Removed two unnecessary `if` conditions.

iOS OCR keyboard input support.

This change updates `SelectableRegion`s right-click gesture to match native platform behavior.

Before: Right-click gesture selects word at position and opens context menu (All Platforms)
After: 
- Linux, toggles context menu on/off, and collapses selection when click was not on an active selection (uncollapsed).
- Windows, Android, Fuchsia, shows context menu at right-clicked position (unless the click is at an active selection).
- macOS, toggles the context menu if right click was at the same position as the previous / or selects word at position and opens context menu.
- iOS, selects word at position and opens context menu.

This change also prevents the `copy` menu button from being shown when there is a collapsed selection (nothing to copy).

Fixes #117561

Fixes a bug when tapping near certain TextFields.

## Description

This adds `AppLifecycleListener`, a class for listening to changes in the application lifecycle, and responding to requests to exit the application.

It depends on changes in the Engine that add new lifecycle states: https://github.com/flutter/engine/pull/42418

Here's a diagram for the lifecycle states. I'll add a similar diagram to the documentation for these classes.

![Application Lifecycle Diagram](https://github.com/flutter/flutter/assets/8867023/f6937002-cb93-4ab9-a221-25de2c45cf0e)

## Related Issues
 - https://github.com/flutter/flutter/issues/30735

## Tests
- Added tests for new lifecycle value, as well as for the `AppLifecycleListener` itself.

I come across this when migrating my codebase. There is indeed a linter rule for it: unnecessary_overrides (see screenshot below for an example). I can help enabling the rule (as well as other rules, and/or dart formatter, etc) for Flutter codebase if needed.

![image](https://github.com/flutter/flutter/assets/5236035/3fe8fa32-cde2-45a9-901a-a383e8457fa1)

Desktop text selection toolbar no longer flashes before closing.

Before this change on a quick touch drag the cursor, where the touch is not on the previous collapsed selection, the cursor would move to the tapped position.

After this change on a quick touch drag the cursor does not move unless the touch is on the previously collapsed selection. This is inline with native behavior.

Before|After|Native
--|--|--
<video src="https://user-images.githubusercontent.com/948037/233224775-f33b42b5-5638-416c-9278-39ecd964e3bb.mov" />|<video src="https://user-images.githubusercontent.com/948037/233224760-2d1af657-8d99-45fc-8499-9567f17d533e.mov" />|<video src="https://user-images.githubusercontent.com/948037/233224790-f5997cfa-7370-4891-8952-11ef8057a729.mov" />

The spell check menu now appears directly below the misspelled word on Android.

fixes https://github.com/flutter/flutter/issues/99360

iOS now hides the selection handles and shows red selection when tapping a misspelled word, like native.

#125151 introduced the magnifier on touch drag gestures, but when showing the magnifier the toolbar is implicitly hidden, this change makes the toolbar re-appear on drag end for double tap + drag.

This change shows the magnifier on touch drag gestures for Android and iOS and hides it when the drag ends.

Fixes #118268

Explain how to do the two-step migration to the context menus feature.

Prepare for adding values to AppLifecycleState

Make sure the removal of deprecated APIs TextSelectionControls.buildToolbar and TextSelectionHandleControls happen in two separate steps.  Will make a tricky migration situation a little easier for affected users.

Remove mouse tap text drag selection throttling to improve responsiveness

TapAndDragGestureRecognizer should declare victory immediately when drag is detected

[iOS] Add spell check suggestions toolbar on tap

Match iOS Longpress behavior with native

Add TextField triple tap/click gestures

Remove 1745 decorative breaks

moving the left handle automatically scrolls EditableText to the right handle, which doesn't happen on native (#105836)

Fixes a scrolling issue when dragging selection handles.

