Have a function first called before the children, and then the main function
called after the children if they did not accept the event. This will allow
processing the Flickable gesture properly
* Rename logo to the more generic meta as keyboard modifier.
* Use control as the real modifier and map command key to it with
winit and keep Qt semantics as-is.
This will give a nicer API to expose to .60. If the struct weren't
repr(C) then the booleans would be nicely packed, but alas that's not
happening. On the other hand we're not keeping many instances of them
around.
Fold CharacterInput into KeyPressed/KeyReleased and store the "key" as a string.
Also, instead of exposing the KeyCode we're encoding special characters
into the string.
Instead of determining the focus item through item tree traversal and
pointer comparison and storing the intermediate indices in the
components in the tree, remember the focus item by a pair of
VWeak<ComponentVTable, Dyn> and item_index: usize.
This speeds up determining the focus item as well as delivering events,
which can now be done directly after retrieving an ItemRef with
get_item_ref.
This also fixes the duplicate line edit focus in the 7gui cells
test case.
This is in preparation for allowing the run-time / items to clone VRc's
of the component.
ComponentVTable functions like visit_children_item contine to take a
ComponentRefPin as "self" parameter type, as a VRc would not be
supported by rust right now. That means the implementation then uses
self_weak to obtain a strong self-reference.
Similar to the mouse_grabber, we use a VisitChildrenResult field to
track the focus item within a component. Unlike the mouse grabber
however, it is set/cleared using dedicated focus events.
The key event now routes the key event directly to the focus item.
The focus can be requested via set_focus_item on a window, which the
TextItem does.
In the future the TextInput will request focus on mouse click,for
example.
Pass the outer-most component through to ItemVTable's input_event.
For the purpose of disambiguating this component from any nested
component instantiated by a repeater or so, it's called the
app_component.
The ComponentVTable takes a reference to a ComponentRefPin instead of a
ComponentRefPin by value, as the vtable macro gets confused otherwise
and thinks it's a self argument.
When selecting to the left, the anchor remains to the right of the cursor.
When deleting such a selection, we fetch the cursor and anchor using a helper
method, which ensures that the anchor is to the left of the cursor.
Finally when setting the cursor then to the anchor, we need to also
set the anchor, since both were swapped.
This also add an automated test for this scenario.
QPainter does not like to draw in an empty QImage.
And the rendering code does not like to render it.
So we would get this on the console:
```
QPainter::begin: Paint device returned engine == 0, type: 3
QPainter::save: Painter not active
QPainter::save: Painter not active
QPainter::setRenderHint: Painter must be active to set rendering hints
QPainter::save: Painter not active
QPainter::setClipRegion: Painter not active
QPainter::setPen: Painter not active
QPainter::setBrush: Painter not active
QPainter::restore: Unbalanced save/restore
QPainter::setPen: Painter not active
QPainter::setBrush: Painter not active
QPainter::restore: Unbalanced save/restore
QPainter::save: Painter not active
QPainter::restore: Unbalanced save/restore
QPainter::restore: Unbalanced save/restore
thread 'main' panicked at 'attempt to subtract with overflow', sixtyfps_runtime/rendering_backends/gl/texture.rs:285:42
```
