Fixed ComboBox style and template

[dipeshmsft]

Fixes #10470 , #10656

Description

In this PR I have restyled the ComboBox style and template to make it more similar to WinUI's style, however the styles are slightly different to make it easier in WPF. Here are the list of few major changes in the PR :

1. Split the control template for ComboBox in two parts : one for normal ComboBox and other for EditableComboBox.
2. Fixed the layout in each of the ComboBox template and matched the height and other parameters to WinUI.
3. Added missing control template triggers to get the correct behavior for different states of controls.
4. Added the correct TextBox style Editable ComboBox and fixed the dropdown button styling.
5. Added the correct resources for ComboBox styles.

Bug Fixes covered in this PR :

• Fixes the chevron icon positioning when ComboBox has custom height.
• Chevron button highlight in PointerOver state in Editable combo box mode.
• Fixes the default height of ComboBox control to 32 px.
• Fixes margins and padding for different sub components of ComboBox.
• Fixes the text selection brush color in ComboBox.
• Fixes triggers for different states of ComboBox.
• Fixes the behavior of ComboBox when it is pressed ( for editable ComboBox )

This is not an exhaustive list.

Customer Impact

Correct style for developers.

Regression

No.

Testing

Local app testing.

Risk

Minimal.

Microsoft Reviewers: Open in CodeFlow

[Copilot]

Copilot reviewed 1 out of 8 changed files in this pull request and generated no comments.

Files not reviewed (7)

• src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Theme/Dark.xaml: Language not supported
• src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Theme/HC.xaml: Language not supported
• src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Theme/Light.xaml: Language not supported
• src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Variables.xaml: Language not supported
• src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml: Language not supported
• src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml: Language not supported
• src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml: Language not supported

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 13.59071%. Comparing base (ee926df) to head (5e90215).

Additional details and impacted files

@@                 Coverage Diff                 @@
##                main      #10818         +/-   ##
===================================================
- Coverage   13.72443%   13.59071%   -0.13373%     
===================================================
  Files           3316        3316                 
  Lines         664822      664822                 
  Branches       74651       74651                 
===================================================
- Hits           91243       90354        -889     
- Misses        570879      571870        +991     
+ Partials        2700        2598        -102     

Flag	Coverage Δ
Debug	13.59071% <ø> (-0.13373%)	⬇️

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[pranav-gupta-msft]

Why has it been commented ? Why not remove this ?

[dipeshmsft]

No reason at all. Will remove this.

[pranav-gupta-msft]

How is this trigger disabled ?

[dipeshmsft]

I will update that, I meant to write, "disabling this setter"

[godlytalias]

May be good to have figma links / recordings of the animations to better understand this

[dipeshmsft]

I don't have any such source. Moreover, the Fluent 2 Design Figma style that is available publicly only mentions the category of animations based on type and timing but they don't mention which type of animation is to be used where.

@godlytalias, if you can point me to any such links it would be a great help.