* Fix typos

* lowercase animated & opacity

* Undo typo fix

---------
Co-authored-by: Michael Goderbauer <goderbauer@google.com>

Co-authored-by: Bruno Leroux <bruno.leroux@gmail.com>

* dart fix --apply

* manual fixes

* Revert "Revert "Add support for double tap and drag for text selection (#109573)" (#117497)"

This reverts commit 39fa0117.

* Allow TapAndDragGestureRecognizer to accept pointer events from any devices -- the TapGestureRecognizer it replaces was previously doing this
Co-authored-by: Renzo Olivares <roliv@google.com>

This reverts commit cd0f15a7.
Co-authored-by: Renzo Olivares <roliv@google.com>

* Replace PanGestureRecognizer in TextSelection with TapAndDragGestureRecognizer

* add tracking of _DragState to new tap_and_drag recognizer and remove some legacy double tap code from text_selection.dart and add logs"

* add dragTapCount, a tap count that is persistent for an entire drag and is set to null on drag end vs the regular tap count which is reset on a timer

* basic double tap to drag functionality and add a local dragTapCount in text_selection.dart to use with the timer callback

* Add offsetFromOrigin and localOffsetFromOrigin to DragUpdateDetails similar to LongPressMoveUpdateDetails, eliminates the need to hold the state of lastDragStartDetails

* make a generic baselongpressgesturerecognizer

* Revert "make a generic baselongpressgesturerecognizer"

This reverts commit aad8f7433bd01e4cd016d527af832c3b1f15fac5.

* rename tap_and_drag to selection_recognizers

* add mixin for consecutivetap

* tap and long press gesture recognizer

* Revert "Revert "make a generic baselongpressgesturerecognizer""

This reverts commit 181350c36718f644eada3e45c1b7b5939f90a340.

* Revert "Revert "Revert "make a generic baselongpressgesturerecognizer"""

This reverts commit 4d69775967858dfd66dd9429e1713da598908a85.

* Add support for secondary button clicks on drag gesture recognizer and separate drag end and tap up callback

* get test running

* rename tapCount to consecutiveTapCount

* dispose timer properly

* add some comments to tests

* Add comments

* Make ConsecutiveTapMixin private and move logic to increment tap count into mixin

* stop tracking pointer when gesture is rejected and detect drags on touch devices

* onCancel for TapAndDrag

* have the TapAndDragGestureRecognizer handle tap downs and tap ups on touch and mouse devices

* add drag to move cursor for android and iOS, and pointer device kind to DragUpdateDetails

* get tests running

* refactor TapAndDragGestureRecognizer moving some logic into _check methods

* Handle cancel properly on TapAndDragGestureRecognizer, having both onTapCancel and onDragCancel, also fix tests

* Fix test mouse drag selects and cannot drag cursor, save _initialPosition based on dragStartBehavior (either on tapDown or dragStart)

* determine if drag has a sufficient global distance to accept and fix some cancel behavior, making _checkCancel clearer

* give up pointer on drag end

* properly stop tracking pointer, fixes test for right click on Apple and non-apple platforms

* clean up some comments from last commit

* remove drag on touch for now

* fix Can select text by dragging with a mouse due to dragStart only being fired on the first PointerMoveEvent, the previous pan gesture recognizer would fire both dragStart and dragUpdate

* Revert "fix Can select text by dragging with a mouse due to dragStart only being fired on the first PointerMoveEvent, the previous pan gesture recognizer would fire both dragStart and dragUpdate"

This reverts commit 124dc79bc3389672c76d7c014ce04edab297abc6.

* correctly use _initialPosition for checkStart and call _checkUpdate after _checkStart if localDelta is not zero

* updates

* fix double tap chains

* Add docs

* Address analyzer

* more analyzer, only issues left are with print statements

* add deadlineTimer to fix conflict with ForcePressGestureRecognizer

* Revert "add deadlineTimer to fix conflict with ForcePressGestureRecognizer"

This reverts commit 3b29ddfff4cde4845edd481ecefb789fea2a0781.

