## The basics
- [x] I [validated my changes](https://developers.google.com/blockly/guides/contribute/core#making_and_verifying_a_change)
## The details
### Resolves
Fixes#8965Fixes#8978Fixes#8970
Fixes https://github.com/google/blockly-keyboard-experimentation/issues/523
Fixes https://github.com/google/blockly-keyboard-experimentation/issues/547
Fixes part of #8910
### Proposed Changes
Fives groups of changes are included in this PR:
1. Support for automatic tab index management for focusable trees.
2. Support for automatic tab index management for focusable nodes.
3. Support for automatically hiding the flyout when back navigating from the toolbox.
4. A fix for `FocusManager` losing DOM syncing that was introduced in #9082.
5. Some cleanups for flyout and some tests for previous behavior changes to `FocusManager`.
### Reason for Changes
Infrastructure changes reasoning:
- Automatically managing tab indexes for both focusable trees and roots can largely reduce the difficulty of providing focusable nodes/trees and generally interacting with `FocusManager`. This facilitates a more automated navigation experience.
- The fix for losing DOM syncing is possibly not reliable, but there are at least now tests to cover for it. This may be a case where a `try{} finally{}` could be warranted, but the code will stay as-is unless requested otherwise.
`Flyout` changes:
- `Flyout` no longer needs to be a focusable tree, but removing that would be an API breakage. Instead, it throws for most of the normal tree/node calls as it should no longer be used as such. Instead, its workspace has been made top-level tabbable (in addition to the main workspace) which solves the extra tab stop issues and general confusing inconsistencies between the flyout, toolbox, and workspace.
- `Flyout` now correctly auto-selects the first block (#9103 notwithstanding). Technically it did before, however the extra `Flyout` tabstop before its workspace caused the inconsistency (since focusing the `Flyout` itself did not auto-select, only selecting its workspace did).
Important caveats:
- `getAttribute` is used in place of directly fetching `.tabIndex` since the latter can apparently default to `-1` (and possibly `0`) in cases when it's not actually set. This is a very surprising behavior that leads to incorrect test results.
- Sometimes tab index still needs to be introduced (such as in cases where native DOM focus is needed, e.g. via `focus()` calls or clicking). This is demonstrated both by updates to `FocusManager`'s tests as well as toolbox's category and separator. This can be slightly tricky to miss as large parts of Blockly now depend on focus to represent their state, so clicking either needs to be managed by Blockly (with corresponding `focusNode` calls) or automatic (with a tab index defined for the element that can be clicked, or which has a child that can be clicked).
Note that nearly all elements used for testing focus in the test `index.html` page have had their tab indexes removed to lean on `FocusManager`'s automatic tab management (though as mentioned above there is still some manual tab index management required for `focus()`-specific tests).
### Test Coverage
New tests were added for all of the updated behaviors to `FocusManager`, including a new need to explicitly provide (and reset) tab indexes for all `focus()`-esque tests. This also includes adding new tests for some behaviors introduced in past PRs (a la #8910).
Note that all of the new and affected conditionals in `FocusManager` have been verified as having at least 1 test that breaks when it's removed (inverted conditions weren't thoroughly tested, but it's expected that they should also be well covered now).
Additional tests to cover the actual navigation flows will be added to the keyboard experimentation plugin repository as part of https://github.com/google/blockly-keyboard-experimentation/pull/557 (this PR needs to be merged first).
For manual testing, I mainly verified keyboard navigation with some cursory mouse & click testing in the simple playground. @rachel-fenichel also performed more thorough mouse & click testing (that yielded an actual issue that was fixed--see discussion below).
The core webdriver tests have been verified to have seemingly the same existing failures with and without these changes.
All of the following new keyboard navigation plugin tests have been verified as failing without the fixes introduced in this branch (and passing with them):
- `Tab navigating to flyout should auto-select first block`
- `Keyboard nav to different toolbox category should auto-select first block`
- `Keyboard nav to different toolbox category and block should select different block`
- `Tab navigate away from toolbox restores focus to initial element`
- `Tab navigate away from toolbox closes flyout`
- `Tab navigate away from flyout to toolbox and away closes flyout`
- `Tabbing to the workspace after selecting flyout block should close the flyout`
- `Tabbing to the workspace after selecting flyout block via workspace toolbox shortcut should close the flyout`
- `Tabbing back from workspace should reopen the flyout`
- `Navigation position in workspace should be retained when tabbing to flyout and back`
- `Clicking outside Blockly with focused toolbox closes the flyout`
- `Clicking outside Blockly with focused flyout closes the flyout`
- `Clicking on toolbox category focuses it and opens flyout`
### Documentation
No documentation changes are needed beyond the code doc changes included in the PR.
