Added TreeItem::last_child to avoid needing to iterate through all children to get to the end. This mainly helps in cases where one TreeItem has many children (1000s), and new children are added to the end, as each add had to iterate through all previously added children.
When a FlowContainer had a TextureRect child using any of the EXPAND_FIT_* expand modes, it could crash when changing the FlowContainer's minimum size, or that of its children. This was due to the TextureRect resizing in FlowContainer::_resort, updating its minimum size, and triggering another _resort. If the TextureRect's minimum size changed in a way that caused any of the FlowContainer's children to be put on a different line, it could repeatedly cause _resort to be called again, moving the children back and forth between the old and new lines.
This change is for FlowContainer::_resort to give a warning for TextureRects with EXPAND_FIT_* expand modes when multiple lines are used, and just keep the TextureRect size the same in that case. This is similar to the check added to AspectRatioContainer in godotengine#73396, but attempting to still support it in FlowContainer when possible. In the case where the TextureRect is forced to stay the same size, there may be some overlap between the FlowContainer's children, but should no longer crash.
Prior to this fix, scrolling via mouse drag on touchscreen devices, and
drag&drop operation on a `TreeItem` element would conflict with each other
preventing the drag scroll from being released when the mouse button is
released.
The issue is addressed by disabling drag&drop when drag scrolling is ongoing.
When a FlowContainer was scaled, the point at which a line wraps would
also be scaled. This would cause a FlowContainer to have lines that did
not fit the container.
FlowContainer no longer factors its scale when resorting children.
Fixes#93439
When calculating minimum size, GridContainer only looks at children that are
returned from `as_sortable_control()`. That defaults to only showing children
visible in the tree, so if the grid has a hidden parent the minimum size
becomes (0, 0).
After this change only the child itself needs to be visible, making
`GridContainer::get_minimum_size()` behave the same way as other controls.
Fixes#91722.
