JDK8/Java8源码在线阅读
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*
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* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
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*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
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*
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package javax.swing.text;
import java.awt.*;
import java.text.BreakIterator;
import javax.swing.event.*;
import java.util.BitSet;
import java.util.Locale;
import javax.swing.UIManager;
import sun.swing.SwingUtilities2;
import static sun.swing.SwingUtilities2.IMPLIED_CR;
/**
* A GlyphView is a styled chunk of text that represents a view
* mapped over an element in the text model. This view is generally
* responsible for displaying text glyphs using character level
* attributes in some way.
* An implementation of the GlyphPainter class is used to do the
* actual rendering and model/view translations. This separates
* rendering from layout and management of the association with
* the model.
* <p>
* The view supports breaking for the purpose of formatting.
* The fragments produced by breaking share the view that has
* primary responsibility for the element (i.e. they are nested
* classes and carry only a small amount of state of their own)
* so they can share its resources.
* <p>
* Since this view
* represents text that may have tabs embedded in it, it implements the
* <code>TabableView</code> interface. Tabs will only be
* expanded if this view is embedded in a container that does
* tab expansion. ParagraphView is an example of a container
* that does tab expansion.
* <p>
*
* @since 1.3
*
* @author Timothy Prinzing
*/
public class GlyphView extends View implements TabableView, Cloneable {
/**
* Constructs a new view wrapped on an element.
*
* @param elem the element
*/
public GlyphView(Element elem) {
super(elem);
offset = 0;
length = 0;
Element parent = elem.getParentElement();
AttributeSet attr = elem.getAttributes();
// if there was an implied CR
impliedCR = (attr != null && attr.getAttribute(IMPLIED_CR) != null &&
// if this is non-empty paragraph
parent != null && parent.getElementCount() > 1);
skipWidth = elem.getName().equals("br");
}
/**
* Creates a shallow copy. This is used by the
* createFragment and breakView methods.
*
* @return the copy
*/
protected final Object clone() {
Object o;
try {
o = super.clone();
} catch (CloneNotSupportedException cnse) {
o = null;
}
return o;
}
/**
* Fetch the currently installed glyph painter.
* If a painter has not yet been installed, and
* a default was not yet needed, null is returned.
*/
public GlyphPainter getGlyphPainter() {
return painter;
}
/**
* Sets the painter to use for rendering glyphs.
*/
public void setGlyphPainter(GlyphPainter p) {
painter = p;
}
/**
* Fetch a reference to the text that occupies
* the given range. This is normally used by
* the GlyphPainter to determine what characters
* it should render glyphs for.
*
* @param p0 the starting document offset >= 0
* @param p1 the ending document offset >= p0
* @return the <code>Segment</code> containing the text
*/
public Segment getText(int p0, int p1) {
// When done with the returned Segment it should be released by
// invoking:
// SegmentCache.releaseSharedSegment(segment);
Segment text = SegmentCache.getSharedSegment();
try {
Document doc = getDocument();
doc.getText(p0, p1 - p0, text);
} catch (BadLocationException bl) {
throw new StateInvariantError("GlyphView: Stale view: " + bl);
}
return text;
}
/**
* Fetch the background color to use to render the
* glyphs. If there is no background color, null should
* be returned. This is implemented to call
* <code>StyledDocument.getBackground</code> if the associated
* document is a styled document, otherwise it returns null.
*/
public Color getBackground() {
Document doc = getDocument();
if (doc instanceof StyledDocument) {
AttributeSet attr = getAttributes();
if (attr.isDefined(StyleConstants.Background)) {
return ((StyledDocument)doc).getBackground(attr);
}
}
return null;
}
/**
* Fetch the foreground color to use to render the
* glyphs. If there is no foreground color, null should
* be returned. This is implemented to call
* <code>StyledDocument.getBackground</code> if the associated
* document is a StyledDocument. If the associated document
* is not a StyledDocument, the associated components foreground
* color is used. If there is no associated component, null
* is returned.
*/
public Color getForeground() {
Document doc = getDocument();
if (doc instanceof StyledDocument) {
AttributeSet attr = getAttributes();
return ((StyledDocument)doc).getForeground(attr);
}
Component c = getContainer();
if (c != null) {
return c.getForeground();
}
return null;
}
/**
* Fetch the font that the glyphs should be based
* upon. This is implemented to call
* <code>StyledDocument.getFont</code> if the associated
* document is a StyledDocument. If the associated document
* is not a StyledDocument, the associated components font
* is used. If there is no associated component, null
* is returned.
