Class SyntaxView

java.lang.Object
javax.swing.text.View
org.fife.ui.rsyntaxtextarea.SyntaxView
All Implemented Interfaces:
SwingConstants, TabExpander, RSTAView, TokenOrientedView
public class SyntaxView extends View implements TabExpander, TokenOrientedView, RSTAView
The javax.swing.text.View object used by RSyntaxTextArea when word wrap is disabled. It implements syntax highlighting for programming languages using the colors and font styles specified by the RSyntaxTextArea.

You don't really have to do anything to use this class, as RSyntaxTextAreaUI automatically sets the text area's view to be an instance of this class if word wrap is disabled.

The tokens that specify how to paint the syntax-highlighted text are gleaned from the text area's RSyntaxDocument.

Version:
0.3

  • Field Details

    • font

      private Font font
      The default font used by the text area. If this changes we need to recalculate the longest line.

    • metrics

      private FontMetrics metrics
      Font metrics for the current font.

    • longLine

      private Element longLine
      The current longest line. This is used to calculate the preferred width of the view. Since the calculation is potentially expensive, we try to avoid it by stashing which line is currently the longest.

    • longLineWidth

      private float longLineWidth

    • tabSize

      private int tabSize

    • tabBase

      private int tabBase

    • host

      private RSyntaxTextArea host
      Cached for each paint() call so each drawLine() call has access to it.

    • lineHeight

      private int lineHeight
      Cached values to speed up the painting a tad.

    • ascent

      private int ascent

    • clipStart

      private int clipStart

    • clipEnd

      private int clipEnd

    • tempToken

      private TokenImpl tempToken
      Temporary token used when we need to "modify" tokens for rendering purposes. Since tokens returned from RSyntaxDocuments are treated as immutable, we use this temporary token to do that work.

  • Constructor Details

    • SyntaxView

      public SyntaxView(Element elem)
      Constructs a new SyntaxView wrapped around an element.
      Parameters:
      elem - The element representing the text to display.

  • Method Details

    • calculateLongestLine

      void calculateLongestLine()
      Iterate over the lines represented by the child elements of the element this view represents, looking for the line that is the longest. The longLine variable is updated to represent the longest line contained. The font variable is updated to indicate the font used to calculate the longest line.

    • changedUpdate

      public void changedUpdate(DocumentEvent changes, Shape a, ViewFactory f)
      Gives notification from the document that attributes were changed in a location that this view is responsible for.
      Overrides:
      changedUpdate in class View
      Parameters:
      changes - the change information from the associated document
      a - the current allocation of the view
      f - the factory to use to rebuild if the view has children
      See Also:

    • damageLineRange

      protected void damageLineRange(int line0, int line1, Shape a, Component host)
      Repaint the given line range.
      Parameters:
      line0 - The starting line number to repaint. This must be a valid line number in the model.
      line1 - The ending line number to repaint. This must be a valid line number in the model.
      a - The region allocated for the view to render into.
      host - The component hosting the view (used to call repaint).

    • drawLine

      private float drawLine(TokenPainter painter, Token token, Graphics2D g, float x, float y, int line)
      Draws the passed-in text using syntax highlighting for the current language. It is assumed that the entire line is either not in a selected region, or painting with a selection-foreground color is turned off.
      Parameters:
      painter - The painter to render the tokens.
      token - The list of tokens to draw.
      g - The graphics context in which to draw.
      x - The x-coordinate at which to draw.
      y - The y-coordinate at which to draw.
      Returns:
      The x-coordinate representing the end of the painted text.

    • drawLineWithSelection

      private float drawLineWithSelection(TokenPainter painter, Token token, Graphics2D g, float x, float y, int selStart, int selEnd)
      Draws the passed-in text using syntax highlighting for the current language. Tokens are checked for being in a selected region, and are rendered appropriately if they are.
      Parameters:
      painter - The painter to render the tokens.
      token - The list of tokens to draw.
      g - The graphics context in which to draw.
      x - The x-coordinate at which to draw.
      y - The y-coordinate at which to draw.
      selStart - The start of the selection.
      selEnd - The end of the selection.
      Returns:
      The x-coordinate representing the end of the painted text.

    • getLineWidth

      private float getLineWidth(int lineNumber)
      Calculates the width of the line represented by the given element.
      Parameters:
      lineNumber - The line number of the specified line in the document.
      Returns:
      The width of the line.

