org.gjt.sp.jedit.textarea

## Class DisplayManager

- java.lang.Object
- - org.gjt.sp.jedit.textarea.DisplayManager

    public class DisplayManager
    extends java.lang.Object

Manages low-level text display tasks, such as folding.

Since:
  jEdit 4.2pre1

### Method Summary

Methods
`static void` `bufferClosed(JEditBuffer buffer)`
`void` `collapseFold(int line)` Collapses the fold at the specified physical line index.
`void` `expandAllFolds()` Expands all folds.
`int` `expandFold(int line, boolean fully)` Expands the fold at the specified physical line index.
`void` `expandFolds(char digit)` This method should only be called from `actions.xml`.
`void` `expandFolds(int foldLevel)` Expands all folds with the specified fold level.
`void` `expandFolds(int foldLevel, boolean update)` Expands all folds with the specified fold level.
`JEditBuffer` `getBuffer()`
`int` `getFirstVisibleLine()` Returns the physical line number of the first visible line.
`int` `getLastVisibleLine()` Returns the physical line number of the last visible line.
`int` `getNextVisibleLine(int line)` Returns the next visible line after the specified line index, or (-1) if there is no next visible line.
`int` `getPrevVisibleLine(int line)` Returns the previous visible line before the specified line index.
`int` `getScreenLineCount(int line)` Returns how many screen lines contains the given physical line.
`int` `getScrollLineCount()` Returns the number of displayable lines It can be greater than the number of lines of the buffer when using soft wrap (a line can count for n lines), or when using folding, if the foldings are collapsed
`boolean` `isLineVisible(int line)` Returns if the specified physical line is visible.
`boolean` `isOutsideNarrowing(int line)` Returns true if the display is narrowed and the specified line is outside of the narrowing.
`void` `narrow(int start, int end)` Narrows the visible portion of the buffer to the specified line range.

### Methods inherited from class java.lang.Object

`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

### Method Detail

#### bufferClosed

    public static void bufferClosed(JEditBuffer buffer)

#### getBuffer

    public JEditBuffer getBuffer()

Since:
  jEdit 4.3pre3

#### isLineVisible

    public final boolean isLineVisible(int line)

Returns if the specified physical line is visible.

Parameters:
  `line` - A physical line index
Since:
  jEdit 4.2pre1

#### isOutsideNarrowing

    public boolean isOutsideNarrowing(int line)

Returns true if the display is narrowed and the specified line is outside of the narrowing.

Parameters:
  `line` - A physical line index
Since:
  jEdit 4.5

#### getFirstVisibleLine

    public int getFirstVisibleLine()

Returns the physical line number of the first visible line.

Since:
  jEdit 4.2pre1

#### getLastVisibleLine

    public int getLastVisibleLine()

Returns the physical line number of the last visible line.

Since:
  jEdit 4.2pre1

#### getNextVisibleLine

    public int getNextVisibleLine(int line)

Returns the next visible line after the specified line index, or (-1) if there is no next visible line.

Parameters:
  `line` - A physical line index
Since:
  jEdit 4.0pre1

#### getPrevVisibleLine

    public int getPrevVisibleLine(int line)

Returns the previous visible line before the specified line index.

Parameters:
  `line` - a physical line index
Returns:
  the previous visible physical line or -1 if there is no visible line
Since:
  jEdit 4.0pre1

#### getScreenLineCount

    public final int getScreenLineCount(int line)

Returns how many screen lines contains the given physical line. It can be greater than 1 when using soft wrap

Parameters:
  `line` - the physical line
Returns:
  the screen line count

#### getScrollLineCount

    public final int getScrollLineCount()

Returns the number of displayable lines It can be greater than the number of lines of the buffer when using soft wrap (a line can count for n lines), or when using folding, if the foldings are collapsed

Returns:
  the number of displayable lines

#### collapseFold

    public void collapseFold(int line)

Collapses the fold at the specified physical line index.

Parameters:
  `line` - A physical line index
Since:
  jEdit 4.2pre1

#### expandFold

    public int expandFold(int line,
                 boolean fully)

Expands the fold at the specified physical line index.

Parameters:
  `line` - A physical line index
  `fully` - If true, all subfolds will also be expanded
Returns:
  the line number of the first subfold, or -1 if none
Since:
  jEdit 4.2pre1

#### expandAllFolds

    public void expandAllFolds()

Expands all folds.

Since:
  jEdit 4.2pre1

#### expandFolds

    public void expandFolds(char digit)

This method should only be called from `actions.xml`.

Since:
  jEdit 4.2pre1

#### expandFolds

    public void expandFolds(int foldLevel,
                   boolean update)

Expands all folds with the specified fold level.

Parameters:
  `foldLevel` - The fold level
  `update` - If true, notify the text area of a fold level change. Since this will automatically move the caret if still inside a fold, this may not be what we want.
Since:
  jEdit 4.5

#### expandFolds

    public void expandFolds(int foldLevel)

Expands all folds with the specified fold level.

Parameters:
  `foldLevel` - The fold level
Since:
  jEdit 4.2pre1

#### narrow

    public void narrow(int start,
              int end)

Narrows the visible portion of the buffer to the specified line range.

Parameters:
  `start` - The first line
  `end` - The last line
Since:
  jEdit 4.2pre1