* refactor(interfaces): Use typeof ... === 'function' to test for methods
Testing for
'name' in object
or
obj.name !== undefined
only checks for the existence of the property (and in the latter
case that the property is not set to undefined). That's fine if
the interface specifies a property of indeterminate type, but in
the usual case that the interface member is a method we can do
one better and check to make sure the property's value is
callable.
* refactor(interfaces): Always check obj is not null/undefined
Since most type predicates take an argument of type any but then
check for the existence of certain properties, explicitly check
that the argument is not null or undefined (or check implicitly
by calling another type predicate that does so first, which
necessitates adding a few casts because tsc infers the type of
the argument too narrowly).
* fix(interfaces): Add missing check to hasBubble type predicate
This appears to have inadvertently been omitted in PR #9004.
* fix(interfaces): Fix misplaced typeof
* fix: Fix typos in JSDocs
* fix(tests): Make Mocks conform to corresponding interfaces
Introduce a new MockFocusable, and add methods to MockIcon,
MockBubbleIcon and MockComment, so that they fulfil the
IFocusableNode, IIcon, IHasBubble and ICommentIcon interfaces
respectively.
* chore(tests): Add assertions verifying mocks conform to predicates
Add (test) runtime assertions that:
- isFocusableNode(MockFocusable) returns true
- isIcon(MockIcon) returns true
- hasBubble(MockBubbleIcon) returns true
- isCommentIcon(MockCommentIcon) returns true
(The latter is currently failing because Blockly is undefined when
isCommentIcon calls the MockCommentIcon's getType method.)
* fix(tests): Don't rely on Blockly being set in Mock methods
For some reason the global Blockly binding is not visible at the
time when isCommentIcon calls MockCommentIcon's getType method,
and presumably this problem would apply to getBubbleSize too,
so directly import the required items.
* refactor(tests): Make MockCommentIcon a MockBubbleIcon
This slightly simplifies it and makes it less likely to accidentally
stop conforming to IHasBubble.
* fix(interfaces): Fix incorrect check in isSelectable
Fix an error which caused ISelectable instances to fail
isSelectable() checks, one of the results of which is that
Blockly.common.getSelected() would generally return null.
Whoops!
## The basics
- [x] I [validated my changes](https://developers.google.com/blockly/guides/contribute/core#making_and_verifying_a_change)
## The details
### Resolves
Fixes#8994
### Proposed Changes
This removes an error that was previously thrown by `FocusManager` when attempting to focus an invalid node (such as one that's been removed from its parent).
### Reason for Changes
https://github.com/google/blockly/issues/8994#issuecomment-2855447539 goes into more detail. While this error did cover legitimately wrong cases to try and focus things (and helped to catch some real problems), fixing this 'properly' may become a leaky boat problem where we have to track down every possible asynchronous scenario that could produce such a case. One class of this is ephemeral focus which had robustness improvements itself in #8981 that, by effect, caused this issue in the first place. Holistically fixing this with enforced API contracts alone isn't simple due to the nature of how these components interact.
This change ensures that there's a sane default to fall back on if an invalid node is passed in. Note that `FocusManager` was designed specifically to disallow defocusing a node (since fallbacks can get messy and introduce unpredictable user experiences), and this sort of allows that now. However, this seems like a reasonable approach as it defaults to the behavior when focusing a tree explicitly which allows the tree to fallback to a more suitable default (such as the first item to select in the toolbox for that particular tree). In many cases this will default back to the tree's root node (such as the workspace root group) since sometimes the removed node is still the "last focused node" of the tree (and is considered valid for the purpose of determining a fallback; tree implementations could further specialize by checking whether that node is still valid).
### Test Coverage
Some new tests were added to cover this case, but more may be useful to add as part of #8910.
### Documentation
No documentation needs to be added or updated as part of this (beyond code documentation changes).
### Additional Information
This original issue was found by @RoboErikG when testing #8995. I also verified this against the keyboard navigation plugin repository.
This introduces new callback methods for IFocusableTree and
IFocusableNode for providing a basis of synchronizing domain state with
focus changes. It also introduces support for implementations of
IFocusableTree to better manage initial state cases, especially when a
tree is focused using tab navigation.
FocusManager has also been updated to ensure functional parity between
tab-navigating to a tree and using focusTree() on that tree. This means
that tab navigating to a tree will actually restore focus back to that
tree's previous focused node rather than the root (unless the root is
navigated to from within the tree itself). This is meant to provide
better consistency between tab and non-tab keyboard navigation.
Note that these changes originally came from #8875 and are required for
later PRs that will introduce IFocusableNode and IFocusableTree
implementations.
This adds new tests for the FocusableTreeTraverser and fixes a number of
issues with the original implementation (one of which required two new
API methods to be added to IFocusableTree). More tests have also been
added for FocusManager, and defocusing tracked nodes/trees has been
fully implemented in FocusManager.
This is the bulk of the work for introducing the central logical unit
for managing and sychronizing focus as a first-class Blockly concept
with that of DOM focus.
There's a lot to do yet, including:
- Ensuring clicks within Blockly's scope correctly sync back to focus
changes.
- Adding support for, and testing, cases when focus is lost from all
registered trees.
- Testing nested tree propagation.
- Testing the traverser utility class.
- Adding implementations for IFocusableTree and IFocusableNode
throughout Blockly.
Introduces the necessary base interfaces for representing different
focusable contexts within Blockly. The actual logic for utilizing and
implementing these interfaces will come in later PRs.
