feature: Add option to set a position of legend (#1430)

* Add option to set a position of legend

* some small changes

---------

Co-authored-by: ClementTsang <34804052+ClementTsang@users.noreply.github.com>

12 files changed, 169 insertions, 41 deletions

diff --git a/docs/content/configuration/command-line-options.md b/docs/content/configuration/command-line-options.md
index 2ce134b4..e0c6286b 100644
--- a/docs/content/configuration/command-line-options.md
+++ b/docs/content/configuration/command-line-options.md
@@ -58,6 +58,7 @@ see information on these options by running `btm -h`, or run `btm --help` to dis
 | ----------------------- | --------------------------------------------------------- |
 | `--enable_cache_memory` | Enable collecting and displaying cache and buffer memory. |
 | `--mem_as_value`        | Defaults to showing process memory usage by value.        |
+| `--memory_legend`       | Where to place the legend for the memory widget.          |
 
 ## Network Options
 
@@ -66,6 +67,7 @@ see information on these options by running `btm -h`, or run `btm --help` to dis
 | `--network_use_binary_prefix` | Displays the network widget with binary prefixes. |
 | `--network_use_bytes`         | Displays the network widget using bytes.          |
 | `--network_use_log`           | Displays the network widget with a log scale.     |
+| `--network_legend`            | Where to place the legend for the network widget. |
 | `--use_old_network_legend`    | DEPRECATED - uses a separate network legend.      |
 
 ## Battery Options
diff --git a/docs/content/configuration/config-file/flags.md b/docs/content/configuration/config-file/flags.md
index c110af6d..f8bacfbb 100644
--- a/docs/content/configuration/config-file/flags.md
+++ b/docs/content/configuration/config-file/flags.md
@@ -7,38 +7,40 @@
 Most of the [command line flags](../command-line-options.md) have config file equivalents to avoid having to type them out
 each time:
 
