feat: added a code right pad option and fixed documentation for highl…

…ight-lines (#245)

README.md

@@ -105,7 +105,7 @@ EOF
 Highlight specified line
 
 ```bash
-silicon main.rs -o main.png --highlight-lines '1; 3-4'
+silicon main.rs -o main.png --highlight-lines '1;3-4'
 ```
 
 Custom the image

src/bin/silicon/config.rs

@@ -114,7 +114,7 @@ pub struct Config {
     #[structopt(long, short, value_name = "FONT", parse(from_str = parse_font_str))]
     pub font: Option<FontList>,
 
-    /// Lines to high light. rg. '1-3; 4'
+    /// Lines to highlight. eg. '1-3;4'
     #[structopt(long, value_name = "LINES", parse(try_from_str = parse_line_range))]
     pub highlight_lines: Option<Lines>,
 
@@ -126,6 +126,10 @@ pub struct Config {
     #[structopt(long, value_name = "PAD", default_value = "2")]
     pub line_pad: u32,
 
+    /// Add PAD padding to the right of the code.
+    #[structopt(long, value_name = "PAD", default_value = "25")]
+    pub code_pad_right: u32,
+
     /// Line number offset
     #[structopt(long, value_name = "OFFSET", default_value = "1")]
     pub line_offset: u32,
@@ -281,7 +285,8 @@ impl Config {
             .shadow_adder(self.get_shadow_adder()?)
             .tab_width(self.tab_width)
             .highlight_lines(self.highlight_lines.clone().unwrap_or_default())
-            .line_offset(self.line_offset);
+            .line_offset(self.line_offset)
+            .code_pad_right(self.code_pad_right);
 
         Ok(formatter.build()?)
     }

src/formatter.rs

@@ -15,6 +15,9 @@ pub struct ImageFormatter<T> {
     /// pad of top of the code area
     /// Default: 50
     code_pad_top: u32,
+    /// pad of right of the code area
+    /// Default: 25
+    code_pad_right: u32,
     /// Title bar padding
     /// Default: 15
     title_bar_pad: u32,
@@ -57,6 +60,8 @@ pub struct ImageFormatter<T> {
 pub struct ImageFormatterBuilder<S> {
     /// Pad between lines
     line_pad: u32,
+    /// Padding to the right of the code 
+    code_pad_right: u32,
     /// Show line number
     line_number: bool,
     /// Font of english character, should be mono space font
@@ -108,6 +113,12 @@ impl<S: AsRef<str> + Default> ImageFormatterBuilder<S> {
         self.line_pad = pad;
         self
     }
+
+    /// Set the pad on the right of the screen
+    pub fn code_pad_right(mut self, pad: u32) -> Self {
+        self.code_pad_right = pad;
+        self
+    }
 
     /// Set the font
     pub fn font(mut self, fonts: Vec<(S, f32)>) -> Self {
@@ -164,6 +175,7 @@ impl<S: AsRef<str> + Default> ImageFormatterBuilder<S> {
             line_pad: self.line_pad,
             code_pad: 25,
             code_pad_top: if title_bar { 50 } else { 0 },
+            code_pad_right: self.code_pad_right,
             title_bar_pad: 15,
             window_controls: self.window_controls,
             window_controls_width: 120,
@@ -205,7 +217,7 @@ impl<T: TextLineDrawer> ImageFormatter<T> {
     /// calculate the size of code area
     fn get_image_size(&mut self, max_width: u32, lineno: u32) -> (u32, u32) {
         (
-            (max_width + self.code_pad).max(150),
+            (max_width + self.code_pad_right).max(150),
             self.get_line_y(lineno + 1) + self.code_pad,
         )
     }