<Swing Dev> [9] Review request for 8156217 Selected text is shifted on HiDPI display
Alexandr Scherbatiy
alexandr.scherbatiy at oracle.com
Thu Sep 1 17:26:39 UTC 2016
On 9/1/2016 7:27 PM, Alexandr Scherbatiy wrote:
> On 9/1/2016 6:49 PM, Semyon Sadetsky wrote:
>>
>> Alexander, did you consider possibility to check if method is really
>> over-riden then to use the old API?
>>
> Could you give a sample how it can be done?
I think it is possible to use a reflection to found the latest
overridden method which uses int coordinates and check does it has a
corresponding overridden method with floating point arguments. But I
doubt that it is a good solution.
Thanks,
Alexandr.
>
> Thanks,
> Alexandr.
>
>> --Semyon
>>
>> On 9/1/2016 3:07 PM, Alexandr Scherbatiy wrote:
>>> On 9/1/2016 11:31 AM, Semyon Sadetsky wrote:
>>>>
>>>> Hi Alexander,
>>>>
>>>> It is a good style to add a note recommending what to use instead
>>>> of the method which is being deprecated.
>>>>
>>> Could you review the updated public API there "replaced by" notes
>>> are added to the deprecated methods:
>>> http://cr.openjdk.java.net/~alexsch/8156217/webrev.05/public-api.02
>>>>
>>>> I did not get for what the useFloatingPointAPI property was
>>>> introduced and moreover is set to false by default. If the old API
>>>> is used then it doesn't matter which value it has because the float
>>>> values will receive ints. And for the new API I would expect
>>>> everything having the float precision, and it is unclear what may
>>>> be the reason to switch it off back to integer. Especially if
>>>>
>>>> " This allows to draw text properly using graphics with scaled
>>>> transform."
>>>>
>>>> so an improper mode is the default?
>>>>
>>> This is has been discussed below. For example new
>>> drawSelectedText(Graphics2D g, float x, float y, int p0, int p1)
>>> with floating point coordinates is added to the PlainView which has
>>> the same method with int coordinates. Suppose someone has a custom
>>> password component which uses and old methods with int coordinates.
>>> --------
>>> public class CustomPasswordField extends FieldView {
>>>
>>> @Override
>>> protected int drawSelectedText(Graphics g, int x, int y, int
>>> p0, int p1) throws BadLocationException {
>>> // draw echo chars
>>> }
>>> }
>>> --------
>>>
>>> If we start to call drawSelectedText() with floating point values
>>> the customization of old components will not be used and the
>>> CustomPasswordField from the example starts to show real text
>>> instead of echo chars. This is incompatible change with previous JDK
>>> releases.
>>>
>>> The solution is to switch to new floating point API only when it is
>>> known that a component properly overrides new methods with floating
>>> point arguments. After that the PlainView.useFloatingPointAPI flag
>>> can be set to true.
>>>
>>> For example, BasicPasswordFieldUI sets the
>>> PasswordView.useFloatingPointAPI flag to true because it is sure
>>> that drawSelectedText() methods with floating point arguments is
>>> overridden. So Swing standard text components are switched to use
>>> new floating point API.
>>>
>>> Thanks,
>>> Alexandr.
>>>
>>>> --Semyon
>>>>
>>>>
>>>> On 19.08.2016 11:03, Alexandr Scherbatiy wrote:
>>>>> On 8/19/2016 2:25 AM, Philip Race wrote:
>>>>>> OK .. I do not know enough about how modelToView is used by Swing
>>>>>> to know what is really needed here. Someone with a bit more Swing
>>>>>> background needs to chime in. I was encouraged that the *API* surface
>>>>>> of the changes was much smaller than it had seemed from the webrev
>>>>>> but maybe that is because you did not include everything. For example
>>>>>> although they are just subclassing the method overrides in
>>>>>> PasswordView
>>>>>> since that is a public class would become part of the spec ..
>>>>>> would they not ?
>>>>>> Just like the "int" counterparts today :-
>>>>>> https://docs.oracle.com/javase/8/docs/api/javax/swing/text/PasswordView.html
>>>>>>
>>>>>> Put another way I was looking for what the content of the CCC
>>>>>> would be.
>>>>> Here is the updated version of the public API change which
>>>>> includes overridden deprecated methods:
>>>>> http://cr.openjdk.java.net/~alexsch/8156217/webrev.05/public-api.01
>>>>>
>>>>> Thanks,
>>>>> Alexandr.
>>>>>>
>>>>>> -phil.
