cmsimagescaler.java

cms是开源的框架

                // select the "right" method of scaling according to the "t" parameter
                case 1:
                    // thumbnail generation mode (like 0 but no image enlargement)
                    image = scaler.resize(image, getWidth(), getHeight(), color, getPosition(), false);
                    break;
                case 2:
                    // scale to exact target size, crop what does not fit
                    image = scaler.resize(image, getWidth(), getHeight(), getPosition());
                    break;
                case 3:
                    // scale and keep image propotions, target size variable
                    image = scaler.resize(image, getWidth(), getHeight(), true);
                    break;
                case 4:
                    // don't keep image propotions, use exact target size
                    image = scaler.resize(image, getWidth(), getHeight(), false);
                    break;
                default:
                    // scale to exact target size with background padding
                    image = scaler.resize(image, getWidth(), getHeight(), color, getPosition(), true);
            }

            if (!m_filters.isEmpty()) {
                Rectangle targetSize = scaler.applyFilterDimensions(getWidth(), getHeight());
                image = scaler.resize(
                    image,
                    (int)targetSize.getWidth(),
                    (int)targetSize.getHeight(),
                    Simapi.COLOR_TRANSPARENT,
                    Simapi.POS_CENTER);
                image = scaler.applyFilters(image);
            }

            // get the byte result for the scaled image
            result = scaler.getBytes(image, imageType);
        } catch (Exception e) {
            if (LOG.isDebugEnabled()) {
                LOG.debug(Messages.get().getBundle().key(Messages.ERR_UNABLE_TO_SCALE_IMAGE_2, rootPath, toString()), e);
            }
        }
        return result;
    }

    /**
     * Returns a scaled version of the given image file according this image scalers parameters.<p>
     *  
     * @param file the image file to scale
     * 
     * @return a scaled version of the given image file according to the provided scaler parameters
     */
    public byte[] scaleImage(CmsFile file) {

        return scaleImage(file.getContents(), file.getRootPath());
    }

    /**
     * Sets the color.<p>
     *
     * @param color the color to set
     */
    public void setColor(Color color) {

        m_color = color;
    }

    /**
     * Sets the color as a String.<p>
     *
     * @param value the color to set
     */
    public void setColor(String value) {

        if (COLOR_TRANSPARENT.indexOf(value) == 0) {
            m_color = Simapi.COLOR_TRANSPARENT;
        }
        m_color = CmsStringUtil.getColorValue(value, Color.WHITE, SCALE_PARAM_COLOR);
    }

    /**
     * Sets the list of filters as a String.<p>
     * 
     * @param value the list of filters to set
     */
    public void setFilters(String value) {

        m_filters = new ArrayList();
        List filters = CmsStringUtil.splitAsList(value, ':');
        Iterator i = filters.iterator();
        while (i.hasNext()) {
            String filter = (String)i.next();
            filter = filter.trim().toLowerCase();
            Iterator j = FILTERS.iterator();
            while (j.hasNext()) {
                String candidate = (String)j.next();
                if (candidate.startsWith(filter)) {
                    // found a matching filter
                    addFilter(candidate);
                    break;
                }
            }
        }
    }

    /**
     * Sets the height.<p>
     *
     * @param height the height to set
     */
    public void setHeight(int height) {

        m_height = height;
    }

    /**
     * Sets the maximum image size (width * height) to apply image blurring when downscaling images.<p> 
     * 
     * @param maxBlurSize the maximum image blur size to set
     * 
     * @see #getMaxBlurSize() for a more detailed description about this parameter
     */
    public void setMaxBlurSize(int maxBlurSize) {

        m_maxBlurSize = maxBlurSize;
    }

    /**
     * Sets the scale position.<p>
     *
     * @param position the position to set
     */
    public void setPosition(int position) {

        switch (position) {
            case Simapi.POS_DOWN_LEFT:
            case Simapi.POS_DOWN_RIGHT:
            case Simapi.POS_STRAIGHT_DOWN:
            case Simapi.POS_STRAIGHT_LEFT:
            case Simapi.POS_STRAIGHT_RIGHT:
            case Simapi.POS_STRAIGHT_UP:
            case Simapi.POS_UP_LEFT:
            case Simapi.POS_UP_RIGHT:
                // pos is fine
                m_position = position;
                break;
            default:
                m_position = Simapi.POS_CENTER;
        }
    }

    /**
     * Sets the image saving quality in percent.<p>
     *
     * @param quality the image saving quality (in percent) to set
     */
    public void setQuality(int quality) {

        if (quality < 0) {
            m_quality = 0;
        } else if (quality > 100) {
            m_quality = 100;
        } else {
            m_quality = quality;
        }
    }

    /**
     * Sets the image rendering mode constant.<p>
     *
     * @param renderMode the image rendering mode to set
     * 
     * @see #getRenderMode() for a list of allowed values for the rendering mode
     */
    public void setRenderMode(int renderMode) {

        if ((renderMode < Simapi.RENDER_QUALITY) || (renderMode > Simapi.RENDER_SPEED)) {
            renderMode = Simapi.RENDER_QUALITY;
        }
        m_renderMode = renderMode;
    }

    /**
     * Sets the scale type.<p>
     *
     * @param type the scale type to set
     * 
     * @see #getType() for a detailed description of the possible values for the type
     */
    public void setType(int type) {

        if ((type < 0) || (type > 4)) {
            // invalid type, use 0
            m_type = 0;
        } else {
            m_type = type;
        }
    }

    /**
     * Sets the width.<p>
     *
     * @param width the width to set
     */
    public void setWidth(int width) {

        m_width = width;
    }

    /**
     * Creates a request parameter configured with the values from this image scaler, also
     * appends a <code>'?'</code> char as a prefix so that this may be direclty appended to an image URL.<p>
     * 
     * This can be appended to an image request in order to apply image scaling parameters.<p>
     * 
     * @return a request parameter configured with the values from this image scaler
     */
    public String toRequestParam() {

