From 7748132fcaaa710cbfe0274fab07eb1708555169 Mon Sep 17 00:00:00 2001
From: Gabriel <faktenlord@gmail.com>
Date: Mon, 10 Oct 2022 20:03:18 +0200
Subject: [PATCH] rewriting X wrapper

---
 src/xwrap/display.rs | 45 ++++++++++++++++++++++++++++++++++++++++++++
 src/xwrap/error.rs   | 22 ++++++++++++++++++++++
 src/xwrap/mod.rs     |  2 ++
 3 files changed, 69 insertions(+)
 create mode 100644 src/xwrap/display.rs
 create mode 100644 src/xwrap/error.rs
 create mode 100644 src/xwrap/mod.rs

diff --git a/src/xwrap/display.rs b/src/xwrap/display.rs
new file mode 100644
index 0000000..e11ec3e
--- /dev/null
+++ b/src/xwrap/display.rs
@@ -0,0 +1,45 @@
+use std::{env, ffi, ptr};
+
+use x11::xlib::{self, BadGC};
+
+use super::error;
+
+pub struct Display {
+    ptr: *mut xlib::Display,
+    name: String,
+}
+
+impl Display {
+    /// Call XOpenDisplay to open a display.
+    /// If `display_name` is `None`, the value of the `DISPLAY` environment variable will be used.
+    pub fn open(display_name: Option<String>) -> anyhow::Result<Self> {
+        let name = ffi::CString::new(if let Some(name) = display_name {
+            name
+        } else {
+            env::var("DISPLAY")?
+        })?;
+
+        let name_ptr = name.as_bytes().as_ptr();
+
+        // try to open display and get either display pointer or null
+        let display_ptr = unsafe { xlib::XOpenDisplay(name_ptr as *const i8) };
+
+        // if display is null, return an error, otherwise return instance successfully
+        if display_ptr == ptr::null_mut::<xlib::_XDisplay>() {
+            Err(error::XError::OpenDisplayError(name.into_string()?).into())
+        } else {
+            Ok(Self {
+                ptr: display_ptr,
+                name: name.into_string()?,
+            })
+        }
+    }
+}
+
+impl Drop for Display {
+    fn drop(&mut self) {
+        if unsafe { xlib::XCloseDisplay(self.ptr) } == BadGC.into() {
+            eprintln!("BadGC Error when closing display '{}'.", self.name);
+        };
+    }
+}
diff --git a/src/xwrap/error.rs b/src/xwrap/error.rs
new file mode 100644
index 0000000..7bfe885
--- /dev/null
+++ b/src/xwrap/error.rs
@@ -0,0 +1,22 @@
+use std::fmt;
+
+/// Various errors to be used in this wrapper
+#[derive(Debug)]
+pub enum XError {
+    OpenDisplayError(String),
+}
+
+impl std::fmt::Display for XError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            f,
+            "{}",
+            match self {
+                XError::OpenDisplayError(display_name) =>
+                    format!("error when opening display '{}'", display_name),
+            }
+        )
+    }
+}
+
+impl std::error::Error for XError {}
diff --git a/src/xwrap/mod.rs b/src/xwrap/mod.rs
new file mode 100644
index 0000000..2848c7e
--- /dev/null
+++ b/src/xwrap/mod.rs
@@ -0,0 +1,2 @@
+pub mod display;
+pub mod error;