>>>>>>
>>>>>>
>>>>>> On 8/15/16, 11:48 AM, Alexander Scherbatiy wrote:
>>>>>>> On 15/08/16 21:43, Phil Race wrote:
>>>>>>>> Why is the caret support added in here ? Same for the modelToView
>>>>>>>> That will just hold this up as the reasoning behind needing
>>>>>>>> those changes is not something
>>>>>>>> I have yet been able to convince myself about - even after
>>>>>>>> reading your last email.
>>>>>>>
>>>>>>> The main change for the Caret public API (methods
>>>>>>> Caret.getMagicCaretPosition2D()/setMagicCaretPosition2D(Point2D
>>>>>>> p)) is not included in the current fix. I only moved the new
>>>>>>> methods JTextComponent.modelToView2D(int
>>>>>>> pos)/viewToModel2D(Point2D pt) from the fix for the Caret to
>>>>>>> this fix. These methods are used not only for caret but in other
>>>>>>> cases like mouse handling, text dragging and others.
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Alexandr.
>>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>> -phil.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On 08/15/2016 04:13 AM, Alexandr Scherbatiy wrote:
>>>>>>>>>
>>>>>>>>> Hello,
>>>>>>>>>
>>>>>>>>> Could you review the updated fix?
>>>>>>>>> webrev which contains only change in public API:
>>>>>>>>> http://cr.openjdk.java.net/~alexsch/8156217/webrev.05/public-api
>>>>>>>>> webrev with contains all changes:
>>>>>>>>> http://cr.openjdk.java.net/~alexsch/8156217/webrev.05/all
>>>>>>>>>
>>>>>>>>> - methods with int coordinates are deprecated
>>>>>>>>> - public isUseFloatingPointAPI()/setUseFloatingPointAPI()
>>>>>>>>> methods are added to the PlainView and WrappedPlainView classes
>>>>>>>>> - JTextComponent.modelToView2D(int
>>>>>>>>> pos)/viewToModel2D(Point2D pt) public methods from fix
>>>>>>>>> JDK-8163124 Add floating point API support to
>>>>>>>>> javax.swing.text.Caret
>>>>>>>>> are added
>>>>>>>>> - some @implSpec descriptions are removed from the new text
>>>>>>>>> drawing methods with floating point arguments
>>>>>>>>> - Built-in L&Fs are updated to use floating point API in
>>>>>>>>> standard Java text components
>>>>>>>>>
>>>>>>>>> Thanks,
>>>>>>>>> Alexandr.
>>>>>>>>>
>>>>>>>>> On 7/28/2016 5:38 PM, Alexandr Scherbatiy wrote:
>>>>>>>>>>
>>>>>>>>>> See comments inline.
>>>>>>>>>>
>>>>>>>>>> On 7/26/2016 11:57 PM, Phil Race wrote:
>>>>>>>>>>> I have a lot of doubts about this as well as trouble getting
>>>>>>>>>>> my head around all of it.
>>>>>>>>>>>
>>>>>>>>>>> Given that apps need to 'buy in' to the floating point I am
>>>>>>>>>>> not sure what we are gaining
>>>>>>>>>>> but I need to make sure I understand the problem.
>>>>>>>>>>>
>>>>>>>>>>> It affects only the methods that the 3rd party code can
>>>>>>>>>>> over-ride
>>>>>>>>>>> in subclasses and that are called by the JDK internal code.
>>>>>>>>>>>
>>>>>>>>>>> There are just two protected methods that matter :-
>>>>>>>>>>> PlainView.drawSelectedText(..)
>>>>>>>>>>> and
>>>>>>>>>>> PlainView.drawUnselectedText(..)
>>>>>>>>>>>
>>>>>>>>>>> The hidpi precison matters since they are drawing a
>>>>>>>>>>> sub-range of the text.
>>>>>>>>>>> Is there any other method that matters / is used in this way ?
>>>>>>>>>> I have found the following methods which relate to text
>>>>>>>>>> drawing, can be overridden and could have floating point
>>>>>>>>>> coordinates:
>>>>>>>>>>
>>>>>>>>>> javax.swing.text.PlainView.drawLine(...)
>>>>>>>>>> javax.swing.text.PlainView.lineToRect(...)
>>>>>>>>>> javax.swing.text.PasswordView.drawEchoCharacter(...)
>>>>>>>>>>
>>>>>>>>>> javax.swing.plaf.TextUI.modelToView(...)
