org.gnome.gtk
Class TextTag

Object
  org.freedesktop.bindings.Pointer
      org.freedesktop.bindings.Proxy
          org.gnome.glib.Object
              org.gnome.gtk.TextTag

public class TextTag
extends Object

TextTags are used to apply markup and formatting for regions of text in a TextBuffer.

All TextTags belong to a TextTagTable, and likewise all TextBuffers are constructed by specifying the TextTagTable that it will draw tags from. That said, if you don't mind sharing your TextTags between all TextBuffers in your application, then you can use the no-arg convenience constructors here and in TextBuffer. We will in all our examples.

You can create a new and unique TextTag every time you go to apply formatting, but in general you'll want to reuse them and that will be more efficient. Given:

 TextTag bold;
 TextBuffer buffer;
 TextIter start, end, pointer;
 ...
 

 bold = new TextTag();
 bold.setWeight(Weight.BOLD);
 ...
 

Now, to make use of the tag, you'll call TextBuffer's applyTag(). It needs a pair of TextIters to delineate the range you want to apply the TextTag to. You could, for example, react to the currently selected region:

 start = buffer.getSelectionBound().getIter();
 end = buffer.getInsert().getIter();
 

 buffer.applyTag(bold, start, end);
 

 buffer.insert(pointer, "Hello World", bold);
 

Finally, if you want to know what TextTags are applying at a given spot in a TextBuffer, then get a TextIter pointing there and use its getTags() method.

All TextTags created in java-gnome are "anonymous"; the underlying library has a notion of named tags but we have no need of this and have not exposed it. In order to reuse a TextTag later just keep a reference to it.

Since:

4.0.9

Author:

Andrew Cowie

TextTag

public TextTag()

Create a new TextTag and place it in the default TextTagTable. This will be usable by a TextBuffer created with the no-arg constructor.

Since:

4.0.9

TextTag

public TextTag(TextTagTable table)

Create a new TextTag. You pass the TextTagTable that will enclose this TextTag as the argument to the constructor.

In native GTK you have to add TextTags to TextTagTables; we do this for you automatically.

Since:

4.0.9

setBackground

public void setBackground(String colour)

Specify the background colour via a String description.

See setForeground() for discussion of allowable colour names.

The default is no explicit setting.

Since:

4.0.9

setEditable

public void setEditable(boolean setting)

Set whether the region of text covered by this TextTag is editable by the user.

Since:

4.0.9

setFamily

public void setFamily(String font)

Specify the font family to be used. This is a family name like "Bitstream Vera" or "DejaVu" or "Liberation".

In general, it is better to use the standard aliases "Serif", "Sans", and "Monospaced" than naming a family by hand as this lets the user assign their own meanings to those terms via the Fonts tab in gnome-appearance-properties.

Note that you need to specify this early; if you set this after setting other propertes on the TextTag, it may reset them.

Since:

4.0.10

setFont

public void setFont(String str)

Pass a string that describes the font you wish to use. This is essentially a convenience wrapper around creating a FontDescription with FontDescription's <init>(String) constructor; see there for details of the syntax allowed.

Since:

4.0.10

setFontDescription

public void setFontDescription(FontDescription desc)

Pass a FontDescription specifying the metrics and characteristics of the font you wish to be active when this TextTag is applied.

Since:

4.0.10

setForeground

public void setForeground(String colour)

Specify the foreground colour by name.

Colours can be specified either:

• as hex, in the form "#rrggbb" where rr, gg, and bb are two hexadecimal characters expressing a values between 0x00 and 0xFF for red, green, and blue respectively; or
• as a symbolic name, such as "blue" and "medium sea green", depending on what constants have been built into your X server. You can likely see a list at /usr/share/X11/rgb.txt. Obviously these are unreliable between different systems, but they are undeniably easy to use.

The default is no explicit setting.

Since:

4.0.9

setIndent

public void setIndent(int pixels)

Specify the amount by which this paragraph is to be indented, in pixels. Interestingly, this can be negative. The default is 0.

Since:

4.0.9

setInvisible

public void setInvisible(boolean setting)

Hide the text formatted with this TextTag.

FIXME what happens when you insert at a point that is marked invisible? Backspace into it? What is the interaction with the editable property and insertInteractive()?

GTK further notes there are problems with invisible text and programmatic navigation of TextBuffers.

Since:

Unstable

setLeftMargin

public void setLeftMargin(int pixels)

Specify the left margin, in pixels. The default is 0.

Since:

4.0.9

setRightMargin

public void setRightMargin(int pixels)

Specify the right margin, in pixels. The default is 0.

Since:

4.0.9

setRise

public void setRise(double rise)

Indicate that a span of characters is to be positioned at other than the baseline. This is typically used to create superscripts and subscripts, although you want to be careful because you are likely also changing font sizes when doing so.

The measurement is in points. A negative number will take you below the baseline.

Be aware that whenever non-uniform sizing is used on a line, the TextView will render that line as higher than the other lines in a document. This can often be an unwanted (but hard to trivially avoid) side-effect.

See also RiseAttribute which is the underlying mechanism which powers this in Pango.

Since:

4.0.14

setScale

public void setScale(Scale scale)

Specify that you want the text scaled up or scaled down from the otherwise extant font size. The default is NORMAL (that is, a scaling factor of 1.0 which thereby has no effect).

Since:

4.0.9

setSize

public void setSize(double size)

Set the font size, in points.

Since:

4.0.10

setStrikethrough

public void setStrikethrough(boolean setting)

Specify that this text be rendered struck through.

Since:

4.0.9

setStyle

public void setStyle(Style style)

Specify the font style to be used ( NORMAL, OBLIQUE and ITALICs).

Since:

4.0.9

setUnderline

public void setUnderline(Underline underline)

Specify the underling mode to be used for this text. Single underlining is SINGLE. NONE is the default, obviously.

Since:

4.0.9

setWeight

public void setWeight(Weight weight)

Specify the font weight. The useful one is BOLD; the default is NORMAL.

Since:

4.0.9

toString

public String toString()

Overrides:

toString in class org.freedesktop.bindings.Pointer

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