/*
* Copyright (c) 2008, Harald Kuhr
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name "TwelveMonkeys" nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.twelvemonkeys.servlet.image;
import com.twelvemonkeys.lang.StringUtil;
import com.twelvemonkeys.servlet.ServletUtil;
import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import java.awt.*;
import java.awt.geom.Rectangle2D;
/**
* This servlet is capable of rendereing a text string and output it as an
* image. The text can be rendered in any given font, size,
* style or color, into an image, and output it as a GIF, JPEG or PNG image,
* with optional caching of the rendered image files.
*
* <P><HR><P>
*
* <A name="parameters"></A><STRONG>Parameters:</STRONG><BR>
* <DL>
* <DT>{@code text}</DT>
* <DD>string, the text string to render.
* <DT>{@code width}</DT>
* <DD>integer, the width of the image
* <DT>{@code height}</DT>
* <DD>integer, the height of the image
* <DT>{@code fontFamily}</DT>
* <DD>string, the name of the font family.
* Default is {@code "Helvetica"}.
* <DT>{@code fontSize}</DT>
* <DD>integer, the size of the font. Default is {@code 12}.
* <DT>{@code fontStyle}</DT>
* <DD>string, the tyle of the font. Can be one of the constants
* {@code plain} (default), {@code bold}, {@code italic} or
* {@code bolditalic}. Any other will result in {@code plain}.
* <DT>{@code fgcolor}</DT>
* <DD>color (HTML form, {@code #RRGGBB}), or color constant from
* {@link java.awt.Color}, default is {@code "black"}.
* <DT>{@code bgcolor}</DT>
* <DD>color (HTML form, {@code #RRGGBB}), or color constant from
* {@link java.awt.Color}, default is {@code "transparent"}.
* Note that the hash character ({@code "#"}) used in colors must be
* escaped as {@code %23} in the query string. See
* {@link StringUtil#toColor(String)}, <A href="#examples">examples</A>.
*
* <!-- inherited from ImageServlet below: -->
*
* <DT>{@code cache}</DT>
* <DD>boolean, {@code true} if you want to cache the result
* to disk (default).
*
* <DT>{@code compression}</DT>
* <DD>float, the optional compression ratio for the output image. For JPEG
* images, the quality is the inverse of the compression ratio. See
* {@link #JPEG_DEFAULT_COMPRESSION_LEVEL},
* {@link #PNG_DEFAULT_COMPRESSION_LEVEL}.
* <DD>Applies to JPEG and PNG images only.
*
* <DT>{@code dither}</DT>
* <DD>enumerated, one of {@code NONE}, {@code DEFAULT} or
* {@code FS}, if you want to dither the result ({@code DEFAULT} is
* default).
* {@code FS} will produce the best results, but it's slower.
* <DD>Use in conjuction with {@code indexed}, {@code palette}
* and {@code websafe}.
* <DD>Applies to GIF and PNG images only.
*
* <DT>{@code fileName}</DT>
* <DD>string, an optional filename. If not set, the path after the servlet
* ({@link HttpServletRequest#getPathInfo}) will be used for the cache
* filename. See {@link #getCacheFile(ServletRequest)},
* {@link #getCacheRoot}.
*
* <DT>{@code height}</DT>
* <DD>integer, the height of the image.
*
* <DT>{@code width}</DT>
* <DD>integer, the width of the image.
*
* <DT>{@code indexed}</DT>
* <DD>integer, the number of colors in the resulting image, or -1 (default).
* If the value is set and positive, the image will use an
* {@code IndexColorModel} with
* the number of colors specified. Otherwise the image will be true color.
* <DD>Applies to GIF and PNG images only.
*
* <DT>{@code palette}</DT>
* <DD>string, an optional filename. If set, the image will use IndexColorModel
* with a palette read from the given file.
* <DD>Applies to GIF and PNG images only.
*
* <DT>{@code websafe}</DT>
* <DD>boolean, {@code true} if you want the result to use the 216 color
* websafe palette (default is false).