>>>>>>>>>> javax.swing.plaf.TextUI.viewToModel(...)
>>>>>>>>>> javax.swing.plaf.TextUI.getToolTipText(...)
>>>>>>>>>>
>>>>>>>>>> There is also a method which relates to a caret position in a
>>>>>>>>>> text:
>>>>>>>>>> javax.swing.text.DefaultCaret.setMagicCaretPosition(Point p)
>>>>>>>>>> This requires additional investigation because DefaultCaret
>>>>>>>>>> extends Rectangle and so its coordinates can't be float.
>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Since 3rd party code is not over-riding these they will get
>>>>>>>>>>> the JDK
>>>>>>>>>>> super-class version, thus losing any customisation they
>>>>>>>>>>> might have done
>>>>>>>>>>> in the no-longer-called int version.
>>>>>>>>>>>
>>>>>>>>>>> Assuming that is correct, what customisation would be lost
>>>>>>>>>>> and how much does it matter?
>>>>>>>>>>
>>>>>>>>>> The example is javax.swing.text.PasswordView class which
>>>>>>>>>> overrides drawSelectedText(...)/drawUnselectedText(...)
>>>>>>>>>> methods and draws echo chars instead of text.
>>>>>>>>>> The similar can be done in a custom component:
>>>>>>>>>> --------
>>>>>>>>>> public class CustomPasswordField extends FieldView {
>>>>>>>>>>
>>>>>>>>>> @Override
>>>>>>>>>> protected int drawSelectedText(Graphics g, int x, int y,
>>>>>>>>>> int p0, int p1) throws BadLocationException {
>>>>>>>>>> // draw echo chars
>>>>>>>>>> }
>>>>>>>>>> }
>>>>>>>>>> --------
>>>>>>>>>>
>>>>>>>>>> Switching to support new methods with floating point
>>>>>>>>>> coordinates will lead that real text will be shown for old
>>>>>>>>>> applications in password fields.
>>>>>>>>>>>
>>>>>>>>>>> My prefernce is to deprecate the int versions and always
>>>>>>>>>>> call the float versions
>>>>>>>>>>> rather than the opt-in approach.
>>>>>>>>>>>
>>>>>>>>>>> Actually my real preference would be to come up with
>>>>>>>>>>> something that does
>>>>>>>>>>> not involve drawing the text in chunks like this.
>>>>>>>>>>>
>>>>>>>>>>> ie Swing should use AttributedCharacterIterator .. it looks
>>>>>>>>>>> like the code to
>>>>>>>>>>> do this might already be there !
>>>>>>>>>>>
>>>>>>>>>>> 106 private float drawElement(int lineIndex, Element elem,
>>>>>>>>>>> Graphics g,
>>>>>>>>>>> 107 float x, float y, boolean fractionalCharBounds)
>>>>>>>>>>> 108 throws BadLocationException
>>>>>>>>>>> 109 {
>>>>>>>>>>> 110 int p0 = elem.getStartOffset();
>>>>>>>>>>> 111 int p1 = elem.getEndOffset();
>>>>>>>>>>> 112 p1 = Math.min(getDocument().getLength(), p1);
>>>>>>>>>>> 113
>>>>>>>>>>> 114 if (lineIndex == 0) {
>>>>>>>>>>> 115 x += firstLineOffset;
>>>>>>>>>>> 116 }
>>>>>>>>>>> 117 AttributeSet attr = elem.getAttributes();
>>>>>>>>>>> 118 if (Utilities.isComposedTextAttributeDefined(attr)) {
>>>>>>>>>>> 119 g.setColor(unselected);
>>>>>>>>>>> 120 x = Utilities.drawComposedText(this, attr, g, x, y,
>>>>>>>>>>> 121 p0-elem.getStartOffset(),
>>>>>>>>>>> 122 p1-elem.getStartOffset());
>>>>>>>>>>> 123 } else {
>>>>>>>>>>>
>>>>>>>>>>> In fact what *that* illustrates is that applications already
>>>>>>>>>>> cannot expect
>>>>>>>>>>> their over-ridden methods to be called, so this fix is
>>>>>>>>>>> trying to fix something
>>>>>>>>>>> that can't be fixed.
>>>>>>>>>> The javadoc for the "protected PlainView.drawLine(...)"
>>>>>>>>>> method is:
>>>>>>>>>> ---------
>>>>>>>>>> /**
>>>>>>>>>> * Renders a line of text, suppressing whitespace at the end
>>>>>>>>>> * and expanding any tabs. This is implemented to make calls
>>>>>>>>>> * to the methods {@code drawUnselectedText} and
>>>>>>>>>> * {@code drawSelectedText} so that the way selected and
>>>>>>>>>> * unselected text are rendered can be customized.
