token.java~1~

具有不同语法高亮的编辑器实例

	 */
	public Token getNextToken() {
		return nextToken;
	}


/*****************************************************************************/


	/**
	 * Returns the position in the document that represents the last character
	 * in the token that will fit into <code>endBeforeX-startX</code> pixels.
	 * For example, if you're using a monospaced 8-pixel-per-character font,
	 * have the token "while" and <code>startX</code> is <code>0</code> and
	 * <code>endBeforeX</code> is <code>30</code>, this method will return the
	 * document position of the "i" in "while", because the "i" ends at pixel
	 * <code>24</code>, while the "l" ends at <code>32</code>.  If not even the
	 * first character fits in <code>endBeforeX-startX</code>, the first
	 * character's position is still returned so calling methods don't go into
	 * infinite loops.
	 *
	 * @param fm The font metrics used to paint the token.
	 * @param e How to expand tabs.
	 * @param startX The x-coordinate at which the token will be painted.  This
	 *               is needed because of tabs.
	 * @param endBeforeX The x-coordinate for which you want to find the last
	 *                   character of <code>t</code> which comes before it.
	 * @return The last document position that will fit in the specified amount
	 *         of pixels.
	 */
	/*
	 * @see #getTokenListOffsetBeforeX
	 * FIXME:  This method does not compute correctly!  It needs to be abstract
	 * and implemented by subclasses.
	 */
	public int getOffsetBeforeX(FontMetrics fm, TabExpander e, float startX,
							float endBeforeX) {

		int i = textOffset;
		int stop = i + textCount;
		float x = startX;

		while (i<stop) {
			if (text[i]=='\t')
				x = e.nextTabStop(x, 0);
			else
				x += fm.charWidth(text[i]);
			if (x>endBeforeX) {
				// If not even the first character fits into the space, go
				// ahead and say the first char does fit so we don't go into
				// an infinite loop.
				int intoToken = Math.max(i-textOffset, 1);
				return offset + intoToken;
			}
			i++;
		}

		// If we got here, the whole token fit in (endBeforeX-startX) pixels.
		return stop-1;

	}


/*****************************************************************************/


	/**
	 * Returns the width of this token given the specified parameters.
	 *
	 * @param fm The metrics of the font used to paint the token.
	 * @param e Describes how to expand tabs.  This parameter cannot be
	 *          <code>null</code>.
	 * @param x0 The pixel-location at which the token begins.  This is needed
	 *           because of tabs.
	 * @return The width of the token, in pixels.
	 * @see #getWidthUpTo
	 */
	public float getWidth(FontMetrics fm, TabExpander e, float x0) {
		return getWidthUpTo(textCount, fm, e, x0);
	}


/*****************************************************************************/


	/**
	 * Returns the width of a specified number of characters in this token.
	 * For example, for the token "while", specifying a value of <code>3</code>
	 * here returns the width of the "whi" portion of the token.<p>
	 *
	 * This method is abstract so subclasses who paint themselves differently
	 * (i.e., {@link VisibleWhitespaceToken} is painted a tad differently than
	 * {@link DefaultToken} when rendering hints are enabled) can still return
	 * accurate results.
	 *
	 * @param numChars The number of characters for which to get the width.
	 * @param fm The font metrics used to paint this token.
	 * @param e How to expand tabs.  This value cannot be <code>null</code>.
	 * @param x0 The pixel-location at which this token begins.  This is needed
	 *           because of tabs.
	 * @return The width of the specified number of characters in this token.
	 * @see #getWidth
	 */
	public abstract float getWidthUpTo(int numChars, FontMetrics fm,
										TabExpander e, float x0);


/*****************************************************************************/


	/**
	 * Returns whether or not this token is "paintable;" i.e., whether or not
	 * the type of this token is one such that it has an associated syntax
	 * style.  What this boils down to is whether the token type is greater
	 * than <code>Token.NULL</code>.
	 *
	 * @return Whether or not this token is paintable.
	 */
	public boolean isPaintable() {
		return type>Token.NULL;
	}


/*****************************************************************************/


	/**
	 * Returns whether or not this token is whitespace.
	 *
	 * @return <code>true</code> iff this token is whitespace.
	 */
	public boolean isWhitespace() {
		return type==WHITESPACE;
	}


/*****************************************************************************/


	/**
	 * Returns the bounding box for the specified document location.  The
	 * location must be in the specified token list; if it isn't,
	 * <code>null</code> is returned.
	 *
	 * @param textArea The text area from which the token list was derived.
	 * @param e How to expand tabs.
	 * @param pos The position in the document for which to get the bounding
	 *            box in the view.
	 * @param x0 The pixel x-location that is the beginning of
	 *           <code>tokenList</code>.
	 * @param rect The rectangle in which we'll be returning the results.  This
	 *             object is reused to keep from frequent memory allocations.
	 * @return The bounding box for the specified position in the model.
	 */
	public abstract Rectangle listOffsetToView(RSyntaxTextArea textArea,
								TabExpander e, int pos, int x0,
								Rectangle rect);