* <DD>Applies to GIF and PNG images only.
* </DL>
*
* @example
* <IMG src="/text/test.gif?height=40&width=600
* &fontFamily=TimesRoman&fontSize=30&fontStyle=italic&fgcolor=%23990033
* &bgcolor=%23cccccc&text=the%20quick%20brown%20fox%20jumps%20over%20the
* %20lazy%20dog&cache=false" />
*
* @example
* <IMG src="/text/test.jpg?height=40&width=600
* &fontFamily=TimesRoman&fontSize=30&fontStyle=italic&fgcolor=black
* &bgcolor=%23cccccc&text=the%20quick%20brown%20fox%20jumps%20over%20the
* %20lazy%20dog&compression=3&cache=false" />
*
* @example
* <IMG src="/text/test.png?height=40&width=600
* &fontFamily=TimesRoman&fontSize=30&fontStyle=italic&fgcolor=%23336699
* &bgcolor=%23cccccc&text=the%20quick%20brown%20fox%20jumps%20over%20the
* %20lazy%20dog&cache=true" />
*
* @author <a href="mailto:harald.kuhr@gmail.com">Harald Kuhr</a>
* @author last modified by $Author: haku $
* @version $Id: TextRenderer.java#2 $
*/
class TextRenderer /*extends ImageServlet implements ImagePainterServlet*/ {
// TODO: Create something usable out of this piece of old junk.. ;-)
// It just needs a graphics object to write onto
// Alternatively, defer, and compute the size needed
// Or, make it a filter...
/** {@code "italic"} */
public final static String FONT_STYLE_ITALIC = "italic";
/** {@code "plain"} */
public final static String FONT_STYLE_PLAIN = "plain";
/** {@code "bold"} */
public final static String FONT_STYLE_BOLD = "bold";
/** {@code text} */
public final static String PARAM_TEXT = "text";
/** {@code marginLeft} */
public final static String PARAM_MARGIN_LEFT = "marginLeft";
/** {@code marginTop} */
public final static String PARAM_MARGIN_TOP = "marginTop";
/** {@code fontFamily} */
public final static String PARAM_FONT_FAMILY = "fontFamily";
/** {@code fontSize} */
public final static String PARAM_FONT_SIZE = "fontSize";
/** {@code fontStyle} */
public final static String PARAM_FONT_STYLE = "fontStyle";
/** {@code textRotation} */
public final static String PARAM_TEXT_ROTATION = "textRotation";
/** {@code textRotation} */
public final static String PARAM_TEXT_ROTATION_UNITS = "textRotationUnits";
/** {@code bgcolor} */
public final static String PARAM_BGCOLOR = "bgcolor";
/** {@code fgcolor} */
public final static String PARAM_FGCOLOR = "fgcolor";
protected final static String ROTATION_DEGREES = "DEGREES";
protected final static String ROTATION_RADIANS = "RADIANS";
/**
* Creates the TextRender servlet.
*/
public TextRenderer() {
}
/**
* Renders the text string for this servlet request.
*/
private void paint(ServletRequest pReq, Graphics2D pRes, int pWidth, int pHeight)
throws ImageServletException {
// Get parameters
String text = pReq.getParameter(PARAM_TEXT);
String[] lines = StringUtil.toStringArray(text, "\n\r");
String fontFamily = pReq.getParameter(PARAM_FONT_FAMILY);
String fontSize = pReq.getParameter(PARAM_FONT_SIZE);
String fontStyle = pReq.getParameter(PARAM_FONT_STYLE);
String bgcolor = pReq.getParameter(PARAM_BGCOLOR);
String fgcolor = pReq.getParameter(PARAM_FGCOLOR);
// TODO: Make them static..