>>>>>>>>>> ---------
>>>>>>>>>>
>>>>>>>>>> Applications can rely on this behaviour and stopping to call
>>>>>>>>>> the drawSelectedText(...)/drawUnselectedText(...) methods
>>>>>>>>>> with int coordinates will be incompatible change.
>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> So why can't we do that ? Just deprecate those int methods,
>>>>>>>>>>> don't add
>>>>>>>>>>> the float methods and use ACI ..
>>>>>>>>>> New float methods allow to easily migrate on new API for
>>>>>>>>>> applications without significant changes.
>>>>>>>>>>
>>>>>>>>>>> BTW getTabSize() is supposed to be a character count isn't
>>>>>>>>>>> it ? Not a pixel
>>>>>>>>>>> count. So why does it need a float version.
>>>>>>>>>> Could you review the updated fix:
>>>>>>>>>> http://cr.openjdk.java.net/~alexsch/8156217/webrev.04
>>>>>>>>>>
>>>>>>>>>> - methods with int coordinates which can be overridden
>>>>>>>>>> are deprecated
>>>>>>>>>> - getFractionalTabSize() method is removed
>>>>>>>>>>
>>>>>>>>>> Thanks,
>>>>>>>>>> Alexandr.
>>>>>>>>>>>
>>>>>>>>>>> -phil
>>>>>>>>>>>
>>>>>>>>>>> On 06/30/2016 08:50 AM, Alexandr Scherbatiy wrote:
>>>>>>>>>>>> On 6/28/2016 8:14 PM, Alan Snyder wrote:
>>>>>>>>>>>>> Suppose an application is only partially fixed to
>>>>>>>>>>>>> use/override the floating point methods. Perhaps it uses a
>>>>>>>>>>>>> library that has not been fixed.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Is there a more fine grained way to detect programmer
>>>>>>>>>>>>> awareness or lack of awareness of the new methods?
>>>>>>>>>>>>
>>>>>>>>>>>> Here is a slightly updated version which adds public
>>>>>>>>>>>> isUseFloatingPointAPI()/setUseFloatingPointAPI() methods to
>>>>>>>>>>>> the PlainView and WrappedPlainView classes:
>>>>>>>>>>>> http://cr.openjdk.java.net/~alexsch/8156217/webrev.02
>>>>>>>>>>>>
>>>>>>>>>>>> Using the floating point API is disabled by default and
>>>>>>>>>>>> enabled for standard Swing text component classes. This has
>>>>>>>>>>>> advantage that selection will work for text component in
>>>>>>>>>>>> users applications on HiDPI display.
>>>>>>>>>>>>
>>>>>>>>>>>> But it still has the same problem. Applications which use
>>>>>>>>>>>> custom View classes needs to updated them to implement
>>>>>>>>>>>> corresponding text drawing methods with floating point
>>>>>>>>>>>> arguments and enable the floating point API usage.
>>>>>>>>>>>>
>>>>>>>>>>>> Thanks,
>>>>>>>>>>>> Alexandr.
>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> Alan
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>> On Jun 28, 2016, at 9:59 AM, Alexandr Scherbatiy
>>>>>>>>>>>>>> <alexandr.scherbatiy at oracle.com
>>>>>>>>>>>>>> <mailto:alexandr.scherbatiy at oracle.com>> wrote:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Hello,
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> I tried to merge this fix with the 8132119 Provide
>>>>>>>>>>>>>> public API for text related methods in SwingUtilities2
>>>>>>>>>>>>>> and found a flow in the used algorithm.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> For each method that uses integer coordinates the fix
>>>>>>>>>>>>>> adds a pair with floating point arguments.
>>>>>>>>>>>>>> The fix 8156217 uses only methods with floating point
>>>>>>>>>>>>>> values to correctly handle a selected text.
>>>>>>>>>>>>>> This leads that overridden method with integer arguments
>>>>>>>>>>>>>> in user code is not called anymore.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> I think that this can be handled in the following way:
>>>>>>>>>>>>>> - Add a property that enables to use methods with
>>>>>>>>>>>>>> floating point arguments in Swing.
>>>>>>>>>>>>>> By default it is false and all work as before. The
>>>>>>>>>>>>>> issue with selected text is reproduced.
