Hi, Prasanta.
Should not we use the real "screen" FontRenderContext instead of "DEFAULT_FRC"?
Did you check do we need to update the similat cases in the same class(we use
getJustifiedLayout() 4 times mostly in the same code pattern)?
On 15/05/2019 22:23, Prasanta Sadhukhan wrote:
Not sure if you are saying it's ok to "push"? I guess I need a 2nd reviewer if
you are ok with this.
Regards
Prasanta
On 16-May-19 12:01 AM, Phil Race wrote:
OK. Let's try that. I am sure it is still going to be non-ideal in a couple of
ways
1) where printed is shorter than screenwidth and we don't adjust, there may
be space after the text and before the "edge" of the component, but at least
there's no clipping and the text should look natural initself
2) Where printed is longer than screenwidth and we do adjust we may still
run into similar cases as this ..
-phil.
On 4/19/19 12:56 AM, Prasanta Sadhukhan wrote:
On 18-Apr-19 12:31 AM, Phil Race wrote:
On 4/16/19 3:38 AM, Prasanta Sadhukhan wrote:
Hi Phil,
It seems screenWidth or "advance of the string at screen-resolution" is 533
whereas string advance calculated using printer fontmetrics is 503
Now, TextLine#getJustifiedLine() [called from TextLayout.getJustifiedLayout] again
calculates "justifyAdvance" for TextLineComponent which comes out to be
503,then it calculates
the actual justification "delta" by subtracting justifyAdvance from screenWidth
which is 533-503=30 and it then does TextJustifier.justify(delta)
which calculates the amount by which each side of each glyph should grow or
shrink.
Then TextLine.getJustifiedLine() applies this value by calling
TextLineComponent.applyJustificationDeltas() where it
handle whitespace by modifying advance but handle everything else by
modifying position before and after,
so "spaces" seem to grow in size resulting in shifting of text with
whitespaces.
The spaces being used to add needed or absorb surplus space is what I
understood the current code to be doing,
However I am not sure what you mean by this :-
"but handle everything else by modifying position before and after,"
Code run through text layout will always have glyph positions assigned, so I
would suppose modifying the position
is how the spaces were handled too .. and of course this means running through
all preceding glyphs to make
it consistent .. and I thought it was only adjusting the spaces, so what is
"everything else"
It seems when TextLineComponent.applyJustificationDeltas() is called,
ExtendedTextSourceLabel.applyJustificationDeltas() handles that
http://hg.openjdk.java.net/jdk/client/file/dc6c5c53669b/src/java.desktop/share/classes/sun/font/ExtendedTextSourceLabel.java#l1015
where it handles "whitespace" a bit different (if block) from other glyph (else
block) where advance is is not considered, which is also conveyed in the comment @1011
Since it was mentioned in TextLayout.getJustifiedLayout() that " For best results,
justificationWidth should not be too different from the current advance of the line"
So for "best" results don't try to adjust a string that's 3 words and 80 pixels
to a 500 pixel width.
I am proposing a fix to conditionally call TextLayout.getJustifiedLayout() only
if the difference between justificationWidth and advance with for printer is
more than 10.
I had proposed investigating what happens if you simply don't use justification
when the text will fit.
Maybe you are refining that but I am not sure about the details.
10 is one arbitrary number and is not proportional to the length - which is
what I would be
thinking about first in succh an approach
And I am not even sure you mean what you say.
You say "more" than 10, yet your code implements "less" than 10.
It was a typo in mail.
Modified webrev to not use justification if string width of text is within
screenWidth
http://cr.openjdk.java.net/~psadhukhan/8214702/webrev.4/
Regards
Prasanta
And moreover its an absolute value you are using, which re-introduces the
clipping problem, doesn't it ?
ie you are purely looking at the difference and it isn't what I has proposed
and I thought you were trying.
-phil
webrev: http://cr.openjdk.java.net/~psadhukhan/8214702/webrev.3/
Regards
Prasanta
On 26-Feb-19 12:30 PM, Philip Race wrote:
On 2/25/19, 10:21 PM, Prasanta Sadhukhan wrote:
Thanks Phil for review. So, you are doubting it will regress swing printing
tests. As you told earlier, I have ran the following regression test with this
fix
It may not regress a test if the test is not being tested under the
same conditions for which it is created but I am telling you for a
fact that the fix is wrong. screenWidth should be "width on the screen"
(https://bugs.openjdk.java.net/browse/JDK-6488219 The bug above is covered by
java/awt/print/PrinterJob/SwingUIText.java)
and I did not notice any regression. Any other test we have for swing printing
that we can run?
No idea which tests will show this today but I know it is an issue.
No way we can push this and then just wait for the complaints.
>>Previously we were using DEFAULT_FRC to make it a screen width which except
for maybe needing to be updated for hi-dpi screens is what we want.
This issue was there from jdk1.6. If it is for hidpi screen, we would have seen
it from jdk9 onwards where we supported hidpi, no?