*/
public Font getFont() {
Document doc = getDocument();
if (doc instanceof StyledDocument) {
AttributeSet attr = getAttributes();
return ((StyledDocument)doc).getFont(attr);
}
Component c = getContainer();
if (c != null) {
return c.getFont();
}
return null;
}
/**
* Determine if the glyphs should be underlined. If true,
* an underline should be drawn through the baseline.
*/
public boolean isUnderline() {
AttributeSet attr = getAttributes();
return StyleConstants.isUnderline(attr);
}
/**
* Determine if the glyphs should have a strikethrough
* line. If true, a line should be drawn through the center
* of the glyphs.
*/
public boolean isStrikeThrough() {
AttributeSet attr = getAttributes();
return StyleConstants.isStrikeThrough(attr);
}
/**
* Determine if the glyphs should be rendered as superscript.
*/
public boolean isSubscript() {
AttributeSet attr = getAttributes();
return StyleConstants.isSubscript(attr);
}
/**
* Determine if the glyphs should be rendered as subscript.
*/
public boolean isSuperscript() {
AttributeSet attr = getAttributes();
return StyleConstants.isSuperscript(attr);
}
/**
* Fetch the TabExpander to use if tabs are present in this view.
*/
public TabExpander getTabExpander() {
return expander;
}
/**
* Check to see that a glyph painter exists. If a painter
* doesn't exist, a default glyph painter will be installed.
*/
protected void checkPainter() {
if (painter == null) {
if (defaultPainter == null) {
// the classname should probably come from a property file.
String classname = "javax.swing.text.GlyphPainter1";
try {
Class c;
ClassLoader loader = getClass().getClassLoader();
if (loader != null) {
c = loader.loadClass(classname);
} else {
c = Class.forName(classname);
}
Object o = c.newInstance();
if (o instanceof GlyphPainter) {
defaultPainter = (GlyphPainter) o;
}
} catch (Throwable e) {
throw new StateInvariantError("GlyphView: Can't load glyph painter: "
+ classname);
}
}
setGlyphPainter(defaultPainter.getPainter(this, getStartOffset(),
getEndOffset()));
}
}
// --- TabableView methods --------------------------------------
/**
* Determines the desired span when using the given
* tab expansion implementation.
*
* @param x the position the view would be located
* at for the purpose of tab expansion >= 0.
* @param e how to expand the tabs when encountered.
* @return the desired span >= 0
* @see TabableView#getTabbedSpan
*/
public float getTabbedSpan(float x, TabExpander e) {
checkPainter();
TabExpander old = expander;
expander = e;
if (expander != old) {
// setting expander can change horizontal span of the view,
// so we have to call preferenceChanged()
preferenceChanged(null, true, false);
}
this.x = (int) x;
int p0 = getStartOffset();
int p1 = getEndOffset();
float width = painter.getSpan(this, p0, p1, expander, x);
return width;
}
/**
* Determines the span along the same axis as tab
* expansion for a portion of the view. This is
* intended for use by the TabExpander for cases
* where the tab expansion involves aligning the
* portion of text that doesn't have whitespace
* relative to the tab stop. There is therefore
* an assumption that the range given does not
* contain tabs.
* <p>
* This method can be called while servicing the
* getTabbedSpan or getPreferredSize. It has to
* arrange for its own text buffer to make the
* measurements.
*
* @param p0 the starting document offset >= 0
* @param p1 the ending document offset >= p0
* @return the span >= 0
*/
public float getPartialSpan(int p0, int p1) {
checkPainter();
float width = painter.getSpan(this, p0, p1, expander, x);
return width;
}
// --- View methods ---------------------------------------------
/**
* Fetches the portion of the model that this view is responsible for.
*
* @return the starting offset into the model
* @see View#getStartOffset
*/
public int getStartOffset() {
Element e = getElement();
return (length > 0) ? e.getStartOffset() + offset : e.getStartOffset();
}
/**
* Fetches the portion of the model that this view is responsible for.