        StringBuffer result = new StringBuffer(128);
        result.append('?');
        result.append(PARAM_SCALE);
        result.append('=');
        result.append(toString());

        return result.toString();
    }

    /**
     * @see java.lang.Object#toString()
     */
    public String toString() {

        if (m_scaleParameters != null) {
            return m_scaleParameters;
        }

        StringBuffer result = new StringBuffer(64);
        result.append(CmsImageScaler.SCALE_PARAM_WIDTH);
        result.append(':');
        result.append(m_width);
        result.append(',');
        result.append(CmsImageScaler.SCALE_PARAM_HEIGHT);
        result.append(':');
        result.append(m_height);
        if (m_type > 0) {
            result.append(',');
            result.append(CmsImageScaler.SCALE_PARAM_TYPE);
            result.append(':');
            result.append(m_type);
        }
        if (m_position > 0) {
            result.append(',');
            result.append(CmsImageScaler.SCALE_PARAM_POS);
            result.append(':');
            result.append(m_position);
        }
        if (m_color != Color.WHITE) {
            result.append(',');
            result.append(CmsImageScaler.SCALE_PARAM_COLOR);
            result.append(':');
            result.append(getColorString());
        }
        if (m_quality > 0) {
            result.append(',');
            result.append(CmsImageScaler.SCALE_PARAM_QUALITY);
            result.append(':');
            result.append(m_quality);
        }
        if (m_renderMode > 0) {
            result.append(',');
            result.append(CmsImageScaler.SCALE_PARAM_RENDERMODE);
            result.append(':');
            result.append(m_renderMode);
        }
        if (!m_filters.isEmpty()) {
            result.append(',');
            result.append(CmsImageScaler.SCALE_PARAM_FILTER);
            result.append(':');
            result.append(getFiltersString());
        }
        m_scaleParameters = result.toString();
        return m_scaleParameters;
    }

    /**
     * Initializes the members with the default values.<p>
     */
    private void init() {

        m_height = -1;
        m_width = -1;
        m_type = 0;
        m_position = 0;
        m_renderMode = 0;
        m_quality = 0;
        m_color = Color.WHITE;
        m_filters = new ArrayList();
        m_maxBlurSize = CmsImageLoader.getMaxBlurSize();
    }

    /**
     * Copys all values from the given scaler into this scaler.<p>
     * 
     * @param source the source scaler
     */
    private void initValuesFrom(CmsImageScaler source) {

        m_width = source.m_width;
        m_height = source.m_height;
        m_type = source.m_type;
        m_position = source.m_position;
        m_renderMode = source.m_renderMode;
        m_quality = source.m_quality;
        m_color = source.m_color;
        m_filters = new ArrayList(source.m_filters);
        m_maxBlurSize = source.m_maxBlurSize;
    }

    /**
     * Parses the scaler parameters.<p>
     * 
     * @param parameters the parameters to parse
     */
    private void parseParameters(String parameters) {

        m_width = -1;
        m_height = -1;
        m_position = 0;
        m_type = 0;
        m_color = Color.WHITE;

        List tokens = CmsStringUtil.splitAsList(parameters, ',');
        Iterator it = tokens.iterator();
        String k;
        String v;
        while (it.hasNext()) {
            String t = (String)it.next();
            // extract key and value
            k = null;
            v = null;
            int idx = t.indexOf(':');
            if (idx >= 0) {
                k = t.substring(0, idx).trim();
                if (t.length() > idx) {
                    v = t.substring(idx + 1).trim();
                }
            }
            if (CmsStringUtil.isNotEmpty(k) && CmsStringUtil.isNotEmpty(v)) {
                // key and value are available
                if (SCALE_PARAM_HEIGHT.equals(k)) {
                    // image height
                    m_height = CmsStringUtil.getIntValue(v, Integer.MIN_VALUE, k);
                } else if (SCALE_PARAM_WIDTH.equals(k)) {
                    // image width
                    m_width = CmsStringUtil.getIntValue(v, Integer.MIN_VALUE, k);
                } else if (SCALE_PARAM_TYPE.equals(k)) {
                    // scaling type
                    setType(CmsStringUtil.getIntValue(v, -1, CmsImageScaler.SCALE_PARAM_TYPE));
                } else if (SCALE_PARAM_COLOR.equals(k)) {
                    // image background color
                    setColor(v);
                } else if (SCALE_PARAM_POS.equals(k)) {
                    // image position (depends on scale type)
                    setPosition(CmsStringUtil.getIntValue(v, -1, CmsImageScaler.SCALE_PARAM_POS));
                } else if (SCALE_PARAM_QUALITY.equals(k)) {
                    // image position (depends on scale type)
                    setQuality(CmsStringUtil.getIntValue(v, 0, k));
                } else if (SCALE_PARAM_RENDERMODE.equals(k)) {
                    // image position (depends on scale type)
                    setRenderMode(CmsStringUtil.getIntValue(v, 0, k));
                } else if (SCALE_PARAM_FILTER.equals(k)) {
                    // image filters to apply
                    setFilters(v);
                } else {
                    if (LOG.isDebugEnabled()) {
                        LOG.debug(Messages.get().getBundle().key(Messages.ERR_INVALID_IMAGE_SCALE_PARAMS_2, k, v));
                    }
                }
            } else {
                if (LOG.isDebugEnabled()) {
                    LOG.debug(Messages.get().getBundle().key(Messages.ERR_INVALID_IMAGE_SCALE_PARAMS_2, k, v));
                }
            }
        }
    }
}