-| Field                        | Type                                                                                           | Functionality                                                                        |
-| ---------------------------- | ---------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------ |
-| `hide_avg_cpu`               | Boolean                                                                                        | Hides the average CPU usage.                                                         |
-| `dot_marker`                 | Boolean                                                                                        | Uses a dot marker for graphs.                                                        |
-| `left_legend`                | Boolean                                                                                        | Puts the CPU chart legend to the left side.                                          |
-| `current_usage`              | Boolean                                                                                        | Sets process CPU% to be based on current CPU%.                                       |
-| `group_processes`            | Boolean                                                                                        | Groups processes with the same name by default.                                      |
-| `case_sensitive`             | Boolean                                                                                        | Enables case sensitivity by default.                                                 |
-| `whole_word`                 | Boolean                                                                                        | Enables whole-word matching by default.                                              |
-| `regex`                      | Boolean                                                                                        | Enables regex by default.                                                            |
-| `basic`                      | Boolean                                                                                        | Hides graphs and uses a more basic look.                                             |
-| `use_old_network_legend`     | Boolean                                                                                        | DEPRECATED - uses the older network legend.                                          |
-| `battery`                    | Boolean                                                                                        | Shows the battery widget.                                                            |
-| `rate`                       | Unsigned Int (represents milliseconds) or String (represents human time)                       | Sets a refresh rate in ms.                                                           |
-| `default_time_value`         | Unsigned Int (represents milliseconds) or String (represents human time)                       | Default time value for graphs in ms.                                                 |
-| `time_delta`                 | Unsigned Int (represents milliseconds) or String (represents human time)                       | The amount in ms changed upon zooming.                                               |
-| `hide_time`                  | Boolean                                                                                        | Hides the time scale.                                                                |
-| `temperature_type`           | String (one of ["k", "f", "c", "kelvin", "fahrenheit", "celsius"])                             | Sets the temperature unit type.                                                      |
-| `default_widget_type`        | String (one of ["cpu", "proc", "net", "temp", "mem", "disk"], same as layout options)          | Sets the default widget type, use --help for more info.                              |
-| `default_widget_count`       | Unsigned Int (represents which `default_widget_type`)                                          | Sets the n'th selected widget type as the default.                                   |
-| `disable_click`              | Boolean                                                                                        | Disables mouse clicks.                                                               |
-| `color`                      | String (one of ["default", "default-light", "gruvbox", "gruvbox-light", "nord", "nord-light"]) | Use a color scheme, use --help for supported values.                                 |
-| `enable_cache_memory`        | Boolean                                                                                        | Enable collecting and displaying cache and buffer memory (not available on Windows). |
-| `mem_as_value`               | Boolean                                                                                        | Defaults to showing process memory usage by value.                                   |
-| `tree`                       | Boolean                                                                                        | Defaults to showing the process widget in tree mode.                                 |
-| `show_table_scroll_position` | Boolean                                                                                        | Shows the scroll position tracker in table widgets.                                  |
-| `process_command`            | Boolean                                                                                        | Show processes as their commands by default.                                         |
-| `disable_advanced_kill`      | Boolean                                                                                        | Hides advanced options to stop a process on Unix-like systems.                       |
-| `network_use_binary_prefix`  | Boolean                                                                                        | Displays the network widget with binary prefixes.                                    |
-| `network_use_bytes`          | Boolean                                                                                        | Displays the network widget using bytes.                                             |
-| `network_use_log`            | Boolean                                                                                        | Displays the network widget with a log scale.                                        |
-| `enable_gpu`                 | Boolean                                                                                        | Shows the GPU widgets.                                                               |
-| `retention`                  | String (human readable time, such as "10m", "1h", etc.)                                        | How much data is stored at once in terms of time.                                    |
-| `unnormalized_cpu`           | Boolean                                                                                        | Show process CPU% without normalizing over the number of cores.                      |
-| `expanded_on_startup`        | Boolean                                                                                        | Expand the default widget upon starting the app.                                     |
+| Field                        | Type                                                                                                               | Functionality                                                    |
+| ---------------------------- | ------------------------------------------------------------------------------------------------------------------ | ---------------------------------------------------------------- |
+| `hide_avg_cpu`               | Boolean                                                                                                            | Hides the average CPU usage.                                     |
+| `dot_marker`                 | Boolean                                                                                                            | Uses a dot marker for graphs.                                    |
+| `left_legend`                | Boolean                                                                                                            | Puts the CPU chart legend to the left side.                      |
+| `current_usage`              | Boolean                                                                                                            | Sets process CPU% to be based on current CPU%.                   |
+| `group_processes`            | Boolean                                                                                                            | Groups processes with the same name by default.                  |
+| `case_sensitive`             | Boolean                                                                                                            | Enables case sensitivity by default.                             |
+| `whole_word`                 | Boolean                                                                                                            | Enables whole-word matching by default.                          |
+| `regex`                      | Boolean                                                                                                            | Enables regex by default.                                        |
+| `basic`                      | Boolean                                                                                                            | Hides graphs and uses a more basic look.                         |
+| `use_old_network_legend`     | Boolean                                                                                                            | DEPRECATED - uses the older network legend.                      |
+| `battery`                    | Boolean                                                                                                            | Shows the battery widget.                                        |
+| `rate`                       | Unsigned Int (represents milliseconds) or String (represents human time)                                           | Sets a refresh rate in ms.                                       |
+| `default_time_value`         | Unsigned Int (represents milliseconds) or String (represents human time)                                           | Default time value for graphs in ms.                             |
+| `time_delta`                 | Unsigned Int (represents milliseconds) or String (represents human time)                                           | The amount in ms changed upon zooming.                           |
+| `hide_time`                  | Boolean                                                                                                            | Hides the time scale.                                            |
+| `temperature_type`           | String (one of ["k", "f", "c", "kelvin", "fahrenheit", "celsius"])                                                 | Sets the temperature unit type.                                  |
+| `default_widget_type`        | String (one of ["cpu", "proc", "net", "temp", "mem", "disk"], same as layout options)                              | Sets the default widget type, use --help for more info.          |
+| `default_widget_count`       | Unsigned Int (represents which `default_widget_type`)                                                              | Sets the n'th selected widget type as the default.               |
+| `disable_click`              | Boolean                                                                                                            | Disables mouse clicks.                                           |
+| `color`                      | String (one of ["default", "default-light", "gruvbox", "gruvbox-light", "nord", "nord-light"])                     | Use a color scheme, use --help for supported values.             |
+| `enable_cache_memory`        | Boolean                                                                                                            | Enable cache and buffer memory stats (not available on Windows). |
+| `mem_as_value`               | Boolean                                                                                                            | Defaults to showing process memory usage by value.               |
+| `tree`                       | Boolean                                                                                                            | Defaults to showing the process widget in tree mode.             |
+| `show_table_scroll_position` | Boolean                                                                                                            | Shows the scroll position tracker in table widgets.              |
+| `process_command`            | Boolean                                                                                                            | Show processes as their commands by default.                     |
+| `disable_advanced_kill`      | Boolean                                                                                                            | Hides advanced options to stop a process on Unix-like systems.   |
+| `network_use_binary_prefix`  | Boolean                                                                                                            | Displays the network widget with binary prefixes.                |
+| `network_use_bytes`          | Boolean                                                                                                            | Displays the network widget using bytes.                         |
+| `network_use_log`            | Boolean                                                                                                            | Displays the network widget with a log scale.                    |
+| `enable_gpu`                 | Boolean                                                                                                            | Shows the GPU widgets.                                           |
+| `retention`                  | String (human readable time, such as "10m", "1h", etc.)                                                            | How much data is stored at once in terms of time.                |
+| `unnormalized_cpu`           | Boolean                                                                                                            | Show process CPU% without normalizing over the number of cores.  |
+| `expanded_on_startup`        | Boolean                                                                                                            | Expand the default widget upon starting the app.                 |
+| `memory_legend`              | String (one of ["none", "top-left", "top", "top-right", "left", "right", "bottom-left", "bottom", "bottom-right"]) | Where to place the legend for the memory widget.                 |
+| `network_legend`             | String (one of ["none", "top-left", "top", "top-right", "left", "right", "bottom-left", "bottom", "bottom-right"]) | Where to place the legend for the network widget.                |
diff --git a/src/app.rs b/src/app.rs
index a149869f..60ad35b8 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -21,6 +21,7 @@ pub use states::*;
 use unicode_segmentation::{GraphemeCursor, UnicodeSegmentation};
 