*
* @return the ending offset into the model
* @see View#getEndOffset
*/
public int getEndOffset() {
Element e = getElement();
return (length > 0) ? e.getStartOffset() + offset + length : e.getEndOffset();
}
/**
* Lazily initializes the selections field
*/
private void initSelections(int p0, int p1) {
int viewPosCount = p1 - p0 + 1;
if (selections == null || viewPosCount > selections.length) {
selections = new byte[viewPosCount];
return;
}
for (int i = 0; i < viewPosCount; selections[i++] = 0);
}
/**
* Renders a portion of a text style run.
*
* @param g the rendering surface to use
* @param a the allocated region to render into
*/
public void paint(Graphics g, Shape a) {
checkPainter();
boolean paintedText = false;
Component c = getContainer();
int p0 = getStartOffset();
int p1 = getEndOffset();
Rectangle alloc = (a instanceof Rectangle) ? (Rectangle)a : a.getBounds();
Color bg = getBackground();
Color fg = getForeground();
if (c != null && ! c.isEnabled()) {
fg = (c instanceof JTextComponent ?
((JTextComponent)c).getDisabledTextColor() :
UIManager.getColor("textInactiveText"));
}
if (bg != null) {
g.setColor(bg);
g.fillRect(alloc.x, alloc.y, alloc.width, alloc.height);
}
if (c instanceof JTextComponent) {
JTextComponent tc = (JTextComponent) c;
Highlighter h = tc.getHighlighter();
if (h instanceof LayeredHighlighter) {
((LayeredHighlighter)h).paintLayeredHighlights
(g, p0, p1, a, tc, this);
}
}
if (Utilities.isComposedTextElement(getElement())) {
Utilities.paintComposedText(g, a.getBounds(), this);
paintedText = true;
} else if(c instanceof JTextComponent) {
JTextComponent tc = (JTextComponent) c;
Color selFG = tc.getSelectedTextColor();
if (// there's a highlighter (bug 4532590), and
(tc.getHighlighter() != null) &&
// selected text color is different from regular foreground
(selFG != null) && !selFG.equals(fg)) {
Highlighter.Highlight[] h = tc.getHighlighter().getHighlights();
if(h.length != 0) {
boolean initialized = false;
int viewSelectionCount = 0;
for (int i = 0; i < h.length; i++) {
Highlighter.Highlight highlight = h[i];
int hStart = highlight.getStartOffset();
int hEnd = highlight.getEndOffset();
if (hStart > p1 || hEnd < p0) {
// the selection is out of this view
continue;
}
if (!SwingUtilities2.useSelectedTextColor(highlight, tc)) {
continue;
}
if (hStart <= p0 && hEnd >= p1){
// the whole view is selected
paintTextUsingColor(g, a, selFG, p0, p1);
paintedText = true;
break;
}
// the array is lazily created only when the view
// is partially selected
if (!initialized) {
initSelections(p0, p1);
initialized = true;
}
hStart = Math.max(p0, hStart);
hEnd = Math.min(p1, hEnd);
paintTextUsingColor(g, a, selFG, hStart, hEnd);
// the array represents view positions [0, p1-p0+1]
// later will iterate this array and sum its
// elements. Positions with sum == 0 are not selected.
selections[hStart-p0]++;
selections[hEnd-p0]--;
viewSelectionCount++;
}
if (!paintedText && viewSelectionCount > 0) {
// the view is partially selected
int curPos = -1;
int startPos = 0;
int viewLen = p1 - p0;
while (curPos++ < viewLen) {
// searching for the next selection start
while(curPos < viewLen &&
selections[curPos] == 0) curPos++;
if (startPos != curPos) {
// paint unselected text
paintTextUsingColor(g, a, fg,
p0 + startPos, p0 + curPos);
}
int checkSum = 0;
// searching for next start position of unselected text
while (curPos < viewLen &&
(checkSum += selections[curPos]) != 0) curPos++;
startPos = curPos;
}
paintedText = true;
}
}
}
}
if(!paintedText)
paintTextUsingColor(g, a, fg, p0, p1);
}
/**
* Paints the specified region of text in the specified color.
