Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Closes #1583

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

The `CanvasBox.positionChanged` signal expects to receive `x` and `y` as
`int`s, but they were being passed as `float`s, which mangled them on
the receiving signal handler.

This manifested as huge `x` and `y` values for canvas boxes, and when
saving and loading projects all boxes would hit the edge of the canvas
and get placed at the extreme edge.

Signed-off-by: falkTX <falktx@falktx.com>

Fixes this error, which would occur after `setPrecision` had been called
with a non-integer value.

```
Traceback (most recent call last):
  File "/usr/share/carla/carla_host.py", line 1442, in slot_handlePluginAddedCallback
    pitem = self.ui.listWidget.createItem(pluginId, self.fSavedSettings[CARLA_KEY_MAIN_CLASSIC_SKIN])
  File "/usr/share/carla/widgets/racklistwidget.py", line 241, in createItem
    return RackListItem(self, pluginId, useClassicSkin)
  File "/usr/share/carla/widgets/racklistwidget.py", line 86, in __init__
    self.recreateWidget(firstInit = True)
  File "/usr/share/carla/widgets/racklistwidget.py", line 176, in recreateWidget
    self.fWidget = createPluginSlot(self.fParent, self.host, self.fPluginId, self.fOptions)
  File "/usr/share/carla/carla_skin.py", line 2090, in createPluginSlot
    return PluginSlot_Default(parent, host, pluginId, skinColor, skinStyle)
  File "/usr/share/carla/carla_skin.py", line 1766, in __init__
    self.ready()
  File "/usr/share/carla/carla_skin.py", line 642, in ready
    paramWidget.setValue(self.host.get_internal_parameter_value(self.fPluginId, paramIndex))
  File "/usr/share/carla/widgets/scalabledial.py", line 282, in setValue
    QDial.setValue(self, qtValue)
TypeError: setValue(self, int): argument 2 has unexpected type 'float'
Error mapping plugin to canvas client: 16 Step Sequencer
```

Signed-off-by: falkTX <falktx@falktx.com>

Under certain circumstances Carla would crash when frequent updates on
the QGraphicsScene occurred, especially in combination with scrolling or
panning by the user. Backtraces showed either a segfault in
QGraphicsItem::parentItem() or around
QGraphicsSceneBspTree::climbTree(). While the first trace points towards
missing calls to pepareGeometryChange() in combination with custom
boundingRect() methods, inserting these did not yield a positive change,
though people with this issue also had success in disabling the
ItemIndexingMethod of their QGraphicsScene[0][1]. Setting this to
NoIndex solves this problem.

The original problem is reproducible with an ever-reconnecting client:

$ while true; do klick 120 & (sleep 0.1; killall klick); done

[0] https://bugreports.qt.io/browse/QTBUG-18021?focusedCommentId=367566&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-367566
[1] https://forum.qt.io/topic/71316/qgraphicsscenefinditembsptreevisitor-visit-crashes-due-to-an-obsolete-paintevent-after-qgraphicsscene-removeitem

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>