 use crate::{
+    canvas::components::time_chart::LegendPosition,
     constants,
     data_collection::temperature,
     data_conversion::ConvertedData,
@@ -62,8 +63,10 @@ pub struct AppConfigFields {
     pub enable_cache_memory: bool,
     pub show_table_scroll_position: bool,
     pub is_advanced_kill: bool,
+    pub memory_legend_position: Option<LegendPosition>,
     // TODO: Remove these, move network details state-side.
     pub network_unit_type: DataUnit,
+    pub network_legend_position: Option<LegendPosition>,
     pub network_scale_type: AxisScaling,
     pub network_use_binary_prefix: bool,
     pub retention_ms: u64,
diff --git a/src/canvas/components/time_graph.rs b/src/canvas/components/time_graph.rs
index 3f438349..361b502e 100644
--- a/src/canvas/components/time_graph.rs
+++ b/src/canvas/components/time_graph.rs
@@ -11,7 +11,9 @@ use tui::{
 };
 use unicode_segmentation::UnicodeSegmentation;
 
-use super::time_chart::{Axis, Dataset, Point, TimeChart, DEFAULT_LEGEND_CONSTRAINTS};
+use super::time_chart::{
+    Axis, Dataset, LegendPosition, Point, TimeChart, DEFAULT_LEGEND_CONSTRAINTS,
+};
 
