Cursor should change when operating sliders

[joulei]

Context

Currently when operating the sliders on the chat settings panel, the cursor always stays as a pointer.
We should add behavior to the sliders to match the visual effects of most platforms.

Goal

When hovering over the handle of a slider, the cursor should change to an open hand, indicating the user to drag. When dragging, the open hand should change to a close hand.

This might require to add the behaviour directly into Makepad's Slider widget.

[Guocork]

@joulei
Hello，I'm currently working on this issue and have submitted a PR to Makepad to fix the problem where cursor: Hand doesn't display properly on Linux. PR606

At the same time, I noticed that Makepad currently doesn't support a "close hand" cursor—grab is commented out and hasn't been implemented for any platform yet. If I want to add corresponding behavior to the slider, I'll need to implement the grab property for Makepad and integrate it across all platforms. What do you think about this?

[joulei]

@Guocork thanks for working on this, I forgot about the cursor issue in Linux. But I'm glad that you found a solution for it.
If you are comfortable with adding support for grab cursor in Makepad, that would be great. I can provide assistance when working on the different platforms.
Otherwise let me know I can put in my to-do list.

[Guocork]

@joulei Alright, I'm happy to handle this issue in Makepad. Currently, I’m facing a problem as I haven’t found the API documentation for the respective platform. Do you have any related documentation? Or could you tell me where I can find the platform’s API documentation?

[joulei]

@Guocork we don't have much documentation surrounding platform, but I will provide you with a guide tomorrow of where you can find the code handling the cursors on each platform and how'd you introduce the new cursor type in Makepad.

[Guocork]

@Guocork we don't have much documentation surrounding platform, but I will provide you with a guide tomorrow of where you can find the code handling the cursors on each platform and how'd you introduce the new cursor type in Makepad.

OK,that's great, thank you.

[joulei]

@Guocork ok so after a quick look it seems like the necessary changes are as follows:

1. Enable the commented-out Grab and Grabbing cursor variants in platform/src/cursor.rs

2. Handle the new variants in each platform

• Apple platform/src/os/apple/apple_util.rs
• Linux x11 platform/src/os/linux/x11/xlib_app.rs
• Web platform/src/os/web/from_wasm.rs - platform/src/os/web/web.js
• Windows platform/src/os/windows/win32_app.rs

You might have to do some research into the names of the pointers in each plaform.
For example, for macOS. The following worked:

// apple_util.rs
pub fn load_mouse_cursor(cursor: MouseCursor) -> ObjcId {
    match cursor {
        ...
        // added these two lines
        MouseCursor::Grab => load_native_cursor("openHandCursor"), 
        MouseCursor::Grabbing => load_native_cursor("closedHandCursor"), 

You can debug this by using cursor: <VariantName> in a View:

 <View> {
     // ...
     cursor: Grab
 }
 <View> {
     // ...
     cursor: Grabbing
 }

Screen.Recording.2024-11-28.at.2.44.14.PM.mov

I can help you test on macOS and Windows.
Does that make sense?

[Guocork]

Okay, thank you. I got it. I'll fix this issue.

[Guocork]

@joulei
Hello, I've finished this task, except on the Windows platform where I couldn't find the corresponding cursor name. pr609
Also, I've enhanced the slider functionality so that users can click on the slider to jump to the desired position, and the cursor changes while dragging. See details for more information. Slider enhancement and pr611

[joulei]

@Guocork great work! I'll review it and add the cursor on Windows, thanks!