Teach dumpRenderTree() to draw actual trees.
Make the TextStyle output terser so it doesn't overflow the output.
Make debugDumpApp() say what mode we're in (checked vs release).
Hide lifecycle state from release mode dumps (since it's checked-only state).
Enabled displaying a scrollbar in ScrollingLists. The scrollbar is painted as an "overlay", i.e. it's painted on top of the scrolling list's visible children.
Added an abstract Painter base class that encapsulates a paint method and the renderer that it's attached to. RenderBlockViewport and HomogenousViewport now support an overlayPainter property. If specified, RenderBlockViewport attaches itself to the overlayPainter when it's attached to the rendering tree. RenderBlockViewport now calls overlayPainter.paint() after it has painted its children.
Added an abstract ScrollingListPainter class that exposes ScrollingList's state which might be needed for painting. Like its scroll direction and scrollOffset. The ScrollingListPainter is notified when a scroll starts and ends.
Defined a Material-specific ScrollingListPainter that renders a scrollbar. The scrollbar thumb is faded in/out when the scroll starts/ends.
Added onScrollStart and onScrollEnd listeners to Scrollable.
Also, fix warnings in rendering/sector_layout.dart
Also, fix hit testing in rendering/sector_layout.dart
Also, add WidgetToRenderBoxAdapter
Also, make the rendering library debugging tools more resilient to
dumping stuff before layout is complete.
Add type annotations in many places.
Fix some identifiers to have more lint-satisfying names.
Make all operator==s consistent in style.
Reorder some functions for consistency.
Make ParentData no longer dynamic, and fix all the code around that.
Added horizontal and vertical alignment properties to Stack so that the origin of non-positioned children can be specified. Currently all of the non-positioned children just end up with their top-left at 0,0. Now, for example, you can center the children by specifying verticalAlignment: 0.5, horizontalAlignment: 0.5.
Added IndexedStack which only paints the stack child specified by the index property. Since it's a Stack, it's as big as the biggest non-positioned child. This component will be essential for building mobile drop down menus.
Added a (likely temporary) example that demonstrates IndexedStack.
Previously, RenderObjectElements didn't support being marked dirty. This
is fine, except for MixedViewport and HomogeneousViewport, which have
builder functions to which they hand themselves as a BuildContext. If
those builder functions call, e.g., Theme.of(), then when the theme
changes, the Inherited logic tries to tell the RenderObjectElement
object that its dependencies changed and that doesn't go down well.
This patch fixes this by making RenderObjectElement a BuildableElement,
and making MixedViewport and HomogeneousViewport hook into that to
rebuild themselves appropriately.
Also, this was only found at all because ThemeData didn't implement
operator==, so we were aggressively marking the entire tree dirty all
the time. That's fixed here too.
Also, I changed card_collection.dart to have more features to make this
easier to test. This found bugs #1524, #1522, #1528, #1529, #1530, #1531.
The margins make using showMenu's menuPosition argument difficult and they're not really needed.
I also made a few small gratuitous changes in navigator.dart.