 /// Represents the data required by the [`TimeGraph`].
 pub struct GraphData<'a> {
@@ -48,6 +50,9 @@ pub struct TimeGraph<'a> {
     /// The title style.
     pub title_style: Style,
 
+    /// The legend position.
+    pub legend_position: Option<LegendPosition>,
+
     /// Any legend constraints.
     pub legend_constraints: Option<(Constraint, Constraint)>,
 
@@ -142,6 +147,7 @@ impl<'a> TimeGraph<'a> {
                 .y_axis(y_axis)
                 .marker(self.marker)
                 .legend_style(self.graph_style)
+                .legend_position(self.legend_position)
                 .hidden_legend_constraints(
                     self.legend_constraints
                         .unwrap_or(DEFAULT_LEGEND_CONSTRAINTS),
@@ -202,6 +208,7 @@ mod test {
             border_style: Style::default().fg(Color::Blue),
             is_expanded: false,
             title_style: Style::default().fg(Color::Cyan),
+            legend_position: None,
             legend_constraints: None,
             marker: Marker::Braille,
         }
diff --git a/src/canvas/components/tui_widget/time_chart.rs b/src/canvas/components/tui_widget/time_chart.rs
index 60c797bc..04f491bc 100644
--- a/src/canvas/components/tui_widget/time_chart.rs
+++ b/src/canvas/components/tui_widget/time_chart.rs
@@ -7,7 +7,7 @@
 mod canvas;
 mod points;
 
-use std::cmp::max;
+use std::{cmp::max, str::FromStr};
 
 use canvas::*;
 use tui::{
@@ -213,6 +213,27 @@ impl LegendPosition {
     }
 }
 
+#[derive(Debug, PartialEq)]
+pub struct ParseLegendPositionError;
+
+impl FromStr for LegendPosition {
+    type Err = ParseLegendPositionError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s.to_ascii_lowercase().as_str() {
+            "top" => Ok(Self::Top),
+            "top-left" => Ok(Self::TopLeft),
+            "top-right" => Ok(Self::TopRight),
+            "left" => Ok(Self::Left),
+            "right" => Ok(Self::Right),
+            "bottom-left" => Ok(Self::BottomLeft),
+            "bottom" => Ok(Self::Bottom),
+            "bottom-right" => Ok(Self::BottomRight),
+            _ => Err(ParseLegendPositionError),
+        }
+    }
+}
+
 /// A group of data points
 ///
 /// This is the main element composing a [`TimeChart`].
diff --git a/src/canvas/widgets/cpu_graph.rs b/src/canvas/widgets/cpu_graph.rs
index b5027bc6..f882b210 100644
--- a/src/canvas/widgets/cpu_graph.rs
+++ b/src/canvas/widgets/cpu_graph.rs
@@ -233,6 +233,7 @@ impl Painter {
                 title,
                 is_expanded: app_state.is_expanded,
                 title_style: self.colours.widget_title_style,
+                legend_position: None,
                 legend_constraints: None,
                 marker,
             }
diff --git a/src/canvas/widgets/mem_graph.rs b/src/canvas/widgets/mem_graph.rs
index b9782e5a..5c814f51 100644
--- a/src/canvas/widgets/mem_graph.rs
+++ b/src/canvas/widgets/mem_graph.rs
@@ -133,6 +133,7 @@ impl Painter {
                 title: " Memory ".into(),
                 is_expanded: app_state.is_expanded,
                 title_style: self.colours.widget_title_style,
+                legend_position: app_state.app_config_fields.memory_legend_position,
                 legend_constraints: Some((Constraint::Ratio(3, 4), Constraint::Ratio(3, 4))),
                 marker,
             }
diff --git a/src/canvas/widgets/network_graph.rs b/src/canvas/widgets/network_graph.rs
index 35ab9373..ec7e5fbd 100644
--- a/src/canvas/widgets/network_graph.rs
+++ b/src/canvas/widgets/network_graph.rs
@@ -162,6 +162,7 @@ impl Painter {
                 title: " Network ".into(),
                 is_expanded: app_state.is_expanded,
                 title_style: self.colours.widget_title_style,
+                legend_position: app_state.app_config_fields.network_legend_position,
                 legend_constraints: Some(legend_constraints),
                 marker,
             }
diff --git a/src/constants.rs b/src/constants.rs
index eb185779..1c3aa097 100644
--- a/src/constants.rs
+++ b/src/constants.rs
@@ -573,7 +573,7 @@ pub const CONFIG_TEXT: &str = r#"# This is a default config file for bottom.  Al
 #battery = false
 # Disable mouse clicks
 #disable_click = false
-# Built-in themes.  Valid values are "default", "default-light", "gruvbox", "gruvbox-light", "nord", "nord-light"
+# Built-in themes. Valid values are "default", "default-light", "gruvbox", "gruvbox-light", "nord", "nord-light"
 #color = "default"
 # Show memory values in the processes widget as values by default
 #mem_as_value = false
@@ -597,6 +597,10 @@ pub const CONFIG_TEXT: &str = r#"# This is a default config file for bottom.  Al
 #enable_cache_memory = false
 # How much data is stored at once in terms of time.
 #retention = "10m"
+# Where to place the legend for the memory widget. One of "none", "top-left", "top", "top-right", "left", "right", "bottom-left", "bottom", "bottom-right".
+#memory_legend = "TopRight".
+# Where to place the legend for the network widget. One of "none", "top-left", "top", "top-right", "left", "right", "bottom-left", "bottom", "bottom-right".
+#network_legend = "TopRight".
 