### Additional Information
An additional PR will be introduced for the keyboard experimentation plugin repository to add tests there (see test coverage above). This description will be updated with a link to that PR once it exists.
* refactor(shortcuts): Rename import isDeletable -> isIDeletable etc.
Some of the existing code is confusing to read because e.g.
isDeletable doesn't check if an item .isDeletable(), but only
whether it is an IDeletable.
By renaming these imports the shortcut precondition functions are
easier to understand, and allows a subsequent to commit to add
an isCopyable function that actually checks copyability.
* refactor(shortcuts): Introduce isCopyable
Create a function, isCopyable, that encapsulates the criteria we
currently use to determine whether an item can be copied.
This facilitate future modification of the copyability criteria
(but is not intended to modify them at all at the present time).
* chore(shortcuts): Add TODO re: copying shadow blocks
Without this Safari (desktop) gets an outline still which tears as you drag.
In the keyboard nav demo an outline was visible before this change in both
Firefox and Safari.
Fixes#9099
* fix: Fix bug that prevented using keyboard shortcuts when the DropDownDiv is open.
* chore: Remove obsolete comment.
* Refactor: Remove unreachable null check.
* chore: Add tests for handling Escape to dismiss the Widget/DropDownDivs.
* chore: Satisfy the linter.
* fix: Fix post-merge test failure.
* WIP on line by line navigation
Doesn't work, likely due to isValid check.
* Add all inputs to the list of siblings
* Fix formatting
* Add tests
* Remove dupe keys
* fix: Make blocks with display: none not focusable
* Undo changes to canBeFocused
* Don't traverse inputs that are invisible
## The basics
- [x] I [validated my changes](https://developers.google.com/blockly/guides/contribute/core#making_and_verifying_a_change)
## The details
### Resolves
Fixes#9078
Fixes part of #8915 (new tests)
### Proposed Changes
Exposes the ability to disable ephemeral focus management for drop-down divs that are shown using `showPositionedByBlock` or `showPositionedByField`. Previously, this was only supported via `show`, but the former methods are also used externally.
This allows the underlying issue reported by #9078 to be fixed downstream for cases when both the widget and drop-down divs are opened simultaneously.
This PR also introduces tab indexes for both widget and drop-down divs (which were noticed missing when adding tests). This is because, currently, taking ephemeral focus on for a node that doesn't have a tab index will do nothing. This fix is useful for future screen reader work, and doesn't have obvious impacts on existing core or keyboard navigation behaviors (per testing and reasoning).
### Reason for Changes
Exposing the ability to disable ephemeral focus management for all public API entrypoints for showing the divs is crucial for providing the maximum flexibility when downstream apps use both the widget and drop-down divs together. This should ensure that all of these cases can be correctly managed in the same way as https://github.com/google/blockly-samples/pull/2521.
### Test Coverage
This introduces a bunch of new tests that were missing originally for both widget and drop-down div (including specifically verifying ephemeral focus). As part of the drop-down div tests, it also introduces actual positioning logic. This isn't great, but it's somewhat reasonable and robust against page changes (since the actual mocha results can move where the elements will end up on the page).
These changes have also been manually tested with both the core simple playground and the keyboard experiment plugin's test environment with no noticed regressions in either. The plugin's tests have also been run against these changes to ensure no new breakages have been introduced.
### Documentation
No documentation changes beyond the code ones introduced in this PR should be needed.
### Additional Information
The new tests may actually act as a basis for avoiding the test backdoor that's used today for the positioning tests for drop-down div tests. This doesn't replace those existing tests nor does it cover other behaviors and entrypoints that would be worth testing, but testing ephemeral focus is a nice improvement (especially in the context of what this PR is fixing).
## The basics
- [x] I [validated my changes](https://developers.google.com/blockly/guides/contribute/core#making_and_verifying_a_change)
## The details
### Resolves
Fixes https://github.com/google/blockly-keyboard-experimentation/issues/87
### Proposed Changes
This updates `FocusManager.focusNode()` to automatically defocus its internal state if it detects that DOM focus (per `document.activeElement`) doesn't match its own internal focus.
It also updates `FocusManager` to avoid duplicate self calls to `focusNode()`.
### Reason for Changes
This is a robustness improvement for `focusNode` that is nice to keep as a "if all else fails" mechanism, but it's currently a hacky workaround to https://github.com/google/blockly-keyboard-experimentation/issues/87. #9081 is tracking introducing a long-term fix for the desynchronizing problem, but that's likely to be potentially much harder to solve and this at least introduces a reasonable correction.