    • getNextVisualPositionFrom

      public int getNextVisualPositionFrom(int pos, Position.Bias b, Shape a, int direction, Position.Bias[] biasRet) throws BadLocationException
      Provides a way to determine the next visually represented model location that one might place a caret. Some views may not be visible, they might not be in the same order found in the model, or they just might not allow access to some locations in the model.
      Overrides:
      getNextVisualPositionFrom in class View
      Parameters:
      pos - the position to convert >= 0
      a - the allocated region to render into
      direction - the direction from the current position that can be thought of as the arrow keys typically found on a keyboard. This may be SwingConstants.WEST, SwingConstants.EAST, SwingConstants.NORTH, or SwingConstants.SOUTH.
      Returns:
      the location within the model that best represents the next location visual position.
      Throws:
      BadLocationException - If the offset specified is invalid.
      IllegalArgumentException - for an invalid direction

    • getPreferredSpan

      public float getPreferredSpan(int axis)
      Determines the preferred span for this view along an axis.
      Specified by:
      getPreferredSpan in class View
      Parameters:
      axis - may be either View.X_AXIS or View.Y_AXIS
      Returns:
      the span the view would like to be rendered into >= 0. Typically, the view is told to render into the span that is returned, although there is no guarantee. The parent may choose to resize or break the view.
      Throws:
      IllegalArgumentException - for an invalid axis

    • getRhsCorrection

      private int getRhsCorrection()
      Workaround for JTextComponents allowing the caret to be rendered entirely off-screen if the entire "previous" character fit entirely.
      Returns:
      The amount of space to add to the x-axis preferred span.

    • getTabSize

      private int getTabSize()
      Returns the tab size set for the document, defaulting to 5.
      Returns:
      The tab size.

    • getTokenListForPhysicalLineAbove

      public Token getTokenListForPhysicalLineAbove(int offset)
      Returns a token list for the physical line above the physical line containing the specified offset into the document. Note that for this plain (non-wrapped) view, this is simply the token list for the logical line above the line containing offset, since lines are not wrapped.
      Specified by:
      getTokenListForPhysicalLineAbove in interface TokenOrientedView
      Parameters:
      offset - The offset in question.
      Returns:
      A token list for the physical (and in this view, logical) line before this one. If offset is in the first line in the document, null is returned.

    • getTokenListForPhysicalLineBelow

      public Token getTokenListForPhysicalLineBelow(int offset)
      Returns a token list for the physical line below the physical line containing the specified offset into the document. Note that for this plain (non-wrapped) view, this is simply the token list for the logical line below the line containing offset, since lines are not wrapped.
      Specified by:
      getTokenListForPhysicalLineBelow in interface TokenOrientedView
      Parameters:
      offset - The offset in question.
      Returns:
      A token list for the physical (and in this view, logical) line after this one. If offset is in the last physical line in the document, null is returned.

    • insertUpdate

      public void insertUpdate(DocumentEvent changes, Shape a, ViewFactory f)
      Gives notification that something was inserted into the document in a location that this view is responsible for.
      Overrides:
      insertUpdate in class View
      Parameters:
      changes - The change information from the associated document.
      a - The current allocation of the view.
      f - The factory to use to rebuild if the view has children.

    • lineToRect

      protected Rectangle lineToRect(Shape a, int line)
      Determine the rectangle that represents the given line.
      Parameters:
      a - The region allocated for the view to render into
      line - The line number to find the region of. This must be a valid line number in the model.

    • modelToView

      public Shape modelToView(int pos, Shape a, Position.Bias b) throws BadLocationException
      Provides a mapping from the document model coordinate space to the coordinate space of the view mapped to it.
      Specified by:
      modelToView in class View
      Parameters:
      pos - the position to convert >= 0
      a - the allocated region to render into
      Returns:
      the bounding box of the given position
      Throws:
      BadLocationException - if the given position does not represent a valid location in the associated document
      See Also:

    • modelToView

      public Shape modelToView(int p0, Position.Bias b0, int p1, Position.Bias b1, Shape a) throws BadLocationException
      Provides a mapping, for a given region, from the document model coordinate space to the view coordinate space. The specified region is created as a union of the first and last character positions.

