Table formatting logic overhaul (#305)

* Table formatting logic overhaul

- Columns now auto-expand and auto-shrink proportionally
- Data column selection logic is now set per-table
- Necessary boilerplate added to allow tables with more (or fewer) columns in the future

* Better naming: `TableLayout` -> `DisplayLayout`

* Fix clippy complaints

* Optimise layout cutoff widths

- These values are pretty much arbitrary. I'm open to further optimising them in the future.

* Updated test snapshots to match new layout settings

* Remove unnecessary logging

* Correct `debug_fn` impl for `column_selector`

* Further optimise bandwidth column display

* Update test snapshots

* Layout width preset minor adjustment

Cargo.toml

@@ -40,6 +40,7 @@ log = "0.4.20"
 simplelog = "0.12.1"
 clap-verbosity-flag = "2.0.1"
 derivative = "2.2.0"
+itertools = "0.11.0"
 
 [target.'cfg(target_os="windows")'.dependencies]
 netstat2 = "0.9.1"
@@ -53,7 +54,6 @@ insta = "1.34.0"
 pnet_base = "0.34.0"
 packet-builder = { version = "0.7.0", git = "https://github.com/cyqsimon/packet_builder.git", branch = "patch-update" }
 rstest = "0.18.2"
-itertools = "0.11.0"
 
 [target.'cfg(target_os="windows")'.build-dependencies]
 anyhow = "1.0.75"

src/display/components/display_bandwidth.rs

@@ -2,25 +2,23 @@ use std::fmt;
 
 pub struct DisplayBandwidth {
     pub bandwidth: f64,
-    pub as_rate: bool,
 }
 
 impl fmt::Display for DisplayBandwidth {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        let suffix = if self.as_rate { "ps" } else { "" };
-        if self.bandwidth > 999_999_999_999.0 {
-            // 1024 * 1024 * 1024 * 1024
-            write!(f, "{:.2}TiB{suffix}", self.bandwidth / 1_099_511_627_776.0,)
-        } else if self.bandwidth > 999_999_999.0 {
-            // 1024 * 1024 * 1024
-            write!(f, "{:.2}GiB{suffix}", self.bandwidth / 1_073_741_824.0)
-        } else if self.bandwidth > 999_999.0 {
-            //  1024 * 1024
-            write!(f, "{:.2}MiB{suffix}", self.bandwidth / 1_048_576.0)
-        } else if self.bandwidth > 999.0 {
-            write!(f, "{:.2}KiB{suffix}", self.bandwidth / 1024.0)
+        // see https://github.com/rust-lang/rust/issues/41620
+        let (div, suffix) = if self.bandwidth >= 1e12 {
+            (1_099_511_627_776.0, "TiB")
+        } else if self.bandwidth >= 1e9 {
+            (1_073_741_824.0, "GiB")
+        } else if self.bandwidth >= 1e6 {
+            (1_048_576.0, "MiB")
+        } else if self.bandwidth >= 1e3 {
+            (1024.0, "KiB")
         } else {
-            write!(f, "{}B{suffix}", self.bandwidth)
-        }
+            (1.0, "B")
+        };
+
+        write!(f, "{:.2}{suffix}", self.bandwidth / div)
     }
 }

src/display/components/header_details.rs

@@ -80,19 +80,19 @@ impl<'a> HeaderDetails<'a> {
     }
 
     fn bandwidth_string(&self) -> String {
-        let c_mode = self.state.cumulative_mode;
-        format!(
-            " Total Up / Down: {} / {}{}",
-            DisplayBandwidth {
-                bandwidth: self.state.total_bytes_uploaded as f64,
-                as_rate: !c_mode,
-            },
-            DisplayBandwidth {
-                bandwidth: self.state.total_bytes_downloaded as f64,
-                as_rate: !c_mode,
-            },
-            if self.paused { " [PAUSED]" } else { "" }
-        )
+        let t = if self.state.cumulative_mode {
+            "Data"
+        } else {
+            "Rate"
+        };
+        let up = DisplayBandwidth {
+            bandwidth: self.state.total_bytes_uploaded as f64,
+        };
+        let down = DisplayBandwidth {
+            bandwidth: self.state.total_bytes_downloaded as f64,
+        };
+        let paused = if self.paused { " [PAUSED]" } else { "" };
+        format!(" Total {t} (Up / Down): {up} / {down}{paused}")
     }
 
     fn render_elapsed_time(

src/display/components/layout.rs

@@ -27,7 +27,7 @@ fn top_app_and_bottom_split(rect: Rect) -> (Rect, Rect, Rect) {
 
 pub struct Layout<'a> {
     pub header: HeaderDetails<'a>,
-    pub children: Vec<Table<'a>>,
+    pub children: Vec<Table>,
     pub footer: HelpText,
 }