> On Aug. 30, 2013, 12:43 p.m., Hugo Pereira Da Costa wrote:
> > I respectfully disagree with the change.
> >
> > If I understand the descripion right, the only thing that matters for
> > QtQuick is to change the default returned value (if all else fail) from 1
> > to FRAME_FRAMEWIDTH. Correct ?
> >
> > The other enumerations, (LineEdit_FrameWidth, ComboBox_FrameWidth, etc.)
> > must stay: even if they have the same values at the moment, this might
> > change in the future (in the near future in fact, since nuno and I want to
> > revisit the metrics, make them more dpi independent, etc.).
> >
> > That the cast wont work for QtQuick is not a good reason to remove it, with
> > all (non quick) applications around, and for which such casts work.
> >
> > Now as for the change needed for QtQuick, this will (must) break (that is:
> > change) all applications that render a frame and don't fall in the
> > cathegories above (think custom widgets). I too have no example of this
> > (but I'm sure there are), and since these are "custom" things, it is normal
> > that they don't show up in oxygen-demo.
> >
> > Please update the change to the "minimal" (namely -> change the default
> > value returned for PM_DefaultFrameWidth), and then, well, we'll need to
> > test ...
> >
>
> David Edmundson wrote:
> I expected this to be a review which started a discussion :)
> It's one that sets precedent for a few other things.
>
> The thing that matters is for QtQuick to get the same width as QLineEdits
> get. This happens to be FRAME_FRAMEWIDTH now.
>
> The reason I removed the LineEdit_FrameWidth is that if someone later
> does decide to change the LineEdit_FrameWidth the QtQuickControls will become
> broken again not matching the desktop counterpart. I'm deliberately taking
> away that option.
>
> The only way we can support QtQuickControls is to support the lowest
> common denominator of QStyle that they both follow even if it makes the
> desktop worse (or at least different).
> This basically means supporting only values in QStyle, and not hacking in
> our own extra granularity determined by casting widgets.
>
> I appreciate this is a very sucky situation to be in, but if we don't we
> will we see a very clear discrepancy in the UI depending on which technology
> happens to be used. I don't think we want that.
>
> By only other options are:
> --
> I could try to add PM_LineEdit and PM_ComboBox into Qt5.2? It would solve
> this particular issue.
> The base implementation of QStyle can then just call PM_DefaultFrameWidth
> for backwards compatibility. I'm not sure it would get in as it relies on all
> styles calling the base implementation for enum values they don't support.
> --
> We make a QML Oxygen theme from 'scratch' a bit like how we have an
> Oxygen GTK theme.. different tech that happens to look the same.
>
> David Edmundson wrote:
> s/By/My
>
> Christoph Feck wrote:
> Why do QtQuickControls need pixelMetric() for line edits? To find out,
> how much margin there is around a styled line edit, it should simply use
> sizeFromContents() and subElementRect().
>
> Hugo Pereira Da Costa wrote:
> "The only way we can support QtQuickControls is to support the lowest
> common denominator of QStyle that they both follow even if it makes the
> desktop worse (or at least different).
> This basically means supporting only values in QStyle, and not hacking in
> our own extra granularity determined by casting widgets."
>
> Two things: this is no hacking. QWidget is an argument passed to the
> method (though it can be zero), there is no hack in using it, casting it,
> etc, as far as I can tell. This is a correct use of Qt's API.
>
> Second: "support the lowest common denominator of QStyle that they both
> follow even"
> I disagree, and besides, I believe this will simply not work. It 'sort of
> does' in this specific case, but then q_object_cast is used all over the
> place in oxygen, to, for instance, install event filters, setup/trigger
> animation, enable mouse-grabbing in empty areas, enable hover on some items
> for which it was not allowed primarily, etc. Bottomline: I fear that the
> smallest common denominator that would work identical between QtQuick and
> QWidget, will be _very_ small, to the point it becomes quite unacceptable;
> and I 'a priori' do not want to follow this path (especially after all the
> hours invested in the above).
>
> I aknowledge the will to make QtQuick look identical to QWidgets via
> oxygen, but imho it must not be done by introducing regressions to the
> QWidget's rendering. Animations for instance are an interesting case: it is
> built-in qt quick (if I understand right), while it is enforced via oxygen
> for widgets. If you drop it from oxygen (for the sake of the common
> denominator), then you actually introduce inconsistencies between the two.
>
> So that I can see:
>
> 1/ add decent fallbacks (for QtQuick) so that it looks "good enough", and
> fix them whenever this gets broken (the case you mentionned)
> 2/ implement missing features in QtQuick so that it allows one to look
> "identical" to what we can do with QWidgets. Naively, I can imagine passing
> "properties" to the QtQuick widgets, that one can test alongside the failing
> q_object_cast in oxygen
> 3/ as you say: clone oxygen for QtQuick. But I really would not advocate
> for this, since it is a pain to maintain, and does not solve anything with
> respect to solution 1/ concerning fixing things that get broken
> (inconsitent).
>
> Note that your patch also drops ComboBox_FrameWidth, the latter being
> also used in a separate enum (PM_ComboBoxFrameWidth).