*/
final void paintTextUsingColor(Graphics g, Shape a, Color c, int p0, int p1) {
// render the glyphs
g.setColor(c);
painter.paint(this, g, a, p0, p1);
// render underline or strikethrough if set.
boolean underline = isUnderline();
boolean strike = isStrikeThrough();
if (underline || strike) {
// calculate x coordinates
Rectangle alloc = (a instanceof Rectangle) ? (Rectangle)a : a.getBounds();
View parent = getParent();
if ((parent != null) && (parent.getEndOffset() == p1)) {
// strip whitespace on end
Segment s = getText(p0, p1);
while (Character.isWhitespace(s.last())) {
p1 -= 1;
s.count -= 1;
}
SegmentCache.releaseSharedSegment(s);
}
int x0 = alloc.x;
int p = getStartOffset();
if (p != p0) {
x0 += (int) painter.getSpan(this, p, p0, getTabExpander(), x0);
}
int x1 = x0 + (int) painter.getSpan(this, p0, p1, getTabExpander(), x0);
// calculate y coordinate
int y = alloc.y + (int)(painter.getHeight(this) - painter.getDescent(this));
if (underline) {
int yTmp = y + 1;
g.drawLine(x0, yTmp, x1, yTmp);
}
if (strike) {
// move y coordinate above baseline
int yTmp = y - (int) (painter.getAscent(this) * 0.3f);
g.drawLine(x0, yTmp, x1, yTmp);
}
}
}
/**
* Determines the minimum span for this view along an axis.
*
* <p>This implementation returns the longest non-breakable area within
* the view as a minimum span for {@code View.X_AXIS}.</p>
*
* @param axis may be either {@code View.X_AXIS} or {@code View.Y_AXIS}
* @return the minimum span the view can be rendered into
* @throws IllegalArgumentException if the {@code axis} parameter is invalid
* @see javax.swing.text.View#getMinimumSpan
*/
@Override
public float getMinimumSpan(int axis) {
switch (axis) {
case View.X_AXIS:
if (minimumSpan < 0) {
minimumSpan = 0;
int p0 = getStartOffset();
int p1 = getEndOffset();
while (p1 > p0) {
int breakSpot = getBreakSpot(p0, p1);
if (breakSpot == BreakIterator.DONE) {
// the rest of the view is non-breakable
breakSpot = p0;
}
minimumSpan = Math.max(minimumSpan,
getPartialSpan(breakSpot, p1));
// Note: getBreakSpot returns the *last* breakspot
p1 = breakSpot - 1;
}
}
return minimumSpan;
case View.Y_AXIS:
return super.getMinimumSpan(axis);
default:
throw new IllegalArgumentException("Invalid axis: " + axis);
}
}
/**
* Determines the preferred span for this view along an
* axis.
*
* @param axis may be either View.X_AXIS or View.Y_AXIS
* @return the span the view would like to be rendered into >= 0.
* Typically the view is told to render into the span
* that is returned, although there is no guarantee.
* The parent may choose to resize or break the view.
*/
public float getPreferredSpan(int axis) {
if (impliedCR) {
return 0;
}
checkPainter();
int p0 = getStartOffset();
int p1 = getEndOffset();
switch (axis) {
case View.X_AXIS:
if (skipWidth) {
return 0;
}
return painter.getSpan(this, p0, p1, expander, this.x);
case View.Y_AXIS:
float h = painter.getHeight(this);
if (isSuperscript()) {
h += h/3;
}
return h;
default:
throw new IllegalArgumentException("Invalid axis: " + axis);
}
}
/**
* Determines the desired alignment for this view along an
* axis. For the label, the alignment is along the font
* baseline for the y axis, and the superclasses alignment
* along the x axis.
*
* @param axis may be either View.X_AXIS or View.Y_AXIS
* @return the desired alignment. This should be a value
* between 0.0 and 1.0 inclusive, where 0 indicates alignment at the
* origin and 1.0 indicates alignment to the full span
* away from the origin. An alignment of 0.5 would be the
* center of the view.
*/
public float getAlignment(int axis) {
checkPainter();
if (axis == View.Y_AXIS) {
boolean sup = isSuperscript();
boolean sub = isSubscript();
float h = painter.getHeight(this);
float d = painter.getDescent(this);
float a = painter.getAscent(this);
float align;
if (sup) {
align = 1.0f;
} else if (sub) {
align = (h > 0) ? (h - (d + (a / 2))) / h : 0;
} else {
align = (h > 0) ? (h - d) / h : 0;
}
return align;
}
return super.getAlignment(axis);
}
/**
* Provides a mapping from the document model coordinate space
* to the coordinate space of the view mapped to it.
