Calculate relative y mouse event cursor position

[TimonPost]

Fixes: crossterm-rs/crossterm#278

With patch:

TOP, LEFT click:

Previously:

TOP, LEFT click

[TimonPost]

@zrzka can you check on macos/linux if the cursor positions from input events are relative to the current window or absolute to the current screen buffer. Otherwise, this patch is not needed to sync the behavior. But I am pretty convinced it was relative to the window... We better double-check.

This PR should be merged before the release

[zrzka]

@TimonPost here's my test code ...

use std::io::Write;

use crossterm_input::{input, InputEvent, KeyEvent, RawScreen, Result};

fn read_asynchronously() -> Result<()> {
    let _raw = RawScreen::into_raw_mode()?;

    let input = input();

    input.enable_mouse_mode()?;

    let mut stdin = input.read_async();

    loop {
        if let Some(key_event) = stdin.next() {
            match key_event {
                InputEvent::Keyboard(KeyEvent::Esc) => break,
                InputEvent::Keyboard(KeyEvent::Up) => {
                    let mut stdout = std::io::stdout();
                    let _ = write!(stdout, "\x1B[5T");
                    let _ = stdout.flush();
                }
                InputEvent::Keyboard(KeyEvent::Down) => {
                    let mut stdout = std::io::stdout();
                    let _ = write!(stdout, "\x1B[5S");
                    let _ = stdout.flush();
                }
                ie => println!("\r{:?}", ie),
            };
        }
    }

    input.disable_mouse_mode()
}

fn main() -> Result<()> {
    read_asynchronously()
}

... no matter how many times I hit Up/Down, the top/left mouse click is reported as 0, 0.

[zrzka]

Also there's no changelog entry, but for now, don't add it. Once you fix the unwrap() and the PR will be merged, I'll add it to the deprecated-release branch (to avoid merge conflict) and will also add it to the release-0.12 PR in the crossterm crate.

[TimonPost]

running your code at TOP LEFT

[zrzka]

Happy :)

[zrzka]

Changelogs updated here & here.

[zrzka]

@TimonPost made more tests on Linux & macOS. Both behaves in the same way, top/left is 0,0 no matter how many times I scroll up/down. If you tested this on Windows, we can merge it.