textlayout.java

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        // set paragraph attributes
        {
            // If there's an embedded graphic at the start of the
            // paragraph, look for the first non-graphic character
            // and use it and its font to initialize the paragraph.
            // If not, use the first graphic to initialize.

            Map paragraphAttrs = text.getAttributes();

            boolean haveFont = TextLine.advanceToFirstFont(text);

            if (haveFont) {
                Font defaultFont = TextLine.getFontAtCurrentPos(text);
                int charsStart = text.getIndex() - text.getBeginIndex();
                LineMetrics lm = defaultFont.getLineMetrics(chars, charsStart, charsStart+1, frc);
                paragraphInit((byte)lm.getBaselineIndex(), lm, paragraphAttrs, chars);
            }
            else {
                // hmmm what to do here?  Just try to supply reasonable
                // values I guess.

                GraphicAttribute graphic = (GraphicAttribute)
                                paragraphAttrs.get(TextAttribute.CHAR_REPLACEMENT);
                byte defaultBaseline = getBaselineFromGraphic(graphic);
                Font dummyFont = new Font(new Hashtable(5, (float)0.9));
                LineMetrics lm = dummyFont.getLineMetrics(" ", 0, 1, frc);

                paragraphInit(defaultBaseline, lm, paragraphAttrs, chars);
            }
        }

        textLine = TextLine.standardCreateTextLine(frc, text, chars, baselineOffsets);
    }

    /*
     * A utility to rebuild the ascent/descent/leading/advance cache.
     * You'll need to call this if you clone and mutate (like justification,
     * editing methods do)
     */
    private void ensureCache() {
        if (!cacheIsValid) {
            buildCache();
        }
    }

    private void buildCache() {
        if (textLine == null) {
            initTextLine();
        }

        lineMetrics = textLine.getMetrics();

        // compute visibleAdvance
        if (textLine.isDirectionLTR()) {

            int lastNonSpace = characterCount-1;
            while (lastNonSpace != -1) {
                int logIndex = textLine.visualToLogical(lastNonSpace);
                if (!textLine.isCharSpace(logIndex)) {
                    break;
                }
                else {
                    --lastNonSpace;
                }
            }
            if (lastNonSpace == characterCount-1) {
                visibleAdvance = lineMetrics.advance;
            }
            else if (lastNonSpace == -1) {
                visibleAdvance = 0;
            }
            else {
                int logIndex = textLine.visualToLogical(lastNonSpace);
                visibleAdvance = textLine.getCharLinePosition(logIndex)
                                        + textLine.getCharAdvance(logIndex);
            }
        }
        else {

            int leftmostNonSpace = 0;
            while (leftmostNonSpace != characterCount) {
                int logIndex = textLine.visualToLogical(leftmostNonSpace);
                if (!textLine.isCharSpace(logIndex)) {
                    break;
                }
                else {
                    ++leftmostNonSpace;
                }
            }
            if (leftmostNonSpace == characterCount) {
                visibleAdvance = 0;
            }
            else if (leftmostNonSpace == 0) {
                visibleAdvance = lineMetrics.advance;
            }
            else {
                int logIndex = textLine.visualToLogical(leftmostNonSpace);
                float pos = textLine.getCharLinePosition(logIndex);
                visibleAdvance = lineMetrics.advance - pos;
            }
        }


        // naturalBounds, boundsRect will be generated on demand
        naturalBounds = null;
        boundsRect = null;