*
* @param pos the position to convert >= 0
* @param a the allocated region to render into
* @param b either <code>Position.Bias.Forward</code>
* or <code>Position.Bias.Backward</code>
* @return the bounding box of the given position
* @exception BadLocationException if the given position does not represent a
* valid location in the associated document
* @see View#modelToView
*/
public Shape modelToView(int pos, Shape a, Position.Bias b) throws BadLocationException {
checkPainter();
return painter.modelToView(this, pos, b, a);
}
/**
* Provides a mapping from the view coordinate space to the logical
* coordinate space of the model.
*
* @param x the X coordinate >= 0
* @param y the Y coordinate >= 0
* @param a the allocated region to render into
* @param biasReturn either <code>Position.Bias.Forward</code>
* or <code>Position.Bias.Backward</code> is returned as the
* zero-th element of this array
* @return the location within the model that best represents the
* given point of view >= 0
* @see View#viewToModel
*/
public int viewToModel(float x, float y, Shape a, Position.Bias[] biasReturn) {
checkPainter();
return painter.viewToModel(this, x, y, a, biasReturn);
}
/**
* Determines how attractive a break opportunity in
* this view is. This can be used for determining which
* view is the most attractive to call <code>breakView</code>
* on in the process of formatting. The
* higher the weight, the more attractive the break. A
* value equal to or lower than <code>View.BadBreakWeight</code>
* should not be considered for a break. A value greater
* than or equal to <code>View.ForcedBreakWeight</code> should
* be broken.
* <p>
* This is implemented to forward to the superclass for
* the Y_AXIS. Along the X_AXIS the following values
* may be returned.
* <dl>
* <dt><b>View.ExcellentBreakWeight</b>
* <dd>if there is whitespace proceeding the desired break
* location.
* <dt><b>View.BadBreakWeight</b>
* <dd>if the desired break location results in a break
* location of the starting offset.
* <dt><b>View.GoodBreakWeight</b>
* <dd>if the other conditions don't occur.
* </dl>
* This will normally result in the behavior of breaking
* on a whitespace location if one can be found, otherwise
* breaking between characters.
*
* @param axis may be either View.X_AXIS or View.Y_AXIS
* @param pos the potential location of the start of the
* broken view >= 0. This may be useful for calculating tab
* positions.
* @param len specifies the relative length from <em>pos</em>
* where a potential break is desired >= 0.
* @return the weight, which should be a value between
* View.ForcedBreakWeight and View.BadBreakWeight.
* @see LabelView
* @see ParagraphView
* @see View#BadBreakWeight
* @see View#GoodBreakWeight
* @see View#ExcellentBreakWeight
* @see View#ForcedBreakWeight
*/
public int getBreakWeight(int axis, float pos, float len) {
if (axis == View.X_AXIS) {
checkPainter();
int p0 = getStartOffset();
int p1 = painter.getBoundedPosition(this, p0, pos, len);
return p1 == p0 ? View.BadBreakWeight :
getBreakSpot(p0, p1) != BreakIterator.DONE ?
View.ExcellentBreakWeight : View.GoodBreakWeight;
}
return super.getBreakWeight(axis, pos, len);
}
/**
* Breaks this view on the given axis at the given length.
* This is implemented to attempt to break on a whitespace
* location, and returns a fragment with the whitespace at
* the end. If a whitespace location can't be found, the
* nearest character is used.
*
* @param axis may be either View.X_AXIS or View.Y_AXIS
* @param p0 the location in the model where the
* fragment should start it's representation >= 0.
* @param pos the position along the axis that the
* broken view would occupy >= 0. This may be useful for
* things like tab calculations.
* @param len specifies the distance along the axis
* where a potential break is desired >= 0.
* @return the fragment of the view that represents the
* given span, if the view can be broken. If the view
* doesn't support breaking behavior, the view itself is
* returned.
* @see View#breakView
*/
public View breakView(int axis, int p0, float pos, float len) {
if (axis == View.X_AXIS) {
checkPainter();
int p1 = painter.getBoundedPosition(this, p0, pos, len);
int breakSpot = getBreakSpot(p0, p1);
if (breakSpot != -1) {
p1 = breakSpot;
}
// else, no break in the region, return a fragment of the
// bounded region.
if (p0 == getStartOffset() && p1 == getEndOffset()) {
return this;
}
GlyphView v = (GlyphView) createFragment(p0, p1);
v.x = (int) pos;
return v;
}
return this;
}
/**
* Returns a location to break at in the passed in region, or
* BreakIterator.DONE if there isn't a good location to break at
* in the specified region.