From a stability perspective, it seems likely that there are multiple classes of failures covered by this fix. Essentially the browser behavior difference in Firefox and Safari over Chrome is that the former do not fire a focus change event when a focused element is removed from the DOM (leading to `FocusManager` getting out of sync). There may be other such cases when a focus event isn't fired, so this robustness improvement at least ensures eventual consistency so long as `focusNode()` is called (and, fortunately, that's done a lot now).
While this is a nice robustness improvement, it's not a perfect replacement for a real fix. For the time between `FocusManager` getting out of sync and `focusNode` getting called, `getFocusedNode` will _not_ match the actual element holding focus. The primary class of issues known is when a DOM element is being moved, and in these cases `focusNode` _is_ called. If there are other such unknown cases where a desync can happen, **`getFocusedNode()` will remain wrong until a later `focusNode()` call**.
Note one other change: originally implemented but removed in earlier PRs for `FocusManager`, this change also includes ensuring `focusNode()` isn't called multiple times for a single request to focus a node. Current logic results in a call to `focusNode()` calling a node's `focus()` which then processes a second call to `focusNode()` (which is fully executed because `FocusManager.focusedNode` isn't updated until after the call to `focus()`). This doesn't actually correct any state, but it's more efficient and provides some resilience against potential logic issues from calling node/tree callbacks multiple times (which was observed up to 3 times in some cases).
### Test Coverage
This has been tested via the keyboard navigation experimental plugin's test environment (with Firefox), plus new unit tests. Note the new test for directly verifying desyncing logic is contrived, but it should be perfectly testing the exact scenario that's being observed on Firefox/Safari. A separate test was added for the existing behavior of focusing a different node still correcting `FocusManager` state even if it was desynced (the bug only happens for the same node being refocused).
New tests were also added for the various lifecycle callbacks (to ensure they aren't called multiple times).
All of the new tests were verified to fail without the two fixes in place (they were verified in isolation), minus the test for focusing a second node when desynced (since that should pass regardless of the new fixes).
Some basic simple playground testing was done, as well, just to verify nothing obvious was broken around selection, gestures, and copy/paste.
### Documentation
No new documentation should be needed here.
### Additional Information
This wasn't explicitly tested in Safari since I only have access to Chrome and Firefox, but I will ask someone else on the team to verify this for me after merging if it isn't checked sooner.
* WIP on line by line navigation
Doesn't work, likely due to isValid check.
* Add all inputs to the list of siblings
* Fix formatting
* Add tests
* Remove dupe keys
* Move block into view before clicking
* fix right click test failures
* Fix drag three blocks test
dragAndDrop is relative to the start and the test window is very small.
* Fix a few more tests
- Switch to using clickBlock instead of getting the block and clicking it
- Update drag positions for some tests so they don't snap and change size
* Add a pause between right clicking a block and waiting for the menu
* Fix mutator test by finding the dragged out elseif block
* Make disable test less flakey
## The basics
- [x] I [validated my changes](https://developers.google.com/blockly/guides/contribute/core#making_and_verifying_a_change)
## The details
### Resolves
Fixes https://github.com/google/blockly-keyboard-experimentation/issues/526
### Proposed Changes
This limits synchronizing in `LineCursor` from `FocusManager` to just nodes that have a corresponding block.
### Reason for Changes
Limiting the synchronizing in this way ensures that navigation can't enter a bad state. The reason for why this is needed is explained in https://github.com/google/blockly-keyboard-experimentation/issues/526#issuecomment-2885117998.
Longer term it would maybe be ideal to do one or both of the following:
- Figure out ways of making navigation a bit more robust (perhaps on the keyboard navigation side) such that if cursor _is_ in a bad state there's some way to recover (rather than ending up permanently broken).
- Remove `Marker`'s internal state in favor of always relying on `FocusManager`'s state to cover the cases where there can be automatic focus shifting.
### Test Coverage
This was manually tested with the keyboard navigation plugin and verified to ensure that both https://github.com/google/blockly-keyboard-experimentation/issues/526 and https://github.com/google/blockly-keyboard-experimentation/issues/499 are (still) working as expected. Some basic testing was done with the core simple playground with the developer console open to ensure there weren't any expected failures.
Automated testing cases would be better addressed as part of resolving #8915.
### Documentation
No new documentation is needed here.
### Additional Information
This behavior is expected to only affect the keyboard navigation plugin.