What I am saying here is that DEFAULT_FRC means "screen frc" and
I think that should have been updated in 1.9 but was missed because
it (hidpi for windows) was not a small or contained task.
This is an ancilliary observation of something that should be looked
at entirely independent of this bug.
-phil.
Regards
Prasanta
On 26-Feb-19 3:25 AM, Phil Race wrote:
The current fix confused me for a while as I could not see how it was
at all different than the existing code, since I can't imagine when we'd
ever take the "else" branch here :
533 TextLayout layout;
534 if (!isFontRenderContextPrintCompatible(frc, deviceFRC)) {
535 layout = createTextLayout(c, text, g2d.getFont(), deviceFRC);
536 } else {
537 layout = createTextLayout(c, text, g2d.getFont(), frc);
538 } Eventually when walking through it I noticed this 531 FontMetrics fm =
g2d.getFontMetrics();
532 float screenWidth = SwingUtilities2.stringWidth(c, fm ,trimmedText);
"fm" from line 532 is getting a FontMetrics from the PRINTER - ie the scaled
FontRenderContext.
It then uses this to calculate the advance width for such a case - ie the
printer
but then *assigns it to a variable called screenWidth*.
Previously we were using DEFAULT_FRC to make it a screen width which except
for maybe needing to be updated for hi-dpi screens is what we want.
So in the updated proposed fix the wrong width is passed to
getJustifiedLayout().
This may not matter here because there is plenty of space, but in other cases
Swing printing will be clipped as a result. And there were many, many, bug
reports about
that. Which is why the code is laying out to the screenwidth because that is
where the
UI component size available came from. Buttons & Label text are the typical
cases where
this showed up.
There maybe other things to change, as well but the incorrect screenWidth is the
main problem I see here.
-phil.
On 2/25/19 12:05 AM, Prasanta Sadhukhan wrote:
On 21-Feb-19 4:50 AM, Sergey Bylokhov wrote:
On 13/02/2019 22:53, Prasanta Sadhukhan wrote:
Hi Sergey,
I believe drawChars() also has same printing issue [and should be changed like modified
drawString()] but I am not able to test it as reproducer testcase uses JLabel whose
constructor can only accept "String" and not char[] so I can only test
drawString(). Using drawChars() implementation in drawString() still reproduces the issue.
Is it possible temporary replace the call to drawString() by the drawChars(),
to check how drawChars() will work?
As I told, it behaves similarly to unmodified drawString and the issue can
still be seen. I think we should commit this drawString() change in this fix
and I can open another bug to investigate drawChars() impl and reproducer. Will
that be fine?
Regards
Prasanta
or probably we can implement drawChars() on top of drawString()?
Regards
Prasanta
On 14-Feb-19 4:12 AM, Sergey Bylokhov wrote:
Hi, Prasanta.
I modified the fix to use deviceFRC if not compatible and in sync with the comment which
says "obtain a TextLayout with advances for the printer graphics FRC"
I used SwingUtilies2.getStringWidth() which calculates the advances of the
string if text layouting is used.
http://cr.openjdk.java.net/~psadhukhan/8214702/webrev.2/
Can you please take a look to the existed drawChars() method, which is
implemented in the similar way as drawStringImpl() and new version of
drawString(), but they have some small difference. Why we cannot use the same
logic?
For example in the drawChars:
=========
FontRenderContext deviceFontRenderContext = g2d.
getFontRenderContext();
FontRenderContext frc = getFontRenderContext(c);
if (frc != null &&
!isFontRenderContextPrintCompatible
(deviceFontRenderContext, frc)) {
String text = new String(data, offset, length);
TextLayout layout = new TextLayout(text, g2d.getFont(),
deviceFontRenderContext);
String trimmedText = trimTrailingSpaces(text);
if (!trimmedText.isEmpty()) {
float screenWidth = (float)g2d.getFont().
getStringBounds(trimmedText, frc).getWidth();
layout = layout.getJustifiedLayout(screenWidth);
==========
Similar but not the same logic in the fix:
524 FontRenderContext frc = getFontRenderContext(c);
525 if (frc.isAntiAliased() || frc.usesFractionalMetrics()) {
526 frc = new FontRenderContext(frc.getTransform(), false,
false);
527 }
528 FontRenderContext deviceFRC = g2d.getFontRenderContext();
529 String trimmedText = trimTrailingSpaces(text);
530 if (!trimmedText.isEmpty()) {
531 FontMetrics fm = g2d.getFontMetrics();
532 float screenWidth = SwingUtilities2.stringWidth(c, fm
,trimmedText);
533 TextLayout layout;
534 if (!isFontRenderContextPrintCompatible(frc,
deviceFRC)) {
535 layout = createTextLayout(c, text, g2d.getFont(),
deviceFRC);
536 } else {
537 layout = createTextLayout(c, text, g2d.getFont(),
frc);
538 }
540 layout = layout.getJustifiedLayout(screenWidth);
--
Best regards, Sergey.