pRes.addRenderingHints(new RenderingHints(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON));
pRes.addRenderingHints(new RenderingHints(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY));
pRes.addRenderingHints(new RenderingHints(RenderingHints.KEY_COLOR_RENDERING, RenderingHints.VALUE_COLOR_RENDER_QUALITY));
// pRes.addRenderingHints(new RenderingHints(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON));
//System.out.println(pRes.getBackground());
// Clear area with bgcolor
if (!StringUtil.isEmpty(bgcolor)) {
pRes.setBackground(StringUtil.toColor(bgcolor));
pRes.clearRect(0, 0, pWidth, pHeight);
//System.out.println(pRes.getBackground());
}
// Create and set font
Font font = new Font(
fontFamily != null ? fontFamily : "Helvetica",
getFontStyle(fontStyle),
fontSize != null ? Integer.parseInt(fontSize) : 12
);
pRes.setFont(font);
// Set rotation
double angle = getAngle(pReq);
pRes.rotate(angle, pWidth / 2.0, pHeight / 2.0);
// Draw string in fgcolor
pRes.setColor(fgcolor != null ? StringUtil.toColor(fgcolor) : Color.black);
float x = ServletUtil.getFloatParameter(pReq, PARAM_MARGIN_LEFT, Float.MIN_VALUE);
Rectangle2D[] bounds = new Rectangle2D[lines.length];
if (x <= Float.MIN_VALUE) {
// Center
float longest = 0f;
for (int i = 0; i < lines.length; i++) {
bounds[i] = font.getStringBounds(lines[i], pRes.getFontRenderContext());
if (bounds[i].getWidth() > longest) {
longest = (float) bounds[i].getWidth();
}
}
//x = (float) ((pWidth - bounds.getWidth()) / 2f);
x = (float) ((pWidth - longest) / 2f);
//System.out.println("marginLeft: " + x);
}
//else {
//System.out.println("marginLeft (from param): " + x);
//}
float y = ServletUtil.getFloatParameter(pReq, PARAM_MARGIN_TOP, Float.MIN_VALUE);
float lineHeight = (float) (bounds[0] != null ?
bounds[0].getHeight() : font.getStringBounds(lines[0], pRes.getFontRenderContext()).getHeight());
if (y <= Float.MIN_VALUE) {
// Center
y = (float) ((pHeight - lineHeight) / 2f)
- (lineHeight * (lines.length - 2.5f) / 2f);
//System.out.println("marginTop: " + y);
}
else {
// Todo: Correct for font height?
y += font.getSize2D();
//System.out.println("marginTop (from param):" + y);
}
//System.out.println("Font size: " + font.getSize2D());
//System.out.println("Line height: " + lineHeight);
// Draw
for (int i = 0; i < lines.length; i++) {
pRes.drawString(lines[i], x, y + lineHeight * i);
}
}
/**
* Returns the font style constant.
*
* @param pStyle a string containing either the word {@code "plain"} or one
* or more of {@code "bold"} and {@code italic}.
* @return the font style constant as defined in {@link Font}.
*
* @see Font#PLAIN
* @see Font#BOLD
* @see Font#ITALIC
*/
private int getFontStyle(String pStyle) {
if (pStyle == null || StringUtil.containsIgnoreCase(pStyle, FONT_STYLE_PLAIN)) {
return Font.PLAIN;
}
// Try to find bold/italic
int style = Font.PLAIN;
if (StringUtil.containsIgnoreCase(pStyle, FONT_STYLE_BOLD)) {
style |= Font.BOLD;
}
if (StringUtil.containsIgnoreCase(pStyle, FONT_STYLE_ITALIC)) {
style |= Font.ITALIC;
}
return style;
}
/**
* Gets the angle of rotation from the request.
*
* @param pRequest the servlet request to get parameters from
* @return the angle in radians.
*/
private double getAngle(ServletRequest pRequest) {
// Get angle
double angle = ServletUtil.getDoubleParameter(pRequest, PARAM_TEXT_ROTATION, 0.0);
// Convert to radians, if needed
String units = pRequest.getParameter(PARAM_TEXT_ROTATION_UNITS);
if (!StringUtil.isEmpty(units) && ROTATION_DEGREES.equalsIgnoreCase(units)) {
angle = Math.toRadians(angle);
}
return angle;
}
}