pdfcontentbyte.java

iText是一个能够快速产生PDF文件的java类库。iText的java类对于那些要产生包含文本

        content.append("'").append_i(separator);
    }
    
    /**
     * Moves to the next line and shows text string, using the given values of the character and word spacing parameters.
     *
     * @param       wordSpacing     a parameter
     * @param       charSpacing     a parameter
     * @param text the text to write
     */
    public void newlineShowText(float wordSpacing, float charSpacing, String text) {
        state.yTLM -= state.leading;
        content.append(wordSpacing).append(' ').append(charSpacing);
        showText2(text);
        content.append("\"").append_i(separator);
        
        // The " operator sets charSpace and wordSpace into graphics state
        // (cfr PDF reference v1.6, table 5.6)
        state.charSpace = charSpacing;
        state.wordSpace = wordSpacing;
    }
    
    /**
     * Changes the text matrix.
     * <P>
     * Remark: this operation also initializes the current point position.</P>
     *
     * @param       a           operand 1,1 in the matrix
     * @param       b           operand 1,2 in the matrix
     * @param       c           operand 2,1 in the matrix
     * @param       d           operand 2,2 in the matrix
     * @param       x           operand 3,1 in the matrix
     * @param       y           operand 3,2 in the matrix
     */
    public void setTextMatrix(float a, float b, float c, float d, float x, float y) {
        state.xTLM = x;
        state.yTLM = y;
        content.append(a).append(' ').append(b).append_i(' ')
        .append(c).append_i(' ').append(d).append_i(' ')
        .append(x).append_i(' ').append(y).append(" Tm").append_i(separator);
    }
    
    /**
     * Changes the text matrix. The first four parameters are {1,0,0,1}.
     * <P>
     * Remark: this operation also initializes the current point position.</P>
     *
     * @param       x           operand 3,1 in the matrix
     * @param       y           operand 3,2 in the matrix
     */
    public void setTextMatrix(float x, float y) {
        setTextMatrix(1, 0, 0, 1, x, y);
    }
    
    /**
     * Moves to the start of the next line, offset from the start of the current line.
     *
     * @param       x           x-coordinate of the new current point
     * @param       y           y-coordinate of the new current point
     */
    public void moveText(float x, float y) {
        state.xTLM += x;
        state.yTLM += y;
        content.append(x).append(' ').append(y).append(" Td").append_i(separator);
    }
    
    /**
     * Moves to the start of the next line, offset from the start of the current line.
     * <P>
     * As a side effect, this sets the leading parameter in the text state.</P>
     *
     * @param       x           offset of the new current point
     * @param       y           y-coordinate of the new current point
     */
    public void moveTextWithLeading(float x, float y) {
        state.xTLM += x;
        state.yTLM += y;
        state.leading = -y;
        content.append(x).append(' ').append(y).append(" TD").append_i(separator);
    }
    
    /**
     * Moves to the start of the next line.
     */
    public void newlineText() {
        state.yTLM -= state.leading;
        content.append("T*").append_i(separator);
    }
    
    /**
     * Gets the size of this content.
     *
     * @return the size of the content
     */
    int size() {
        return content.size();
    }
    
    /**
     * Escapes a <CODE>byte</CODE> array according to the PDF conventions.
     *
     * @param b the <CODE>byte</CODE> array to escape
     * @return an escaped <CODE>byte</CODE> array
     */
    static byte[] escapeString(byte b[]) {
        ByteBuffer content = new ByteBuffer();
        escapeString(b, content);
        return content.toByteArray();
    }
    
    /**
     * Escapes a <CODE>byte</CODE> array according to the PDF conventions.
     *
     * @param b the <CODE>byte</CODE> array to escape
     * @param content the content
     */
    static void escapeString(byte b[], ByteBuffer content) {
        content.append_i('(');
        for (int k = 0; k < b.length; ++k) {
            byte c = b[k];
            switch ((int)c) {
                case '\r':
                    content.append("\\r");
                    break;
                case '\n':
                    content.append("\\n");
                    break;
                case '\t':
                    content.append("\\t");
                    break;
                case '\b':
                    content.append("\\b");
                    break;
                case '\f':
                    content.append("\\f");
                    break;
                case '(':
                case ')':
                case '\\':
                    content.append_i('\\').append_i(c);
                    break;
                default:
                    content.append_i(c);
            }
        }
        content.append(")");
    }
    