*/
private int getBreakSpot(int p0, int p1) {
if (breakSpots == null) {
// Re-calculate breakpoints for the whole view
int start = getStartOffset();
int end = getEndOffset();
int[] bs = new int[end + 1 - start];
int ix = 0;
// Breaker should work on the parent element because there may be
// a valid breakpoint at the end edge of the view (space, etc.)
Element parent = getElement().getParentElement();
int pstart = (parent == null ? start : parent.getStartOffset());
int pend = (parent == null ? end : parent.getEndOffset());
Segment s = getText(pstart, pend);
s.first();
BreakIterator breaker = getBreaker();
breaker.setText(s);
// Backward search should start from end+1 unless there's NO end+1
int startFrom = end + (pend > end ? 1 : 0);
for (;;) {
startFrom = breaker.preceding(s.offset + (startFrom - pstart))
+ (pstart - s.offset);
if (startFrom > start) {
// The break spot is within the view
bs[ix++] = startFrom;
} else {
break;
}
}
SegmentCache.releaseSharedSegment(s);
breakSpots = new int[ix];
System.arraycopy(bs, 0, breakSpots, 0, ix);
}
int breakSpot = BreakIterator.DONE;
for (int i = 0; i < breakSpots.length; i++) {
int bsp = breakSpots[i];
if (bsp <= p1) {
if (bsp > p0) {
breakSpot = bsp;
}
break;
}
}
return breakSpot;
}
/**
* Return break iterator appropriate for the current document.
*
* For non-i18n documents a fast whitespace-based break iterator is used.
*/
private BreakIterator getBreaker() {
Document doc = getDocument();
if ((doc != null) && Boolean.TRUE.equals(
doc.getProperty(AbstractDocument.MultiByteProperty))) {
Container c = getContainer();
Locale locale = (c == null ? Locale.getDefault() : c.getLocale());
return BreakIterator.getLineInstance(locale);
} else {
return new WhitespaceBasedBreakIterator();
}
}
/**
* Creates a view that represents a portion of the element.
* This is potentially useful during formatting operations
* for taking measurements of fragments of the view. If
* the view doesn't support fragmenting (the default), it
* should return itself.
* <p>
* This view does support fragmenting. It is implemented
* to return a nested class that shares state in this view
* representing only a portion of the view.
*
* @param p0 the starting offset >= 0. This should be a value
* greater or equal to the element starting offset and
* less than the element ending offset.
* @param p1 the ending offset > p0. This should be a value
* less than or equal to the elements end offset and
* greater than the elements starting offset.
* @return the view fragment, or itself if the view doesn't
* support breaking into fragments
* @see LabelView
*/
public View createFragment(int p0, int p1) {
checkPainter();
Element elem = getElement();
GlyphView v = (GlyphView) clone();
v.offset = p0 - elem.getStartOffset();
v.length = p1 - p0;
v.painter = painter.getPainter(v, p0, p1);
v.justificationInfo = null;
return v;
}
/**
* Provides a way to determine the next visually represented model
* location that one might place a caret. Some views may not be
* visible, they might not be in the same order found in the model, or
* they just might not allow access to some of the locations in the
* model.
* This method enables specifying a position to convert
* within the range of >=0. If the value is -1, a position
* will be calculated automatically. If the value < -1,
* the {@code BadLocationException} will be thrown.
*
* @param pos the position to convert
* @param a the allocated region to render into
* @param direction the direction from the current position that can
* be thought of as the arrow keys typically found on a keyboard.
* This may be SwingConstants.WEST, SwingConstants.EAST,
* SwingConstants.NORTH, or SwingConstants.SOUTH.
* @return the location within the model that best represents the next
* location visual position.
* @exception BadLocationException the given position is not a valid
* position within the document
* @exception IllegalArgumentException for an invalid direction
*/
public int getNextVisualPositionFrom(int pos, Position.Bias b, Shape a,
int direction,
Position.Bias[] biasRet)
throws BadLocationException {
if (pos < -1) {
throw new BadLocationException("invalid position", pos);
}
return painter.getNextVisualPositionFrom(this, pos, b, a, direction, biasRet);
}
/**
* Gives notification that something was inserted into
* the document in a location that this view is responsible for.