      This is implemented to subtract the width of the second character, as this view's modelToView actually returns the width of the character instead of "1" or "0" like the View implementations in javax.swing.text. Thus, if we don't override this method, the View implementation will return one character's width too much for its consumers (implementations of javax.swing.text.Highlighter).

      Overrides:
      modelToView in class View
      Parameters:
      p0 - the position of the first character (>=0)
      b0 - The bias of the first character position, toward the previous character or the next character represented by the offset, in case the position is a boundary of two views; b0 will have one of these values:
      • Position.Bias.Forward
      • Position.Bias.Backward
      p1 - the position of the last character (>=0)
      b1 - the bias for the second character position, defined one of the legal values shown above
      a - the area of the view, which encompasses the requested region
      Returns:
      the bounding box which is a union of the region specified by the first and last character positions
      Throws:
      BadLocationException - if the given position does not represent a valid location in the associated document
      IllegalArgumentException - if b0 or b1 are not one of the legal Position.Bias values listed above
      See Also:

    • nextTabStop

      public float nextTabStop(float x, int tabOffset)
      Returns the next tab stop position after a given reference position. This implementation does not support things like centering so it ignores the tabOffset argument.
      Specified by:
      nextTabStop in interface TabExpander
      Parameters:
      x - the current position >= 0
      tabOffset - the position within the text stream that the tab occurred at >= 0.
      Returns:
      the tab stop, measured in points >= 0

    • paint

      public void paint(Graphics g, Shape a)
      Actually paints the text area. Only lines that have been damaged are repainted.
      Specified by:
      paint in class View
      Parameters:
      g - The graphics context with which to paint.
      a - The allocated region in which to render.

    • possiblyUpdateLongLine

      private boolean possiblyUpdateLongLine(Element line, int lineNumber)
      If the passed-in line is longer than the current longest line, then the longest line is updated.
      Parameters:
      line - The line to test against the current longest.
      lineNumber - The line number of the passed-in line.
      Returns:
      true iff the current longest line was updated.

    • removeUpdate

      public void removeUpdate(DocumentEvent changes, Shape a, ViewFactory f)
      Gives notification that something was removed from the document in a location that this view is responsible for.
      Overrides:
      removeUpdate in class View
      Parameters:
      changes - the change information from the associated document
      a - the current allocation of the view
      f - the factory to use to rebuild if the view has children

    • setSize

      public void setSize(float width, float height)
      Overrides:
      setSize in class View

    • updateDamage

      protected void updateDamage(DocumentEvent changes, Shape a, ViewFactory f)
      Repaint the region of change covered by the given document event. Damages the line that begins the range to cover the case when the insert/remove is only on one line. If lines are added or removed, damages the whole view. The longest line is checked to see if it has changed.

    • updateMetrics

      private void updateMetrics()
      Checks to see if the font metrics and longest line are up-to-date.

    • viewToModel

      public int viewToModel(float fx, float fy, Shape a, Position.Bias[] bias)
      Provides a mapping from the view coordinate space to the logical coordinate space of the model.
      Specified by:
      viewToModel in class View
      Parameters:
      fx - the X coordinate >= 0
      fy - the Y coordinate >= 0
      a - the allocated region to render into
      Returns:
      the location within the model that best represents the given point in the view >= 0

    • yForLine

      public int yForLine(Rectangle alloc, int line)
      Description copied from interface: RSTAView
      Returns the y-coordinate of the specified line.

      This method is quicker than using traditional modelToView(int) calls, as the entire bounding box isn't computed.

      Specified by:
      yForLine in interface RSTAView
      Parameters:
      alloc - The area the text area can render into.
      line - The line number.
      Returns:
      The y-coordinate of the top of the line, or -1 if this text area doesn't yet have a positive size or the line is hidden (i.e. from folding).

    • yForLineContaining

      public int yForLineContaining(Rectangle alloc, int offs) throws BadLocationException
      Description copied from interface: RSTAView
      Returns the y-coordinate of the line containing a specified offset.

      This method is quicker than using traditional modelToView(int) calls, as the entire bounding box isn't computed.

      Specified by:
      yForLineContaining in interface RSTAView
      Parameters:
      alloc - The area the text area can render into.
      offs - The offset info the document.
      Returns:
      The y-coordinate of the top of the offset, or -1 if this text area doesn't yet have a positive size or the line is hidden (i.e. from folding).
      Throws:
      BadLocationException - If offs isn't a valid offset into the document.