[layouts] Copy/paste, templates, etc

[nyalldawson]

Next instalment in layouts work - porting and improving item copy/paste, template handling, serialization

End user highlights:

• right click context menu entries for cutting/copying, and pasting items
• "copy" and "delete" actions in right click menu for layout item panel
• support drag and drop of QPT templates onto layout windows to add items from template to the layout

...getting close now!

[nirvn]

@nyalldawson , testing this, I get a crasher when creating a layout in the layout manager, closing the layout, and subsequently re-opening the layout via the manager.

Steps to reproduce

• Open the layout manager
• Create a new layout
• Add a label item in the newly created layout
• Close the layout
• In the layout manager, select the previously opened layout, and re-open it using the [ show ] button
• boom QGIS dies

Here's the gdb output:

#0  0x00007ffff549e140 in QGraphicsView::transform() const () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#1  0x00007ffff19525a9 in QgsLayoutMouseHandles::rectHandlerBorderTolerance() (this=0x55555e760790)
    at /home/webmaster/dev/cpp/QGIS/src/gui/layout/qgslayoutmousehandles.cpp:316
#2  0x00007ffff1950be7 in QgsLayoutMouseHandles::paint(QPainter*, QStyleOptionGraphicsItem const*, QWidget*) (this=0x55555e760790, painter=0x7fffffffba70, itemStyle=0x55555e625ee8, pWidget=0x55555e7839c0)
    at /home/webmaster/dev/cpp/QGIS/src/gui/layout/qgslayoutmousehandles.cpp:69
#3  0x00007ffff5483cb6 in  () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#4  0x00007ffff54842c8 in  () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#5  0x00007ffff5484aba in  () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#6  0x00007ffff54a7716 in QGraphicsView::paintEvent(QPaintEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#7  0x00007ffff51bbdc8 in QWidget::event(QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#8  0x00007ffff529b2de in QFrame::event(QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#9  0x00007ffff54a624b in QGraphicsView::viewportEvent(QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#10 0x00007ffff4400acc in QCoreApplicationPrivate::sendThroughObjectEventFilters(QObject*, QEvent*) ()
    at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#11 0x00007ffff517b445 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#12 0x00007ffff5182d34 in QApplication::notify(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#13 0x00007ffff5f06807 in QgsApplication::notify(QObject*, QEvent*) (this=0x7fffffffda70, receiver=0x55555e7839c0, event=0x7fffffffc060)
    at /home/webmaster/dev/cpp/QGIS/src/core/qgsapplication.cpp:317

[nirvn]

@nyalldawson , great job as always.

Regarding the right-click menu paste action, IMHO, the item should be pasted at the location the user right-clicked, not at the location the user left-clicked on the "Paste" menu item.

[nyalldawson]

@nirvn

, testing this, I get a crasher when creating a layout in the layout manager, closing the layout, and subsequently re-opening the layout via the manager.

Thanks, fixed

[nyalldawson]

Regarding the right-click menu paste action, IMHO, the item should be pasted at the location the user right-clicked, not at the location the user left-clicked on the "Paste" menu item.

Fixed