        // hashCode will be regenerated on demand
        hashCodeCache = 0;

        cacheIsValid = true;
    }

    private Rectangle2D getNaturalBounds() {
        ensureCache();

        if (naturalBounds == null) {
            int leftmostCharIndex = textLine.visualToLogical(0);
            float angle = textLine.getCharAngle(leftmostCharIndex);
            float leftOrTop = isVerticalLine? -dy : -dx;
            if (angle < 0) {
                leftOrTop += angle*textLine.getCharAscent(leftmostCharIndex);
            }
            else if (angle > 0) {
                leftOrTop -= angle*textLine.getCharDescent(leftmostCharIndex);
            }

            int rightmostCharIndex = textLine.visualToLogical(characterCount-1);
            angle = textLine.getCharAngle(rightmostCharIndex);

            float rightOrBottom = lineMetrics.advance;
            if (angle < 0) {
                rightOrBottom -=
                            angle*textLine.getCharDescent(rightmostCharIndex);
            }
            else if (angle > 0) {
                rightOrBottom +=
                            angle*textLine.getCharAscent(rightmostCharIndex);
            }

            float lineDim = rightOrBottom - leftOrTop;

            if (isVerticalLine) {
                naturalBounds = new Rectangle2D.Float(
                            -lineMetrics.descent, leftOrTop,
                            lineMetrics.ascent + lineMetrics.descent, lineDim);
            }
            else {
                naturalBounds = new Rectangle2D.Float(
                            leftOrTop, -lineMetrics.ascent,
                            lineDim, lineMetrics.ascent + lineMetrics.descent);
            }
        }

        return naturalBounds;
    }

    /**
     * Creates a copy of this <code>TextLayout</code>.
     */
    protected Object clone() {
        /*
         * !!! I think this is safe.  Once created, nothing mutates the
         * glyphvectors or arrays.  But we need to make sure.
         * {jbr} actually, that's not quite true.  The justification code
         * mutates after cloning.  It doesn't actually change the glyphvectors
         * (that's impossible) but it replaces them with justified sets.  This
         * is a problem for GlyphIterator creation, since new GlyphIterators
         * are created by cloning a prototype.  If the prototype has outdated
         * glyphvectors, so will the new ones.  A partial solution is to set the
         * prototypical GlyphIterator to null when the glyphvectors change.  If
         * you forget this one time, you're hosed.
         */
        try {
            return super.clone();
        }
        catch (CloneNotSupportedException e) {
            throw new InternalError();
        }
    }

    /*
     * Utility to throw an expection if an invalid TextHitInfo is passed
     * as a parameter.  Avoids code duplication.
     */
    private void checkTextHit(TextHitInfo hit) {
        if (hit == null) {
            throw new IllegalArgumentException("TextHitInfo is null.");
        }

        if (hit.getInsertionIndex() < 0 ||
            hit.getInsertionIndex() > characterCount) {
            throw new IllegalArgumentException("TextHitInfo is out of range");
        }
    }

    /**
     * Creates a copy of this <code>TextLayout</code> justified to the 
     * specified width.
     * <p>
     * If this <code>TextLayout</code> has already been justified, an
     * exception is thrown.  If this <code>TextLayout</code> object's 
     * justification ratio is zero, a <code>TextLayout</code> identical 
     * to this <code>TextLayout</code> is returned.
     * @param justificationWidth the width to use when justifying the line.
     * For best results, it should not be too different from the current
     * advance of the line.
     * @return a <code>TextLayout</code> justified to the specified width.
     * @exception Error if this layout has already been justified, an Error is
     * thrown.
     */
    public TextLayout getJustifiedLayout(float justificationWidth) {

        if (justificationWidth <= 0) {
            throw new IllegalArgumentException("justificationWidth <= 0 passed to TextLayout.getJustifiedLayout()");
        }

        if (justifyRatio == ALREADY_JUSTIFIED) {
            throw new Error("Can't justify again.");
        }

	ensureCache(); // make sure textLine is not null

        // default justification range to exclude trailing logical whitespace
        int limit = characterCount;
        while (limit > 0 && textLine.isCharWhitespace(limit-1)) {
            --limit;
        }