* remove unecessary changes to tests

* secondaryButton should not drag

* Revert "Revert "add deadlineTimer to fix conflict with ForcePressGestureRecognizer""

This reverts commit 0a008f029f5796acd48c17c1897c0b700d5ef3a7.

* updates

* Revert "updates"

This reverts commit 4803b8443a2b67f0b8d29e9a01f712dfcb0f588c.

* Revert "Revert "Revert "add deadlineTimer to fix conflict with ForcePressGestureRecognizer"""

This reverts commit 79251a7af88d5dbb1460a960afc77e65dea18bff.

* fix shift + tap + drag tests, this was happening because a double tap + drag was being registered and not a single tap, added a duration to pumpAndSettle to fix this

* remove TapAndLongPressGestureRecognizer

* fix cupertino text field tests related to shift + tap + drag

* deadline timer try 2

* more logs

* Should reset taps when tap cancel is called, and should wait until gesture is accepted to initiate a drag

* should clear _down and _up when gesture is rejected

* remove erroneous log

* fix selectable text double tap chains test

* dont restart timer until tap up

* reset consecutiveTapCount on drag end

* fix selectableText test

* fix material text field tests

* reject TapAndDragGestureRecognizer when it is neither a tap nor a drag

* remove prints

* clean up

* shift aware

* clean up

* fix cupertino test

* fix text field focus tests

* Add 100ms delay to cupertino test, to prevent a double tap

* clean up test comments

* add comment to test

* uncomment test

* remove longpress changes

* Fix drag on mobile

* remove debug

* Fix drag to move cursor on iOS

* left over from drag fix

* add tests for drag on touch devices

* add test for double tap + drag mouse devices

* add tests

* Fix bug where initialPosition was used before it was set

* Address some review comments and fix issue where if double tap was held too long then long press gesture recognizer would take over

* remove _isDoubleTap flag since it is no longer needed due to previous commit

* Add docs for onTapCancel and onDragCancel

* analyzer fixes

* Do not test selection handles on macOS, since macOS does not support touch

* Add assert for dragStartBehavior

* add double tap + drag tests to cupertino

* use kDoubleTapTimeout instead of const Duration(milliseconds: 300) for readability

* analyzer issues

* update docs

* update more docs

* address comments

* more doc updates

* fix docs

* unused import

* fix docs

* Add more tests

* Add more tests and reject a tap up if we have exceeded the tap tolerance

* updates

* Address comments

* fix test naming

* update documentation

* move selection_recognizers to selection_gestures

* fix analyzer

* fix analyzer

* keysPressedOnDown instead of isShiftPressed

* update docs

* update docs

* Add drag update throttle to TapAndDragGestureRecognizer

* update comments

* missed from merge

* Replace _ConsecutiveTapMixin with _TapStatusTrackerMixin

* updates

* correctly cancel tap when when past tap tolerance with new implementation

* Should call tap and drag cancel if we are giving up a pointer without succesfully tracking a PointerUpEvent

* comments

* move pastTapTolerance to tap tracker

* move pastTapTolerance to tap tracker

* clean up check for nulls and remove use of consecutiveTapCountWhileDragging

* move call to super.acceptGesture to top

* remove print

* clean up

* Fix tests where both PanGestureRecognizer and TapAndDragGestureRecognizer lost

* clean up

* _GestureState -> _DragState

* more docs clean up

* more clean up

* Add onSecondaryTapCancel

* Add docs

* more docs

* Fix broken isPointerAllowed when attempting a right click drag - the _initialButtons is never reset

* revert debug flag

* make primaryPointer private

* Add support for upper count limit in TapAndDragGestureRecognizer, the tap counter should not be allowed to grow infinitely unless that is desired

* fix analyzer

* Use new TapDrag details objects and callbacks

* clean up docs

* clean up and add test for upperLimit

* Add docs for TapAndDragGestureRecognizer and remove some ambiguity of onStart onUpdate and onEnd parameters

* Address review comments

* analyzer fixes

* Call cancel before rejecting the gesture so we can still access _initialButtons

* Recognizer should reject any pointer differing from the original

* Revert "Recognizer should reject any pointer differing from the original"

This reverts commit afd9807480bd11e119bdd2b7d520631511973bab.