>>>>>>>>>>>>>> An application with enabled property does not have
>>>>>>>>>>>>>> issue with the selected text but a user should override
>>>>>>>>>>>>>> all methods with floating point values if he uses
>>>>>>>>>>>>>> corresponding methods with integer values.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Here is a proposed solution where new public system
>>>>>>>>>>>>>> property "javax.swing.floatingPoints.enabled" is added:
>>>>>>>>>>>>>> http://cr.openjdk.java.net/~alexsch/8156217/webrev.01
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> - Fix the enhancement JDK-8157461 Glyph image rendering
>>>>>>>>>>>>>> for HiDPI displays
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>>> Alexandr.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> On 6/16/2016 6:07 PM, Alexandr Scherbatiy wrote:
>>>>>>>>>>>>>>> On 6/16/2016 4:47 PM, Alexandr Scherbatiy wrote:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> I tried to look deeper in the code and it seems there
>>>>>>>>>>>>>>>> is a rounding issue when float values are summed up.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Suppose a transform with scale 1.5 is used and the 'a'
>>>>>>>>>>>>>>>> char advance is 10 in a dev space.
>>>>>>>>>>>>>>>> The 'a' char has advance 10 / 1.5 = 6.666666666666667
>>>>>>>>>>>>>>>> as double value and 6.6666665 when it is cast to float
>>>>>>>>>>>>>>>> in user space.
>>>>>>>>>>>>>>>> The width of a string which consists of 15 'a' chars is
>>>>>>>>>>>>>>>> 15 * 6.6666665 = 100.000000.
>>>>>>>>>>>>>>>> But the same width calculated as sum of each glyph
>>>>>>>>>>>>>>>> advance in StandardGlyphVector.initPositions() method
>>>>>>>>>>>>>>>> is 99.999992.
>>>>>>>>>>>>>>>> --------------
>>>>>>>>>>>>>>>> double scale = 1.5;
>>>>>>>>>>>>>>>> float advance = (float) (10 / scale);
>>>>>>>>>>>>>>>> int N = 15;
>>>>>>>>>>>>>>>> System.out.printf("%d * %f = %f\n", N, advance,
>>>>>>>>>>>>>>>> N * advance);
>>>>>>>>>>>>>>>> float sum = 0;
>>>>>>>>>>>>>>>> for (int i = 0; i < N; i++) {
>>>>>>>>>>>>>>>> sum += advance;
>>>>>>>>>>>>>>>> }
>>>>>>>>>>>>>>>> System.out.printf("sum: %f\n", sum);
>>>>>>>>>>>>>>>> --------------
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Because of this a string drawn from float position
>>>>>>>>>>>>>>>> 99.999998 is shifted one pixel left which affects the
>>>>>>>>>>>>>>>> text selection code in Swing:
>>>>>>>>>>>>>>>> ------------------------
>>>>>>>>>>>>>>>> g.scale(1.5, 1.5);
>>>>>>>>>>>>>>>> String TEXT = "aaaaaaaaaaaaaaaa";
>>>>>>>>>>>>>>>> Rectangle2D rect = font.getStringBounds(TEXT,
>>>>>>>>>>>>>>>> 0, index, g.getFontMetrics().getFontRenderContext());
>>>>>>>>>>>>>>>> float selectedTextPosition = (float)
>>>>>>>>>>>>>>>> rect.getWidth(); // 99.999992
>>>>>>>>>>>>>>>> g.drawString(TEXT.substring(0, index), x, y);
>>>>>>>>>>>>>>>> // non-selected text
>>>>>>>>>>>>>>>> g.drawString(TEXT.substring(index,
>>>>>>>>>>>>>>>> TEXT.length()), x + selectedTextPosition, y); //
>>>>>>>>>>>>>>>> selected text is shifted to one pixel left
>>>>>>>>>>>>>>>> ------------------------
>>>>>>>>>>>>>>> The last step is how coordinates are scaled in
>>>>>>>>>>>>>>> Graphics2D.drawString() method.
>>>>>>>>>>>>>>> If the graphics has scale 1.5 and zero translate the
>>>>>>>>>>>>>>> transformed coordinates are:
>>>>>>>>>>>>>>> (99.999992 + 0) * 1.5 = 149.999985
>>>>>>>>>>>>>>> (100.000000 + 0) * 1.5 = 150.000000
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Both of them are rounded to the same value.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> If the translate is set to integer 1 value:
>>>>>>>>>>>>>>> (99.999992 + 1) * 1.5 = 151.499989 // shifted to
>>>>>>>>>>>>>>> one pixel left
>>>>>>>>>>>>>>> (100.000000 + 1) * 1.5 = 151.500000
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> A position 99.999992 in user space is rounded to 151 in
>>>>>>>>>>>>>>> dev space.