/*****************************************************************************/


	/**
	 * Makes this token start at the specified offset into the document.<p>
	 *
	 * This method is abstract because some token implementations may need
	 * to adjust cached values, such as widths
	 * (such as <code>GlyphVectorToken</code>).
	 *
	 * @param pos The offset into the document this token should start at.
	 *            Note that this token must already contain this position; if
	 *            it doesn't, an exception is thrown.
	 */
	public abstract void makeStartAt(int pos);


/*****************************************************************************/


	/**
	 * Paints this token.
	 *
	 * @param g The graphics context in which to paint.
	 * @param x The x-coordinate at which to paint.
	 * @param y The y-coordinate at which to paint.
	 * @param scheme The syntax highlighting scheme to use.
	 * @param host The text area this token is in.
	 * @param e How to expand tabs.
	 * @return The x-coordinate representing the end of the painted text.
	 */
	public final float paint(Graphics2D g, float x, float y,
								SyntaxScheme scheme,
								RSyntaxTextArea host, TabExpander e) {
		return paint(g, x,y, scheme, host, e, 0);
	}


/*****************************************************************************/


	/**
	 * Paints this token.
	 *
	 * @param g The graphics context in which to paint.
	 * @param x The x-coordinate at which to paint.
	 * @param y The y-coordinate at which to paint.
	 * @param scheme The syntax highlighting scheme to use.
	 * @param host The text area this token is in.
	 * @param e How to expand tabs.
	 * @param clipStart The left boundary of the clip rectangle in which we're
	 *        painting.  This optimizes painting by allowing us to not paint
	 *        paint when this token is "to the left" of the clip rectangle.
	 * @return The x-coordinate representing the end of the painted text.
	 */
	public abstract float paint(Graphics2D g, float x, float y,
							SyntaxScheme scheme, RSyntaxTextArea host,
							TabExpander e, float clipStart);


/*****************************************************************************/


	/**
	 * Paints the background of a token.
	 *
	 * @param x The x-coordinate of the token.
	 * @param y The y-coordinate of the token.
	 * @param width The width of the token (actually, the width of the part of
	 *              the token to paint).
	 * @param height The height of the token.
	 * @param g The graphics context with which to paint.
	 * @param fontAscent The ascent of the token's font.
	 * @param host The text area.
	 * @param color The color with which to paint.
	 */
	protected void paintBackground(float x, float y, float width, float height,
							Graphics2D g, int fontAscent,
							RSyntaxTextArea host, Color color) {		
		g.setXORMode(host.getBackground()); // Never null.
		g.setColor(color);
		g.fill(new Rectangle2D.Float(x,y-fontAscent, width,height));
		g.setPaintMode();
	}


/*****************************************************************************/


	/**
	 * Sets the value of this token to a particular segment of a document.
	 * The "next token" value is cleared.
	 *
	 * @param line The segment from which to get the token.
	 * @param beg The first character's position in <code>line</code>.
	 * @param end The last character's position in <code>line</code>.
	 * @param offset The offset into the document at which this token begins.
	 * @param type A token type listed as "generic" above.
	 */
	public void set(final char[] line, final int beg, final int end,
							final int offset, final int type) {
		this.text = line;
		this.textOffset = beg;
		this.textCount = end - beg + 1;
		this.type = type;
		this.offset = offset;
		nextToken = null;
	}


/*****************************************************************************/


	/**
	 * Sets the "next token" pointer of this token to point to the specified
	 * token.
	 *
	 * @param nextToken The new next token.
	 * @see #getNextToken
	 */
	public void setNextToken(Token nextToken) {
		this.nextToken = nextToken;
	}


/*****************************************************************************/


	/**
	 * Returns the position in the document corresponding to the specified
	 * position in this token's internal char array (<code>textOffset</code> -
	 * <code>textOffset+textCount-1</code>).<p>
	 * Note that this method does NOT do any bounds checking; you can pass in
	 * an invalid token position, and you will not receive an Exception or any
	 * other indication that the returned document position is invalid.  It is
	 * up to the user to ensure valid input.
	 *
	 * @param pos A position in the token's internal char array
	 *        (<code>textOffset</code> - <code>textOffset+textCount</code>).
	 * @return The corresponding position in the document.
	 * @see #documentToToken
	 */
	public int tokenToDocument(int pos) {
		return pos + (offset-textOffset);
	}


/*****************************************************************************/


	/**
	 * Returns this token as a <code>String</code>, which is useful for
	 * debugging.
	 *
	 * @return A string describing this token.
	 */
	public String toString() {
		return "[Token: " +
				(type==Token.NULL ? "<null token>" :
					"text: '" +
						(text==null ? "<null>" :
						new String(text, textOffset, textCount)) + "'; " +
		       		"offset: " + offset + "; type: " + type + "; " +
			   		"isPaintable: " + isPaintable() +
			   		"; nextToken==null: " + (nextToken==null)) +
			   "]";
	}


/*****************************************************************************/

}