* Address reviewer comments

* Correct cancel behavior

* Fix consecutive tap + drag because _dragStart state was not being set when consecutive tap is greater than one

* Add more tests

* Add documentation on behavior with TapGestureRecognizer and DragGestureRecognizer

* more docs

* more docs

* remove comments

* updates

* fix multiple pointer behavior

* only handle the primary pointer

* Clean up dangerous assumptions in gesture details objects

* forgot from rebase

* update docs

* updates

* Clean up some redundant code

* remove whitespace

* fix tests as a result of #115849

* update test docs

* Fix same test from last commit for material variants

* More clean up of redundant code and update docs

* Clean up didStopTrackingLastPointer and untie TapAndDragGestureRecognizer cancel behavior from TapStatusTrackerMixin.currentUp state

* untie pastTapTolerance

* updates

* Add slopTolerance

* update docs

* Have secondary tap handled by TapGestureRecognizer

* update docs

* fix analyzer and address comments

* Add more docs

* Update cancel behavior tol not call on tap cancel when a drag has been accepted

* Change cancel behavior to only cancel if the tap down callback has been sent and merge tapcancel and dragcancel

* update docs;

* Rename selection_gestures to tap_and_drag_gestures

* Address some reviewer comments

* make deadline and slopTolerance private

* updates

* updates

* Address review comments

* remove _initialButtons

* fix docs

* trackTrap -> trackTap

* fix analyzer

* Add test to verify that tap up is called when recognizer accepts before handleEvent is called

* implement Diagnosticable for Details objects;

* sentTapDown == wonArenaForPrimaryPointer, so the implementation now only uses sentTapDown

* Count user tap up immediately and do not wait to win the arena

* Do not need to call super from TapAndDragGestureRecognizer.acceptGesture anymore because mixin implementation is gone

* Do not start selection drag on Android, iOS, and Fuchshsia touch devices if renderEditable does not have focus, this fixes many scubas

* Address reviewer comments

* fix test

* TapAndDragGestureRecognizer should wait for other recognizer to lose before winning the arena

* Address review comments

* Dont check for drag if the start was already found

* Only check for a drag if it has not already been found"

* fix from rebase
Co-authored-by: Renzo Olivares <roliv@google.com>

* Add spell check suggestions toolbar

* Fix test and move menu

* Cleanup

* Cleanup and fix bug

* More cleanup

* Make height dynamic and use localized delete

* Begin adding tests

* Create var checking for results

* Add tests

* Fix analyze (sorta)

* Add back hideToolbar call for testing

* Add back hidetoolbar in ts and delete one in et

* Remove unecessary calls to hidToolbar

* Fix analyze and docs

* Test fix

* Fix container issue

* Clean up

* Fix analyze

* Move delegate

* Fix typos

* Start addressing review

* Continue addressing review

* Add assert

* Some refactoring

* Add test for button behavior

* Undo test change

* Make spell check results public

* Rearrange test

* Add comment

* Address review

* Finish addressing review

* remove unused imports

* Address nits

* Address review

* Fix formatting

* Refactor findsuggestionspanatcursorindex and textselectiontoolbar constraints

* Fix analyze:

* Add selection feedback for both selection area and text field

* Addressing comment

* Fixes more test

Improves the feel of dragging text selection vertically between lines on mobile.

* Can show context menus anywhere in the app, not just on text.
* Unifies all desktop/mobile context menus to go through one class (ContextMenuController).
* All context menus are now just plain widgets that can be fully customized.
* Existing default context menus can be customized and reused.