>
> David Edmundson wrote:
> @Cristoph
> sizeFromContents takes the frame as a parameter which oxygen uses. The
> frame lineWidth comes from the pixel metric for frames.
> This must also happen for QWidgets as otherwise we wouldn't have a test
> for QLineEdits inside the pixelMetric function.
>
> From qquickstyleitem.cpp for LineEdits:
> QStyleOptionFrame frame;
> frame.state = m_styleoption->state;
> frame.lineWidth =
> qApp->style()->pixelMetric(QStyle::PM_DefaultFrameWidth, m_styleoption, 0);
> frame.rect = m_styleoption->rect;
> size = qApp->style()->sizeFromContents(QStyle::CT_LineEdit,
> &frame, QSize(width, height));
>
>
>
> Hugo Pereira Da Costa wrote:
> @David,
> reading this code, I understand
> - that my "fears" above might be overstated. ;)
> - that this is code you do not have control on, unless committing to Qt
> directly.
> May I suggest to reformulate the patch to change the existing enums (in
> oxygenpixelmetrics.h) to
> LineEdit_FrameWidth = Frame_FrameWidth;
> (and same for the others; + add a comment that changing this will breack
> QtQuickControl)
> so that the "properties" idea is not easily applicable.
> - leave the q_object_cast and enumerations
> - change the default return value to Fram_FrameWidth.
>
> This way, you don't remove functionality, but warn developpers that bad
> things will happen if they get use (and that discussion should be triggered)
>
>
> Eike Hein wrote:
> It's hard for me to come up with a general opinion on this, I think it
> probably needs case-by-case examination in a lot of, well, cases. Generally
> speaking though I don't think we should be dropping features from Oxygen at
> this time until we've exhausted attempts at upstream solutions. It's unlikely
> we'll manage to make Controls styling regression-free that way in the 5.2
> timeframe of course, but improving Controls for our use cases has to be a
> long-term goal anyway.
>
> When it comes to lowest common denominator styling, I don't think Oxygen
> is a good candidate for that. The more similar it looks, the more will
> feature and visual regressions be felt. If we do want to go with lowest
> common denominator styling, I think we might need to come up with a new,
> simplified visual design to go along with it.
>
> As for the specific case, I think the ability to set widget-specific
> frame widths is actually fairly important to do a good job at form styling.
> Oxygen doesn't really do much there right now, but I think it's a concern
> that upstream should answer somehow. So I think the code should probably stay
> and agree with Hugo on the short-term band-aid of syncing up the default
> return value ...
>
> David Edmundson wrote:
> Ignore all my original patch.
>
> I can get access to the QML type being used in the theme.
>
> option->styleObject is a QQuickStyleItem. Whilst this is private, it has
> exported the useful part as a property.
>
> I can get it wtih.
>
> if (option && option->styleObject) {
> qDebug() << option->styleObject->property("elementType");
> }
>
>
> This produces output like "spinbox" "edit", "checkbox". etc. I can do
> this alongside the qobject_cast code to get work out which hints to use.
>
> It slightly complicates the oxygen code, but it means we can fix this
> without any regressions.
>
> \o/
>
Nifty!
- Eike
-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
http://git.reviewboard.kde.org/r/112375/#review38928
-----------------------------------------------------------
On Aug. 30, 2013, 11:11 a.m., David Edmundson wrote:
>
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> http://git.reviewboard.kde.org/r/112375/
> -----------------------------------------------------------
>
> (Updated Aug. 30, 2013, 11:11 a.m.)
>
>
> Review request for Plasma and Hugo Pereira Da Costa.
>
>
> Description
> -------
>
> Use a single frame width for all PM_DefaultFrameWidth
>
> The current code sets a width of 3 for all line edits, combo boxes
> and frames, otherwise it returns a width of 1.
>
> The QtQuickControls engine cannot qobject_cast() the widget so always
> return a frame width of 1 for qtquickcontrol line edits and combo boxes.
>
> This simplifies the code and solves that issue.
>
> I can think of no other way to resolve this without editing Qt, and even then
> it would be difficult to extend the PixelMetric enum without breaking
> compatibility.
>
> Note this is potentially a visual change in oxygen, however I have yet to see
> anything actually different.
>
>
> Diffs
> -----
>
> kstyles/oxygen/oxygenmetrics.h 0643ae5b20d0c9efa328a87e08707cebaabf9f5e
> kstyles/oxygen/oxygenstyle.cpp 86b5cdf3054f5d362d90f0f76c30bfb4f2646911
>
> Diff: http://git.reviewboard.kde.org/r/112375/diff/
>
>
> Testing
> -------
>
>
> File Attachments
> ----------------
>
> QML After
> http://git.reviewboard.kde.org/media/uploaded/files/2013/08/30/spell1.png
> QML_Before
> http://git.reviewboard.kde.org/media/uploaded/files/2013/08/30/spell1_1.png
> Normal oxygen demo
> http://git.reviewboard.kde.org/media/uploaded/files/2013/08/30/oxygen1.png
>
>
> Thanks,
>
> David Edmundson
>
>
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