Name: krT82822 Date: 05/30/99


These are lines from ParagraphView.java in javax.swing.text
package ( swing 1.1 ). This constraint does not allow me to
specify a line spacing of 0.5 and have it work. This should be
removed
// Adjust for line spacing
if(lineSpacing > 1) {
float height = row.getPreferredSpan(View.Y_AXIS);
float addition = (height * lineSpacing) - height;
if(addition > 0) {
row.setInsets(row.getTopInset(), row.getLeftInset(),
(short) addition, row.getRightInset());
}
}
(Review ID: 53458)
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Name: rlT66838 Date: 12/10/99


java version "1.3beta"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3beta-O)
Java(TM) HotSpot Client VM (build 1.3beta-O, mixed mode)


javax.swing.text.ParagraphView does not implement linespacing correctly. The
bug lies in ParagraphView.createRow:

ParagraphView.createRow():
[cut]
// Adjust for line spacing
if(lineSpacing > 1) {
float height = row.getPreferredSpan(View.Y_AXIS);
float addition = (height * lineSpacing) - height;
if(addition > 0) {
row.setInsets(row.getTopInset(), row.getLeftInset(),
(short) addition, row.getRightInset());
}
[cut]

The problem is that, at the time the row is created, it contains no text and
therefore returns zero for its getPreferredSpan(), meaning that the addition
variable always gets set to zero.

Solution 1. One quick solution on the Swing code side would be to store a
linespacing variable in the ParagraphView.Row class, and override getMinimumSpan
(), getPreferredSpan(), and getMaximumSpan() be multiplied by this LineSpacing
variable before the value is returned. This has the drawback of actually making
each row higher, instead of providing space between the rows, though. This is
partly a technicality.

Solution 2. A better solution would be to add a TileSpanMultiplier variable (or
something similar) to FlowView, which means that ParagraphView, when setting
its linespacing, would actually call FlowView.setTileSpanMultiplier
(lineSpacing) inside ParagraphView.setPropertiesFromAttributes(). This way,
FlowView.FlowStrategy could be modified to insert the above code inside
FlowView.FlowStrategy.layout():

int next = layoutRow(fv, rowIndex, p0); //existing
if (row.getViewCount() == 0) { //existing
row.append(createView(fv, p0, Integer.MAX_VALUE,
rowIndex)); //existing
next = row.getEndOffset(); //existing
} //existing
//<--move code from ParagraphView.createRow() to here

**Problem lurking in the background**
However, I don't understand how the ParagraphView.createRow() code compiles in
the first place: it calls row.setInsets(), row.getTopInset(), etc. which are
all protected inside CompositeView (from which ParagraphView.Row derives).
Perhaps since Row is an internal class, this should still be visible; in any
case, JBuilder 3 does not compile it. (In fact, to make matters worse, copying
ParagraphView.Row into a derived MyParagraph.MyParagraphRow causes JBuilder 3
to throw a null pointer exception when compiling
MyParagraphView.MyParagraphRow.getAlignment() {...switch(justification)...} --
perhaps because justification is private in the parent class (ParagraphView) of
the class in which MyParagraphRow resides (MyParagraphView).)
(Review ID: 98867)
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