    /**
     * Adds an outline to the document.
     *
     * @param outline the outline
     * @deprecated not needed anymore. The outlines are extracted
     * from the root outline
     */
    public void addOutline(PdfOutline outline) {
        // for compatibility
    }
    /**
     * Adds a named outline to the document.
     *
     * @param outline the outline
     * @param name the name for the local destination
     */
    public void addOutline(PdfOutline outline, String name) {
        checkWriter();
        pdf.addOutline(outline, name);
    }
    /**
     * Gets the root outline.
     *
     * @return the root outline
     */
    public PdfOutline getRootOutline() {
        checkWriter();
        return pdf.getRootOutline();
    }
    
    /**
     * Computes the width of the given string taking in account
     * the current values of "Character spacing", "Word Spacing"
     * and "Horizontal Scaling".
     * The additional spacing is not computed for the last character
     * of the string.
     * @param text the string to get width of
     * @param kerned the kerning option
     * @return the width
     */

    public float getEffectiveStringWidth(String text, boolean kerned) {
        BaseFont bf = state.fontDetails.getBaseFont();
        
        float w;
        if (kerned)
            w = bf.getWidthPointKerned(text, state.size);
        else
            w = bf.getWidthPoint(text, state.size);
        
        if (state.charSpace != 0.0f && text.length() > 1) {
            w += state.charSpace * (text.length() -1);
        }
        
        int ft = bf.getFontType();
        if (state.wordSpace != 0.0f && (ft == BaseFont.FONT_TYPE_T1 || ft == BaseFont.FONT_TYPE_TT || ft == BaseFont.FONT_TYPE_T3)) {
            for (int i = 0; i < (text.length() -1); i++) {
                if (text.charAt(i) == ' ')
                    w += state.wordSpace;
            }
        }
        if (state.scale != 100.0)
            w = (w * state.scale) / 100.0f;
        
        //System.out.println("String width = " + Float.toString(w));
        return w;
    }
    
    /**
     * Shows text right, left or center aligned with rotation.
     * @param alignment the alignment can be ALIGN_CENTER, ALIGN_RIGHT or ALIGN_LEFT
     * @param text the text to show
     * @param x the x pivot position
     * @param y the y pivot position
     * @param rotation the rotation to be applied in degrees counterclockwise
     */
    public void showTextAligned(int alignment, String text, float x, float y, float rotation) {
        showTextAligned(alignment, text, x, y, rotation, false);
    }
    
    private void showTextAligned(int alignment, String text, float x, float y, float rotation, boolean kerned) {
        if (state.fontDetails == null)
            throw new NullPointerException("Font and size must be set before writing any text");
        if (rotation == 0) {
            switch (alignment) {
                case ALIGN_CENTER:
                    x -= getEffectiveStringWidth(text, kerned) / 2;
                    break;
                case ALIGN_RIGHT:
                    x -= getEffectiveStringWidth(text, kerned);
                    break;
            }
            setTextMatrix(x, y);
            if (kerned)
                showTextKerned(text);
            else
                showText(text);
        }
        else {
            double alpha = rotation * Math.PI / 180.0;
            float cos = (float)Math.cos(alpha);
            float sin = (float)Math.sin(alpha);
            float len;
            switch (alignment) {
                case ALIGN_CENTER:
                    len = getEffectiveStringWidth(text, kerned) / 2;
                    x -=  len * cos;
                    y -=  len * sin;
                    break;
                case ALIGN_RIGHT:
                    len = getEffectiveStringWidth(text, kerned);
                    x -=  len * cos;
                    y -=  len * sin;
                    break;
            }
            setTextMatrix(cos, sin, -sin, cos, x, y);
            if (kerned)
                showTextKerned(text);
            else
                showText(text);
            setTextMatrix(0f, 0f);
        }
    }
    
