen()
Moves the cursor to the currently visible region of the buffer, it it isn't there already. |
void |
removeListener(TextViewListener listener)
Unregister an object that was receiving text view event notification. |
boolean |
scrollToIter(TextIter iter,
double withinMargin)
Scrolls text view so that iter is on the screen. |
boolean |
scrollToIter(TextIter iter,
double withinMargin,
double xAlign,
double yAlign)
Scrolls text view so that iter is on the screen in the position indicated by xalign and yalign. |
void |
scrollToMark(TextMark mark,
double withinMargin)
Scrolls the view so that mark is on the screen. |
void |
scrollToMark(TextMark mark,
double withinMargin,
boolean useAlign,
double xAlign,
double yAlign)
Scrolls the view so that mark is on the screen in the position indicated by xAlign and yAlign. |
void |
setBuffer(TextBuffer buffer)
Sets buffer as the buffer being displayed by the view. |
void |
setCursorVisible(boolean setting)
Toggles whether the insertion point is displayed. |
void |
setEditable(boolean setting)
Sets the default editability of the GtkTextView. |
void |
setIndent(int indent)
Sets the default indentation for paragraphs in text_view. |
void |
setJustification(Justification justification)
Sets the default justification of text in text_view. |
void |
setLeftMargin(int leftMargin)
Sets the default left margin for text in text_view. |
void |
setPixelsAboveLines(int pixelsAboveLines)
Sets the default number of blank pixels above paragraphs in text_view. |
void |
setPixelsBelowLine(int pixelsBelowLines)
Sets the default number of pixels of blank space to put below paragraphs in text_view. |
void |
setPixelsInsideWrap(int pixelsInsideWrap)
Sets the default number of pixels of blank space to leave between display/wrapped lines within a paragraph. |
void |
setRightMargin(int rightMargin)
Sets the default right margin for text in text_view. |
void |
setTabs(TabArray tabStops)
Sets the default tab stops for paragraphs in text_view. |
void |
setWrapMode(WrapMode wrapMode)
Sets the line wrapping for the view. |
Methods inherited from class org.gnu.gtk.Container |
add, addListener, getBorderWidth, getResizeMode, remove, removeListener, resizeChildren, setBorderWidth, setResizeMode |
Methods inherited from class org.gnu.glib.GObject |
addEventHandler, addEventHandler, addEventHandler, addEventHandler, addEventHandler, addEventHandler, equals, getData, getHandle, removeEventHandler, setData |
Methods inherited from class java.lang.Object |
getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Constructor Detail |
public TextView()
public TextView(TextBuffer buffer)
buffer
- Buffer to usepublic TextView(int handle)
Method Detail |
public void setBuffer(TextBuffer buffer)
buffer
- The new buffer to displaypublic TextBuffer getBuffer()
public void scrollToMark(TextMark mark, double withinMargin, boolean useAlign, double xAlign, double yAlign)
mark
- A TextMark
withinMargin
- Margin as a fraction of screen sizeuseAlign
- Whether to use alignment arguments.xAlign
- Horizontal alignment of mark within visible area.yAlign
- : vertical alignment of mark within visible areapublic void scrollToMark(TextMark mark, double withinMargin)
mark
- A TextMark
withinMargin
- Margin as a fraction of screen sizepublic boolean scrollToIter(TextIter iter, double withinMargin, double xAlign, double yAlign)
iter
- a TextIterwithinMargin
- Margin as a [0.0,0.5) fraction of screen size.xAlign
- : horizontal alignment of mark within visible area.yAlign
- : vertical alignment of mark within visible area
public boolean scrollToIter(TextIter iter, double withinMargin)
iter
- a TextIterwithinMargin
- Margin as a [0.0,0.5) fraction of screen size.
public boolean moveCursorOnScreen()
public void addChild(Widget child, TextChildAnchor anchor)
child
- A Widgetanchor
- A TextChildAnchor in the TextBuffer for his viewpublic void setWrapMode(WrapMode wrapMode)
wrapMode
- A WrapModepublic void setEditable(boolean setting)
setting
- Whether it's editablepublic boolean getEditable()
public void setCursorVisible(boolean setting)
setting
- Whether to show the insertion cursorpublic void setPixelsAboveLines(int pixelsAboveLines)
pixelsAboveLines
- Pixels above paragraphspublic void setPixelsBelowLine(int pixelsBelowLines)
pixelsBelowLines
- Pixels below paragraphspublic void setPixelsInsideWrap(int pixelsInsideWrap)
pixelsInsideWrap
- Default number of pixels between wrapped linespublic void setJustification(Justification justification)
justification
- The justification to use.public void setLeftMargin(int leftMargin)
leftMargin
- Size of left margin, in pixelspublic void setRightMargin(int rightMargin)
rightMargin
- Size of right margin, in pixelspublic void setIndent(int indent)
indent
- Indentation in pixelspublic void setTabs(TabArray tabStops)
tabStops
- tabs as a PangoTabArraypublic TextAttributes getDefaultAttributes()
public java.lang.Class getEventListenerClass(java.lang.String signal)
getEventListenerClass
in class Container
public GtkEventType getEventType(java.lang.String signal)
getEventType
in class Container
public void addListener(TextViewListener listener)
listener
- The object that has implemented the
TextViewListener interface that is to receive the text view events.public void removeListener(TextViewListener listener)
listener
- The object that is to no longer receive
text view events.public static Type getType()
|
Please send any bug reports, comments, or suggestions for the API or documentation to java-gnome-developer@lists.sf.net | ||||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |