Search - add search box control and implement search experience

[KaiyuWang16]

This is the PR for feature Search: #605
This PR includes the newly introduced SearchBoxControl in TermControl dir, which is the search bar for the search experience. And the codes that enable Search in Windows Terminal.

The PR that migrates the Conhost search module: #3279
Spec (still actively updating): #3299

PR Checklist

• Closes Feature Request: Search #605
• CLA signed. If not, go over here and sign the CLA
• Tests added/passed
• Requires documentation to be updated
• I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx

These functionalities are included in the search experience.

1. Search in Terminal text buffer.
2. Automatic wrap-around.
3. Search up or down switch by clicking different buttons.
4. Search case sensitively/insensitively by clicking a button. S. Move the search box to the top/bottom by clicking a button.
5. Close by clicking 'X'.
6. Open search by ctrl + F.

When the searchbox is open, the user could still interact with the terminal by clicking the terminal input area.

While I already have the search functionalities, currently there are still some known to-do works and I will keep updating my PR:

1. Optimize the search box UI, this includes:
   1) Theme adaptation. The search box background and font color
   should change according to the theme,
   2) Add background. Currently the elements in search box are all
   transparent. However, we need a background.
   3) Move button should be highlighted once clicked.
2. Accessibility: search process should be able to performed without mouse. Once the search box is focused, the user should be able to navigate between all interactive elements on the searchbox using keyboard.

To test:

1. checkout this branch.
2. Build the project.
3. Start Windows Terminal and press Ctrl+F
4. The search box should appear on the top right corner.

[zadjii-msft]

I've only taken a cursory glance at a couple files so far, but I'm just gonna go ahead and pre-emptively block this PR until the spec (#3299) is merged

I am updating the spec today.

[zadjii-msft]

Fundamentally, this works so that's good. But there's definitely a few problems that need resolving before this can get merged. For me, the two remaining blocking issues are:

• the placeholder text color is wrong in dark mode
• RenderData::GetTextBufferEndPosition should not be GetCursorPosition

The other things I'm concerned about, but not blocking over:

• "Find..." needs to be localizable
• Search event should have a delegate with more args
• Escape should be handled in the control too, as opposed to bubbling
• The whole _goForward=!_goForward;_Search();_goForward=!_goForward thing is weird

[DHowett-MSFT]

There are still some outstanding comments.

[KaiyuWang16]

There are still some outstanding comments.

Unblocking ones are moved to #3942

[DHowett-MSFT]

I'm comfortable with this as long as we follow up on the followup issues.

[zadjii-msft]

Thanks for cleaning those blocking things up! We can fix the rest in post 😝

[zadjii-msft]

(I'm merging this since there's a hyper-quorum on it)

[ghost]

Hello @zadjii-msft!

Because this pull request has the AutoMerge label, I will be glad to assist with helping to merge this pull request once all check-in policies pass.

p.s. you can customize the way I help with merging this pull request, such as holding this pull request until a specific person approves. Simply @mention me (@msftbot) and give me an instruction to get started! Learn more here.

[KaiyuWang16]

Thanks for cleaning those blocking things up! We can fix the rest in post 😝

Thanks for merging ! I am working on the follow-ups these days.

[ghost]

🎉Windows Terminal Preview v0.8.10091.0 has been released which incorporates this pull request.:tada:

Handy links:

• Release Notes
• Store Download

[kell18]

Yeees!