        TextLine newLine = textLine.getJustifiedLine(justificationWidth, justifyRatio, 0, limit);
        if (newLine != null) {
            return new TextLayout(newLine, baseline, baselineOffsets, ALREADY_JUSTIFIED);
        }

        return this;
    }

    /**
     * Justify this layout.  Overridden by subclassers to control justification
     * (if there were subclassers, that is...)
     *
     * The layout will only justify if the paragraph attributes (from the
     * source text, possibly defaulted by the layout attributes) indicate a
     * non-zero justification ratio.  The text will be justified to the
     * indicated width.  The current implementation also adjusts hanging
     * punctuation and trailing whitespace to overhang the justification width.
     * Once justified, the layout may not be rejustified.
     * <p>
     * Some code may rely on immutablity of layouts.  Subclassers should not
     * call this directly, but instead should call getJustifiedLayout, which
     * will call this method on a clone of this layout, preserving
     * the original.
     *
     * @param justificationWidth the width to use when justifying the line.
     * For best results, it should not be too different from the current
     * advance of the line.
     * @see #getJustifiedLayout(float)
     */
    protected void handleJustify(float justificationWidth) {
      // never called
    }


    /**
     * Returns the baseline for this <code>TextLayout</code>.
     * The baseline is one of the values defined in <code>Font</code>,
     * which are roman, centered and hanging.  Ascent and descent are
     * relative to this baseline.  The <code>baselineOffsets</code>
     * are also relative to this baseline.
     * @return the baseline of this <code>TextLayout</code>.
     * @see #getBaselineOffsets()
     * @see Font
     */
    public byte getBaseline() {
        return baseline;
    }

    /**
     * Returns the offsets array for the baselines used for this 
     * <code>TextLayout</code>.
     * <p>
     * The array is indexed by one of the values defined in 
     * <code>Font</code>, which are roman, centered and hanging.  The 
     * values are relative to this <code>TextLayout</code> object's 
     * baseline, so that <code>getBaselineOffsets[getBaseline()] == 0</code>.
     * Offsets are added to the position of the <code>TextLayout</code> 
     * object's baseline to get the position for the new baseline.
     * @return the offsets array containing the baselines used for this
     *    <code>TextLayout</code>.
     * @see #getBaseline()
     * @see Font
     */
    public float[] getBaselineOffsets() {
        float[] offsets = new float[baselineOffsets.length];
        System.arraycopy(baselineOffsets, 0, offsets, 0, offsets.length);
        return offsets;
    }

    /**
     * Returns the advance of this <code>TextLayout</code>.
     * The advance is the distance from the origin to the advance of the
     * rightmost (bottommost) character measuring in the line direction.
     * @return the advance of this <code>TextLayout</code>.
     */
    public float getAdvance() {
        if (optInfo != null) {
            try {
                return optInfo.getAdvance();
            }
            catch (Error e) {
                // cache was flushed under optInfo
            }
        }
        ensureCache();
        return lineMetrics.advance;
    }

    /**
     * Returns the advance of this <code>TextLayout</code>, minus trailing 
     * whitespace.
     * @return the advance of this <code>TextLayout</code> without the
     *      trailing whitespace.
     * @see #getAdvance()
     */
    public float getVisibleAdvance() {
        ensureCache();
        return visibleAdvance;
    }

    /**
     * Returns the ascent of this <code>TextLayout</code>.
     * The ascent is the distance from the top (right) of the 
     * <code>TextLayout</code> to the baseline.  It is always either 
     * positive or zero.  The ascent is sufficient to
     * accomodate superscripted text and is the maximum of the sum of the
     * ascent, offset, and baseline of each glyph.
     * @return the ascent of this <code>TextLayout</code>.
     */
    public float getAscent() {
        if (optInfo != null) {
            return optInfo.getLineMetrics().getAscent();
        }
        ensureCache();
        return lineMetrics.ascent;
    }

    /**
     * Returns the descent of this <code>TextLayout</code>.
     * The descent is the distance from the baseline to the bottom (left) of
     * the <code>TextLayout</code>.  It is always either positive or zero.  
     * The descent is sufficient to accomodate subscripted text and is the 
     * maximum of the sum of the descent, offset, and baseline of each glyph.
     * @return the descent of this <code>TextLayout</code>.
     */