 # These are flags around the process widget.
 #[processes]
diff --git a/src/options.rs b/src/options.rs
index 902c5c87..e36685ea 100644
--- a/src/options.rs
+++ b/src/options.rs
@@ -24,7 +24,7 @@ use starship_battery::Manager;
 use self::config::{layout::Row, IgnoreList, StringOrNum};
 use crate::{
     app::{filter::Filter, layout_manager::*, *},
-    canvas::{styling::CanvasStyling, ColourScheme},
+    canvas::{components::time_chart::LegendPosition, styling::CanvasStyling, ColourScheme},
     constants::*,
     data_collection::temperature::TemperatureType,
     utils::{
@@ -126,6 +126,9 @@ pub fn init_app(
         }
     };
 
+    let network_legend_position = get_network_legend(matches, config)?;
+    let memory_legend_position = get_memory_legend(matches, config)?;
+
     // TODO: Can probably just reuse the options struct.
     let app_config_fields = AppConfigFields {
         update_rate: get_update_rate(matches, config)
@@ -150,6 +153,8 @@ pub fn init_app(
         enable_cache_memory: get_enable_cache_memory(matches, config),
         show_table_scroll_position: is_flag_enabled!(show_table_scroll_position, matches, config),
         is_advanced_kill,
+        memory_legend_position,
+        network_legend_position,
         network_scale_type,
         network_unit_type,
         network_use_binary_prefix,
@@ -772,6 +777,48 @@ fn get_retention(matches: &ArgMatches, config: &Config) -> error::Result<u64> {
     }
 }
 
+fn get_network_legend(
+    matches: &ArgMatches, config: &Config,
+) -> error::Result<Option<LegendPosition>> {
+    let error =
+        |_| BottomError::ConfigError("network_legend is set to an invalid value".to_string());
+    if let Some(s) = matches.get_one::<String>("network_legend") {
+        match s.to_ascii_lowercase().trim() {
+            "none" => Ok(None),
+            position => Ok(Some(position.parse::<LegendPosition>().map_err(error)?)),
+        }
+    } else if let Some(flags) = &config.flags {
+        if let Some(legend) = &flags.network_legend {
+            Ok(Some(legend.parse::<LegendPosition>().map_err(error)?))
+        } else {
+            Ok(Some(LegendPosition::default()))
+        }
+    } else {
+        Ok(Some(LegendPosition::default()))
+    }
+}
+
+fn get_memory_legend(
+    matches: &ArgMatches, config: &Config,
+) -> error::Result<Option<LegendPosition>> {
+    let error =
+        |_| BottomError::ConfigError("memory_legend is set to an invalid value".to_string());
+    if let Some(s) = matches.get_one::<String>("memory_legend") {
+        match s.to_ascii_lowercase().trim() {
+            "none" => Ok(None),
+            position => Ok(Some(position.parse::<LegendPosition>().map_err(error)?)),
+        }
+    } else if let Some(flags) = &config.flags {
+        if let Some(legend) = &flags.memory_legend {
+            Ok(Some(legend.parse::<LegendPosition>().map_err(error)?))
+        } else {
+            Ok(Some(LegendPosition::default()))
+        }
+    } else {
+        Ok(Some(LegendPosition::default()))
+    }
+}
+
 #[cfg(test)]
 mod test {
     use clap::ArgMatches;
diff --git a/src/options/args.rs b/src/options/args.rs
index b410eba4..c8fe35320 100644
--- a/src/options/args.rs
+++ b/src/options/args.rs
@@ -436,6 +436,24 @@ fn mem_args(cmd: Command) -> Command {
             to showing it by percentage.",
         );
 
+    let memory_legend = Arg::new("memory_legend")
+        .long("memory_legend")
+        .action(ArgAction::Set)
+        .value_name("POSITION")
+        .ignore_case(true)
+        .help("Where to place the legend for the memory widget.")
+        .value_parser([
+            "none",
+            "top-left",
+            "top",
+            "top-right",
+            "left",
+            "right",
+            "bottom-left",
+            "bottom",
+            "bottom-right",
+        ]);
+
     #[cfg(not(target_os = "windows"))]
     {
         let enable_cache_memory = Arg::new("enable_cache_memory")
@@ -443,11 +461,11 @@ fn mem_args(cmd: Command) -> Command {
             .action(ArgAction::SetTrue)
             .help("Enable collecting and displaying cache and buffer memory.");
 
-        cmd.args(args![mem_as_value, enable_cache_memory])
+        cmd.args(args![mem_as_value, memory_legend, enable_cache_memory])
     }
     #[cfg(target_os = "windows")]
     {
-        cmd.arg(mem_as_value)
+        cmd.args(args![mem_as_value, memory_legend])
     }
 }
 
@@ -464,6 +482,24 @@ fn network_args(cmd: Command) -> Command {
             display is not tested anymore and may be broken.",
         );
 
+    let network_legend = Arg::new("network_legend")
+        .long("network_legend")
+        .action(ArgAction::Set)
+        .value_name("POSITION")
+        .ignore_case(true)
+        .help("Where to place the legend for the network widget.")
+        .value_parser([
+            "none",
+            "top-left",
+            "top",
+            "top-right",
+            "left",
+            "right",
+            "bottom-left",
+            "bottom",
+            "bottom-right",
+        ]);
+
     let network_use_bytes = Arg::new("network_use_bytes")
         .long("network_use_bytes")
         .action(ArgAction::SetTrue)
@@ -487,6 +523,7 @@ fn network_args(cmd: Command) -> Command {
 
     cmd.args(args![
         use_old_network_legend,
+        network_legend,
         network_use_bytes,
         network_use_log,
         network_use_binary_prefix,
diff --git a/src/options/config.rs b/src/options/config.rs
index 23c2f956..6b3643f0 100644
--- a/src/options/config.rs
+++ b/src/options/config.rs
@@ -68,6 +68,8 @@ pub(crate) struct ConfigFlags {
     pub(crate) battery: Option<bool>,
     pub(crate) disable_click: Option<bool>,
     pub(crate) no_write: Option<bool>,
+    pub(crate) network_legend: Option<String>,
+    pub(crate) memory_legend: Option<String>,
     /// For built-in colour palettes.
     pub(crate) color: Option<String>,
     pub(crate) mem_as_value: Option<bool>,