The labels in bar an pie charts are realized as individual
QSG pixmap nodes with an alpha channel. Sadly, rendering
bright labels onto a transparent background gives very
ugly artifacts.
As a stop gap measure, until the problem is understood,
render on a background with the color of the pie slice
or bar.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
The code was wrong, because it deleted the ChartItems in the
main UI thread, not the render thread. This would delete the
QSG nodes in the UI thread and then crash on mobile.
Therefore refactor this part of the code by adding the
items to be deleted to a list that will be deleted by the
render thread.
As a drop in replacement of std::unique_ptr, implement
a silly ChartItemPtr class, which auto-initializes to null.
This turns the deterministic and easily controlled memory
management into a steaming pile of insanity. Obviously,
this can be made much more elegant, but this has to do for now.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
All series are converted to QSG. Thus, the pointer to the
QGraphicsView can be removed from the common base class.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
To replace the QGraphicsScene, we need the possibility of
showing and hiding items.
Turns out, the QSG API is completely insane.
Whether an item should be shown is queried by the virtual
function isSubtreeBlocked(), which is supposed to be
overriden by the derived classes.
However, the common nodes for rectangles and pixmaps are
supposed to be created by QQuickWindow, for hardware
optimization. This gives nodes that cannot be derived
from and therefore whether the item is shown or not cannot
be controlled.
There are therefore two distinct cases to consider: The
node is allocated by the code directly or indirectly by
QQuickWindow.
In the latter case, we use a proxy node with the only
purpose of having a "visible" flag and add the obtained
node as a child.
This madness is performed with template trickery to get
unified code.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
To this end, two new ChartItems were added: A "bar" (a rectangle
with a border) and a "text" (multiple lines of text).
It turns out that the text on the bars now looks atrocious.
The reason appears to be that the antialiasing of the font-rendering
does not blend into the alpha channel, but into a supposed
background color? This will have to be investigated.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
A small step in converting from QGraphicsScene to QQuickItem.
This is the second item to be converted (after the legend)
and for now items are drawn in order of creation, which means
that the infobox is on top of the legend. This will have
to be made deterministic in follow-up commits.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
The series were passed a pointer to the QGraphicsScene to add
their item. In the future these items will be replaced by
QSGNodes. To add these, the series need a reference to the StatsView.
Therefore pass it in the constructor. Once everything is
replaces by QSGNodes, remove the QGraphicsScene member.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
Android and iOS use qmake, so add the code to the .pro file.
This also removes all remnants of QCharts includes and uses and all the
references to QCharts in our various build systems.
That was a brief but extremely useful detour.
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
It turns out that the wrong base class was used for the chart.
QQuickWidget can only be used on desktop, not in a mobile UI.
Therefore, turn this into a QQuickItem and move the container
QQuickWidget into desktop-only code.
Currently, this code is insane: The chart is rendered onto a
QGraphicsScene (as it was before), which is then rendered into
a QImage, which is transformed into a QSGTexture, which is then
projected onto the device. This is performed on every mouse
move event, since these events in general change the position
of the info-box.
The plan is to slowly convert elements such as the info-box into
QQuickItems. Browsing the QtQuick documentation, this will
not be much fun.
Also note that the rendering currently tears, flickers and has
antialiasing artifacts, most likely owing to integer (QImage)
to floating point (QGraphicsScene, QQuickItem) conversion
problems. The data flow is
QGraphicsScene (float) -> QImage (int) -> QQuickItem (float).
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
Replace by custom implementation, with the ultimate goal to
remove the QtCharts module. This doesn't yet display axis
titles or a grid.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
The bars were set to the z-value of the labels. Not an issue,
since the labels are generated after the bars and therefore
plot later. Still, do the right thing.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
Implement a bar series, which can plot stacked, grouped and single
bar charts in horizontal or vertical ways. On hovering over a
bar, an information is shown. The shown information depends on
whether the chart is count or value based, or is a multi-bin
chart.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
