Fixes #2489. Create new ScrollBar based on a new Scroll and remove ScrollBarView/ScrollView

[BDisp]

Fixes

• Fixes Create new ScrollBar based on a new Scroll and remove ScrollBarView/ScrollView #2489

Proposed Changes/Todos

• Add Scroll class and unit tests
• Add ScrollSlider class and unit tests
• Add ScrolBar class and unit tests
• Add ScrollButton class
• Add @tig View.ScrollBars
• Remove ScrollBarView
• Remove ScrollView

Pull Request checklist:

• I've named my PR in the form of "Fixes #issue. Terse description."
• My code follows the style guidelines of Terminal.Gui - if you use Visual Studio, hit CTRL-K-D to automatically reformat your files before committing.
• My code follows the Terminal.Gui library design guidelines
• I ran dotnet test before commit
• I have made corresponding changes to the API documentation (using /// style comments)
• My changes generate no new warnings
• I have checked my code and corrected any poor grammar or misspellings
• I conducted basic QA to assure all features are working

[BDisp]

I would appreciate the Scroll class being reviewed before moving forward with the ScollBar class. Thanks.

[tig]

Ooooh! I'm super excited to review this! Will do asap.

[BDisp]

The width/height of the Scroll is not limited to 1 but only to what the user wants.

[BDisp]

@tig how about you creating a new Content or Viewport box in the AdornmentsEditor to set the foreground and background colors. Instead of using Top, Right, Bottom and Left, it can use the Axis, ContentSize or whatever. What do you think?

[tig]

Really slick!!

I've got a PR with some changes that you might like. I'll submit it vs. making a lot of comments.

[tig]

@tig how about you creating a new Content or Viewport box in the AdornmentsEditor to set the foreground and background colors. Instead of using Top, Right, Bottom and Left, it can use the Axis, ContentSize or whatever. What do you think?

You mean being able to set the Normal.Background/Forground color for the View itself? Like the colorpicker in Content Scrolling does?

[BDisp]

You mean being able to set the Normal.Background/Forground color for the View itself? Like the colorpicker in Content Scrolling does?

Yes or for the view passed on the ViewToEdit property. That's more or less the idea.

[BDisp]

@tig did you reorganize by placing the backfields before the properties by hand, or through some automatic system? I normally use R#'s Ctrl+E+C and it's not reformatting that way.

[tig]

@tig did you reorganize by placing the backfields before the properties by hand, or through some automatic system? I normally use R#'s Ctrl+E+C and it's not reformatting that way.

By hand. It's still broken.

[tig]

You mean being able to set the Normal.Background/Forground color for the View itself? Like the colorpicker in Content Scrolling does?

Yes or for the view passed on the ViewToEdit property. That's more or less the idea.

Greet idea. I'll do it as part of #3376 where I've already completely re-done AdornmentEditor. I'm going to rename it to ViewEditor as well. I also want to integrate ViewEditor into AllViewsTester because I use that a lot to audit view behaviors and being able to tweak settings live is super useful.

I also added the abilty to just click on any view in the Scenario and ViewToEdit will be set to that view.

[tig]

I just submitted another PR with quesitons / comments inline.

[tig]

IMO, View sub-classes should not have the word "View" in them as a general principle. `

ScrollBarView should be ScrollBar.

[BDisp]

I think it's working much better now. When you have time please test it. Thanks.

[tig]

I would like to maintaining the ShowScrollIndicator property because it will indicates that the visibility is false due the AutoHideScrollBar is true (visible if size is greater than the content size or invisible otherwise) and thus this check get => _showScrollIndicator && Visible; is crucial to to get the real state if the scroll visibility. If you don't agree please let me know.

I think ShowScrollIndicator is misnamed. "Indicator" should be "Bar", and "Show" is a verb, not a noun, so it's very confusing.

I do think you're correct that we need something more than just using Visible as I did in my prototype.

Here's a suggestion:

Add to ViewportSettings:

public enum ViewportSettings
{
...
    /// <summary>
    ///     If set, the vertical scroll bar (see <see cref="View.HorizontalScrollBar"/>) will be enabled and automatically made visible
    ///     when the dimension of the <see cref="View.Viewport"/> is smaller than the dimension of <see cref="View.GetContentSize()"/>.
    /// </summary>
    EnableHorizontalScrollBar = 64,

    /// <summary>
    ///     If set, the vertical scroll bar (see <see cref="View.VerticalScrollBar"/>) will be enabled and automatically made visible
    ///     when the dimension of the <see cref="View.Viewport"/> is smaller than the dimension of <see cref="View.GetContentSize()"/>.
    /// </summary>
    EnableVerticalScrollBar = 128,

    /// <summary>
    ///     If set, the horizontal and vertical scroll bars (see cref="View.HorizontalScrollBar"/> and <see cref="View.VerticalScrollBar"/>)
    ///     will be enabled and automatically made visible when the dimension of the <see cref="View.Viewport"/> is smaller than the
    ///     dimension of <see cref="View.GetContentSize()"/>.
    /// </summary>
    EnableScrollBars = EnableHorizontalScrollBar | EnableVerticalScrollBar

This moves the automatic behavior out of ScrollBar and into View and encapsulates that logic in View.ScrollBars.cs and consolodates content scrolling functionality.

If these flags are NOT set, then the developer can use view.Horizontal/VerticalScrollbar = true/false to manage visibility themselves.

What do you think of this idea?

[tig]

Can I just say how much I love the work @BDisp is doing in this PR? Love. Love. Love.

[tig]

@BDisp see my comment here:

• Merge Responder into View #464

When you nuke the old ScrollView etc..., can you please take care of IsOverriden too?

[tig]

@BDisp what's the status of this PR?

In #3761 I'm fighting with the old hackyScrollView and ScrollBarView code that does a lot of unnatural things w.r.t. drawing and layout. Instead of spending time & energy fixing those things (and views that depend on them), i'd much rather have us spend time getting the new classes working well.

Thanks.

[BDisp]

@BDisp what's the status of this PR?

In #3761 I'm fighting with the old hackyScrollView and ScrollBarView code that does a lot of unnatural things w.r.t. drawing and layout. Instead of spending time & energy fixing those things (and views that depend on them), i'd much rather have us spend time getting the new classes working well.

Thanks.

Sorry, I never worked on it again. I'm busy with some other stuff. But I'll get back to it as soon as I can.

[tig]

@BDisp what's the status of this PR?
In #3761 I'm fighting with the old hackyScrollView and ScrollBarView code that does a lot of unnatural things w.r.t. drawing and layout. Instead of spending time & energy fixing those things (and views that depend on them), i'd much rather have us spend time getting the new classes working well.
Thanks.

Sorry, I never worked on it again. I'm busy with some other stuff. But I'll get back to it as soon as I can.

No problem. I'm working on it right now on top of the branch I'm using for #3798 .

[BDisp]

No problem. I'm working on it right now on top of the branch I'm using for #3798 .

Thanks for the help. Then I'll focused on others things, ok?

[tig]

Yep. Love the driver work you're doing!

[BDisp]

I've a branch where I already removed the old scroll bars and starting the implementation with the views that were use them. But a long time ago I already have done that before and I had some tedious working on this again. But I'll see if I can reanime again to work with it.

[tig]

New PR based on this great work: #3811.

Closing this one.