* This is implemented to call preferenceChanged along the
* axis the glyphs are rendered.
*
* @param e the change information from the associated document
* @param a the current allocation of the view
* @param f the factory to use to rebuild if the view has children
* @see View#insertUpdate
*/
public void insertUpdate(DocumentEvent e, Shape a, ViewFactory f) {
justificationInfo = null;
breakSpots = null;
minimumSpan = -1;
syncCR();
preferenceChanged(null, true, false);
}
/**
* Gives notification that something was removed from the document
* in a location that this view is responsible for.
* This is implemented to call preferenceChanged along the
* axis the glyphs are rendered.
*
* @param e the change information from the associated document
* @param a the current allocation of the view
* @param f the factory to use to rebuild if the view has children
* @see View#removeUpdate
*/
public void removeUpdate(DocumentEvent e, Shape a, ViewFactory f) {
justificationInfo = null;
breakSpots = null;
minimumSpan = -1;
syncCR();
preferenceChanged(null, true, false);
}
/**
* Gives notification from the document that attributes were changed
* in a location that this view is responsible for.
* This is implemented to call preferenceChanged along both the
* horizontal and vertical axis.
*
* @param e the change information from the associated document
* @param a the current allocation of the view
* @param f the factory to use to rebuild if the view has children
* @see View#changedUpdate
*/
public void changedUpdate(DocumentEvent e, Shape a, ViewFactory f) {
minimumSpan = -1;
syncCR();
preferenceChanged(null, true, true);
}
// checks if the paragraph is empty and updates impliedCR flag
// accordingly
private void syncCR() {
if (impliedCR) {
Element parent = getElement().getParentElement();
impliedCR = (parent != null && parent.getElementCount() > 1);
}
}
/** {@inheritDoc} */
@Override
void updateAfterChange() {
// Drop the break spots. They will be re-calculated during
// layout. It is necessary for proper line break calculation.
breakSpots = null;
}
/**
* Class to hold data needed to justify this GlyphView in a PargraphView.Row
*/
static class JustificationInfo {
//justifiable content start
final int start;
//justifiable content end
final int end;
final int leadingSpaces;
final int contentSpaces;
final int trailingSpaces;
final boolean hasTab;
final BitSet spaceMap;
JustificationInfo(int start, int end,
int leadingSpaces,
int contentSpaces,
int trailingSpaces,
boolean hasTab,
BitSet spaceMap) {
this.start = start;
this.end = end;
this.leadingSpaces = leadingSpaces;
this.contentSpaces = contentSpaces;
this.trailingSpaces = trailingSpaces;
this.hasTab = hasTab;
this.spaceMap = spaceMap;
}
}
JustificationInfo getJustificationInfo(int rowStartOffset) {
if (justificationInfo != null) {
return justificationInfo;
}
//states for the parsing
final int TRAILING = 0;
final int CONTENT = 1;
final int SPACES = 2;
int startOffset = getStartOffset();
int endOffset = getEndOffset();
Segment segment = getText(startOffset, endOffset);
int txtOffset = segment.offset;
int txtEnd = segment.offset + segment.count - 1;
int startContentPosition = txtEnd + 1;
int endContentPosition = txtOffset - 1;
int lastTabPosition = txtOffset - 1;
int trailingSpaces = 0;
int contentSpaces = 0;
int leadingSpaces = 0;
boolean hasTab = false;
BitSet spaceMap = new BitSet(endOffset - startOffset + 1);
//we parse conent to the right of the rightmost TAB only.
//we are looking for the trailing and leading spaces.
