feat: find dialog 1760

[MayurSMahajan]

This PR aims at creating a FInd Dialog, that is able to find string patterns in editor document.

This PR introduces three new files for implementing this feature:

1. find_menu_service.dart
2. find_replace_widget.dart
3. search_service.dart

Find Menu Service
This service is actually implemented by FindReplaceMenu, which is responsible for popping a Find Replace Menu onto the editor.
It is able to do so by adding a new OverlayEntry to the editor.

Find Replace Widget
It is simply a widget component strictly used for presentation. It separates the FindMenuService from the SearchService. It describes the UI of the Find Replace Menu.

Search Service
The Heavy Logic Lifting is done by a class called SearchService. This class contains public methods like:
findAndHighlight: finds the pattern and highlights it.
navigateToMatch: navigates between matched patterns in the vertical direction.
unHighlight: unhighlights the matches when a new pattern is searched or the find dialog is closed.

It also contains a bunch of private utility methods, one particularly interesting method is the _boyerMooreSearch method, which implements the world-renowned Boyer Moore Search algorithm for searching the pattern in the editor.

Limitations

• Scrolling to the next match using arrow keys, does not behave as expected.
• Behaviour on already highlighted patterns.

Features Yet to be implemented

• Replace handler
• Tests

[codecov]

Codecov Report

Merging #106 (90ba926) into main (953249f) will increase coverage by 0.47%.
The diff coverage is 93.72%.

@@            Coverage Diff             @@
##             main     #106      +/-   ##
==========================================
+ Coverage   75.60%   76.07%   +0.47%     
==========================================
  Files         247      252       +5     
  Lines        9920    10182     +262     
==========================================
+ Hits         7500     7746     +246     
- Misses       2420     2436      +16     

Files Changed	Coverage Δ
...k_component/rich_text/appflowy_rich_text_keys.dart	100.00% <ø> (ø)
...tor/block_component/standard_block_components.dart	100.00% <ø> (ø)
...editor/toolbar/desktop/items/color/color_menu.dart	0.00% <0.00%> (ø)
...rc/editor/find_replace_menu/find_menu_service.dart	82.92% <82.92%> (ø)
.../command_shortcut_events/find_replace_command.dart	88.88% <88.88%> (ø)
.../editor/find_replace_menu/find_replace_widget.dart	93.15% <93.15%> (ø)
...b/src/editor/find_replace_menu/search_service.dart	98.94% <98.94%> (ø)
.../block_component/rich_text/appflowy_rich_text.dart	92.17% <100.00%> (+0.27%)	⬆️
lib/src/editor/command/text_commands.dart	93.75% <100.00%> (ø)
...ditor_component/service/scroll_service_widget.dart	83.72% <100.00%> (+0.58%)	⬆️
... and 7 more

[MayurSMahajan]

@Xazin I wanted to ask you this: Currently I am using the default highlight color which comes from the editor styles to highlight found matches, should I use a different color instead?

[a-wallen]

Very nice, I'm stoked for this. Could you add a handful of unit tests for the search algorithm?

[MayurSMahajan]

Sure @a-wallen !

[Xazin]

@Xazin, the core feature is complete with this set of commits, however, there are two issues to address:

1. I am using a constant color for highlighting, we want to be able to use a customizable color instead, currently, @LucasXu0 and I are discussing the same.

2. When multiple matches are found, the scrolling speed while navigating between these found matches is very slow, this is something I would you to take a look at, if possible.

Hey Mayur, thanks for the update.

If possible leave these two issues to me, I will take a look on Monday and give you an update. 👌

[MayurSMahajan]

@Xazin, the core feature is complete with this set of commits, however, there are two issues to address:

1. I am using a constant color for highlighting, we want to be able to use a customizable color instead, currently, @LucasXu0 and I are discussing the same.
2. When multiple matches are found, the scrolling speed while navigating between these found matches is very slow, this is something I would you to take a look at, if possible.

Hey Mayur, thanks for the update.

If possible leave these two issues to me, I will take a look on Monday and give you an update. 👌

Sure!

[Xazin]

CC @LucasXu0

[LucasXu0]

@Xazin @MayurSMahajan Is this PR ready for merging? The CI failed.

[Xazin]

@Xazin @MayurSMahajan Is this PR ready for merging? The CI failed.

I'm fixing it right now and will merge in 2 minutes. (+ some, need to fix tests)