    /**
     * Shows text kerned right, left or center aligned with rotation.
     * @param alignment the alignment can be ALIGN_CENTER, ALIGN_RIGHT or ALIGN_LEFT
     * @param text the text to show
     * @param x the x pivot position
     * @param y the y pivot position
     * @param rotation the rotation to be applied in degrees counterclockwise
     */
    public void showTextAlignedKerned(int alignment, String text, float x, float y, float rotation) {
        showTextAligned(alignment, text, x, y, rotation, true);
    }
    
    /**
     * Concatenate a matrix to the current transformation matrix.
     * @param a an element of the transformation matrix
     * @param b an element of the transformation matrix
     * @param c an element of the transformation matrix
     * @param d an element of the transformation matrix
     * @param e an element of the transformation matrix
     * @param f an element of the transformation matrix
     **/
    public void concatCTM(float a, float b, float c, float d, float e, float f) {
        content.append(a).append(' ').append(b).append(' ').append(c).append(' ');
        content.append(d).append(' ').append(e).append(' ').append(f).append(" cm").append_i(separator);
    }
    
    /**
     * Generates an array of bezier curves to draw an arc.
     * <P>
     * (x1, y1) and (x2, y2) are the corners of the enclosing rectangle.
     * Angles, measured in degrees, start with 0 to the right (the positive X
     * axis) and increase counter-clockwise.  The arc extends from startAng
     * to startAng+extent.  I.e. startAng=0 and extent=180 yields an openside-down
     * semi-circle.
     * <P>
     * The resulting coordinates are of the form float[]{x1,y1,x2,y2,x3,y3, x4,y4}
     * such that the curve goes from (x1, y1) to (x4, y4) with (x2, y2) and
     * (x3, y3) as their respective Bezier control points.
     * <P>
     * Note: this code was taken from ReportLab (www.reportlab.org), an excelent
     * PDF generator for Python (BSD license: http://www.reportlab.org/devfaq.html#1.3 ).
     *
     * @param x1 a corner of the enclosing rectangle
     * @param y1 a corner of the enclosing rectangle
     * @param x2 a corner of the enclosing rectangle
     * @param y2 a corner of the enclosing rectangle
     * @param startAng starting angle in degrees
     * @param extent angle extent in degrees
     * @return a list of float[] with the bezier curves
     */
    public static ArrayList bezierArc(float x1, float y1, float x2, float y2, float startAng, float extent) {
        float tmp;
        if (x1 > x2) {
            tmp = x1;
            x1 = x2;
            x2 = tmp;
        }
        if (y2 > y1) {
            tmp = y1;
            y1 = y2;
            y2 = tmp;
        }
        
        float fragAngle;
        int Nfrag;
        if (Math.abs(extent) <= 90f) {
            fragAngle = extent;
            Nfrag = 1;
        }
        else {
            Nfrag = (int)(Math.ceil(Math.abs(extent)/90f));
            fragAngle = extent / Nfrag;
        }
        float x_cen = (x1+x2)/2f;
        float y_cen = (y1+y2)/2f;
        float rx = (x2-x1)/2f;
        float ry = (y2-y1)/2f;
        float halfAng = (float)(fragAngle * Math.PI / 360.);
        float kappa = (float)(Math.abs(4. / 3. * (1. - Math.cos(halfAng)) / Math.sin(halfAng)));
        ArrayList pointList = new ArrayList();
        for (int i = 0; i < Nfrag; ++i) {
            float theta0 = (float)((startAng + i*fragAngle) * Math.PI / 180.);
            float theta1 = (float)((startAng + (i+1)*fragAngle) * Math.PI / 180.);
            float cos0 = (float)Math.cos(theta0);
            float cos1 = (float)Math.cos(theta1);
            float sin0 = (float)Math.sin(theta0);
            float sin1 = (float)Math.sin(theta1);
            if (fragAngle > 0f) {
                pointList.add(new float[]{x_ce