//position after the leading spaces (startContentPosition)
//position before the trailing spaces (endContentPosition)
for (int i = txtEnd, state = TRAILING; i >= txtOffset; i--) {
if (' ' == segment.array[i]) {
spaceMap.set(i - txtOffset);
if (state == TRAILING) {
trailingSpaces++;
} else if (state == CONTENT) {
state = SPACES;
leadingSpaces = 1;
} else if (state == SPACES) {
leadingSpaces++;
}
} else if ('\t' == segment.array[i]) {
hasTab = true;
break;
} else {
if (state == TRAILING) {
if ('\n' != segment.array[i]
&& '\r' != segment.array[i]) {
state = CONTENT;
endContentPosition = i;
}
} else if (state == CONTENT) {
//do nothing
} else if (state == SPACES) {
contentSpaces += leadingSpaces;
leadingSpaces = 0;
}
startContentPosition = i;
}
}
SegmentCache.releaseSharedSegment(segment);
int startJustifiableContent = -1;
if (startContentPosition < txtEnd) {
startJustifiableContent =
startContentPosition - txtOffset;
}
int endJustifiableContent = -1;
if (endContentPosition > txtOffset) {
endJustifiableContent =
endContentPosition - txtOffset;
}
justificationInfo =
new JustificationInfo(startJustifiableContent,
endJustifiableContent,
leadingSpaces,
contentSpaces,
trailingSpaces,
hasTab,
spaceMap);
return justificationInfo;
}
// --- variables ------------------------------------------------
/**
* Used by paint() to store highlighted view positions
*/
private byte[] selections = null;
int offset;
int length;
// if it is an implied newline character
boolean impliedCR;
boolean skipWidth;
/**
* how to expand tabs
*/
TabExpander expander;
/** Cached minimum x-span value */
private float minimumSpan = -1;
/** Cached breakpoints within the view */
private int[] breakSpots = null;
/**
* location for determining tab expansion against.
*/
int x;
/**
* Glyph rendering functionality.
*/
GlyphPainter painter;
/**
* The prototype painter used by default.
*/
static GlyphPainter defaultPainter;
private JustificationInfo justificationInfo = null;
/**
* A class to perform rendering of the glyphs.
* This can be implemented to be stateless, or
* to hold some information as a cache to
* facilitate faster rendering and model/view
* translation. At a minimum, the GlyphPainter
* allows a View implementation to perform its
* duties independant of a particular version
* of JVM and selection of capabilities (i.e.
* shaping for i18n, etc).
*
* @since 1.3
*/
public static abstract class GlyphPainter {
/**
* Determine the span the glyphs given a start location
* (for tab expansion).
*/
public abstract float getSpan(GlyphView v, int p0, int p1, TabExpander e, float x);
public abstract float getHeight(GlyphView v);
public abstract float getAscent(GlyphView v);
public abstract float getDescent(GlyphView v);
/**
* Paint the glyphs representing the given range.
*/
public abstract void paint(GlyphView v, Graphics g, Shape a, int p0, int p1);
/**
* Provides a mapping from the document model coordinate space
* to the coordinate space of the view mapped to it.
* This is shared by the broken views.
*
* @param v the <code>GlyphView</code> containing the
* destination coordinate space
* @param pos the position to convert
* @param bias either <code>Position.Bias.Forward</code>
* or <code>Position.Bias.Backward</code>
* @param a Bounds of the View
* @return the bounding box of the given position
* @exception BadLocationException if the given position does not represent a
* valid location in the associated document
* @see View#modelToView
*/
public abstract Shape modelToView(GlyphView v,
int pos, Position.Bias bias,
Shape a) throws BadLocationException;
/**
* Provides a mapping from the view coordinate space to the logical
* coordinate space of the model.
*
* @param v the <code>GlyphView</code> to provide a mapping for
* @param x the X coordinate
* @param y the Y coordinate
* @param a the allocated region to render into
* @param biasReturn either <code>Position.Bias.Forward</code>
* or <code>Position.Bias.Backward</code>
* is returned as the zero-th element of this array
* @return the location within the model that best represents the
* given point of view
* @see View#viewToModel
*/
public abstract int viewToModel(GlyphView v,
float x, float y, Shape a,
Position.Bias[] biasReturn);
/**
* Determines the model location that represents the
* maximum advance that fits within the given span.
* This could be used to break the given view. The result
* should be a location just shy of the given advance. This
* differs from viewToModel which returns the closest
* position which might be proud of the maximum advance.
*
* @param v the view to find the model location to break at.
* @param p0 the location in the model where the
* fragment should start it's representation >= 0.
* @param x the graphic location along the axis that the
* broken view would occupy >= 0. This may be useful for
* things like tab calculations.
* @param len specifies the distance into the view
* where a potential break is desired >= 0.
* @return the maximum model location possible for a break.
* @see View#breakView
*/
public abstract int getBoundedPosition(GlyphView v, int p0, float x, float len);
/**
* Create a painter to use for the given GlyphView. If
* the painter carries state it can create another painter
* to represent a new GlyphView that is being created. If
* the painter doesn't hold any significant state, it can
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