>>>>>>>>>>>>>>> A position 100.000000 in user space is rounded to 152
>>>>>>>>>>>>>>> in dev space.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> And this difference can depend on the translate even it
>>>>>>>>>>>>>>> has integer value in user space because it is multiplied
>>>>>>>>>>>>>>> on the graphics scale.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>>>> Alexandr.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>>>>> Alexandr.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> On 6/2/2016 11:41 PM, Alexandr Scherbatiy wrote:
>>>>>>>>>>>>>>>>> On 5/31/2016 10:40 PM, Phil Race wrote:
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> I applied this and it is *much* better but there
>>>>>>>>>>>>>>>>>> still seem to be some tiny quirks.
>>>>>>>>>>>>>>>>>> When I drag the mouse to select text down and then up
>>>>>>>>>>>>>>>>>> again, as I pass the
>>>>>>>>>>>>>>>>>> original mouse click point vertically, repaint seem
>>>>>>>>>>>>>>>>>> to jiggle vertically by a pixel.
>>>>>>>>>>>>>>>>>> Perhaps a rounding issue in the repaint code's
>>>>>>>>>>>>>>>>>> calculation of the location of
>>>>>>>>>>>>>>>>>> the target y. I think I may see the same in
>>>>>>>>>>>>>>>>>> left/right dragging along a line too.
>>>>>>>>>>>>>>>>>> So I think this is repaint and not text related. Can
>>>>>>>>>>>>>>>>>> you take a look.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> I am able to reproduce this only using a floating
>>>>>>>>>>>>>>>>> point scale.
>>>>>>>>>>>>>>>>> It looks like 2d issue. I used a test which draws
>>>>>>>>>>>>>>>>> a text in two pieces. The second piece of the text is
>>>>>>>>>>>>>>>>> shifted from the first piece by the floating point
>>>>>>>>>>>>>>>>> size of the the first piece of the text.
>>>>>>>>>>>>>>>>> -----------
>>>>>>>>>>>>>>>>> Rectangle2D rect = font.getStringBounds(TEXT, 0,
>>>>>>>>>>>>>>>>> index, g.getFontMetrics().getFontRenderContext());
>>>>>>>>>>>>>>>>> float selectedTextPosition = (float) rect.getWidth();
>>>>>>>>>>>>>>>>> g.drawString(TEXT.substring(0, index), x, y);
>>>>>>>>>>>>>>>>> g.drawString(TEXT.substring(index, TEXT.length()), x +
>>>>>>>>>>>>>>>>> selectedTextPosition, y);
>>>>>>>>>>>>>>>>> -----------
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> The second piece of the text can be shifted in the 2
>>>>>>>>>>>>>>>>> cases:
>>>>>>>>>>>>>>>>> a) graphics scale is 1.5 and translation is 1.
>>>>>>>>>>>>>>>>> b) graphics scale is 2.25 without applied translation
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> I have filed an issue on it:
>>>>>>>>>>>>>>>>> JDK-8158370 Text drawn from float pointing
>>>>>>>>>>>>>>>>> position and with float pointing scale is shifted
>>>>>>>>>>>>>>>>> https://bugs.openjdk.java.net/browse/JDK-8158370
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>>>>>> Alexandr.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> -phil.
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> On 05/06/2016 12:31 PM, Alexandr Scherbatiy wrote:
>>>>>>>>>>>>>>>>>>> Hello,
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> Could you review the fix:
>>>>>>>>>>>>>>>>>>> bug: https://bugs.openjdk.java.net/browse/JDK-8156217
>>>>>>>>>>>>>>>>>>> webrev:
>>>>>>>>>>>>>>>>>>> http://cr.openjdk.java.net/~alexsch/8156217/webrev.00
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> This is the second part of the fix related to the
>>>>>>>>>>>>>>>>>>> fact that char width can be fractional in user space.
>>>>>>>>>>>>>>>>>>> http://mail.openjdk.java.net/pipermail/swing-dev/2016-May/005814.html
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> The Font.getStringBounds(...) method is used for
>>>>>>>>>>>>>>>>>>> the fractional string width calculation by Swing in
>>>>>>>>>>>>>>>>>>> user space.
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>>>>>>>> Alexandr.
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>
>>>>
>>>
>>
>
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